Patent Publication Number: US-9900652-B2

Title: Methods and apparatus for transcoding metadata

Description:
RELATED APPLICATIONS 
     This patent is a continuation of U.S. patent application Ser. No. 14/089,279, entitled “Methods and Apparatus for Transcoding Metadata” and filed on Nov. 25, 2013, which is a continuation of U.S. patent application Ser. No. 12/890,216, entitled “Methods and Apparatus for Transcoding Metadata” and filed on Sep. 24, 2010, which is a continuation of U.S. patent application Ser. No. 10/540,611, entitled “Methods and Apparatus for Transcoding Metadata” and filed on Jun. 24, 2005, which is a U.S. national stage application of International Patent Application Serial No. PCT/US03/14970, entitled “Methods and Apparatus for Transcoding Metadata” and filed on May 13, 2003, which claims priority from U.S. Provisional Application Ser. No. 60/436,714, entitled “Transcoding of Metadata” and filed on Dec. 27, 2002. U.S. patent application Ser. Nos. 10/540,611, 12/890,216 and 14/089,279, International Patent Application Serial No. PCT/US03/14970 and U.S. Provisional Application Ser. No. 60/436,714 are hereby incorporated by reference in their respective entireties. 
    
    
     FIELD OF THE DISCLOSURE 
     This disclosure relates generally to transcoding and, more particularly, to methods and apparatus for transcoding metadata. 
     BACKGROUND 
     Through the advancement of technology, media content is finding its way into homes by various non-traditional means. For instance, with the advent of broadband data connections, media content is now being supplied to homes via the Internet and other digital distribution sources as well as the traditional means of television and radio broadcasts. In addition, home networking standards such as HAVi and wired and wireless protocols such as IEEE 1394, IEEE 802.11, ultra wide band (UWB), cellular and pager networks and Bluetooth now allow a variety of different media consumption devices to communicate via a home network. Thus, media content received at a home can be distributed via a home network for display on any of the media consumption devices connected to the home network. 
     These advancements in home networking and media content delivery mechanisms provide users with enhanced access to media content, but also present new challenges for measuring the consumption of media content. More specifically, conventional media consumption meters are typically configured to measure media signals consumed in a particular format by a specific type of media consumption device. For example, television content consumption is measured using meters adapted to measure signals formatted for television. Likewise, computer content consumption is measured using meters adapted to measure signals formatted for a computer. Although this approach works well for media consumption devices that are not networked together, it does not allow for media consumption measurement in a home networked environment because of the manner in which media content is transmitted via a home network. Specifically, a home network typically comprises a variety of media consumption devices that are networked together and that are each adapted to process media provided in a particular format. To enable communication between the networked devices, home networks include one or more transcoders that transcode or convert media content signals transmitted via the home network between the various signal formats required by the networked devices. For example, a typical home network may be configured to include a television coupled to a computer with a transcoder disposed between the television and the computer. Media content that is received at the television and then selected for viewing at the computer is converted by the transcoder from a television format to a computer format so that the media content received at the television can be processed for display/viewing at the computer. 
     Unfortunately, the format conversion process performed by home network transcoders to enable communication between dissimilar devices also causes the corruption or loss of valuable audience measurement data. More specifically, data that enables media consumption measurement is embedded into media content by media content providers. The data is then extracted by media content consumption meters for use in determining the identity of the media content as well as other information about the media content which can then be reported for purposes of measuring consumption of that media content. However, home network transcoders are not adapted to convert this embedded data into a format suitable for use by downstream consumption measuring devices and, as a result, the embedded data is either stripped from the media content or corrupted during the transcoding process. Consequently, consumption of the converted media content cannot be accurately measured. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of an example home network having a set of transcoders that convert data embedded in media content for use by a set of media consumption metering devices. 
         FIG. 2  is a block diagram that depicts an example manner in which the transcoder of  FIG. 1  may be implemented. 
         FIG. 3  is a block diagram that depicts an example manner in which one of the media consumption metering devices of  FIG. 1  may be implemented. 
         FIG. 4  is a flow chart that depicts a method for performing metadata transcoding. 
         FIG. 5A  is a diagram that depicts a set of metadata fields suitable for use with media content provided in a broadcast television format. 
         FIG. 5B  is a diagram that depicts a set of metadata fields suitable for use with media content provided in a streaming media format. 
         FIG. 6  is a flow chart that depicts an example method for creating a watermark that represents a particular media content and for creating correlation information that may be used to correlate the watermark with the particular media content. 
         FIGS. 7A-7C  are flow charts that align to depict an example method for determining the sensing capabilities of a metering device. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a home network  10  includes a plurality of media consumption devices  12 , each representing one of a variety of devices including, for example, a TV, a radio, a personal computer, a personal digital assistant (PDA), a telephone and a digital video disk (DVD) player, a personal video recorder (PVR). Each of the media consumption devices  12  are adapted to receive media content from one or more different media sources collectively represented in  FIG. 1  as a media content cloud  14 . The content provided by the media content cloud  14  may include, for example, broadcast content, streaming or web content from the Internet, or content supplied by a local device, such as, for example, a DVD player, a video cassette recorder (VCR), a media server or any other local source. The media consumption devices  12  are in communication with each other such that media content transmitted via the home network  10  may be consumed via the media consumption devices  12 , may be shared between multiple media consumption devices  12  or may be stored on a media storage database  16 , also coupled to the home network  10 , for later retrieval and consumption. The home network may be configured in either a wired or wireless manner. In some embodiments, the home network may include a combination of both wired and wireless communication. 
     To enable audience measurement, a set of content consumption metering devices  18 , hereinafter “meters”, are also coupled to the home network  10  and are adapted to measure the content consumed by the media consumption devices  12 . Each of the meters  18  may be configured to meter a single one of the media consumption devices  12  or may be configured to meter multiple media consumption devices  12 . Additionally, each meter  18  may be adapted to operate independently or each may instead be adapted to operate under the control of a master or central metering unit (not shown). The meters  18  may be coupled to the network  10  wirelessly or in a wired fashion. For example, if the meter  18  is implemented as a portable meter to be carried by a household member for purposes of measuring the consumption habits of that household member, then the meter will likely communicate with the network wirelessly. Such communication may be as limited as receiving codes from a media consumption device or may be as robust as two-way communication between the portable meter and other network devices. Audience measurement data collected by each meter  18  is supplied to a measurement collection unit  20  where the data is either analyzed or stored for later transmission to a remote data collection facility (not shown) for analysis. The measurement collection unit  20  may be disposed within the same residence as the home network  10  or may instead be disposed outside of the residence that houses the home network  10 . As can be seen in  FIG. 1 , the meters  18  may be separate from, or integral with, the media consumption devices  12  being metered. 
     Referring still to  FIG. 1 , a set of transcoders  22  are coupled to the home network  10  at various locations and are configured to transcode or convert media content transmitted via the home network  10  between one or more formats thereby causing the media content to be suitable for consumption by one or more of the media consumption devices  12 . In an example configuration, the transcoders  22  are adapted to receive media content from one or more of the media consumption devices  12 , to transcode the media content and to provide the transcoded media content for consumption to one or more of the media consumption devices  12  according to a method described in greater detail below. 
     A home network media server  24  coupled to and in communication with the home network media storage database  16  may be adapted to control communication on the home network  10 , may be adapted to function as a media content consumption device  12  and may be further adapted to receive content from the media cloud  14 . The home network media server  24  may provide content to the various devices coupled to the home network  10  by streaming the content, pushing the content, allowing the content to be downloaded or by any other manner. Additionally, the home network media server  24  may act as a central repository for all of the media content that is consumed in the home network  10 . Alternatively, the media content may be received at any of the media consumption devices  12  and then supplied to the home network  10  for consumption/viewing/display at any of the other media consumption devices  12 . 
     As will be appreciated by one having ordinary skill in the art, the home network  10  may be configured in any desired manner and may include any number of network devices. Moreover, the devices coupled to the home network  10  may communicate and interface in any desired manner including, for example, using either a wired or wireless communication protocol such as HAVi, Wi-Fi, BlueTooth, IEEE 1394, DVI, HDMI or any other high speed interface protocol or using an Ethernet protocol. 
     Referring now to  FIG. 2 , in an example embodiment, each meter  18  is equipped with a processor  26  which executes a set of instructions stored in a memory  28  to control the operation of the meter  18  and a home network interface  30  that allows communication between the meter  18  and the other devices coupled to the home network  10  and that may be implemented using, for example, a software application program interface (API). As will be appreciated by one having ordinary skill in the art, the home network interface  30  may be implemented using any type of device capable of translating between a communication protocol used by the home network  10  and a communication protocol used by the processor  26  disposed in the meter  18 . In addition, each meter  18  includes one or more interfaces  32   a ,  32   b  for interfacing with other devices and one or more sensors  32   c - 32   e  for sensing media content consumption. The interfaces  32   a ,  32   b  may include, for example, an interface  32   a  adapted to communicate with a people meter that senses the presence of one or more network users/audience members and/or a data collection interface  32   b  adapted to communicate with the collection measurement unit  20 . The sensors  32   c - 32   e  supply sensed information to the processor  26  which processes the information and causes the information to be transmitted to the measurement collection unit  20  via the home network  10 . The measurement collection unit  20  then transmits the data to a remote data collection facility (not shown) for analysis. In addition, the processor  26  is adapted to respond to queries sent by the transcoder  22  via the home network  10 . Alternatively, the measurement collection unit  20  need not be coupled to the home network  10  but may instead be adapted to receive media consumption measurement data directly from the meters  18  via one or more data collection interfaces  32   b , disposed in one or more of the meters  18 . 
     The sensors  32   c - 32   e  associated with each meter  18  are adapted to sense the type of output signals supplied by a corresponding media consumption device and may be implemented using, for example, a microphone  32   c  for sensing audio signals, a video sensor  32   d  for sensing video signals, and/or a digital data sensor  32   e  for sensing data supplied in a digital bitstream. Due to the plurality of sensor types that may be installed in the meters  18 , the meters  18  may be adapted to sense a variety of signals and may be further adapted to recognize and process a variety of codes embedded in such signals. These codes may include video based codes such as closed captioning, automated measurement of lineup (AMOL), interactive television triggers in the vertical blanking interval (VBI) of a traditional NTSC or PAL television signal, imperceptible codes in active analog/digital video, and codes included in the user data of digital video packets, to name a few. In addition, these codes may include inaudible audio codes, auxiliary data codes, digitally compressed audio packets as well as information in digital packets containing program guide information such as PSI, PSIP and A-90 data packets. Such codes may be formatted using existing broadcast standards or may instead be formatted according to standards that are currently being developed or that will be developed in the future such as, for example, the standard recently developed by the BBC and presented to TV-Anytime, the content identifier standard being developed by ATSC called Versioned ISAN (VISAN) and the standard known as AD-ID that was recently defined by the American Association of Advertising Agencies. Instead of, or in addition to, sensing signals containing codes associated with media content, one or more of the sensors may be adapted to receive signals that indicate usage of a computer software application. For example, one or more of the sensors may be adapted to monitor a computer software application that controls access to the database  16  to determine, for example, how often particular media content is being transferred into, or out of, the database  16 . 
     The codes are transmitted as metadata via the media signal. The metadata may include a variety of information associated with the media content, such as, for example, content identification information, source identification information (SID), destination device identification information, distribution channel identification information and/or data and timestamps identifying the creation and/or transmission dates of the media content. Metadata may additionally include signal characteristics such as frequency, format, signal strength, bitrates, frame rates, and sampling frequency, to name a few. The signal format information may be used to transcode the signal from a first format to a second format to enable consumption of the signal at a consumption device that is able to recognize and process the second format. 
     As will be appreciated by one having ordinary skill in the art, the meters  18  may be implemented using any combination of software and hardware adapted to perform core metering functions such as receiving and processing consumption data and supplying the consumption data to a central data collection facility. As will further be appreciated by one having ordinary skill in the art, existing media consumption metering technology spans from the very simple to the complex. Yet, the present invention is not limited to use with either type of metering technology but instead may be used with a variety of meters  18  having a range of complexity. For example, the meters  18  used with the present invention may be capable of communicating via the home network  10  as well as metering media consumption or the meters  18  may instead be standalone devices that are configured to meter a particular type of media consumed via a particular type of media consumption device  12 . In addition, the meters  18  may be implemented as simple, hardware based devices that collect channel tuning information or as more sophisticated, software based devices that perform intelligent data collection and processing functions. 
     The location of each of the meters  18  within the home network  10  depends on the type of metering to be performed. For example, if the meter  18  is adapted to perform metering by sensing a signal output by one of the media consumption devices  12 , such as an audio or video signal, then the meter  18  is typically positioned near that content consumption device  12  so that it may access the signal to be metered. If, instead, the meter  18  is adapted to meter a signal supplied by the transcoder  22 , then the meter  18  need not be positioned in close, physical proximity to the media consumption device  12  but must be either proximate to the transcoder  22  or arranged to remotely receive the signal output by the transcoder  22 . Of course, in the latter embodiment, the meter  18  detects the flow of signals through the transcoder  22  instead of the consumption of those signals by a media content consumption device  12 . Such an arrangement may be especially useful with a meter  18  adapted to detect the flow of signals through the transcoder  22  and having a software application interface (not shown) adapted to query the transcoder  22  about the media content being transcoded. 
     Referring to  FIG. 3 , the transcoder  22  of the present invention is adapted to transcode both media content and metadata transmitted with the media content and may be implemented to include a home network interface  30 , an input media demultiplexer  34 , a processor  36 , a memory  38 , an output media codec  40 , an encode manager  42 , and an audio/video watermark codec  44  that is adapted to detect watermarks and to encode new watermarks. The various components included in the transcoder  22  are controlled by the processor  36  which executes a set of software instructions stored in the memory  38  and each transcoder component may be implemented using software, firmware, hardware of any combination thereof. For example, commercially available devices may be used to implement any of the transcoder components provided that the functionality of each device has been modified as needed to operate as described herein. In addition, one or more of the components, such as the encode manager  42 , may be implemented as software routines stored in the memory  38  and executed by the processor  36 . 
     Referring also to  FIG. 4 , the transcoder  22  may be adapted to perform a method  50  that enables the transcoder  22  to transcode media content and accompanying metadata received from a first media consumption device  12  coupled to the home network  10 , such as a television, and to supply the transcoded media content and accompanying metadata to a second media consumption device  12 , such as a personal computer, also coupled to the home network  10 . The method  50  may be performed by the various components of the transcoder  22 , as described below, operating under the control of the processor  36  which executes a set of software instructions stored in the memory  38 . In an example embodiment, the method  50  may begin when the transcoder  22  receives media content at the home network interface  30  (block  52 ). The home network interface  30  disposed in the transcoder  22  enables communication between the transcoder  22  and the other devices in the home network  10 . As described with respect to the home network interface  30  disposed in the meter  18 , the home network interface  30  disposed in the transcoder  22  may be implemented using any type of device capable of translating between the communication protocol used by the home network  10  and the communication protocol used by the processor  36  disposed in the transcoder  22 . Also at the block  52 , the home network interface  30  stores the media content in the memory  38 . 
     After the media content has been stored in the memory  38 , the input media demultiplexer  34  demultiplexes the media content to extract the metadata transmitted therewith (block  54 ). The media content received at the home network interface  30  need not be stored before being demultiplexed by the demultiplexer  34  but may instead be delivered by the home network interface  30  to the demultiplexer  34  as the media content arrives at the transcoder  22 . The demultiplexer  34  may demultiplex the media content as it is received and then cause the demultiplexed content, i.e., the media content and the extracted metadata to be stored in the memory  38 . The method  50  may then continue with the encode manager  42  examining the extracted metadata to identify a media format, “Format A”, in which the media content was supplied to the transcoder  22  by the television (block  56 ). For example, the metadata may indicate that the media content received at the transcoder  22  is formatted as a television broadcast signal such that Format A is a standard broadcast television signal format such as, for example, an NTSC signal. In addition, the encode manager  42  examines the metadata to identify a metadata format, Format A1, in which the metadata extracted from the media content is formatted. In this example embodiment, the transcoder  22  is described as being adapted to examine the incoming media content and metadata to determine the identities of Format A and Format A1. The ability of the transcoder  22  to make such a determination is especially useful for transcoders adapted to receive media content and metadata from a variety of media consumption device types. If, instead, the transcoder  22  is configured within the home network  10  to receive media content and metadata from only a single media consumption device type, then the transcoder  22  may be pre-programmed with the identities of Format A and Format A1 such that the encode manager  42  need not determine the identities of Format A and Format A1 (block  56 ). 
     Next, the encode manager determines a media format, “Format B”, associated with the second network device to which the transcoded media content shall be delivered for consumption (block  58 ). By way of example, the personal computer may have a Windows operating system and a Windows media player such that the media content must be supplied to the personal computer in a streaming media format suitable for display via the Windows media player. Thus, for this example, media Format B is a streaming media signal format. The encode manager  42  may be pre-programmed with the media format used by the personal computer, i.e., Format B, such that the encode manager retrieves this format information from the memory  38 . Alternatively, the encode manager  42  may be configured to query the personal computer to obtain media Format B. In addition, the encode manager  42  also identifies a metadata format, Format B1, to which the extracted metadata shall be transcoded before delivery to the personal computer (block  58 ). Format B1 is the metadata format recognized by the meter  18  configured to measure media consumption at the personal computer. The encode manager  42  may be pre-programmed with the identity of the metadata format, Format B1, or the encode manager  42  may be adapted to obtain the identity of Format B1 from the meter  18  associated with the personal computer by performing one or more of a set of querying methods described in greater detail below. 
     Once the encode manager  42  has identified the applicable media formats, Formats A and B, and the applicable metadata formats, Format A1 and B1, the method continues with the encode manager  42  instructing the output media codec  40  to transcode the media content from Format A to Format B and the extracted metadata from Format A1 to Format B1 and providing the output media codec  40  with the parameters needed to perform such transcoding functions (block  60 ). In addition, the encode manager  42  supplies the output media codec  40  with instructions and parameters necessary for combining the transcoded metadata with the transcoded media content to form an output media signal for subsequent delivery to the personal computer. Lastly, the transcoded media signal having the transcoded metadata embedded therein is supplied by the transcoder  22  to the personal computer for consumption thereat (block  62 ). 
     As will be appreciated by one having ordinary skill in the art, methods for performing transcoding functions that convert a signal from a first media format to a second media format are well known in the art. For example, the transcoder  22  may be adapted to convert a signal containing media content from a broadcast format to any of a 1) streaming media format, 2) JPEG format, e.g., deriving a still picture from a movie for use in a digital photo frame, 3) MP3 format, e.g., playing a soundtrack to a broadcast movie, and/or 4) a digital video recorder format. Alternatively, the transcoder  22  may be adapted to convert a signal from a digital video recorder format to any of a 1) streaming media format, 2) MP3 format, and/or 3) a JPEG format. By way of further example, the transcoder  22  may be adapted to convert a signal from a streaming media format to either of a 1) JPEG format and/or 2) MP3 format. As will further be appreciated by one having ordinary skill in the art, any of these well-known transcoding techniques may be adapted to enable transcoding of the metadata from a first metadata format to a second metadata format. 
     As will further be appreciated by one having ordinary skill in the art, the metadata formats may be configured in a variety of different ways and, in some instances, the metadata formats may be at least partially dependent on the media format of the media content associated with the metadata. For example, if the media content associated with the metadata is provided in a broadcast television media format, then the metadata format will likely be formatted to include data fields related to broadcast television. Referring now to  FIG. 5A , Format A1, if associated with a digital broadcast television media format, such as, for example, ATSC, may include a set of fields  70  for containing a variety of broadcast television signal information such as a minor channel number  72 , a major channel number  74 , a transport ID  76 , a name of a program transmitted in the media content  78 , a program number  80 , a program description  82 , a source ID  84 , a date/time stamp  86 , a transport rate  88 , a video bitrate  90 , an audio bitrate  92 , an audio sampling rate  94 , and a video frame rate  96 . In this example, the minor channel number and major channel number are each 10 bits long, the transport ID is 16 bits long, the program name is represented as a sequence of one to seven 16 bit character codes coded in accordance with the Basic Multilingual Plane (BMP) of Unicode™, as specified in ISO 10646-1, the program number is 8 bits long, the program description is represented as a sequence of one to seven 16-bit character codes coded in accordance with the Basic Multilingual Plane (BMP) of Unicode™, as specified in ISO 10646-1, the source ID is 16 bits long, and the date/time stamp is a 32 bit long number in UTC format. 
     In contrast, metadata associated with media content that is to be supplied in a streaming media format for consumption/display at a personal computer will likely be formatted as a data header including data fields  98  for containing information about the media content in a digital data format. Thus, for example, Format B1 may include fields for containing information such as the program name  100 , the program number  102 , the program description  104 , a source ID  106 , a broadcast date/time stamp  108 , a transcoded date/time stamp  110 , an author  112 , a device ID  114 , a home ID  116 , a format  118 , a video bitrate  120 , an audio bitrate  122 , an audio sampling rate  124 , and a video frame rate  126 . In addition, the data fields of Format B1 may be defined to include data in a specific code or a data string having a specific number of bits. For example, the fields of Format B1 may be defined such that the program name  100  is ASCII encoded, the program number  102  is 8 bits long, the program description  104  is ASCII encoded, the source ID  106  is identical in format to the source ID of Format A, the broadcast date/time stamp  108  is the same as in the broadcast metadata, the transcoded date/time stamp  110  is a 32 bit number reflecting the date and time of transcoding by transcoder  104 , the author field  112  is an ASCII representation of the user of the transcoder  104 , the device ID  114  is an 8 bit ASCII encoded number identifying the transcoder  104 , and the home ID  116  is a 32 bit ASCII encoded number assigned to identify the home network  10 . In addition to identifying Formats A1 and B1, the encode manager  42  may be configured to generate the data contained in one or more of the fields of Format B1 including, for example, the data associated with the author  112 , device ID  114 , home ID  116  and format  118  fields. 
     The metadata format, Format B1, may also be affected by the type of meter  18  that will be used to collect the metadata for purposes of measuring consumption of the media content that is associated with the metadata. For example, if the meter  18  is configured to detect audio codes, then the metadata format, Format B1, will be suitable for insertion into an audio signal and recognition by an audio code meter and/or if the meter is configured to detect video codes, then the metadata format, Format B1, will be suitable for insertion into a video signal and recognition by a video code meter. Likewise, if the meter  18  is configured to detect digital data, then the metadata format, Format B1, will be suitable for insertion into a digital data stream and detection by a digital data sensor. 
     The transcoding capabilities of the transcoder  22  may also vary depending upon the position of the transcoder  22  within the home network  10 . For example, if the transcoder  22  is positioned to receive input from multiple media consumption devices  12  and to provide transcoded media content to multiple media consumption devices  12 , then the transcoder  22  will likely be adapted to transcode media content between the multiple formats used by the media consumption devices  12  coupled thereto. Alternatively, if the transcoder  22  is positioned to receive input from a single media consumption device  12  and to supply transcoded media content to a single media consumption device  12 , then the transcoder  22  need only be adapted to transcode between the media formats used by the two media consumption devices  12  configured to supply/receive media content to/from the transcoder  22 . 
     Referring now to  FIG. 6 , depending on the capabilities of the meter  18  associated with the second network device, e.g., the personal computer, and whether one or more conditions are satisfied, as is described in greater detail below, the method  50  may be expanded to include a submethod, identified generally with reference numeral  130 , for causing the audio/video watermark codec  44  to insert a watermark into the media content in a manner that causes the inserted watermark to be imperceptible to the human senses so that the inserted watermark does not interfere with the consumption of the media content at the personal computer. In such an arrangement, the encode manager  42  may use the metadata associated with the media content to identify the media content and then cause the audio/video watermark codec  44  to generate a watermark that uniquely represents that media content and to insert the watermark into the transcoded media content (block  132 ). Next, the transcoder  22  supplies information that correlates the identity of the media content with the unique watermark to the meter  18  which may be adapted to transmit this correlation information directly to a remote data collection facility (not shown) or via the measurement collection unit  20  (see  FIG. 1 ) (block  122 ). Alternatively, the transcoder  22  may be adapted to supply this correlation information directly to the measurement collection unit  20  via the home network  10 . When the media content having the inserted watermark is consumed at the personal computer, and the meter  18  associated with the personal computer extracts the watermark and reports the presence of the watermark to the measurement collection unit  20  or the remote data collection facility, the data collection facility may use the correlation information to determine the identity of the consumed media content based on the reporting of the unique watermark. 
     Referring again to  FIG. 1 , it should be understood that not all of the transcoding functions need to be performed by a single network component but may instead be performed by any of the consumption devices  12 , or any other network device or combination of network devices, provided that such devices are adapted to perform the transcoding functions described herein. For example, the transcoder  22  may be configured to demultiplex an incoming media content signal to separate the metadata contained in the signal from the programming or other media content as described with respect to  FIGS. 3 and 4 . Alternatively, a media consumption device  12  may be configured to perform this demultiplexing function such that the metadata extracted thereby is transmitted to the transcoder  22  separately from the media content. Likewise, any of the media consumption devices  12  may be configured to decode or otherwise process the media content signal before the signal is transmitted to the transcoder  22 . For example, any of the media consumption devices  12  may be configured to receive and demodulate/downconvert a digitally compressed broadcast signal provided in an ATSC, DVB or MPEG format via an RF transmission. Any of the media consumption devices  12  may further be configured to include a demultiplexer that demultiplexes the demodulated bitstream to obtain a set of elementary components, including an elementary video stream, an elementary audio stream and the metadata transmitted in the broadcast. The elementary video and audio streams may then be decoded by an MPEG/AC3 audio decoder and an MPEG video decoder, respectively, both of which may also be disposed in any of the media consumption devices  12 . The decoded video and audio streams may subsequently be transmitted to the transcoder  22  for transcoding in accordance with the blocks  56 - 62  of the method  50  shown in  FIG. 4  described above. After the transcoding has been performed, the transcoder  22  may be adapted to yield a streaming media signal that may be delivered to one of the media consumption devices  12  configured to consume/display streaming media or may instead be stored in the memory  16  by the server  24  for consumption at a later time. In addition, the meter  18  used to meter the media consumption device  12  at which the streaming media is consumed may be configured to receive the transcoded metadata directly from the transcoder  22  or may instead be configured to extract the transcoded metadata embedded in the streaming media signal delivered by the transcoder  22  as it is consumed by the media consumption device  12 . 
     Referring still to  FIG. 1 , in an embodiment in which the transcoder  22  supplies the transcoded metadata directly to a first meter  18 , the transcoder  22  may be disposed in or in communication with a second meter  18  configured to meter consumption at a media consumption device  12 . The second meter  18  may be implemented using, for example, a set top box  18  that is configured to meter consumption of television programming via, for example, a television  12 . In this embodiment, the set top box  18  collects metadata as the corresponding television programming is consumed at the television  12 . The set top box  18  then supplies the collected metadata to the transcoder  22  which transcodes the metadata from the first format, Format B1, to the second format, Format B2, suitable for delivery to and reception at the first meter  18 . The transcoder  22  may be integrated with the set top box  18 , disposed within the set top box  18 , or separate from but in communication with the set top box  18 . The first meter  18  may be implemented using, for example, a portable meter  18  designed to collect audio codes or designed to collect data transmitted wirelessly using any wireless protocol. Of course, if the first meter  18  is designed to receive data wirelessly using a wireless protocol such as Bluetooth, then the transcoder  22  will be configured to transcode the metadata to a Bluetooth format and the second meter  18  will be configured to transmit the data in Bluetooth format. The portable meter  18  may be configured to be carried by a household member for purposes of metering that household member&#39;s viewing habits. The portable meter  18  may additionally be configured to meter media consumption by that household member that occurs out of the home by detecting audio codes emitted by media consumption devices  12  disposed outside the home and may be configured to detect media consumption within the home by wireless reception of transcoded metadata from the set top box  18  as described above. Alternatively, the portable meter  18  may be designed to detect audio codes emitted by the television  12  as well as metadata transcoded and transmitted by the set top box  12  such that the portable meter  18  receives two sets of data representing the same viewing event while disposed in the home. These two data sets may then be compared for consistency to increase confidence in the accuracy of the data. Of course, the two data sets must be treated such that the sets are only counted as a single viewing event. In another example embodiment, the set top box  18  may configured to supplement the code capturing capabilities of the portable meter  18  by detecting codes that are not detectable by the portable meter  18 , by transcoding such codes to a format suitable for detection by the portable meter  18  and by then supplying the transcoded codes to the portable meter  18 . In such an embodiment, the portable meter  18  may be designed to detect a first type of code such as an SID, emitted by the television  12 , but not a second type of code, such as a time stamp. The set top meter  18  may be designed to detect either or both of the first and second types of code. For example, the set top meter  18  may detect the SID and the time stamp emitted by the television  12  and may transcode the SD and timestamp to a format suitable for reception/processing by the portable meter  18 . Thereafter, the set top meter  18  may transmit one or both of the transcoded time stamp and SID to the portable meter  18  via, for example, radio frequency signals, infra-red signals, Wi-Fi signals, audio signals, etc. Of course, the set top and portable meters  18  will have to be equipped to communicate using such signals. 
     The transcoder  22  may be pre-programmed with the identity of Format A1 and Format B1 such that the transcoder  22  may automatically convert metadata received at the transcoder from Format A1 to Format B1. In fact, such an arrangement may be preferred when the transcoder  22  is adapted to receive media in a single format only and to transmit data in a single format only. Alternatively, referring also to  FIG. 7A , as mentioned above, the transcoder  104  may be adapted to perform a variety of methods to query one or more networked meters  18  for information about the detection capabilities of the meters  18  so that the format in which the metadata is to be supplied to the meters  18 , i.e., Format B1, can be determined. For example, one such method  140  may comprise a set of submethods, each submethod designed to test for the presence of a different type of sensor. The first such submethod  142  may test for the presence of an audio sensor capable of sensing audio watermarks and may begin when the transcoder  22  queries the meter  18  to determine whether it includes an audio watermark sensor (block  144 ). If the meter  18  responds to the query in the negative, i.e., the meter  18  does not have an audio watermark sensor, then the transcoder  22  bypasses the remainder of the submethod  142  and instead proceeds to additional submethods for testing whether the meter  18  includes one or more other types of sensors as described in greater detail below with reference to  FIGS. 7B and 7C . 
     If instead, in response to the query performed at the block  64 , the meter  18  responds in the positive, i.e., the meter  18  does have an audio watermark sensor, then the submethod  62  continues with the transcoder  22  determining whether an audio watermark has been detected in the media content supplied to the transcoder  22  for transcoding (block  146 ). If an audio watermark is not detected in the media content, then the transcoder  22  creates a new audio watermark and causes the new audio watermark to be embedded into the media content (block  148 ). As will be appreciated by one having ordinary skill in the art, the audio/video watermark codec  44  may be configured to detect the presence of an audio watermark supplied in the media content and to create a new audio watermark for insertion in the content. Moreover, the capabilities and functionality of a standard audio/video watermark codec are well known in the art are not described further herein. The transcoder  22  may also cause all or a portion of the submethod  130 , described with respect to  FIG. 6 , to be performed thereby causing correlation information to be generated and transmitted to the measurement collection unit  20  and/or a remote data collection facility where it may be used to correlate the watermark to the program or other content it represents. 
     If an audio watermark has been detected at the block  146 , then the transcoder  22  determines whether the audio watermark, if inserted into the signal to be output by the transcoder  22 , will survive the compression performed by the output media codec  40  (block  150 ). Specifically, the output media codec  40  is adapted to compress the media content signal having the inserted watermark before the signal is transmitted via the home network  10 . The output media codec  40  compresses the signal by suppressing one or more of the signal frequencies. However, watermarks are created by modulating a particular set of signal frequencies in a manner such that the modulated frequencies uniquely represent a particular program or other media content. Thus, the compression performed by the output media codec  40 , may cause one or more of the frequencies modulated to create the watermark to be suppressed thereby causing the audio watermark to be unrecoverable by the meter  18 . The transcoder  22  may be adapted to perform a variety of methods for determining whether the watermark will survive compression by the output media codec  40 . For example, the transcoder  22  may cause the output media codec  40  to insert the watermark into the media content and the resulting signal may be processed by the transcoder  22 , in much the same way an input signal would be processed, to determine whether the audio watermark is recoverable. In another embodiment, the transcoder  22  may be pre-programmed with information pertaining to signal compression ratios that the watermark will be able to withstand/survive. Specifically, before inserting a particular watermark into a media content signal, the watermark may be tested to determine a range of suitable signal compression ratios, i.e., compression ratios that the watermark will survive. These suitable ratios may then be provided to the manufacturers/developers of the transcoder  22  and used to pre-program the transcoder  22  so that when watermarks are encountered, the transcoder  22  may use the pre-programmed information to compare to the ratio used by the output media codec  40  to determine whether the compression ratio used by the output media codec  40  is suitable inserting and for transmitting the watermark in a recoverable, distortion-free manner. In a still further embodiment, information about suitable compression ratios may be transmitted with the signal containing the watermark and extracted from the signal by the transcoder  22  for use in determining whether the watermark will survive the compression ratio used by the output media codec  40 . If the audio watermark will survive, then the sub method  142  causes the output media codec  40  to insert the watermark (block  152 ) (if it is not already inserted) after which the submethod  142  is complete and the method  140  continues at another submethod described below with respect to  FIG. 7B  and  FIG. 7C . 
     If, at the block  150 , the transcoder  22  determines that the compression ratio used by the output media codec  40  is not suitable, i.e., will cause the watermark to be unrecoverable, then the transcoder  22  may decrease the compression ratio by a desired amount. As will be understood by one having ordinary skill in the art, the compression ratio refers to the ratio of the data in the uncompressed signal to the data in the compressed signal. In addition, the signal compression ratio is inversely related to the output bit rate, i.e., as the compression ratio decreases, the output bit rate increases. Thus, if the compression ratio is too high and would cause the watermark to be unrecoverable, then the transcoder  22  may decrease the compression ratio of the output media codec  40  by increasing the output bit rate of the output media codec  40  by a desired amount such as, for example, 30 Kb/sec (block  154 ). After increasing the output bit rate, the transcoder  22  determines whether the new, increased output bit rate exceeds the maximum allowable bit rate supported by the home network  10  (block  156 ). As will be appreciated by one having ordinary skill in the art, if the bit rate is higher than that supported by the home network  10 , then the home network  10  may not be able to carry the signal without causing it to be distorted. As a result, the transcoder  22  decreases the output bit rate to a value that is within the bandwidth of the home network  10  (block  158 ), and the submethod  142  returns to the block  148  at which a new audio watermark is created and inserted into the media content, as described above. As is also described above, when the transcoder  22  causes the output media codec  40  to create a new audio watermark the transcoder  22  may also perform all or a portion of the submethod  130  shown in  FIG. 6 , for causing correlation information to be created and transmitted to the meter  18  for reporting to the remote data collection facility (not shown). 
     If, the output bit rate does not exceed the maximum rate supported by the home network  10  (block  156 ), then the submethod  142  returns to the block  150 , and the blocks subsequent thereto, at which the transcoder  22  again tests to determine whether the codec compression ratio is suitable for transmission of the watermark, as described above. 
     Referring also to  FIG. 7B , which includes a continuation of the flow chart of  FIG. 7A  as indicated by the alignment points A, after performing the submethod  142  for detecting the presence of an audio watermark sensor, a submethod  162  for determining whether the meter has a sensor capable of sensing a video watermark may be performed. The submethod  162  for detecting the presence of a video watermark sensor begins when the transcoder  22  queries the meter  18  to determine whether it includes a video watermark sensor (block  164 ). If the meter  18  responds to the query in the negative, i.e., the meter  18  does not have a video watermark sensor, then the transcoder  22  proceeds to additional submethods for testing whether the meter includes one or more other types of sensors as described in greater detail below with reference to  FIG. 7C . If instead, in response to the query performed at the block  164 , the meter  18  responds in the positive, i.e., the meter  18  does have a video watermark sensor, then the submethod  162  continues with the transcoder  22  querying the meter  18  to determine whether a video watermark has been detected in the media content supplied to the transcoder  22  for transcoding (block  166 ). If a video watermark is not detected in the media content, then the submethod  162  may continue at a block  168  at which the transcoder  22  creates a new video watermark and causes the new video watermark to be inserted into the media content. As discussed above, the capabilities and functionality of a standard audio/video watermark codec are well known in the art and are not described further herein. The transcoder  22  may also cause all or a portion of the submethod  130 , described with respect to  FIG. 6 , to be performed thereby causing correlation information to be generated and transmitted to the measurement collection unit  20  and/or a remote data collection facility (not shown) where it may be used to correlate the watermark to the program or other content it represents. 
     If a video watermark has been detected at the block  166 , then the transcoder  22  determines whether the video watermark, if inserted into the signal to be output by the transcoder  22 , will survive the compression performed by the output media codec  40  (block  170 ). Specifically, the output media codec  40  is adapted to compress the media content signal having the inserted watermark before the signal is transmitted via the home network  10 . The output media codec  40  compresses the signal by suppressing one or more of the signal frequencies. However, watermarks are created by modulating a particular set of signal frequencies in a manner such that the modulated frequencies uniquely represent a particular program or other media content. Thus, the compression performed by the output media codec, may cause one or more of the frequencies modulated to create the watermark to be suppressed thereby causing the video watermark to be unrecoverable by the meter  18 . The transcoder  22  may be adapted to perform a variety of methods for determining whether the watermark will survive compression by the output media codec  40 . For example, the transcoder  22  may cause the output media codec  40  to insert the watermark into the media content and the resulting signal may be processed by the transcoder  22 , in much the same way that an input signal is processed, to determine whether the video watermark is recoverable. In another embodiment, the transcoder  22  may be pre-programmed with information pertaining to signal compression ratios that the watermark will be able to withstand/survive. Specifically, before inserting a particular watermark into a media content signal, the watermark may be tested to determine a range of suitable signal compression ratios, i.e., compression ratios that the watermark will survive. These suitable ratios may then be provided to the manufacturers/developers of the transcoder  22  and used to pre-program the transcoder  22  so that when watermarks are encountered, the transcoder  22  may use the pre-programmed information to compare to the compression ratio of the output media codec  40  to determine whether the compression ratio used by the output media codec  40  is suitable for inserting and transmitting the watermark in a recoverable, distortion-free manner. In a still further embodiment, information about suitable compression ratios may be transmitted with the signal containing the watermark and extracted from the signal by the transcoder  22  for use in determining whether the watermark will survive the compression ratio used by the output media codec  40 . If the video watermark will survive compression, the submethod  162  causes the output media codec  40  to insert the watermark (block  172 ) into the media content (if it is not already inserted) after which the submethod  162  is complete and the method  140  continues at another submethod described below with respect to  FIG. 7B  and  FIG. 7C . 
     If, at the block  170 , the transcoder  22  determines that the compression ratio of the output media codec  40  is not suitable, i.e., will cause the watermark to be unrecoverable, then the transcoder  22  may decrease the compression ratio by a desired amount. As will be understood by one having ordinary skill in the art, the compression ratio refers to the ratio of the quantity of data in the uncompressed signal to the quantity of data in the compressed signal. In addition, the signal compression ratio is inversely related to the output bit rate, i.e., as the compression ratio decreases, the output bit rate increases. Thus, if the compression ratio is too high and would cause the watermark to be unrecoverable, then the transcoder  22  may decrease the compression ratio of the output media codec  40  by increasing the output bit rate of the output media codec  40  by a desired amount such as, for example, 30 Kb/sec (block  174 ). After increasing the output bit rate, the transcoder  22  determines whether the new, increased output bit rate exceeds the maximum allowable bit rate supported by the home network  10  (block  176 ). As will be appreciated by one having ordinary skill in the art, if the bit rate is higher than that supported by the home network  10 , then the home network  10  may not be able to carry the signal without causing it to be distorted. As a result, the transcoder  22  decreases the output bit rate to a value that is within the bandwidth of the home network  10  (block  178 ), and the submethod  162  returns to the block  168  at which a new video watermark is created for insertion into the media content, as described above. As is also described above, the block  168  at which the transcoder  22  causes the output media codec  40  to create a new video watermark may also include all or a portion of the submethod  130  shown in  FIG. 6 , for causing correlation information to be created and transmitted to the meter  18  for reporting to the remote data collection facility (not shown). 
     If, at the block  176 , the output bit rate does not exceed the maximum rate supported by the home network  10 , then the submethod  162  returns to the block  170 , and the blocks subsequent thereto, at which the transcoder  22  again tests to determine whether the codec compression ratio is suitable for transmission of the watermark, as described above. 
     In addition to testing for the presence of an audio watermark sensor and a video watermark sensor, the transcoder  22  may be adapted to query the 18 meter to determine whether it includes other types of sensors as well, such as digital sensors, database sensors and/or software sensors. Specifically, with reference also to  FIG. 7C  which includes a continuation of the flow chart of  FIGS. 7A and 7B  as indicated by the alignment points B, such a submethod  200  may begin with the transcoder  22  querying the meter  18  to determine whether it includes a sensor capable of parsing a digital bitstream to decode metadata embedded in the stream (block  202 ). If the meter  18  responds that it does include such a digital sensor, then the transcoder  22  causes the output media codec  40  to encode the metadata received with the media content into the desired format (block  204 ) and to digitally insert the encoded metadata into the bitstream of the transcoded media content to be output by the transcoder (block  206 ). 
     If the meter  18  indicates that it does not include a digital sensor (block  202 ), then the method continues at a submethod  210  at which the transcoder  22  queries the meter  18  to determine whether it includes a database sensor, i.e., a sensor that can identify when media content is being read from a media database (block  212 ). If such a database sensor is present, then the submethod  200  continues with the transcoder  22  transcoding the metadata, embedding the transcoded metadata in the transcoded media content and then causing the media content to be stored in a media database (block  214 ). 
     If, at the block  212 , a database meter is not detected, then the method continues at a submethod  216  for determining whether the meter  18  includes a software sensor adapted to extract metadata from a media consumption device using software APIs associated with the consumption device, e.g. DASE/MHP API (block  218 ). If such a software sensor is detected, then the transcoder  22  causes the output media codec  40  to format the metadata in a manner suitable for extraction by the software sensor and to embed the metadata into the transcoded media signal that is output by the transcoder  22  (block  220 ). 
     If a software sensor is not detected, then the transcoder  22  may query the home network  10  for the presence of other meters  18  that are configured to meter the consumption device to which the transcoder  22  supplies transcoded media content (block  222 ). If another meter  18  is detected, then the transcoder  22  may return to the beginning of the method  140  and cause it to be performed again with respect to the newly detected meter  18 . If another meter is not detected, then the transcoder  22  may forego repeating the method  140 . 
     As described, the method  140  for querying a meter  18  to determine the sensing capabilities of the meter  18  actually comprises a set of sub-methods each adapted to query the meter  18  for a specific type of sensor. Although the sub-methods are described as being performed in a specific order, the sub-methods may actually be performed in any desired order. Likewise, the submethods may be performed in parallel instead of serially. In addition, the transcoder  22  need not be configured to perform all of the submethods of  FIGS. 7A-7C  but may instead be configured to perform any combination of a subset of these sub-methods. Moreover, the transcoder  22  may be configured to perform any number of additional sub-methods as necessary to determine the sensing capabilities of the meter  18  so that the metadata may be formatted accordingly. 
     The querying methods described above need not be performed at all if the transcoder  22  is pre-programmed with information about the sensing capabilities of the meter  18 . In such an embodiment, the meters  18  need not be capable of communicating via the home network  10  and need not even be coupled to the home network  10 . Instead, the meters  18  need only be capable of metering consumption at a media consumption device  12 . 
     Depending on whether frequent changes to the configuration of the home network  10  are anticipated, the transcoder  22  may be adapted to perform the method  140  every time new media content is received or only a single time, e.g., upon installing the transcoder  22  in the home network  10 . Alternatively, the transcoder  22  may be adapted to query for sensor types only after the home network  10  has been reconfigured. Of course, all or portions of the submethods  142  and  162  for detecting the presence of an audio watermark sensor and a video watermark sensor, respectively, may need to be performed every time media content is supplied since at least portions of the submethods  142  and  162  operate to test for the presence of an audio watermark or a video watermark supplied with the media content. 
     The submethods of  FIGS. 7A, 7B and 7C  are described as including blocks at which the transcoder  22  determines whether a particular type of sensor is detected and, if such a sensor type is detected, then causes the metadata to be transcoded in a manner suitable for detection by that sensor type, and then proceeds to perform tests for a different type of sensor. However, the submethods may instead be structured such that the transcoder first detects the presence (or absence) of each type of sensor and then, after each sensor type has been detected, causes the metadata to transcoded in a manner suitable for the detected sensor types. In addition, the metadata may be transcoded into more than one metadata format thereby enabling detection by more than one type of sensor. 
     As described herein, the media content and its corresponding metadata received at the transcoder  22  are stored in the memory device  38  and accessed by the various transcoder components for purposes of transcoding the media content and metadata. Instead, the transcoder  22  may include a plurality of memory devices arranged as registers associated with the various components of the transcoder  22  between which the data may be transferred. Alternatively, the transcoders  22  may be adapted to process and store the media content and metadata in any desired manner. 
     The home network  10 , although described as being disposed within a home residence, may instead be disposed at any type of location and may be configured to enable communication between network devices located at any number of different locations. For example, the home network  10  may be installed in a place of business or at any public location. Any network that enables communication between multiple media consumption devices is sufficient to qualify as a “home network,” as that term is used herein. 
     As will be appreciated by one having ordinary skill in the art, if the consumption device  12  is metered using only a single meter  18  and that single meter  18  is limited to signature sensing only, then any metadata extracted from the media content need not be transcoded at the trancoder  22  because signature metering involves capturing signal characteristic information, i.e., signature information, and does not involve the extraction of codes. Thus, the querying method  60  of  FIGS. 7A-7C  does not illustrate querying for the presence of a signature sensor. Or, as is more often the case, a consumption device  12  may be metered using multiple meters, one of which is capable of sensing signatures. In a system configured in this manner, metadata transcoding will likely be required as signature sensing is more often used as a back up sensing mechanism instead of a primary sensing mechanism. Thus, the transcoders  22  will not typically be configured to forego metadata transcoding functions upon the detection of a meter  18  having signature sensing capabilities. 
     The transcoder  22  may additionally be adapted to query the media content consumption device  12  that supplies media content to the transcoder  22  for identification purposes such as, for example, device type and/or model information and the transcoder  22  may then transmit this identifying information to the meter  18  configured to measure consumption at the media consumption device to which the transcoder delivers the transcoded media content. 
     While the present invention has been described with respect to several embodiments, it is to be understood that the invention is not limited to these disclosed embodiments. To the contrary, the invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.