Patent Publication Number: US-6989773-B2

Title: Media data encoding device

Description:
TECHNICAL FIELD 
   Embodiments of the present invention relate to encoding devices. More specifically, embodiments of the present invention relate to encoding devices that enable other devices, such as transcoders and decoders to operate on encoded data without requiring knowledge of the encoding scheme. 
   BACKGROUND ART 
   Data delivery systems present many challenges for the system designer. For instance, clients can have different display, power, communication, and computational capabilities. In addition, communication links in the system can have different maximum bandwidths, quality levels, and time-varying characteristics. A successful data delivery system should be able to deliver data streams to a multitude of diverse clients over heterogeneous networks with time-varying characteristics. 
   Providing proper security in order to protect content from eavesdroppers is another important consideration in the design of data delivery systems. Generally, to provide security, data are transported in encrypted form. 
   Intermediate nodes in the system may be used to perform stream adaptation, or transcoding, to scale data streams for different downstream client capabilities and network conditions. A transcoder takes a compressed, or encoded, data stream as an input, and then processes it to produce another encoded data stream as an output. Examples of transcoding operations include bit rate reduction, rate shaping, spatial downsampling, and frame rate reduction. Transcoding can improve system scalability and efficiency, for example, by adapting the spatial resolution of an image to a particular client&#39;s display capabilities or by dynamically adjusting the bit rate of a data stream to match a network channel&#39;s time-varying characteristics. 
   Intermediate nodes can collect and update information about local and downstream network conditions and downstream client capabilities, and then scale the data according to that information. This can be more efficient than scaling the data at the source, because it is more difficult for the source to collect up-to-date and detailed information about conditions inside the network, especially at locations in the network relatively far removed from the source. Also, the source provides only one control point at the beginning of the delivery path, while intermediate transcoding nodes provide many additional control points at more strategic locations along the delivery path. 
   While network transcoding facilitates scalability in data delivery systems, it also presents a number of challenges. The process of transcoding can place a substantial computational load on transcoding nodes. While computationally efficient transcoding algorithms have been developed, they may not be well-suited for processing hundreds or thousands of streams at intermediate network nodes. 
   Furthermore, transcoding poses a threat to the security of the delivery system because conventional transcoding operations generally require that an encrypted stream be decrypted before transcoding. The transcoded result is re-encrypted but is decrypted at the next transcoder. Each transcoder thus presents a possible breach in the security of the system. This is not an acceptable situation when end-to-end security is required. 
   Compression, or encoding, techniques are used to reduce the redundant information in data, thereby facilitating the storage and distribution of the data by, in effect, reducing the quantity of data. The JPEG (Joint Photographic Experts Group) standard describes one popular, contemporary scheme for encoding image data. While JPEG is satisfactory in many respects, it has its limitations when it comes to current needs. A newer standard, the JPEG2000 standard, is being developed to meet those needs. However, even with the JPEG2000 standard, decryption of encrypted data is needed for transcoding, and transcoding processes remain computationally intensive. Furthermore, the introduction of a new standard such as JPEG2000 means that each of the large number of network nodes, as well as client devices, needs to be updated in order to be made compliant with the JPEG2000 standard. 
   Accordingly, a method and/or system that can allow scaling (e.g., transcoding) of data in a secure and computationally efficient manner would be advantageous. A system and/or method that can accomplish those objectives on legacy devices would be more advantageous. The present invention provides these as well as other advantages. 
   DISCLOSURE OF THE INVENTION 
   Embodiments of the present invention pertain to devices that receive media data, generate scalable media based on the media data, receive scalable attribute criteria, generate scalable profile data based, at least in part, on the scalable media and the scalable attribute criteria, and output the scalable profile data. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention: 
       FIG. 1  is an example of a bit stream including data according to one embodiment of the present invention. 
       FIG. 2  illustrates examples of data segments in a bit stream according to one embodiment of the present invention. 
       FIG. 3  is a block diagram showing functional elements in a simplified data delivery system according to one embodiment of the present invention. 
       FIG. 4A  shows information flowing into and out of an encoder according to one embodiment of the present invention. 
       FIG. 4B  shows information flowing into and out of an encoder according to a second embodiment of the present invention. 
       FIG. 5A  shows information flowing into and out of a data scaler according to one embodiment of the present invention. 
       FIG. 5B  shows information flowing into and out of a data scaler according to a second embodiment of the present invention. 
       FIG. 6  is a flowchart of a process for scaling (e.g., transcoding) data according to one embodiment of the present invention. 
       FIG. 7  is a flowchart of a process for encoding data according to one embodiment of the present invention. 
       FIG. 8  is a flowchart of a process for decoding data according to one embodiment of the present invention. 
       FIG. 9A  shows a system for coupling data with a scalable media according to one embodiment of the present invention. 
       FIG. 9B  shows a system for coupling data with a scalable media according to one embodiment of the present invention. 
       FIG. 10  shows information flowing into and out of a data scaler according to a second embodiment of the present invention. 
       FIG. 11  shows the steps performed in a method for associating data with portions of a scalable media according to one embodiment of the present invention. 
       FIG. 12  is a flowchart of the steps performed in a method of scaling encrypted scalable media according to one embodiment of the present invention. 
       FIG. 13  is a flowchart of the steps performed in a method of decoding scalable media according to one embodiment of the present invention. 
       FIG. 14  illustrates a method for encoding a progressively encrypted sequence of scalable data according to one embodiment of the present invention. 
       FIG. 15A  illustrates the transcoding by truncation of a progressively encrypted sequence of scalable data according to one embodiment of the present invention. 
       FIG. 15B  illustrates the transcoding by truncation of a progressively encrypted sequence of scalable data according to an alternate embodiment of the present invention. 
       FIG. 16A  illustrates the transcoding by truncation of a progressively encrypted sequence of scalable data according to one embodiment of the present invention. 
       FIG. 16B  illustrates the transcoding by truncation of a progressively encrypted sequence of scalable data according to one embodiment of the present invention. 
       FIG. 17  is a flowchart of the steps performed in a method for encoding a progressively encrypted sequence of scalable data according to one embodiment. 
       FIG. 18  is a flowchart of the steps performed in a method of transcoding a progressively encrypted sequence of scalable data according to one embodiment. 
       FIG. 19  is a flowchart of the steps performed in a method of decoding a progressively encrypted sequence of scalable data according to one embodiment of the present invention. 
       FIGS. 20 ,  21  and  22  are block diagrams of encoders, according to embodiments of the present invention. 
       FIGS. 23 ,  24  and  25  are block diagrams depicting decoders, according to embodiments of the present invention. 
       FIGS. 26 ,  27 ,  28 ,  29 ,  30 ,  31  and  32  are block diagrams depicting transcoders, according to embodiments of the present invention. 
   

   The drawings referred to in this description should not be understood as being drawn to scale except if specifically noted. 
   BEST MODE FOR CARRYING OUT THE INVENTION 
   Reference will now be made in detail to various embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with these embodiments, it will be understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following description of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the present invention. In other instances, well-known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the present invention. 
   Overview 
   Embodiments in accordance with the present invention are discussed primarily in the context of digital image data, in particular for still images. Digital image data can result from “real world” capture using a digital camera, for example. Digital image data can also be computer-generated using, for example, a paint program, screen capture, or the conversion of a graphic into a bitmap image. However, the present invention is not limited to digital image data. Instead, embodiments of the present invention are well suited for use with speech-based data, audio-based data, video-based data, web page-based data, graphic data, text-based data (e.g., electronic documents), and the like. 
   Furthermore, embodiments in accordance with the present invention are described for data that are scalably encoded using an encoding scheme compliant with, or substantially compliant with, the JPEG2000 standard. However, the present invention is not so limited. In general, embodiments according to the present invention are directed toward any data that can be scalably encoded and, specifically, any data that combines scalable encoding with progressive encryption. 
   For purposes of the present application, scalable encoding is defined as a process which takes original data as input and creates scalably encoded data as output, where the scalably encoded data has the property that portions of it can be used to reconstruct the original data at different levels of quality, resolution and the like. Specifically, the scalably encoded data is often thought of as an embedded bit stream. A portion of the bit stream can be used to decode a baseline-quality reconstruction of the original data, without requiring any information from other portions of the bit stream. Progressively larger portions of the bit stream can be used to decode improved reconstructions of the original data. JPEG2000 is one example of a scalable encoding scheme. Other scalable encoding schemes that may be used in accordance with embodiments of the present invention include, but are not limited to, 3D subband coding and MPEG-4 FGS (Moving Picture Experts Group-4 Fine Granularity Scalability). 
   For purposes of the present application, progressive encryption is defined as a process which takes original data (plain text) as input and creates progressively encrypted data (cipher text) as output, where the progressively encrypted data has the property that a first portion of the encrypted data can be decrypted alone, without requiring information from the remainder of the original data. Progressively larger portions can be decrypted with this same property, in which decryption can require data from earlier but not later portions of the bit stream. Progressive encryption techniques that may be used in accordance with the present invention include, but are not limited to, popular encryption primitives such as the Data Encryption Standard (DES), Triple-Des (3DES), and the Advanced Encryption Standard (AES). 
   General Discussion of JPEG2000 Encoding 
   In general, a number of stages constitute an encoding process compliant with the JPEG2000 standard. These stages are referred to herein as 1) preprocessing; 2) discrete wavelet transformation; 3) quantization; 4) embedded block coding; 5) rate control; and 6) bit stream organization. Embodiments of the present invention are not limited to these stages, and are also not limited to the particulars of the JPEG2000 standard described below. In fact, as will be seen, embodiments of the present invention introduce features beyond the syntax of the JPEG2000 standard, resulting in scaling (e.g., transcoding) processes that are more computationally efficient, and allowing scaling to be performed by devices that perhaps are not aware of the JPEG2000 standard. 
   JPEG2000 allows for both lossless and lossy compression; the focus herein is on lossy compression. During preprocessing, tiling can be optionally performed to partition an original image into tiles. Also during preprocessing, the input data may be adjusted so that the data has a nominal dynamic range centered on the value zero. Finally during preprocessing, color data may be transformed into Y, C r  and C b  color components. 
   During discrete wavelet transformation, image tiles can be decomposed into high and low subbands. Tiles can also be partitioned into code-blocks (e.g., 64×64 or 32×32 samples). More specifically, each subband is divided into rectangular blocks called “precincts,” and each precinct is further divided into non-overlapping rectangles called code-blocks. 
   The wavelet coefficients are quantized during the quantization stage. In the embedded block coding stage, each code-block is encoded separately. Rate control is a process by which the encoded bit stream is altered so that a target bit rate can be reached. Each encoded code-block may be reviewed to determine the extent to which it can be truncated in order to achieve the target bit rate. 
   In bit stream organization, encoded data are separated into what are referred to in the JPEG2000 standard as “packets” (the contents of a JPEG2000 packet are described by the JPEG2000 standard). The packets are then multiplexed together in an ordered manner into a bit stream. Note that the use of the term “packets” according to JPEG2000 is generally different from the more conventional use of that term. That is, JPEG2000 packets are multiplexed into a bit stream, which may then be packetized into data packets that are sent over a network, for example. 
   According to JPEG2000, the order of the data (e.g., the JPEG2000 packets) in the bit stream is referred to as a “progression.” There are a number of different ways to order the packets, such as precinct-component-resolution-quality or resolution-quality-component-precinct. According to JPEG2000, “quality” may instead be referred to as “layer.” These terms are known to those who are familiar with the JPEG2000 standard. 
   The order of the data in the bit stream may extend through the length of the bit stream. Alternatively, the order of the data in the bit stream may change to a different order at some point in the bit stream. The order of the data at any particular point in the bit stream is not of significance to the discussion herein; what is of significance is that the data are in a particular order that is prescribed by the encoding scheme, in this case an encoding scheme compliant or substantially compliant with the JPEG2000 standard. 
     FIG. 1  is an example of a JPEG2000 bit stream  10  including a header  11  and encoded data  12  according to one embodiment of the present invention. Header  11  includes a start of code stream marker SOC, an image and tile size marker SIZ, a coding style default marker COD, a quantization default marker QCD, a start of tile-part marker SOT, and a start of data marker SOD. Bit stream  10  also includes an end of code stream marker EOC. The functions performed by each of these markers is understood by those familiar with the JPEG2000 standard. 
   In the example of  FIG. 1 , the encoded data  12  is ordered according to a precinct-component-resolution progression; however, as presented above, different progressions can be used. In the example of  FIG. 1 , there are n precincts (P 0 , P 1 , . . . , Pn), three components (C 0 , C 1 , and C 2 ), and three resolutions (R 0 , R 1  and R 2 ). (For simplicity of illustration, quality is not included in the progression.) Encoded data  12  is ordered from most significant to least significant. In the example of  FIG. 1 , the encoded data  12  is ordered first by precinct, then by component, then by resolution. 
   To decode a bit stream of encoded data, a process that is in essence the opposite of the encoder process discussed above is employed. The encoded bit stream can be decoded in many different ways, depending on, for example, the capabilities of the displaying device and other practical considerations, as well as the specific interests of the viewer (e.g., one use may be satisfied with a low resolution image, while another may desire a high resolution image). According to JPEG2000, it is possible to locate, extract and decode the data required for the desired image product, without decoding the entire bit stream. However, the bits that can be conventionally extracted are limited by the syntax of JPEG2000. Also, to extract those bits, knowledge of the scheme used to encode the data (e.g., a JPEG2000-compliant scheme) is also required. For instance, to find the bits to extract, a device needs to be aware of JPEG2000 in order to read the bit stream  10 . As will be seen, embodiments of the present invention allow bits to be extracted beyond the syntax of JPEG2000 and without requiring knowledge of the encoding scheme. 
   Scaling Encoded Data without Requiring Knowledge of the Encoding Scheme 
   In the example of  FIG. 1 , the encoded data  12  includes a sequence of N bits, labeled  0  through N. According to embodiments of the present invention, different segments of bits are identified within the sequence of N bits. These segments are identified in  FIG. 1  as data segments  13 ,  14  and  15 . As illustrated by  FIG. 1 , the data segments may overlap each other in part or in entirety. Also, there can be data segments that do not overlap any other data segments. For example, segments  13  and  14  overlap, while segment  15  does not overlap either segment  13  or  14 . 
   Importantly, the segments  13 ,  14  and  15  are not constrained by the syntax of JPEG2000. That is, the beginning and ending points of a data segment are independent of the format of bit stream  10  that is dictated by JPEG2000. Thus, for example, segment  13  extends from the portion of bit stream  10  that includes C 0  into the portion that includes C 1 . Also, segment  13  begins at a point in the midst of the P 0 -C 0 -R 1  portion and ends in the midst of the P 0 -C 1 -R 2  portion. Furthermore, as will be seen, the locations of the data segments  13 ,  14  and  15  in bit stream  10  can be determined without reading bit stream  10 , including the information in header  11 . 
   In general, a data segment according to the present invention (e.g., data segments  13 ,  14  and  15 ) can begin and end anywhere in the bit stream  10 , and segments can overlap each other. Any number of such data segments can be identified, and a segment can have any length within encoded data  12 . Thus, a particular bit or sequence of bits can be a member of more than one data segment. The segments do not necessarily encompass the entire length of the encoded data  12 . That is, there may be one or more portions of encoded data  12  that are not included in a data segment defined according to the present invention. 
   Furthermore, data segments defined according to the present invention have these important characteristics: they are independently decodable; they are independently encryptable and decryptable; and they are independently checkable. That is, each data segment can be decoded independent of any other segment. Similarly, each data segment can be encrypted and decrypted independent of any other segment. Also, a checksum, for example, can be applied to each data segment independent of any other segment. 
     FIG. 2  illustrates examples of data segments in a bit stream according to one embodiment of the present invention. As just described, encoded data  12  includes N bits that are ordered and formatted depending on the encoding scheme. According to embodiments of the present invention, a number of segments are identified within the encoded data  12 . 
   In the example of  FIG. 2 , encoded data  12  includes bits identified as b 1 , b 2  and b 3 , and other bits identified as r 1 , r 2  and r 3  (these bits all lie within encoded data  12 ; however, they are separately illustrated for clarity). Thus, for example, a segment can be defined as extending from bit  0  to bit b 1 , another segment can be defined as extending from bit b 1  to bit b 2 , and so on. A segment can instead be identified as beginning at a certain bit number and having a certain length (measured in bits). For example, a data segment can be defined as beginning at bit b 0  and having a length equal to b 1  bits, another segment can be identified as beginning at bit b 1  and having a length of (b 2 –b 1 ) bits, and so on. Furthermore, a segment can extend from bit b 1  to bit b 3 , or from bit b 1  to N, and so on. That is, as mentioned above, a segment can have any length, beginning at any bit and ending at any other bit, and two or more segments can overlap. For example, the data segment defined by bits r 2  to r 3  overlaps the data segment defined by bits b 2  to b 3 . Segments may or may not be of different lengths. 
   Importantly, the data segments defined according to the present invention and exemplified by  FIG. 2  have starting and ending points that are independent of the format specified by an encoding scheme for encoded data  12 . As will be seen, the data segments defined according to the present invention allow data, particularly encoded data, to be extracted or parsed from bit stream  10  without requiring knowledge of the encoding scheme that was used to encode the data. Moreover, the data can be extracted from the bit stream  10  ( FIG. 1 ) without decrypting the data if the data are encrypted. 
   The capability to extract/parse data in this manner can be advantageously applied to data scaling (e.g., transcoding) and decoding (decompressing), as will be seen. For example, to achieve a reduction in bit rate, the two data segments ranging from bits  0  to b 1  and b 2  to b 3  may be extracted from bit stream  10  as part of a transcoding operation. Then, those two segments can be combined in a scaled version of the encoded data and sent over the data delivery system. To achieve a reduction in frame rate, for example, one or more data segments (e.g., the data segment ranging from r 1  to r 2 ) are similarly chosen. Thus, the single set of data  12 , ranging from bits  0  to N, can be organized into data segments that allow scaling to be performed for a number of different scalable attributes (e.g., bit rate, frame rate, etc.). For example, the single set of data  12  can be organized into a first set of data segments that pertain to bit rate reduction, another set of data segments that pertain to frame rate reduction, and so on. The set of data segments chosen for bit rate reduction may or may not include some portion of the set of data segments chosen for frame rate reduction, and vice versa. 
   Importantly, in the above examples, the segments selected for bit rate reduction, frame rate reduction, or the like are intelligently selected during encoding to achieve the desired scaling result while minimizing to a practical extent the impact on the image product. It is also important to note that a much finer granularity in data segment lengths can be achieved than that illustrated by  FIG. 2 . As a result, scaling operations can be performed to finer degrees. 
     FIG. 3  is a block diagram showing functional elements in a simplified data delivery system  30  according to one embodiment of the present invention. In the example of  FIG. 3 , system  30  includes an encoder  32 , a transcoder  34 , a first decoder  36  and a second decoder  38 . System  30  may be part of a larger system or network that includes similar functional elements as well as other types of functional elements (e.g., storage elements, packetizers, streaming elements and the like). In the present embodiment, encoder  32  encodes (compresses) data, transcoder  34  transcodes (e.g., scales) encoded data, and decoders  36  and  38  decode (decompress) data. These functionalities may be performed in a single device or distributed among one or more devices that may be connected in some type of network. 
   Also, the elements  32 ,  34 ,  36  and  38  may perform functions other than those just described. For example, encoder  32  may also encrypt data and calculate checksums or cryptographic checksums for checking the data, encoder  32  may also scale encoded data before sending the encoded data to another block, and decoder  38  may scale encoded data before decoding it. In one embodiment, encoder  32  uses an encoding scheme based on the JPEG2000 standard. 
   In addition, transcoder  34  may instead send a scaled version of encoded data to another transcoder, which in turn scales the scaled data and sends it to another transcoder, and so on. Also, even though decoder  36  receives scaled data from transcoder  34 , decoder  36  may further scale the scaled data. Furthermore, the decoder  36  and  38  may not be the end-user device. For example, decoder  36  and  38  may decode encoded data, and send the decoded data to, for example, a mobile phone that renders and displays the image product. 
   Moreover, the data scaling function may be performed by a storage device or driver. For example, a storage device (e.g., a disk drive or DVD player) may scale the encoded data, passing only the appropriate data segments to the actual decoder. In this manner, resources or time are not wasted sending unnecessary information. This can also simplify the decoder, because the decoder does not need to perform this processing. 
     FIG. 4A  shows information flowing into and out of an encoder  32  according to one embodiment of the present invention. In the present embodiment, encoder  32  receives input data (e.g., data such as image data that are to be encoded). Encoder  32  also receives values of scalable attributes. 
   For purposes of the present application, a scalable attribute is defined as an attribute having a range of values that specifies how the encoded data are to be subsequently scaled. For image data, a scalable attribute can be, for example, bit rate, frame rate, resolution, color or black and white, region of interest, tile, quality, image objects, or foreground versus background. 
   Scalable attribute values are values specified for the scalable attributes. For example, scalable attribute values for bit rate can include full bit rate (B), one-half bit rate (B/2), one-fourth bit rate (B/4), and so on. 
   Scalable attributes and values can be similarly defined for other types of data (e.g., audio data, graphics data, and the like). For example, a scalable attribute value for audio data can indicate whether an audio track is stereo or mono. Electronic documents and text-based data may also be organized via scalable attributes that describe the content of the document or text-based data (e.g., chapters, sections, images, graphs, index, appendices, associated software, extra audiovisual material, etc.). It is beneficial to be able to adapt the selection of content, as well as the size of the content, to meet end-user preferences or device constraints such as available storage space. In addition, certain portions of these documents may be encrypted, either for confidentiality reasons or for commercial reasons (e.g., pay to read), while other portions of these documents may be in plain text. 
   In the present embodiment, encoder  32  encodes the input data using an encoding scheme such as an encoding scheme based on JPEG2000. As mentioned above, encoder  32  can provide other functionality. As a result of the encoding process, a bit stream such as that exemplified by bit stream  10  of  FIG. 1 , or a file containing such a bit stream, is generated. The file or bit stream is organized according to the encoding scheme; that is, the bits are in a certain order that is established by the encoding scheme. The output of encoder  32  includes what is referred to herein as scalable data, because the encoded data can be subsequently scaled by a transcoder or decoder. 
   Another output of encoder  32  includes what is referred to herein as scalable profile data. In essence, scalable profile data includes a cross-reference of scalable attribute values and corresponding data segments within the scalable, encoded data. For example, the scalable profile data may be in the form of an index or lookup table that cross-references data segments and scalable attribute values, exemplified by Table 1 below (with reference also to  FIG. 2 ). 
   
     
       
         
             
           
             
               TABLE 1 
             
           
          
             
                 
             
             
               Exemplary Scalable Profile Data 
             
          
         
         
             
             
             
          
             
                 
               Scalable 
               List of Data Segments 
             
             
                 
               Attribute 
               (Bit Numbers) 
             
             
                 
                 
             
             
                 
               Full Bit Rate (B) 
               0–N 
             
             
                 
               B/2 (R2, Q2) 
               0–b1 and b2–b3 
             
             
                 
               B/2 (R1, Q3) 
               0–b2 
             
             
                 
               B/4 
               0–b1 
             
             
                 
                 
             
          
         
       
     
   
   It is appreciated that the format of Table 1 is exemplary only, and that the scalable profile data can be stored in just about any computer-readable format. In Table 1, bits are identified by their bit numbers, but other addressing mechanisms may be used. Also, instead of identifying data segments by their bit range, other mechanisms can be used to identify data segments. In general, the scalable profile data includes enough information to correlate a value of scalable attribute with one or more data segments in the bit stream  10  of  FIG. 1 . 
   Furthermore, Table 1 only addresses bit rate (B), resolution (R) and quality (Q), but in actuality such a table can include any scalable attributes and scalable attribute values selected by the user as input to encoder  32  ( FIG. 3 ). In addition, the scalable profile data can include multiple choices of data segments for each scalable attribute value. This can provide greater flexibility downstream at the transcoder or decoder. For example, in one application, a bit rate reduction of one-half can be achieved at a resolution level  2  (R 2 ) and quality level  2  (Q 2 ), or at resolution level  1  (R 1 ) and quality level  3  (Q 3 ). R 1  may be better than R 2 , and Q 2  may be better than Q 3 , so that the same bit rate can be achieved but with tradeoffs in resolution and quality. Thus, by including multiple choices of data segments for each scalable attribute value in the scalable profile data, a user at a downstream node (e.g., at a transcoder or decoder) can select the type and degree of scaling that suits his or her needs, for example. 
   In one embodiment, the scalable profile data also includes information about the distortion that will be produced depending on which segments are extracted and hence which are discarded. The distortion can be measured in terms of conventional mean-squared error (MSE) or in terms of a perceptual distortion. The scaler (e.g., transcoder) can use the information about distortion to determine which segments are most important and should be retained (e.g., extracted), and which segments have lesser importance and can be discarded. There may be a separate distortion parameter per data segment, or per group of segments, or per scalable attribute value (e.g., image resolution, quality level, bit rate, etc.). Accordingly, the decision as to which segments to extract or discard can be performed by accounting for the associated distortions in combination with the type and degree of scaling that suits the end-user&#39;s needs, as well as the type and degree of scaling selected according to network performance characteristics, downstream device capabilities, and other factors. 
   The distortion associated with each data segment, group of segments or scalable attribute can be a measured distortion or an estimated distortion. For example, the measured distortion associated with discarding a particular data segment can be computed by, in essence, dropping that data segment from the bit stream and computing the resulting distortion that would be produced when decoding the remaining data packets. This measurement can be performed as the media are encoded or for pre-encoded data. For pre-encoded data, a data segment can be dropped from the encoded (compressed) bit stream, the remainder of the data can be decoded, and the resulting distortion can be computed. As an alternative to measured distortion, estimated distortion can be accomplished, for example, by extracting information from the encoded bit stream that provides an indication of the distortion that may result should a particular data segment be discarded. Measured distortion is more accurate than estimated distortion; however, measured distortion is more complex to compute. 
   Note that the predicted distortion can be a single number corresponding to the expected distortion, or it may be a distribution of expected distortions, or something in between (e.g., expected distortions with a tolerance band corresponding to, for example, one standard deviation). Alternatively, some form of cumulative distribution function for the distortion can be determined. 
   In the embodiment of  FIG. 4A , the scalable data and the scalable profile data are stored together. For example, the scalable profile data can be appended to the bit stream or file that contains the scalable data. For instances in which there is a large quantity of scalable data, portions of the scalable profile data may be spaced at intervals within the bit stream or file. 
   Alternatively, the scalable profile data can be stored and handled separately from the scalable data, as illustrated by  FIG. 4B . In the embodiment of  FIG. 4B , it is not even necessary that the scalable profile data travel with the scalable data. For example, with reference to  FIG. 2 , the scalable profile data can travel to transcoder  34 , decoder  36  or decoder  38  by a path that is different from the path traveled by the scalable data. Alternatively, the scalable profile data and the scalable data can be stored in separate locations, and then accessed and correlated by transcoder  34 , decoder  36  or decoder  38  whenever necessary. 
   In operation, the encoder  32  of  FIGS. 4A and 4B  functions as follows. In one embodiment, values of scalable attributes are input by a user. Alternatively, values of scalable attributes may be automatically selected based on information known by encoder  32  about network performance, downstream device capabilities, and the like. Network performance characteristics such as available bandwidth may be monitored, and that information fed to encoder  32 . Also, downstream devices (including the end-user device) may communicate directly with encoder  32 . 
   Encoder  32  then encodes the input data in a conventional manner, using the encoding scheme it is employing (e.g., a JPEG2000 encoding scheme). In addition, the encoder  32  generates scalable profile data for the encoded bit stream (the scalable data). That is, in one embodiment, for each of the input values of scalable attributes, encoder  32  identifies corresponding data segments within the encoded data. 
   Importantly, according to the embodiments of the present invention, the scalable (encoded) data that is output by encoder  32  can be scaled without requiring knowledge of the encoding scheme employed by encoder  32 . Whether the data are encoded using a JPEG2000 scheme or some other encoding scheme, a transcoder or decoder need only specify the type of scaling to be performed (e.g., reduce bit rate by one-fourth) to extract/parse from bit stream  10  ( FIG. 1 ) the data segment(s) associated with that type of scaling. 
   In one embodiment, encoder  32  can identify several choices or combinations of data segments that correspond to a particular value of a scalable attribute. For example, to achieve a bit rate reduction of one-half (B/2), encoder  32  may identify several different combinations of data segments that are satisfactory. For image data, one combination may result in the reduced bit rate being applied to all portions of the image product. Another combination may result in full bit rate (B) being applied to a region of interest in the image product, and a bit rate reduced by a greater amount (e.g., B/4) being applied to other regions of the image product, such that the average bit rate is B/2. 
   At the encoding stage, encoder  32  can apply intelligence (either programmed intelligence or intelligence based on user input) to decide which combination or combinations of data segments to include in the scalable profile data. Alternatively, all combinations can be included; the transcoder or decoder can then decide which combination of data segments to use based on user input or other considerations such as network performance characteristics or end-user device capabilities. 
   Note that the data ultimately included by encoder  32  in the encoded bit stream or file can depend on the input values of the scalable attributes. For example, suppose that there is not a need for the scalable data to include data corresponding to the full bit rate case. Instead, only the cases of B/2 and B/4 are to be considered. Encoder  32  identifies data segments corresponding to B/2 and B/4, but these data segments do not encompass all of the encoded data. That is, there is some portion of the encoded data that is not indexed to B/2 or B/4 in the scalable profile data. If that portion of data is not associated with another scalable attribute, encoder  32  can decide to not include that data in the encoded bit stream or file. 
   In another embodiment, data segments associated with various values of scalable attributes may be defined ahead of time. In essence, the scalable profile data exemplified by Table 1 is established in advance of the data encoding. In this embodiment, the data are encoded and then placed in the bit stream in an order that corresponds to the order defined by the scalable profile data. For example, referring to  FIG. 2 , the scalable profile data may define in advance that bits  0 -b 2  are reserved for bit rate reduction by one-half (B/2). Accordingly, encoder  32  will compress the data by the amount necessary to fit data associated with B/2 into bits  0 -b 2 , and will place that data into those locations within the bit stream  10 . 
   In yet another embodiment, an encoded file, organized according to an encoding scheme, is reorganized based on desired goals and on knowledge of the scalable attributes, and then, for example, stored or streamed. For instance, using scalable profile data (e.g., a cross-reference of data segment and scalable attribute) to locate relevant data segments in the encoded file, it may be useful to take an encoded file that is organized first by color component and second by resolution and reorganize the file so that it is instead ordered first by resolution and second by color component. By taking advantage of the scalable profile data, the reorganization can be achieved without requiring knowledge of the details of the encoding format. 
     FIG. 5A  shows information flowing into and out of a data scaler  54  according to one embodiment of the present invention. Data scaler  54  may be a transcoder such as transcoder  34  of  FIG. 3 , or it may be a decoder that performs a scaling or parsing function (e.g., decoder  38  of  FIG. 3 ). 
   As input, data scaler  54  of  FIG. 5A  receives scalable data and scalable profile data. As mentioned above in conjunction with  FIGS. 4A and 4B , the scalable data and scalable profile data may be traveling together (e.g., in the same bit stream or file) or apart. The input may be streamed to data scaler  54  (from encoder  32 , for example), or it may retrieved by data scaler  54  from some type of storage element. 
   Using the scalable profile data, scaler  54  can parse the scalable data and create a scaled version of the encoded data. For example, if scaler  54  wants to reduce bit rate by one-fourth, it can determine from the scalable profile data which bits in the encoded data can be selected to achieve the desired bit rate reduction (see Table 1, for example). Scaler  54  can then create a scaled version of the encoded data using the identified data segments, by either discarding the bits not required, or by extracting the identified data segments and combining them into a new bit stream or file. 
   As mentioned above, the scalable profile data presented to scaler  54  can include multiple choices of data segments for each scalable attribute value (refer to the discussion in conjunction with Table 1). The decision as to which segment(s) to extract or discard can be performed by accounting for the type and degree of scaling that suits the end-user&#39;s needs, the type and degree of scaling selected according to network performance characteristics and/or downstream device capabilities, the distortion information included in the scalable profile data, or other factors, and combinations thereof. For example, if scaler  54  is to reduce bit rate by one-half, but is presented with different ways of achieving that bit rate reduction, scaler  54  can make a selection considering the characteristics of the end-user device and/or the amount of distortion associated with each possible selection. Perhaps the end-user device is a mobile phone with a relatively small display screen that permits color displays, in which case scaler  54  may extract data segments that achieve the bit rate reduction at a lower resolution while preserving color components, or that achieve the desired bit rate reduction while minimizing the amount of distortion. 
   Importantly, scaler  54  can perform its functions without requiring knowledge of the encoding scheme that was used to encode the data. Also, scaler  54  can perform these functions without decrypting the encoded data, if the data are encrypted. To parse the scalable data, scaler  54  simply identifies which bits (data segments) to extract, locates those bits (data segments) in the bit stream or file, and extracts those bits (data segments). Scaler  54  does not need to read the bits in the data segments, nor does scaler  54  need to read the information in header  11  ( FIG. 1 ) to locate the bits (data segments). As such, the scaling operation can be efficiently accomplished, without unduly taxing computational resources. Furthermore, because scaler  54  does not need to read the bits in the data segments, scaler  54  does not require knowledge of the encoding scheme. Accordingly, scaling can be accomplished on legacy devices even when the encoding scheme is relatively new and perhaps unknown to scaler  54 . Specifically, scaler  54  does not need to be aware of JPEG2000 in order to scale the encoded data. 
   Moreover, the data scaling function may be performed by a storage device or driver without requiring knowledge of the encoding syntax. For example, a storage device (e.g., a disk drive or DVD player) may scale the encoded data, passing only the appropriate data segments to the actual decoder. In this manner, resources or time are not wasted sending unnecessary information. This can also simplify the decoder, because the decoder does not need to perform this processing. 
   To locate and extract the data segments dictated by the scalable profile data, scaler  54  can be provided with the capability to read the scalable profile data by various means. For example, a driver can be preloaded onto scaler  54 , or such a driver can be provided with the scalable profile data. Alternatively, the scalable profile data can be based on, for example, the Extensible Markup Language (XML), which can be read and acted on by the scaler  54 . 
   As a result of the scaling operation, the scalable profile data that was received by scaler  54  may need to be modified. For example, after the encoded data are scaled, some data segments referenced in the scalable profile data may not be present in the encoded data, or some scaling operations may no longer be possible. Furthermore, some scaling operations may need to be redefined in terms of their associated data segments, because after scaling the data segments may be identified by different bit numbers. There may be other reasons for modifying the scalable profile data. 
     FIG. 5B  shows information flowing into and out of a data scaler  54  according to a second embodiment of the present invention, in which scaler  54  creates modified scalable profile data. Scaler  54  can modify the scalable profile data in much the same way that encoder  32  created the scalable profile data. In the present embodiment, the modified scalable profile data is then output from scaler  54 , either together with or separate from the scaled version of the encoded data, as described above. 
     FIG. 6  is a flowchart  60  of a process for scaling (e.g., transcoding) data according to one embodiment of the present invention.  FIG. 7  is a flowchart  70  of a process for encoding data according to one embodiment of the present invention.  FIG. 8  is a flowchart of a process  80  for decoding data according to one embodiment of the present invention. Although specific steps are disclosed in flowcharts  60 ,  70  and  80 , such steps are exemplary. That is, embodiments of the present invention are well-suited to performing various other steps or variations of the steps recited in flowcharts  60 ,  70  and  80 . It is appreciated that the steps in flowcharts  60 ,  70  and  80  may be performed in an order different than presented, and that not all of the steps in flowcharts  60 ,  70  and  80  may be performed. All of, or a portion of, the methods described by flowcharts  60 ,  70  and  80  may be implemented using computer-readable and computer-executable instructions which reside, for example, in computer-usable media of a computer system. 
   Generally, flowchart  60  is implemented by scaler  54  of  FIGS. 5A and 5B  (e.g., transcoder  34  or decoder  38  of  FIG. 3 ); flowchart  70 , by encoder  32  of  FIGS. 3 ,  4 A and  4 B; and flowchart  80 , by decoder  36  of  FIG. 3 . However, as mentioned above, different functional blocks can perform different functions, one device may perform multiple functions, or a function or functions may be distributed across multiple devices. 
   Referring first to  FIG. 6 , in step  61 , a sequence of encoded data is accessed (e.g., in a bit stream or a file). The encoded data are organized according to an encoding scheme that was used to encode the data. In one embodiment, the encoding scheme is based on the JPEG2000 standard. Some or all of the encoded data may also be encrypted. 
   In step  62 , a value for a scalable attribute is determined. The scalable attribute identifies how the encoded data are to be scaled. A scalable attribute may be, for example, bit rate (B), and the value of the scalable attribute may be B/4. 
   In one embodiment, the value for the scalable attribute is received from another device in communication with the scaling device. In one such embodiment, when the other device is to be the recipient of the scaled version of the encoded data, the encoded data are to be scaled based on the characteristics of that other device. To determine those characteristics, the scaling device can access profile information that provides the characteristics of the other device, and select the value of the scalable attribute according to the profile information. Alternatively, the scaling device can receive profile information from the other device, and select the value of the scalable attribute accordingly. 
   In step  63 , information (e.g., scalable profile data) that includes a reference to segments of the encoded data that are associated with the scalable attribute is accessed. Importantly, the reference is beyond the syntax of the encoding scheme. 
   In one embodiment, the reference information (e.g., scalable profile data) is stored with the sequence of encoded data. In another embodiment, the reference information is stored separately from the sequence of encoded data. 
   In step  64 , the scalable profile data is used to locate the segments in the encoded data. Importantly, the segments are found without requiring knowledge by the scaling device of the encoding scheme. 
   In step  65 , a scaled version of the encoded data is created using the segments. Also, the scaled version of the encoded data is created without decrypting encrypted data. 
   In step  66 , in one embodiment, the scaled version of the encoded data is forwarded to the downstream device. 
   In step  67 , in one embodiment, modified reference information (e.g., modified scalable profile data) is generated based on the scaled version of the encoded data. Segments in the scaled version are associated with selected values of scalable attributes, independent of the encoding scheme, thereby allowing another device to locate the segments in the scaled version and to scale the scaled version without requiring knowledge of the encoding scheme. The modified reference information can be stored with or separate from the scaled version of the encoded data. 
   Referring now to  FIG. 7 , in step  71 , data are encoded using an encoding scheme and stored in a file. In one embodiment, the encoding scheme is substantially compliant with the JPEG2000 standard. 
   In step  72 , locations of data segments in the file are identified. 
   In step  73 , the data segments and selected values of scalable attributes are indexed. A scalable attribute specifies how encoded data are to be scaled in a subsequent scaling operation. The index is independent of the encoding scheme, and allows a device to locate the segments and to scale encoded data without requiring knowledge of the encoding scheme. In one embodiment, the selected values of scalable attributes are input to the encoding device. 
   In step  74 , reference information including the index of the data segments and the selected values of scalable attributes is stored. In one embodiment, the index is added to the file of encoded data. In another embodiment, the index is stored separately from the file. 
   In step  75 , in one embodiment, at least some of the encoded data is encrypted. In one such embodiment, each data segment of encoded data is progressively encrypted. 
   Now with reference to  FIG. 8 , in step  81 , a sequence of encoded data is accessed. The encoded data are ordered according to an encoding scheme used to encode the data. In one embodiment, the encoding scheme is substantially compliant with the JPEG2000 standard. 
   In step  82 , the decoding device determines how the encoded data are to be scaled for decoding. 
   In step  83 , information (e.g., scalable profile data) that identifies certain segments of the encoded data is accessed. This information is in addition to the syntax of the encoding scheme. The data segments are identified based on how the encoded data are to be scaled for decoding. 
   More specifically, in one embodiment, a value for a scalable attribute is determined. The value may be a user input, or it may be derived based on the characteristics and capabilities of the decoding device. The value of the scalable attribute identifies how the encoded data are to be scaled. The scalable profile data includes a reference from the scalable attribute value to certain data segments in the encoded data. 
   In step  84 , using the information from step  83 , the data segments are found in the encoded data. Importantly, the segments are located without requiring knowledge by the decoding device of the encoding scheme. 
   In step  85 , the encoded data included in the data segments found in step  84  are decoded. If the encoded data is encrypted, then the data in the data segments can also be decrypted. 
   In summary, embodiments of the present invention allow scaling (e.g., transcoding) of encoded data in a secure and computationally efficient manner. Scaling can be accomplished without requiring knowledge of the scheme used to encode the data, and accordingly scaling can be accomplished on legacy devices even when the encoding scheme is relatively new and perhaps unknown to the scaling device. 
   Protection Profile Data Generating System and Method 
     FIG. 9A  shows a system for coupling data with a scalable media according to one embodiment of the present invention.  FIG. 9A  illustrates information flow into and out of encoder  32  according to one embodiment of the present invention. In the embodiment of  FIG. 9A , data is associated with scalable media that identifies the portions of the scalable media that may combined in order to produce media that is scaled to possess a desired scalable attribute. Thereafter, the scalable media is encrypted. In addition, data is associated with the individual portions of the scalable media that identifies the protection attributes of the encryption scheme that is used to encrypt the individual portions of the scalable media. 
   In the present embodiment, encoder  32  receives input data (e.g., data such as image data that are to be encoded). Encoder  32  also receives data that details the attributes of the encryption scheme used to encrypt the input data. 
   For purposes of the present application, a protection attribute is defined as an attribute having a range parameters and associated values that specifies how the encoded data are to be protected. Protection attributes can include but are not limited to encryption primitives, encryption modes, CCSs, and mapping of crypto to scalable media segments. 
   Protection attribute values are values specified for the protection attributes. For example, protection attribute values for encryption primitive can include DES, 3-DES, AEC, etc. Protection attributes and values can be similarly defined for other types of data (e.g., audio data, graphics data, and the like). For example, a protection attribute value for audio data can indicate whether an audio track is protected using MAC or keyed-hashes as cryptographic checksums. 
   As previously discussed, encoder  32  encodes the input data using an encoding scheme such as an encoding scheme based on JPEG2000. As mentioned above, encoder  32  can provide other functionality. As a result of the encoding process, a bit stream such as that exemplified by bit stream  10  of  FIG. 1 , or a file containing such a bit stream, is generated. The output of encoder  32  includes what is referred to herein as scalable data, because the encoded data can be subsequently scaled by a transcoder or decoder. 
   Referring again to  FIG. 9A , another output of encoder  32  includes what is referred to herein as protection profile data. In essence, protection profile data includes a cross-reference of protection attribute values and corresponding data segments within the scalable data. For example, the protection profile data may be configured as an index or lookup table that cross-references data segments and protection attribute values, as exemplified in Table 2 below (with reference also to  FIG. 2 ). 
   
     
       
         
             
           
             
               TABLE 2 
             
           
          
             
                 
             
             
               Exemplary Protection Profile Data 
             
          
         
         
             
             
             
          
             
                 
               Protection 
               List of Data Segments 
             
             
                 
               Attribute/Values 
               (Byte Numbers) 
             
             
                 
                 
             
             
                 
               Encryption 
               0–N 
             
             
                 
               Primitive/AES 
             
             
                 
               Encryption 
               0–b1 and b2–b3 
             
             
                 
               Mode/CBC 
             
             
                 
               CCS/MAC 
               0–b2 
             
             
                 
               Mapping/Multiple 
               0–b1 
             
             
                 
               Keying 
             
             
                 
               Digital 
               0–N 
             
             
                 
               Signature/DSS 
             
             
                 
                 
             
          
         
       
     
   
   It is appreciated that the format of Table 2 is exemplary only, and that the protection profile data can be stored in just about any computer-readable format. In Table 2, bytes are identified by their byte numbers, but other addressing mechanisms may be used. Also, instead of identifying data segments by their byte or bit or block (e.g. 8 byte) range, other mechanisms can be used to identify data segments. In general, the protection profile data includes enough information to correlate a value of a protection attribute with one or more data segments in the bit stream  10  of  FIG. 1 . 
   It should be appreciated that Table 2 can include any protection attributes and protection attribute values selected by the user as an input to encoder  32  ( FIG. 3 ). In addition, the list of data segments to which a particular protection attribute is to be applied can include multiple choices of data segments for each protection attribute value. This can provide a wide range of data protection flexibility at the encoder. Thus, the choice flexibility of exemplary embodiments, that allows the inclusion of multiple choices of data segments for each protection attribute value in the protection profile data, allows a user (e.g., providing input to the encoder) to select the type and degree of protection that suits his or her needs. 
   It should be noted that the scalable data (encoded and encrypted) that is output by encoder  32  can be scaled without requiring knowledge of the encoding scheme, or the encryption scheme employed by encoder  32 . Whether the data are encoded using a JPEG2000 scheme or some other encoding scheme, a transcoder or decoder need only specify the type of scaling to be performed (e.g., reduce bit rate by one-fourth) to extract/parse from bit stream  10  ( FIG. 1 ) the data segment(s) associated with that type of scaling. 
   In the embodiment of  FIG. 9A , the scalable data and the protection profile data are stored together. For example, the protection profile data can be appended to the bit stream or file that contains the scalable data. For instances in which there is a large quantity of scalable data, portions of the scalable profile data may be spaced at intervals within the bit stream or file. 
   Alternatively, the protection profile data can be stored and handled separately from the scalable data, as illustrated by  FIG. 9B . In the embodiment of  FIG. 9B , it is not even necessary that the scalable profile data travel with the scalable data. For example, with reference to  FIG. 3 , the protection profile data can travel to transcoder  34 , decoder  36  or decoder  38  by a path that is different from the path traveled by the scalable data. Alternatively, the protection profile data and the scalable data can be stored in separate locations, and then accessed and correlated by transcoder  34 , decoder  36  or decoder  38  whenever necessary. 
   In operation, the encoder  32  of  FIGS. 9A and 9B  functions as follows. In one embodiment, values of protection attributes are input by a user, which may include the content creator, content distributor, or content consumer. Alternatively, values of protection attributes may be automatically selected based on information known by encoder  32  about network performance, downstream device capabilities, digital right management (DRM) policies, security concerns or vulnerabilities, and the like. Network performance characteristics such as available bandwidth may be monitored, and that information fed to encoder  32 . Also, downstream devices (including the end-user device) may communicate directly with encoder  32 . 
   Encoder  32  then encodes the input data in a conventional manner, using the encoding scheme it is employing (e.g., a JPEG2000 encoding scheme). In addition, the encoder  32  generates protection profile data for the encoded bit stream (the scalable data). That is, in one embodiment, for each of the input values of protection attributes, encoder  32  identifies corresponding data segments within the encoded data to which the protection attribute may be associated. 
   In one embodiment, encoder  32  can identify several choices or combinations of data segments that are associated with a particular value of a protection attribute. For example, in the image product context, for a particular encryption primitive, encoder  32  may identify several different combinations of data segments that may be encrypted using that encryption primitive. According to one embodiment, one combination may result in the same encryption primitive being applied to all portions of the image product. Another combination may result in one encryption primitive being applied to one region of interest in the image product, and another encryption primitive being applied to other regions of interest in the image product. 
   At the encoding stage, encoder  32  can apply intelligence (either programmed intelligence or intelligence based on user input) to decide which combination or combinations of data segments to associate with the protection profile data. Alternatively, all combinations can be associated with protection profile data; the encoder can decide which combination (e.g., some or all) of data segments to associate with a particular protection attribute based on user input or other considerations such as network performance characteristics, end-user device capabilities, digital rights management policies (DRM), or security vulnerabilities. 
   In another embodiment, data segments associated with various values of protection attributes may be defined ahead of time. In essence, the protection profile data exemplified by Table 1 is established in advance of data encoding. In this embodiment, the data are encoded and then encrypted in a manner that corresponds to the manner defined by the protection profile data. For example, referring to  FIG. 2 , the protection profile data may define in advance that bytes  0 -b 2  are to be encrypted using an encryption primitive having protection attribute value AES. The encoder would then encrypt these bytes accordingly. 
     FIG. 10  shows information flowing into and out of a data scaler  54  according to a second embodiment of the present invention, in which scaler  54  creates modified protection profile data. Scaler  54  can modify the protection profile data in much the same way that encoder  32  created the protection profile data. In the present embodiment, the modified scalable profile data is then output from scaler  54 , either together with or separate from the scaled version of the encoded data, as described above. 
   In the present embodiment, protection profile data that is associated with individual portions of the scalable media identifies protection attributes that can include but is not limited to encryption primitives, encryption modes, cryptographic checksums, and the mapping of crypto to scalable media such as is shown in Table 2. Moreover, the protection profile data is used in the decryption of an encryption algorithm and a cryptographic technique that is used in the encryption scheme used to encrypt the individual portions of the scalable media. 
   In the present embodiment, respective individual portions of the scalable media may have different keys that are used to decrypt the individual portions of the scalable media, may use different encryption algorithms, and may use different CCSs. It should be appreciated that, respective classes of keys may be required to decrypt respective classes of scalable media. For example, a first key may be required to gain access to a file containing media having a first resolution while a second key may be required to gain access to a file containing media having a second resolution. 
   According to one embodiment, parameters of the protection profile data may change over time. It should be appreciated that the protection profile data can be remapped to reflect changes made to a sequence of data to which it is associated. 
     FIG. 11  shows the steps performed in a method for scaling portions of a scalable media according to one embodiment of the present invention. At step  1101 , data is associated with scalable media that identifies portions of the scalable media to combine in order to produce media that is scaled to possess a desired scalable attribute. In the present embodiment, the scalable profile data that is associated with the individual portions of scalable media may be coupled to the scalable media or signaled remotely. At step  1103 , the portions of the scalable media identified in step  1101 , are encrypted. According to one embodiment, as discussed herein, the scalable media portions that constitute the scalable media can be encrypted using the same or different schemes. 
   At step  1105 , data is associated with the identified portions of the scalable media that identifies protection attributes of the encryption scheme used to encrypt the identified portions of the scalable media. In the present embodiment, the protection profile data that is associated with the individual portions of scalable media may be coupled to the scalable media or signaled remotely. 
     FIG. 12  is a flowchart of the steps performed in a method of scaling encrypted scalable media without decoding according to one embodiment of the present invention. At step  1201 , data is accessed that is associated with the encrypted scalable media and that identifies portions of the encrypted scalable media to combine in order to produce media that is scaled to possess a desired scalable attribute. At step  1203 , one or more of the portions of the encrypted scalable media and associated cryptographic checksums are combined into a transmittable sequence of data. At step  1205 , data associated with the scalable media that identifies portions of the scalable media to combine in order to produce media that is scaled to possess a desired scalable attribute is remapped. 
   At step  1207 , data associated with the portions of the scalable media that identifies protection attributes of the encryption system used to encrypt portions of the scalable media is remapped. It should be appreciated that one or more portions of the encrypted scalable media and associated cryptographic checksums can constitute a scaled version of the encrypted scalable media. 
     FIG. 13  is a flowchart of the steps performed in a method of decoding scalable media according to one embodiment of the present invention. At step  1301 , data associated with portions of the scalable media that identifies protection attributes of the encryption system used to encrypt the portions of the scalable media are accessed. At step  1303 , data associated with the scalable media that identifies portions of the scalable media to combine in order to produce media that is scaled to possess a desired scalable attribute is accessed. 
   At step  1305 , the portions of the scalable media are decrypted based on the data associated with the portions of the scalable media that identifies protection attributes of the encryption system used to encrypt them. At step  1307 , the portions of the scalable media are decoded based on the data associated with the scalable media that identifies portions of the scalable media to combine in order to produce media that is scaled to possess a desired scalable attribute. 
   In summary, methods for associating data with portions of a scalable media are disclosed. Data is associated with the scalable media that identifies portions of the scalable media to combine in order to produce media that is scaled to possess a desired scalable attribute. Portions of the scalable media are encrypted. Data is associated with the portions of the scalable media that identifies protection attributes of the encryption scheme used to encrypt the portions of the scalable media. 
   Scaling Progressively Encrypted Data without Knowledge of Encoding Scheme 
     FIG. 14  illustrates a method for encoding a progressively encrypted sequence of scalable data according to one embodiment of the present invention. 
   In the  FIG. 14  embodiment, data (e.g., scalable profile data discussed with reference to  FIGS. 4A and 4B ) is associated with a sequence of scalable data that identifies combinable portions of the sequence of scalable data to combine in order to produce a scaled version of the progressively encrypted sequence of data. In the present embodiment, the scaled version of the progressively encrypted sequence of scalable data is scaled without knowledge of the encoding scheme of the progressively encrypted sequence of scalable data. Moreover, a cryptographic checksum (CCS) can be computed and associated with at least one combinable portion of the progressively encrypted sequence of scalable data.  FIG. 14  shows a progressively encrypted sequence of media content  301  that is separated, at  312 , into segments  304 ,  305 ,  306  and  307  (e.g., combinable portions). 
   It should be appreciated that each segment (e.g., combinable portion) can include at least one independently decodable part. In the  FIG. 14  embodiment, the independently decodable parts are labeled A, B, C and D with each segment including only one independently decodable part. In alternate embodiments, more than one independently decodable part can be included in a segment. 
   According to one embodiment, a cryptographic checksum can be computed for each segment  304 ,  305 ,  306  and  307 . In the  FIG. 14  embodiment, at  313 , after the computation of cryptographic checksums, each identified segment  304 ,  305 ,  306  and  307  is associated with a corresponding cryptographic checksum  314 ,  315 ,  316  and  317 . The identified segments (e.g., combinable portions) and their associated cryptographic checksums are combined into a media segment  321 ,  322 ,  323  and  324 . 
   It should be appreciated that the length of each segment, in embodiments of the present invention, is chosen so that its length plus that of its associated CCS is less than the maximum media segment payload size allowable or the maximum transmittable unit (MTU) allowable for the network. As discussed herein, a media segment can comprise a single truncatable unit or a plurality of truncatable units. It is noted also that, though there are four media segments illustrated in  FIG. 14 , any number of media segments can be used. 
   It should be appreciated that the terms “independently decodable part” and “truncatable unit” can have different meanings in the descriptions of embodiments of the present invention made herein. An independently decodable part of a media segment is a portion of the media segment&#39;s payload that can be decoded without the necessity of decoding other portions of the media segment payload. Moreover, if encrypted, the independently decodable part can be decrypted without the need to decrypt the remainder of the payload. A truncatable unit is a portion of a media segment payload that can be truncated from the media segment, with or without decryption, without detrimentally effecting the remainder of the media segment. It should be appreciated that although the terms can be used somewhat interchangeably, in the discussions made herein they maintain their separate meanings. 
     FIG. 15A  illustrates the transcoding by truncation of a progressively encrypted sequence of scalable media content according to one embodiment of the present invention. In the embodiment illustrated in  FIG. 15A , media content  411  is separated, at  412 , into segments, that each comprise one or more independently decodable parts (A, B, etc.). As discussed above with reference to  FIG. 14 , a media segment&#39;s payload can comprise one or more independently decodable parts. Moreover, according to some embodiments, the independently decodable parts can further comprise independently truncatable units. 
   In the  FIG. 15A  embodiment, a cryptographic checksum is computed for each of the decodable parts or truncatable units of media segment  413  in order of priority and for the entire preceding packet payload. First, a cryptographic checksum  415  is computed for the first truncatable unit A (e.g.,  403 ) resulting in CCS(A)  415 . Subsequently, a cryptographic checksum  416  is computed for the entire preceding media segment payload which includes independently decodable part A (e.g.,  403 ), cryptographic checksum CCS(A) (e.g.,  415 ), and independently decodable part B (e.g.,  404 ). The resulting checksum is shown in  FIG. 4A  as CCS(A,CCS(A),B),  416 . It should be appreciated that, if a third independently decodable part were included, the next cryptographic checksum could be represented as:
 
CCS(A,CCS(A),B,CCS(A,CCS(A),B),C).
 
   In the present embodiment, a transcoder-readable header,  414 , can be associated with media segment  413 . According to exemplary embodiments, the transcoder readable header can contain information such as the location of the truncation points in scalable media segments, such as media segment  413 , and scalable profile data that identifies segments of the scalable media segment data (e.g., media segment) that can be extracted in order to produce media that is scaled to possess a desired scalable attribute. In alternate embodiments, scalable profile data can reside in the middle the end or at different locations in the scalable media segment. 
   In the present embodiment, when a transcoding session is conducted (e.g.,  417 ) the transcoder can truncate selected truncatable units in order to achieve a desired scaling result. According to exemplary embodiments, if a media segment being transcoded is encrypted, decryption is not required in order to perform this form of transcoding. In the example illustrated in  FIG. 14A , truncatable unit B and its associated cryptographic checksum,  416 , are truncated. The untruncated, and undecrypted, remainder of the media segment,  418 , is then forwarded with its necessary cryptographic checksum, CCS(A)  415 , independently decodable part A  403 , and header  414 , intact. 
   In the embodiment of the present invention illustrated in  FIG. 15A , any number of truncatable units and their associated cryptographic checksum can be truncated from a media segment as necessary to meet transcoding requirements (e.g., to obtain a desired scalable attribute). In each case, the truncatable unit, its associated cryptographic checksum and subsequent truncatable units whose cryptographic checksums include calculation for the truncated units are also truncated. 
     FIG. 15B  illustrates the transcoding by truncation of a progressively encrypted sequence of scalable media content according to an alternate embodiment of the present invention. In the  FIG. 15B  embodiment, media content  421  is separated at  422  into segments which, as discussed above, may comprise any number of independently decodable parts, shown as A, B, C, D, etc. It is noted that, in this example, some segments comprise more independently decodable parts than others because of the size of each part (see  FIG. 15B ). In the  FIG. 15B  embodiment, the selection of the number of independently decodable parts is, predicated on the maximum size of the media segment. For example, independently decodable parts A, (e.g.,  433 ), B (e.g.,  434 ), and C (e.g.,  435 ), are combined in one segment while independently decodable part D,  436 , constitutes a similarly-sized segment by itself. 
   In the embodiment illustrated in  FIG. 15B , a cryptographic checksum is calculated for each independently decodable part. According to this embodiment, the calculation of the cryptographic checksum is made independently of other independently decodable parts. Media segment  423  is formed from the combination of independently decodable part A (e.g.,  433 ) and CCS(A) (e.g.,  425 ), independently decodable part B (e.g.,  434 ) and CCS(B) (e.g.,  426 ), and independently decodable part C (e.g.,  435 ) and CCS(C) (e.g.,  427 ). 
   In the embodiment illustrated in  FIG. 15B , the transcoding  428 , of media segment  423  then involves truncating the selected independently decodable parts, or truncatable units, and their associated cryptographic checksums. In the example illustrated in  FIG. 15B , truncatable unit C (e.g.,  435 ) and CCS(C) (e.g.,  427 ) are truncated. In this embodiment, transcoder-readable header  424  remains intact and retains it&#39;s information regarding the truncation points. Truncated media segment  429 , therefore, is available to be transcoded by truncation subsequently by truncating either truncatable unit B (e.g.,  434 ) and CCS(B) (e.g.,  426 ) or truncatable unit A (e.g.,  433 ) CCS(A) (e.g.,  425 ). 
   In this fashion, transcoding can occur at any desired point in a network without any media segment having to be decrypted and re-encrypted to achieve a desired transcoding result. After each truncation, the remainder of the media segment, undecrypted, retains its necessary cryptographic checksums, and the security of the data remains intact. 
   It should be appreciated, in some embodiments, transcoding can be executed by deleting entire media segments from the media content. It is also noted that cryptographic checksums can also be used in unencrypted media streams, such as for media segment verification. 
     FIG. 16A  illustrates the transcoding of a progressively encrypted sequence of scalable media content according to one embodiment of the present invention. In the  FIG. 16A  embodiment, media content  500  (constituted by scalable data portions A, B and C, etc.) is separated (e.g.,  501 ), into truncatable units (e.g.,  502 ). Each media segment payload, in the secure media stream, is encrypted (e.g.,  503 ) and appended with an independent cryptographic checksum (CCS). Referring to  FIG. 16A , the cryptographic checksums are designated as CCS(A) (e.g.,  506 ), CCS(B) (e.g.,  507 ), and CCS(C) (e.g.,  508 ). According to exemplary embodiments, the encrypted truncatable units, along with their associated cryptographic checksums, are combined to form appropriate length transmittable media segment (see  FIG. 16A ). 
   It is noted here that cryptographic checksums may be of many different types. A common checksum can involve a well-known hash function, which provides a fingerprint of the data contained in an encrypted media segment and can guarantee the authenticity of received data and the validity of decrypted data. Other examples of checksum functions that can be used to provide cryptographic checksum capability include Message Authentication Codes (MAC), keyed hashes such as MD4 &amp; MD5 (Message Digest algorithms), SHA (Secure Hash Algorithm), RIPEMD (RACE Integrity Primitives Evaluation Message Digest), and HMAC (keyed-Hashing for Message Authentication). Also, in some implementations, digital signature schemes may also be used. 
   In another embodiment of the present invention, the separation of data segments into truncatable units is referred to as secure scalable streaming (SSS). Each media segment can be transcoded by truncating the media segment at appropriate truncation points which may be defined in a header included in the media segment. For example, during transcoding, bit rate reduction, frame rate reduction, or the like is achieved by truncating, or eliminating, one or more truncatable units from the media segment. 
   In the  FIG. 16A  embodiment, a transcoder-readable header  505  is written and coupled to a transmittable media segment. As discussed with reference to  FIG. 16A , above, the transcoder-readable header (e.g., scalable profile data, protection profile data, etc.) includes information relating to the media segment payloads accompanying the media segment but does not disclose the contents of the media segment&#39;s payloads. By reading the transcoder-readable header, the transcoder can delete portions (e.g.,  509 ) or “scale down” a transmittable media segment without decrypting either the deleted part or the remainder of the media segment, as is illustrated in  FIG. 16A  at  510 . In the example shown, independently decodable part B with its associated cryptographic checksum, is deleted with no effect on independently decodable parts A or C or their associated cryptographic checksums. Consequently, end-to-end security of the streamed media data is maintained and a receiver of the streamed media can validate the integrity of the transcoded data. 
   In the embodiments illustrated in  FIGS. 16A and 16B , after transcoding is completed, a new transcoder-readable header,  511 , may be written to reflect the content of the newly constituted media segment,  510 . As in the previous transcoder-readable header, information about the start and end points of the included media segment payloads and the media segment payload priority can be included but information disclosing the contents is not. Moreover, because the new transcoder-readable header can be written by a transcoder that does not have the key with which to decrypt the media segment payloads or to evaluate the CCSs, the new transcoder-readable header is not capable of disclosing media segment payload contents. 
   With a new transcoder-readable header, possible further transcoding and scaling can be performed at other downstream locations. In addition to media segment payload size and location, media segment payload priority can be included in the transcoder-readable header. For example, priority information can be included, such as that identifying components of a web page that are considered discardable by the web page owner. In the case of transmission to a handheld device with a lower display capability than a large desktop computer, much of the information in complex web pages can be lost. By making lower priority information removable in early transcoding, valuable bandwidth can be preserved for other uses when transmitting data to such smaller devices. 
   Embodiments of the present invention are enabled to process media segments that are not streamed.  FIG. 16B  illustrates, in block format, the process of another embodiment. Here, stored data is manipulated without disturbing the cryptographic checksums. Large media segment  514 , comprising segments A, B, &amp; C, is taken from storage medium  521 . In the example of  FIG. 16B , data is in essence compressed to reduce storage space. This is accomplished by the removal of a segment of data, in this case segment B, and its associated CCS,  517 , by transcoding,  519 . The result of such transcoding is the smaller media segment  522 . It is noted that transcoding in this manner leaves segments A and C intact and, significantly, CCS(A)  516  and CCS(C)  518 , are undisturbed. If necessary to later operations, transcoder-readable header  515  can be replaced by new transcoder readable header  511 . 
   It is noted that the transcoding schemes provided by embodiments of the present invention are not limited to streamed data but can also be used wth stored data. Additionally, the transcoding techniques are useful for unencrypted data as well as encrypted data. In either case, transcoding can occur without disruption of the cryptographic checksums and without having to read the encoded data. 
   In the present embodiment, media segments may be any appropriate division that allows one or more of the segments and their associated cryptographic checksums, to fit into a communication media segment. An example of appropriately separated independently decodable parts is parts of highly detailed compressed images, such as can be transmitted with the compression standard developed by the Joint Picture Expert Group (JPEG), for example JPEG-2000. 
   It should be appreciated that in many instances, the first data transmitted contains data sufficient to produce a highly pixilated image. Subsequently transmitted data then successively refines the image detail. The presentation of such an image on a large display can make use of the enhanced detail. However, the display on a handheld computer may show no difference between the image after the first refinement and the image after the last and most highly detailed refinement. Consequently, a logical transcode can remove the more highly detailed data from the stream if the receiver is unable to use the detail. In some instances of transmitted data, a single packet may contain data comprising several levels of detail. However, some larger images may require several media segments to carry all the requisite data. 
     FIGS. 17–19  are flowcharts of the steps performed in methods for scaling progressively encrypted data without knowledge of its encoding scheme. Although specific steps are disclosed in the flowcharts, such steps are exemplary. That is, embodiments of the present invention are well-suited to performing various other steps or variations of the steps recited in the flowcharts. It is appreciated that the steps in the flowcharts may be performed in an order different than presented, and that not all of the steps in the flowcharts may be performed. All of, or a portion of, the methods described by the flowcharts may be implemented using computer-readable and computer-executable instructions which reside, for example, in computer-usable media of a computer system. 
     FIG. 17  is a flowchart of the steps performed in a method for encoding a progressively encrypted sequence of scalable data according to one embodiment. At step  1701 , data is associated with a progressively encrypted sequence of scalable data that identifies combinable portions of the progressively encrypted sequence of scalable data to combine in order to produce a version of the progressively encrypted sequence of scalable data that is scaled to possess a desired scalable attribute. According to one embodiment, the scaled version of said progressively encrypted sequence of scalable data is scaled without being decoded. At step  1703 , a cryptographic checksum is computed for at least one portion of the progressively encrypted sequence of scalable data. At step  1705 , a cryptographic checksum is associated with at least one portion of the progressively encrypted sequence of scalable data. 
     FIG. 18  is a flowchart of the steps performed in a method of transcoding a progressively encrypted sequence of scalable data according to one embodiment. At step  1801 , data associated with the progressively encrypted sequence of scalable data is accessed that identifies combinable portions of the progressively encrypted sequence of scalable data to combine in order to produce a scaled version of the sequence of data that is scaled to possess a desired scalable attribute. According to one embodiment, the scaled version of said progressively encrypted sequence of scalable data is scaled without being decoded. At step  1803 , one or more of the combinable portions of the progressively encrypted sequence of scalable data and their associated cryptographic checksums are combined into a transmittable sequence of data. 
     FIG. 19  is a flowchart of the steps performed in a method of decoding a progressively encrypted sequence of scalable data according to one embodiment of the present invention. At step  1801 , an encoded and progressively encrypted sequence of scalable data is accessed. At step  1803 , data associated with the encoded and progressively encrypted sequence of scalable data is accessed that identifies how combinable portions of the progressively encrypted sequence of scalable data are to be scaled to achieve a desired scalable attribute. In the present embodiment, scaling is accomplished without decoding the progressively encrypted sequence of scalable data. 
   At step  1905 , a cryptographic checksum is used in order to authenticate the contents of at least one combinable portion of the progressively encrypted sequence of scalable data. At step  1907 , the encoded and progressively encrypted sequence of scalable data is decoded based on the data that is associated with the encoded and progressively encrypted sequence of scalable data. This data identifies how combinable portions of the encoded and progressively encrypted scalable data are to be scaled to achieve a desired scalable attribute. 
   According to one embodiment, at least one combinable portion of the progressively encrypted scalable data and a cryptographic checksum can be encrypted. In exemplary embodiments, at least one combinable portion can be enabled to be decrypted independently of other combinable portions that constitute the progressively encrypted scalable data. Moreover, a cryptographic checksum can be computed for each combinable portion of the progressively encrypted sequence of scalable data. 
   According to one embodiment, the at least one combinable portion of the progressively encrypted sequence of scalable data is enabled to be decrypted independently of other portions comprising said progressively encrypted sequence of scalable data. In the present embodiment, the progressively encrypted sequence of scalable data comprises a plurality of combinable portions. Moreover, a first cryptographic checksum can be calculated for a first combinable portion of said progressively encrypted sequence of scalable data, and a second cryptographic checksum can be calculated for the combination of a second combinable portion of the progressively encrypted sequence of scalable data, the first combinable portion of the progressively encrypted sequence of scalable data, and the first cryptographic checksum. 
   According to one embodiment, the cryptographic checksum can be computed using a hash function. In addition, the data associated with the encoded and progressively encrypted sequence of scalable data can include information related to the combinable portions of the progressively encrypted sequence of scalable data and the cryptographic checksums. It should be appreciated that the data associated with the encoded and progressively encrypted sequence of scalable data can enable the transcoding of the progressively encrypted sequence of scalable data. 
   According to one embodiment the combinable portions of the progressively encrypted sequence of scalable data and the cryptographic checksums can be enabled to be encrypted independently of a transcoder readable header. Moreover, the combinable portions of the progressively encrypted sequence of scalable data and the cryptographic checksums can be enabled to be decrypted independently of the data associated with the progressively encrypted sequence of scalable data. In addition, the data associated with the progressively encrypted sequence of scalable data can be enabled to be read independently of the combinable portions of the progressively encrypted sequence of scalable data and the cryptographic checksums. 
   According to one embodiment, a cryptographic checksum can be computed based on one of the combinable portions of the progressively encrypted sequence of scalable data. The cryptographic checksum can be computed based on a plurality of combinable portions and associated checksums. Moreover, the cryptographic checksum can be calculated using a hash function. In an alternative embodiment, the cryptographic checksum can be calculated using a message digest function. 
   According to one embodiment, the cryptographic checksum can be calculated using a message authentication code function. In another embodiment, the cryptographic checksum can be calculated using a keyed-hashing-for-message-authentication function. In yet another embodiment, the cryptographic checksum can be calculated using a digital signature function. 
   According to one embodiment, the data associated with the progressively encrypted sequence of scalable data is enabled to be written independently of combinable portions of the progressively encrypted sequence of scalable data and the cryptographic checksums. It should be appreciated that each of the combinable portions of the progressively encrypted sequence of scalable data can be enabled to be extracted from a transmittable packet independently of other combinable portions of the progressively encrypted sequence of scalable data in the packet. 
   In the present embodiment, data that is associated with the progressively encrypted sequence of scalable data includes information related to the combinable portions of the progressively encrypted sequence of scalable data and a cryptographic checksum. According to one embodiment, the data associated with the progressively encrypted sequence of scalable data enables the transcoding of a data packet. 
   It should be appreciated that the combinable portions of the progressively encrypted sequence of scalable data and the cryptographic checksums can be enabled to be encrypted independently of a transcoder readable header. In one embodiment, the combinable portions of the progressively encrypted sequence of scalable data and the cryptographic checksums are enabled to be decrypted independently of the data associated with the encoded and progressively encrypted sequence of scalable data. Moreover, the data associated with the progressively encrypted sequence of scalable data can be enabled to be read independently of the combinable portions of the progressively encrypted sequence of scalable data and the cryptographic checksums. 
   In summary, the methods of the present invention provide a method for scaling a progressively encrypting sequence of scalable data for scaling a progressively encrypted sequence of scalable data without having knowledge of its encryption scheme. The method includes associating data with the progressively encrypted sequence of scalable data that identifies combinable portions of the progressively encrypted sequence of scalable data to combine in order to produce a scaled version of the progressively encrypted sequence of scalable data. The scaled version of the progressively encrypted sequence of scalable data is scaled to possess a desired scalable attribute. Moreover, the scaled version of the progressively encrypted sequence of scalable data is scaled without being decoded. A cryptographic checksum is computed for at least one combinable portion of the progressively encrypted sequence of scalable data and, a cryptographic checksum is associated with the at least one combinable portion of the progressively encrypted sequence of scalable data. 
   Encoders 
     FIG. 20  is a block diagram that depicts a scalable media encoder, according to one embodiment of the present invention. 
   According to one embodiment, scalable media encoder  2020  is any device, such as a portable communications device, a stationary computing device, or a digital image capturing device, that can encode any type of scalable media using an encoding scheme such as JPEG 2000 or MPEG. Examples of portable communications devices include, but are not limited to, pocket personal computers, laptops, digital cameras, video cameras and cell phones. Examples of stationary computing devices include, but are not limited to, personal computers, televisions, and servers. The servers may be ASIC servers. Examples of digital image capturing devices include, but are not limited to, digital cameras and video cameras. 
   According to one embodiment, scalable media encoder  2020  receives media data  2012 , scalable attribute criteria  2014 , and protection attribute criteria  2016 . The scalable attribute criteria  2014  may list scalable attributes that the scalable media encoder  2020  may use for generating the segments of the scalable media  2052  that may be extracted by another device, as described herein. Examples of scalable attributes include but are not limited to resolution, bitrate, color, as described herein. Examples of devices that may extract segments include but are not limited to translators and decoders. 
   In yet another embodiment, as depicted in  FIG. 20 , scalable media encoder  2020  includes a media data receiver  2022  that is configured to receive media data  2012 . Media data  2012  may be scalable media such as an image in JPEG 2000 format or a non-scaled image such as a scanned image of a picture, according to one embodiment. 
   Scalable media encoder  2020 , further includes, as depicted in  FIG. 20 , a scalable media generator  2024  that is coupled to media data receiver  2022 , according to one embodiment. For example, in one embodiment, scalable media generator  2024  may generate scalable media  2052 , in the case where media data  2012  is a non-scaled image. 
   Still referring to  FIG. 20 , scalable media encoder  2020 , also includes a scalable media outputter  2026  that is coupled to scalable media generator  2024  and that is adapted to outputting scalable media  2052 , in one embodiment. 
   Scalable media encoder  2020 , as depicted in  FIG. 20 , further includes a scalable attribute criteria receiver  2032  that is configured to receive scalable attribute criteria  2014 , according to one embodiment. In yet another embodiment, scalable attribute criteria receiver  2032  is coupled to a scalable profile data generator  2034  that is adapted to generate scalable profile data  2054 , which may include segments that another device, such as a translator or a decoder, may extract from scalable media  2052  to achieve the desired results for one or more scalable attributes, as described herein. The scalable profile data generator  2034 , in yet another embodiment, is coupled to a scalable profile data outputter  2036  which is adapted for outputting scalable profile data  2054 . 
   Still referring to  FIG. 20 , scalable media encoder  2020 , according to one embodiment, further includes a protection attribute criteria receiver  2042  that is configured to receive protection attribute criteria  2016 , as already described herein. The protection attribute criteria receiver  2042 , according to still another embodiment, is coupled to a protection profile data generator  2044  that is adapted to generate protection profile data  2056  based, at least in part, on the protection attribute criteria  2016  that scalable media encoder  2020  received, according to a embodiments described herein. The protection profile data generator  2044  is coupled to a protection profile data outputter  2046 , which is adapted to output the protection profile data  2056 , according to another embodiment. In still another embodiment, the scalable media  2052  may be encrypted using the protection profile data  2056 , according to embodiments already described herein. In yet another embodiment, the scalable media  2052  may be unencrypted. There are a number of protection mechanisms that may be applied. For example, cryptographic checksums may be applied for integrity checking, or digital signatures for authentication, etc. 
   According to one embodiment, the scalable attribute criteria receiver  2032  and/or the protection attribute criteria receiver  2042  may be generalized user interfaces (GUIs). For example, a user may use a GUI to enter attributes, such as resolutions, bitrates, etc., to indicate how the scalable media generator  2024  may generate scalable profile data  2054  for those attributes, according to embodiments already described herein. Similarly, a user may use a GUI to enter attributes, such as Data Encryption Standard (DES), encryption modes such as Electronic Code Book (ECB), etc., to indicate how the protection profile data generator  2044  may generate protection profile data  2056  indicating how portions of scalable media  2052  should be or are protected with those attributes, according to embodiments already described herein. 
   According to one embodiment, the processing performed by scalable media encoder  2020  may be complex or simple. For example, the scalable media generator  2024  of scalable media encoder  2020  may generate scalable media  2052  that may be scaled in many alternative ways or with only a few alternative, as already described herein. 
   Media data  2012 , scalable attribute criteria  2014 , and/or protection attribute criteria  2016  may be communicated to scalable media encoder  2020  using a network, according to one embodiment. In another embodiment, media data  2012 , scalable attribute criteria  2014 , and/or protection attribute criteria  2016  may be retrieved by scalable media encoder  2020  from a storage device, such as a compact disk (CD), a digital video disk (DVD), or a direct access storage device (DASD). 
   As depicted in  FIG. 20 , scalable media  2052 , scalable profile data  2054 , and/or protection profile data  2056  may be transmitted to another device, such as a transcoder or a decoder, using a network, according to one embodiment. According to another embodiment, scalable media  2052 , scalable profile data  2054 , and/or protection profile data  2056  may be transmitted to another device, such as a transcoder or a decoder, via a storage device, such as a compact disk (CD), a digital video disk (DVD), or a direct access storage device (DASD). 
   In still another embodiment, two or more of the outputters ( 2026 ,  2036 ,  2046 ) may be combined. For example, scalable media outputter  2052  and the scalable profile data outputter  2036  may be combined into one outputter. Similarly, scalable media outputter  2026  and protection profile data outputter  2046  may be combined into one outputter. Alternatively, all three outputters ( 2026 ,  2036 ,  2046 ) may be combined into one outputter. 
   Scalable media  2052 , scalable profile data  2054 , and protection profile data  2056  may be separate files or combined together in a single file in any combination, according to one embodiment, For example, scalable media  2052 , scalable profile data  2054 , and protection profile data  2056  may be in a single file together. In a second example, scalable media  2052  and scalable profile data  2054  may be in a file together, while protection profile data  2056  is in a separate file. In a third example, scalable media  2052  and protection profile data  2056  may be in a file together, while scalable profile data  2054  is in a separate file. 
     FIG. 21  is a block diagram that depicts a scalable media encoder, according to another embodiment of the present invention.  FIG. 21  depicts a scalable media encoder  2120  that is similar to the scalable media encoder  2020  depicted in  FIG. 20 , except that scalable media encoder  2120  does not include a protection attribute criteria receiver  2042  which receives protection attribute criteria  2016 , a protection profile data generator  2044  and a protection profile data outputter  2046  that outputs a protection profile data  2056 . 
   In one embodiment, the process of encrypting the scalable media  2052  may be performed using a web page. For example, since scalable media encoder  2120  does not include a protection attribute criteria receiver  2042 , protection profile data generator  2044 , and a protection profile data outputter  2046 , the scalable media  2052  may be encrypted using protection profile data  2056  some where other than at scalable media encoder  2020 , such as a web page. 
     FIG. 22  is a block diagram that depicts a scalable media encoder, according to another embodiment of the present invention.  FIG. 22  depicts a scalable media encoder  2220  that is similar to the scalable media encoder  2020  depicted in  FIG. 20 , except that scalable media encoder  2220  does not include a scalable attribute criteria receiver  2032  which receives scalable attribute criteria  2014 , a scalable profile data generator  2034  and a scalable profile data outputter  2036  that outputs a scalable profile data  2054 . 
   Decoders 
     FIG. 23  is a block diagram that depicts a decoder, according to one embodiment of the present invention. According to one embodiment, decoder  2320  is any device, such as a portable communications device, a stationary computing device, or a digital image capturing device, that can decode any type of scalable media, such as JPEG 2000 or MPEG. 
   Typically, users interact with a client device, such as a television, a PDA, a DVD player, or a computer monitor, to request that one or more images be displayed on the client device. A decoder  2320  may communicate with or be a part of a client device  2380 . As a part of providing the image to the client device  2380  for viewing by a user, the decoder  2320  and client  2380  may communicate about the client&#39;s  2380  capabilities for displaying the images and/or the users desire in how to view the images. As a part of this communication, the decoder  2320  may request the desired scalability attribute  2372 . For example, the desired scalability attribute  2372  may indicate the band width that the client  2380  capable of handling or whether the user want to see the images in black and white or in color. The client  2380  may return the desired scalable attribute  2374  to the decoder  2320 . Other examples of client devices include, but are not limited to, a portable communications device, a stationary computing device and a digital image capturing device. 
   There are many legacy decoders that are not capable of decoding and/or decrypting scalable media, such as JPEG 2000 files or MPEG files. According to one embodiment, decoder  2320  is a legacy device. By installing software or components such as scalable media receiver  2330 , scalable profile data receiver  2340 , protection profile data receiver  2350 , and renderer  2362  onto a legacy decoder  2320 , that legacy decoder  2320  may become capable of decoding and/or decrypting scalable media  2052 , according to embodiments already described herein. For example, renderer  2362  may decode and/or decrypt scalable media  2052  to provide rendered media data  2376  for viewing on client  2380 . 
   As depicted in  FIG. 23 , scalable media receiver  2330  is configured to receive scalable media  2052 , scalable profile data  2054 , and protection profile data  2056 . According to one embodiment, the scalable media receiver  2330  includes receivers  2330 ,  2340 ,  2350  that are configured to receive the scalable media  2052 , scalable profile data  2054 , and protection profile data  2056 . The receivers  2330 ,  2340 ,  2350  are coupled to renderer  2362 , according to another embodiment. According to embodiments already described herein, renderer  2362  decodes scalable media  2052  using scalable profile data  2054  by extracting portions of scalable media  2052  based on the scalable profile data  2054  and/or decrypts scalable media  2052  using protection profile data  2056 . 
   In still another embodiment, two or more of the receivers ( 2330 ,  2340 ,  2350 ) may be combined. For example, scalable media receiver  2330  and the scalable profile data receiver  2340  may be combined into one receiver. Similarly, scalable media receiver  2330  and protection profile data receiver  2350  may be combined into one receiver. Alternatively, all three receivers ( 2330 ,  2340 ,  2350 ) may be combined into one receiver. 
   Scalable media  2052 , scalable profile data  2054 , and protection profile data  2056  may be separate files or combined together in a single file in any combination, according to one embodiment, For example, scalable media  2052 , scalable profile data  2054 , and protection profile data  2056  may be in a single file together. In a second example, scalable media  2052  and scalable profile data  2054  may be in a file together, while protection profile data  2056  is in a separate file. In a third example, scalable media  2052  and protection profile data  2056  may be in a file together, while scalable profile data  2054  is in a separate file. 
     FIG. 24  is a block diagram that depicts a decoder, according to another embodiment of the present invention.  FIG. 24  depicts a decoder  2420  that is similar to the decoder  2320  depicted in  FIG. 23 , except that decoder  2420  does not include a protection profile data receiver  2350  which receives protection profile data  2056 . Therefore, according to one embodiment, unlike renderer  2362  depicted in  FIG. 23 , renderer  2462  in  FIG. 24  does not decrypt scalable media  2052  with protection profile data  2350 . However, in yet another embodiment, renderer  2462  may decrypt scalable media  2052  using another technique. 
     FIG. 25  is a block diagram that depicts a decoder, according to yet another embodiment of the present invention.  FIG. 25  depicts a decoder  2520  that does not include a scalable profile data receiver which receives scalable profile data  2054 . Therefore, according to one embodiment, renderer  2562  in  FIG. 25  may include logic for parsing scalable media  2052  without a scalable profile data  2054 . For example, assuming that scalable media  2052  is a JPEG 2000 file, renderer  2562  may be able to read a table of contents for scalable media  2052  to determine what segments of scalable media  2052  correspond to segments referred to in the cryptographic mapping associated with protection profile data  2056  in order to decrypt scalable media  2052 . However, in yet another embodiment, renderer  2462  may decrypt scalable media  2052  using another technique. In yet another embodiment, renderer  2462  may not be fully aware of a table of contents associated with scalable media  2052 , but, may only have a minimal amount of logic for parsing certain aspects of the table of contents. 
   According to one embodiment, any one of scalable media  2052 , scalable profile data  2054 , and/or protection profile data  2056  may be communicated to a decoder  2320 ,  2420 ,  2520  over a network. According to another embodiment, any one of scalable media  2052 , scalable profile data  2054 , and/or protection profile data  2056  may be retrieved by decoder  2320 ,  2420 ,  2520  from a storage device. The storage device may be a part of the decoder  2320 ,  2420 ,  2520 . 
   According to one embodiment, decoders  2320 ,  2420 ,  2520  may transmit rendered media data  2376  over a network to a client  2380 . In yet another embodiment, rendered media data  2376  may be stored on a storage device where it is subsequently retrieved by a client  2380 . The storage device may be a part of the decoder  2320 ,  2420 ,  2520 . 
   The discussion of decoders  2320 ,  2420 ,  2520  in this section has assumed that the decoders  2320 ,  2420 ,  2520  were at the end of a chain of devices that include encoders, transcoders, and possible other decoders before delivering an image to a client  2380 . According to one embodiment, renderers  2362 ,  2462 ,  2562  may have logic for parsing enough of the table of contents associated with a scalable media  2052  to decompress the scalable media  2052  and provide an image to a client  2380 . 
   Transcoders 
   There are legacy devices that are not capable of transcoding scalable media, such as JPEG 2000 files or MPEG files. In this section, many ways of upgrading legacy devices with various software, hardware, and/or microcode components so that the legacy devices are capable of transcoding scalable media shall be discussed. 
     FIG. 26  is a block diagram that depicts a transcoding unit, according to one embodiment of the present invention. Transcoding unit  2620  may be any device, such as a portable communications device, a stationary computing device, or a digital image capturing device that can transcode any type of scalable media, such as JPEG 2000 or MPEG. As with the previously described decoders, transcoding unit  2620  may request a desired scalable attribute  2372  from a device  2670 , according to one embodiment. In this case, device  2670  may provide the desired scalable attribute  2374 . According to one embodiment, device  2670  may be another transcoding unit, a decoder, or a client device, among other things. 
   As depicted in  FIG. 26 , transcoding unit  2620  receives scalable media  2052 , scalable profile data  2054 , and protection profile data  2056 , according to one embodiment. Transcoding unit  2620 , performs operations on scalable media  2052 , scalable profile data  2054 , and protection profile data  2056  to produce new scalable media  2662 , new scalable media data  2664 , and new protection profile data  2666 , according to another embodiment. Further, transcoding unit  2620 , according to yet another embodiment, includes a transcoder  2630  that extracts segments from scalable media  2052  based on scalable profile data  2054 , according to embodiments described here, and combines those segments to produce transcoded media  2640  that is communicated to an encoder  2650 . 
   The encoder  2650 , according to one embodiment, receives transcoded media  2640 , which may be scalable media or a non-scaled data such as a bit map. Encoder  2650  may be a scalable media encoder, such as a JPEG 2000 or an MPEG encoder, that is capable of taking a non-scaled bit map to create new scalable media  2662 , according to one embodiment. In another embodiment, encoder  2650  may only have enough logic to generate scalable media  2662  for certain attributes. 
   Further, as depicted in  FIG. 26 , encoder  2650  includes a scalable profile data generator  2654  and a protection profile data generator  2656  that generate new scalable profile data  2664  and new protection profile data  2666 , according to one embodiment. In one embodiment, encoder  2650  generates the scalable profile data  2664  and protection profile data  2666  by analyzing the transcoded media  2640 . In another embodiment, encoder  2650  may receive input, such as scalable attribute criteria  2014  and/or protection attribute criteria  2016 , as already described herein, to generate scalable profile data  2664  and protection profile data  2666 . 
   In yet another embodiment, encoder  2650  produces new scalable profile data  2664  by altering the offsets associated with the segments indicated in the new scalable profile data  2054  to produce new scalable profile data  2664  to reflect that certain segments have been extracted from scalable media  2052 , according to embodiments already described herein. In still another embodiment, encoder  2650  produces new scalable profile data  2664  by marking what transcoding operations have been performed, e.g., what segments have been extracted, according to embodiments already described herein. 
   Similarly, according to another embodiment, encoder  2650  may produce new protection profile data  2666  by modifying the cryptographic mapping associated with the protection profile data  2056  to produce protection profile data  2666 . In one embodiment, the cryptographic mapping may be modified by altering offsets associated with the segments extracted from scalable media  2052  on scalable profile data  2054 , according to embodiments already described herein. In another embodiment, the cryptographic mapping may be modified by marking what transcoding operations have been performed on scalable media  2052 , according to embodiments already described herein. 
     FIG. 27  is a block diagram that depicts a transcoding unit, according to another embodiment of the present invention. Transcoding unit  2720  may be any device, such as a portable communications device, a stationary computing device, or a digital image capturing device that can transcode any type of scalable media, such as JPEG 2000 or MPEG. 
     FIG. 27  depicts a transcoding unit  2720  that does not include a scalable profile data receiver which receives scalable profile data  2054 . Therefore, according to one embodiment, transcoder  2730  in  FIG. 27  may include logic for parsing scalable media  2052  without a scalable profile data  2054 . For example, assuming that scalable media  2052  is a JPEG 2000 file, transcoder  2730  may be able to read a table of contents for scalable media  2052  to determine what segments of scalable media  2052  correspond to segments referred to in the cryptographic mapping associated with protection profile data  2056  in order to transcode scalable media  2052  and produce transcoded media  2640 . Transcoder  2730  may only have a minimal amount of logic for parsing certain aspects of the table of contents. 
   Transcoding unit  2720  further includes, an encoder  2750 , according to one embodiment, that receives transcoded media  2640 , which may be scalable media or non-scaled data such as a bit map. Encoder  2750  may be a scalable media encoder, such as a JPEG 2000 or an MPEG encoder, that is capable of taking a non-scaled bit map to create new scalable media  2662 , according to one embodiment. In another embodiment, encoder  2750  may only have enough logic to generate scalable media  2662  for certain attributes. 
   As depicted in  FIG. 27 , encoder  2750  includes a protection profile data generator  2656  that generates the new protection profile data  2666 , according to one embodiment. In one embodiment, protection profile data generator  2656  generates the protection profile data  2666  by analyzing the transcoded media  2640 . In another embodiment, protection profile data generator  2656  may receive input, such as protection attribute criteria  2016 , as already described herein, to generate protection profile data  2666 . 
     FIG. 28  is a block diagram that depicts a transcoding unit, according to another embodiment of the present invention. Transcoding unit  2820  may be any device, such as a portable communications device, a stationary computing device, or a digital image capturing device that can transcode any type of scalable media, such as JPEG 2000 or MPEG. 
   According to one embodiment, transcoding units do not need the protection profile data  2656  since, typically, transcoding units do not decrypt the media data, such as scalable media data  2052 , that the transcoding units receive. For example,  FIG. 28  depicts a transcoding unit  2820  that is similar to the transcoding unit  2620  depicted in  FIG. 26 , except that transcoding unit  2820  does not include a protection profile data receiver  2626 . Therefore, according to one embodiment, transcoder  2830  depicted in  FIG. 28  does not require logic for parsing protection profile data  2056 . 
   Transcoding unit  2820  further includes, an encoder  2850 , according to one embodiment, that receives transcoded media  2640 , which may be scalable media or a non-scaled data such as a bit map. Encoder  2850  may be a scalable media encoder, such as a JPEG 2000 or an MPEG encoder, that is capable of taking a non-scaled bit map to create new scalable media  2662 , according to one embodiment. In another embodiment, encoder  2750  may only have enough logic to generate scalable media  2662  for certain attributes. 
   Encoder  2850  includes a scalable profile data generator  2654  that generates the new scalable profile data  2664 , according to one embodiment. In one embodiment, scalable profile data generator  2654  generates the scalable profile data  2664  by analyzing the transcoded media  2640 . In another embodiment, scalable profile data generator  2654  may receive input, such as scalable attribute criteria  2014 , as already described herein, to generate scalable profile data  2664 . 
     FIG. 29  is a block diagram that depicts a transcoding unit, according to another embodiment of the present invention. Transcoding unit  2920  may be any device, such as a portable communications device, a stationary computing device, or a digital image capturing device that can transcode any type of scalable media, such as JPEG 2000 or MPEG. As with transcoding unit  2620 , transcoding unit receives scalable media  2052 , scalable profile data  2054 , and protection profile data  2056  with respective receivers ( 2622 ,  2624 ,  2626 ), according to one embodiment. Further transcoding unit  2920  outputs scalable media  2662 , scalable profile data j 64 , and protection profile data j 66  with respective outputters ( 2942 ,  2944 ,  2946 ), according to another embodiment. 
   As depicted in  FIG. 29 , according to one embodiment, transcoding unit  2920  includes a transcoder  2930  that extracts segments from scalable media  2052  based on scalable profile data  2054 , according to embodiments described here, to produce new scalable media  2662 . Further, according to another embodiment, transcoder  2930  processes scalable profile data  2054  to produce new scalable profile data  2664 . 
   In one embodiment, transcoder  2930  produces new scalable profile data  2664  by altering the offsets associated with the segments indicated in the new scalable profile data  2054  to produce scalable profile data  2664  to reflect that certain segments have been extracted from scalable media  2052 , according to embodiments already described herein. In another embodiment, transcoder  2930  produces new scalable profile data  2664  by marking what transcoding operations have been performed, e.g., what segments have been extracted from scalable media  2052 , according to embodiments already described herein. 
   Transcoder  2930  may produce new protection profile data  2666  by modifying the cryptographic mapping associated with the protection profile data  2056  to produce protection profile data  2666 . In one embodiment, the cryptographic mapping may be modified by altering offsets associated with the segments extracted from scalable media  2052  based on scalable profile data  2054 , according to embodiments already described herein. In another embodiment, the cryptographic mapping may be modified by marking what transcoding operations have been performed, according to embodiments already described herein. 
     FIG. 30  is a block diagram that depicts a transcoding unit, according to another embodiment of the present invention. Transcoding unit  3020  may be any device, such as a portable communications device, a stationary computing device, or a digital image capturing device that can transcode any type of scalable media, such as JPEG 2000 or MPEG. 
     FIG. 30  depicts a transcoding unit  3020  that does not include a scalable profile data receiver which receives scalable profile data  2054 . Therefore, according to one embodiment, transcoder  3030  in  FIG. 30  may include logic for parsing scalable media  2052  without a scalable profile data  2054 . For example, assuming that scalable media  2052  is a JPEG 2000 file, transcoder  3030  may be able to read a table of contents for scalable media  2052  to determine what segments of scalable media  2052  correspond to segments referred to in the cryptographic mapping associated with protection profile data  2056  in order to modify the cryptographic mapping as already described herein. In yet another embodiment, transcoder  3030  may not be fully aware of a table of contents associated with scalable media  2052 , but, may only have a minimal amount of logic for parsing certain aspects of the table of contents. 
     FIG. 31  is a block diagram that depicts a transcoding unit, according to another embodiment of the present invention.  FIG. 31  depicts a transcoding unit  3120  that is similar to the transcoding unit  2920  depicted in  FIG. 29 , except that transcoding unit  3120  does not include a protection profile data receiver  2626 . Therefore, according to one embodiment, transcoder  2830  depicted in  FIG. 28  does not require logic for parsing protection profile data or for modifying the cryptographic mapping of a protection profile data, according to embodiments already described herein. 
     FIG. 32  is a block diagram that depicts a transcoding unit, according to another embodiment of the present invention.  FIG. 32  depicts a transcoding unit  3220  that is similar to the transcoding unit  2920  depicted in  FIG. 29 , except that transcoding unit  3220  includes a transcoder  3230  with a protection modifier  3232 . According to one embodiment, protection modifier  3232  may modify protection or add layers of protection, according to embodiments described herein. Although only  FIG. 32  depicts a protection modifier  3232 , according to another embodiment, the transcoding units  2620 ,  2720 ,  2820 ,  2920 ,  3020 ,  3120 ,  3220  ( FIGS. 26–32 ) may also include protection modifiers. 
   In yet another embodiment, input, such as scalable attribute criteria  2014  and/or protection attribute criteria  2016  may be received by an encoder  2650 ,  2750 ,  2850  ( FIGS. 26–28 ) to generate scalable profile data  2664  and/or protection profile data  2666 . 
   According to one embodiment, the scalable profile data  2054  and/or the protection profile data  2056  may be encrypted, in which case, whatever transcoding unit  2620 ,  2720 ,  2820 ,  2920 ,  3020 ,  3120 ,  3220  ( FIGS. 26–32 ) that receives the data ( 2054 ,  2056 ) would need the key to decrypt the data ( 2054 ,  2056 ). 
   There are legacy transcoders that are not capable of transcoding scalable media, such as JPEG 2000 files or MPEG files. According to one embodiment, transcoding units  2620 ,  2720 ,  2820 ,  2920 ,  3020 ,  3120 ,  3220  ( FIGS. 26–32 ) are legacy devices. By installing software, hardware, and/or microcode components such as receivers  2622 ,  2624 ,  2626 , transcoders  2630 ,  2730 ,  2830 ,  2930 ,  3030 ,  3130 ,  3230  encoders  2650 ,  2750 ,  2850 , and outputters  2942 ,  2944 ,  2946  onto transcoding units  2620 ,  2720 ,  2820 ,  2920 ,  3020 ,  3120 ,  3220  the transcoding units  2620 ,  2720 ,  2820 ,  2920 ,  3020 ,  3120 ,  3220  may become capable of transcoding scalable media  2052 , according to embodiments already described herein. 
   According to one embodiment, scalable media  2052  is encrypted. For example, scalable profile data  2054  enable transcoders  2630 ,  2830 ,  2930 ,  3130 ,  3230  ( FIGS. 26 ,  28 ,  29 ,  31 ,  32 ) to extract segments from scalable media  2052 , according to embodiments already described herein. In order to do this, the transcoders  2630 ,  2830 ,  2930 ,  3130 ,  3230  may receive the keys to un-encrypt the scalable media  2052 . According to another embodiment, scalable media  2052  is not encrypted. 
   Scalable media data  2052 , scalable profile data  2054 , and/or protection profile data  2056  may be communicated to transcoding units  2620 ,  2720 ,  2820 ,  2920 ,  3020 ,  3120 ,  3220  ( FIGS. 26–32 ) from another device, such as an encoder or another transcoder, using a network, according to one embodiment. In another embodiment, scalable media data  2052 , scalable profile data  2054 , and/or protection profile data  2056  may be retrieved by transcoding units  2620 ,  2720 ,  2820 ,  2920 ,  3020 ,  3120 ,  3220  from a storage device. In still another embodiment, the storage device may be a part of the respective transcoding unit  2620 ,  2720 ,  2820 ,  2920 ,  3020 ,  3120 ,  3230 . 
   Scalable media  2662 , scalable profile data  2664 , and/or protection profile data  2666  ( FIGS. 26–32 ) may be transmitted to another device, such as another transcoder or a decoder, using a network, according to one embodiment. According to another embodiment, scalable media  2662 , scalable profile data  2664 , and/or protection profile data  2666  may be stored on a storage device where another device, such as a transcoder or a decoder may retrieve them. In still another embodiment, the storage device may be a part of the respective transcoding unit  2620 ,  2720 ,  2820 ,  2920 ,  3020 ,  3120 ,  3220 . 
   In yet another embodiment, two or more of the receivers  2622 ,  2624 ,  2626  ( FIGS. 26–32 ) may be combined into one receiver. For example, scalable media receiver  2622  and scalable profile data receiver  2624  may be combined into one receiver. Similarly, scalable media receiver  2622  and protection profile data receiver  2626  may be combined into one receiver. Alternatively, all three receivers ( 2622 ,  2624 ,  2626 ) may be combined into one receiver. 
   In still another embodiment, two or more of the outputters  2942 ,  2944 ,  2946   FIGS. 29 ,  30 ,  31 ,  32 ) may be combined into one outputter. For example, scalable media outputter  2942  and scalable profile data outputter  2944  may be combined into one outputter. Similarly, scalable media outputter  2942  and protection profile data outputter  2946  may be combined into one outputter. Alternatively, all three outputters ( 2942 ,  2944 ,  2946 ) may be combined into one outputter. 
   In yet another embodiment, the generators  2654 ,  2656  ( FIGS. 29 ,  30 ,  31 ,  32 ) may be combined into one generator. 
   As already discussed, scalable media  2052 , scalable profile data  2054 , and protection profile data  2056  ( FIGS. 26–32 ) may be in separate files or combined together in a single file in any combination, according to one embodiment. 
   According to another embodiment, to maintain the security of scalable media  2052 , the transcoding unit  2620 ,  2720 ,  2820 ,  2920 ,  3020 ,  3120 ,  3220  ( FIGS. 26–32 ) does not receive the keys that were used for encrypting the scalable media  2052 . In this case, only a decoder ( 2320 ,  2420 ,  2520 ) would receive the keys in order to decrypt the scalable media  2052 . 
   Encoders  2020 ,  2120 ,  2220  ( FIGS. 20–22 ) and transcoding units  2620 ,  2720 ,  2820 ,  2920 ,  3020 ,  3120 ,  3220  ( FIGS. 26–32 ) may be in a single device, according to one embodiment. Encoders  2020 ,  2120 ,  2220  ( FIGS. 20–22 ) and decoders  2320 ,  2420 ,  2520  ( FIGS. 23–25 ) may be in a single device, according to another embodiment. In yet another embodiment. In still another embodiment, transcoding units  2620 ,  2720 ,  2820 ,  2920 ,  3020 ,  3120 ,  3220  ( FIGS. 26–32 ) and decoders  2320 ,  2420 ,  2520  ( FIGS. 23–25 ) may be in a single device. Encoders  2020 ,  2120 ,  2220  ( FIGS. 20–22 ), transcoding units  2620 ,  2720 ,  2820 ,  2920 ,  3020 ,  3120 ,  3220  ( FIGS. 26–32 ), and decoders  2320 ,  2420 ,  2520  ( FIGS. 23–25 ) may all three be in a single device. 
   The functions associated with the encoders  2020 ,  2120 ,  2220 , transcoding units  2620 ,  2720 ,  2820 ,  2920 ,  3020 ,  3120 ,  3220 , and decoders  2320 ,  2420 ,  2520  depicted in  FIGS. 26–32 , m may be moved around and combined in many ways that would be apparent to one of ordinary skill in the art. 
   Embodiments of the present invention are thus described. While the present invention has been described in particular embodiments, it should be appreciated that the present invention should not be construed as limited by such embodiments, but rather construed according to the following claims.