Abstract:
A system is provided for creating binary codewords for transform coefficients used for relating transform units (TUs) divided into coding units (CUs) in a High Efficiency Video Coding (HEVC) system. The system provides binarization of the codewords and removes unnecessary operations to reduce system complexity and increase compression performance. The system generates transform coefficients that relate the TUs and begins by providing a parameter variable (cRiceParam) set to an initial value of zero. Significant transform coefficients are converted into binary codewords based on the current value of the parameter variable, and the parameter variable is then updated with a new current value after each transform coefficient has been converted. Updating can be provided with reference to table values or the values can be provided from combination logic.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This Application claims priority under 35 U.S.C. §119(e) from earlier filed U.S. Provisional Application Ser. No. 61/595,134, filed Feb. 5, 2012, and earlier filed U.S. Provisional Application Ser. No. 61/595,153, filed Feb. 6, 2012, the entirety of which are incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present disclosure relates to the field of video compression, particularly video compression using High Efficiency Video Coding (HEVC) that employ block processing. 
         [0004]    2. Related Art 
         [0005]      FIG. 1  depicts a content distribution system  100  comprising a coding system  110  and a decoding system  140  that can be used to transmit and receive HEVC data. In some embodiments, the coding system  110  can comprise an input interface  130 , a controller  111 , a counter  112 , a frame memory  113 , an encoding unit  114 , a transmitter buffer  115  and an output interface  135 . The decoding system  140  can comprise a receiver buffer  150 , a decoding unit  151 , a frame memory  152  and a controller  153 . The coding system  110  and the decoding system  140  can be coupled with each other via a transmission path which can carry a compressed bitstream  105 . The controller  111  of the coding system  110  can control the amount of data to be transmitted on the basis of the capacity of the receiver buffer  150  and can include other parameters such as the amount of data per a unit of time. The controller  111  can control the encoding unit  114  to prevent the occurrence of a failure of a received signal decoding operation of the decoding system  140 . The controller  111  can be a processor or include, by way of a non-limiting example, a microcomputer having a processor, a random access memory and a read only memory. 
         [0006]    Source pictures  120  supplied from, by way of a non-limiting example, a content provider can include a video sequence of frames including source pictures in a video sequence. The source pictures  120  can be uncompressed or compressed. If the source pictures  120  are uncompressed, the coding system  110  can have an encoding function. If the source pictures  120  are compressed, the coding system  110  can have a transcoding function. Coding units can be derived from the source pictures utilizing the controller  111 . The frame memory  113  can have a first area that can be used for storing the incoming frames from the source pictures  120  and a second area that can be used for reading out the frames and outputting them to the encoding unit  114 . The controller  111  can output an area switching control signal  123  to the frame memory  113 . The area switching control signal  123  can indicate whether the first area or the second area is to be utilized. 
         [0007]    The controller  111  can output an encoding control signal  124  to the encoding unit  114 . The encoding control signal  124  can cause the encoding unit  114  to start an encoding operation, such as preparing the Coding Units based on a source picture. In response to the encoding control signal  124  from the controller  111 , the encoding unit  114  can begin to read out the prepared Coding Units to a high-efficiency encoding process, such as a prediction coding process or a transform coding process which process the prepared Coding Units generating video compression data based on the source pictures associated with the Coding Units. 
         [0008]    The encoding unit  114  can package the generated video compression data in a packetized elementary stream (PES) including video packets. The encoding unit  114  can map the video packets into an encoded video signal  122  using control information and a program time stamp (PTS) and the encoded video signal  122  can be transmitted to the transmitter buffer  115 . 
         [0009]    The encoded video signal  122 , including the generated video compression data, can be stored in the transmitter buffer  115 . The information amount counter  112  can be incremented to indicate the total amount of data in the transmitter buffer  115 . As data is retrieved and removed from the buffer, the counter  112  can be decremented to reflect the amount of data in the transmitter buffer  115 . The occupied area information signal  126  can be transmitted to the counter  112  to indicate whether data from the encoding unit  114  has been added or removed from the transmitted buffer  115  so the counter  112  can be incremented or decremented. The controller  111  can control the production of video packets produced by the encoding unit  114  on the basis of the occupied area information  126  which can be communicated in order to anticipate, avoid, prevent, and/or detect an overflow or underflow from taking place in the transmitter buffer  115 . 
         [0010]    The information amount counter  112  can be reset in response to a preset signal  128  generated and output by the controller  111 . After the information counter  112  is reset, it can count data output by the encoding unit  114  and obtain the amount of video compression data and/or video packets which have been generated. The information amount counter  112  can supply the controller  111  with an information amount signal  129  representative of the obtained amount of information. The controller  111  can control the encoding unit  114  so that there is no overflow at the transmitter buffer  115 . 
         [0011]    In some embodiments, the decoding system  140  can comprise an input interface  170 , a receiver buffer  150 , a controller  153 , a frame memory  152 , a decoding unit  151  and an output interface  175 . The receiver buffer  150  of the decoding system  140  can temporarily store the compressed bitstream  105 , including the received video compression data and video packets based on the source pictures from the source pictures  120 . The decoding system  140  can read the control information and presentation time stamp information associated with video packets in the received data and output a frame number signal  163  which can be applied to the controller  153 . The controller  153  can supervise the counted number of frames at a predetermined interval. By way of a non-limiting example, the controller  153  can supervise the counted number of frames each time the decoding unit  151  completes a decoding operation. 
         [0012]    In some embodiments, when the frame number signal  163  indicates the receiver buffer  150  is at a predetermined capacity, the controller  153  can output a decoding start signal  164  to the decoding unit  151 . When the frame number signal  163  indicates the receiver buffer  150  is at less than a predetermined capacity, the controller  153  can wait for the occurrence of a situation in which the counted number of frames becomes equal to the predetermined amount. The controller  153  can output the decoding start signal  164  when the situation occurs. By way of a non-limiting example, the controller  153  can output the decoding start signal  164  when the frame number signal  163  indicates the receiver buffer  150  is at the predetermined capacity. The encoded video packets and video compression data can be decoded in a monotonic order (i.e., increasing or decreasing) based on presentation time stamps associated with the encoded video packets. 
         [0013]    In response to the decoding start signal  164 , the decoding unit  151  can decode data amounting to one picture associated with a frame and compressed video data associated with the picture associated with video packets from the receiver buffer  150 . The decoding unit  151  can write a decoded video signal  162  into the frame memory  152 . The frame memory  152  can have a first area into which the decoded video signal is written, and a second area used for reading out decoded pictures  160  to the output interface  175 . 
         [0014]    In various embodiments, the coding system  110  can be incorporated or otherwise associated with a transcoder or an encoding apparatus at a headend and the decoding system  140  can be incorporated or otherwise associated with a downstream device, such as a mobile device, a set top box or a transcoder. 
         [0015]    The coding system  110  and decoding system  140  can be utilized separately or together to encode and decode video data according to various coding formats, including High Efficiency Video Coding (HEVC). HEVC is a block based hybrid spatial and temporal predictive coding scheme. In HEVC, input images, such as video frames, can be divided into square blocks called Largest Coding Units (LCUs)  200 , as shown in  FIG. 2 . LCUs  200  can each be as large as 128×128 pixels, unlike other coding schemes that break input images into macroblocks of 16×16 pixels. As shown in  FIG. 3 , each LCU  200  can be partitioned by splitting the LCU  200  into four Coding Units (CUs)  202 . CUs  202  can be square blocks each a quarter size of the LCU  200 . Each CU  202  can be further split into four smaller CUs  202  each a quarter size of the larger CU  202 . By way of a non-limiting example, the CU  202  in the upper right corner of the LCU  200  depicted in  FIG. 3  can be divided into four smaller CUs  202 . In some embodiments, these smaller CUs  202  can be further split into even smaller sized quarters, and this process of splitting CUs  202  into smaller CUs  202  can be completed multiple times. 
         [0016]    With higher and higher video data density, what is needed are further improved ways to code the CUs so that large input images and/or macroblocks can be rapidly, efficiently and accurately encoded and decoded. 
       SUMMARY 
       [0017]    The present invention provides an improved system for HEVC. In embodiments for the system, a method of determining binary codewords for transform coefficients in an efficient manner is provided. Codewords for the transform coefficients within transform units (TUs) that are subdivisions of the CUs  202  are used in encoding input images and/or macroblocks. In some embodiments, the codewords can have a Truncated Rice portion having a predefined maximum number of bits. 
         [0018]    In one embodiment, a method is provided that comprises providing a transform unit comprising one or more groups of the transform coefficients, each of the transform coefficients having a quantized value, coding a first flag for each of the transform coefficients that have an absolute value greater than one until a first condition is reached, coding a second flag for each of the transform coefficients that have an absolute value greater than two until a second condition is reached, determining a symbol for each of the remaining transform coefficients for which the first flag and the second flag were not coded, each symbol having an associated syntax element, providing a parameter variable, initially setting the parameter variable to a value of zero, converting each symbol into a binary codeword based on the value of the parameter variable, and updating the parameter variable after each symbol has been converted by setting the parameter variable to a new value, the new value being based at least in part on the value of the parameter variable preceding the updating and the syntax element of the most recently converted symbol, wherein each the binary codeword comprises a Truncated Rice portion having up to a predefined maximum number of bits. 
         [0019]    In another embodiment, a video processing system is provided that comprises a memory configured to store one or more transform coefficients each having a quantized value, a processor coupled with the memory, the processor being configured to code a first flag for each of the transform coefficients that have an absolute value greater than one until a first condition is reached, code a second flag for each of the transform coefficients that have an absolute value greater than two until a second condition is reached, obtain a symbol for each of the remaining transform coefficients for which the first flag and the second flag were not coded, each symbol having an associated syntax element, set a parameter variable to an initial value of zero, convert the symbol to the binary codeword based on the value of the parameter variable, and update the value of the parameter variable after the symbol has been converted, wherein the binary codeword comprises a Truncated Rice portion having up to a predefined maximum number of bits. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]    Further details of the present invention are explained with the help of the attached drawings in which: 
           [0021]      FIG. 1  depicts an embodiment of a content distribution system. 
           [0022]      FIG. 2  depicts an embodiment of an input image divided into Large Coding Units. 
           [0023]      FIG. 3  depicts an embodiment of a Large Coding Unit divided into Coding Units. 
           [0024]      FIG. 4  depicts a quadtree representation of a Large Coding Unit divided into Coding Units. 
           [0025]      FIG. 5  depicts possible exemplary arrangements of Prediction Units within a Coding Unit. 
           [0026]      FIG. 6  depicts a block diagram of an embodiment of a method for encoding and/or decoding a Prediction Unit. 
           [0027]      FIG. 7  depicts an exemplary embodiment of a Coding Unit divided into Prediction Units and Transform Units. 
           [0028]      FIG. 8  depicts an exemplary embodiment of a quadtree representation of a Coding Unit divided into Transform Units. 
           [0029]      FIG. 9  depicts an embodiment of a method of performing context-based adaptive binary arithmetic coding for transform coefficient encoding/decoding. 
           [0030]      FIG. 10  depicts an exemplary embodiment of a significance map. 
           [0031]      FIG. 11  depicts an embodiment of a method of obtaining coefficient levels and symbols for transform coefficients. 
           [0032]      FIG. 12  depicts exemplary embodiments of maximum symbol values for associated parameter variable values of 0, 1, 2, and 3. 
           [0033]      FIG. 13  depicts a first exemplary embodiment of a table for converting symbols into binary codewords based on parameter variable values of 0, 1, 2, and 3. 
           [0034]      FIG. 14  depicts a flowchart for a method for coding symbols and updating parameter variables. 
           [0035]      FIG. 15  depicts a first exemplary embodiment of a low complexity updating table with possible parameter variables values of 0, 1, 2, and 3. 
           [0036]      FIG. 16  depicts a first exemplary embodiment of maximum symbol values for associated parameter variable values of 0, 1, 2, 3, and 4. 
           [0037]      FIG. 17  depicts a first exemplary embodiment of a table for converting symbols into binary codewords based on parameter variable values of 0, 1, 2, 3, and 4. 
           [0038]      FIG. 18  depicts a second exemplary embodiment of maximum symbol values for associated parameter variable values of 0, 1, 2, 3, and 4. 
           [0039]      FIG. 19  depicts a second exemplary embodiment of a table for converting symbols into binary codewords based on parameter variable values of 0, 1, 2, 3, and 4. 
           [0040]      FIG. 20  depicts an alternate embodiment of a method of obtaining coefficient levels and symbols for transform coefficients. 
           [0041]      FIG. 21  depicts an alternate flowchart for a method for coding symbols and updating parameter variables. 
           [0042]      FIG. 22  depicts a first exemplary embodiment of a low complexity updating table with possible parameter variables values of 0, 1, 2, 3, and 4. 
           [0043]      FIG. 23  depicts a first exemplary embodiment of a combination logic representation of conditions for updating a parameter variable with possible parameter variables values of 0, 1, 2, 3, and 4. 
           [0044]      FIG. 24  depicts a second exemplary embodiment of a low complexity updating table with possible parameter variables values of 0, 1, 2, and 3. 
           [0045]      FIG. 25  depicts a second exemplary embodiment of a low complexity updating table with possible parameter variables values of 0, 1, 2, 3, and 4. 
           [0046]      FIG. 26  depicts a second exemplary embodiment of a combination logic representation of conditions for updating a parameter variable with possible parameter variables values of 0, 1, 2, 3, and 4. 
           [0047]      FIG. 27  depicts a third exemplary embodiment of a low complexity updating table with possible parameter variables values of 0, 1, 2, 3, and 4. 
           [0048]      FIG. 28  depicts a third exemplary embodiment of a combination logic representation of conditions for updating a parameter variable with possible parameter variables values of 0, 1, 2, 3, and 4. 
           [0049]      FIG. 29  depicts a fourth exemplary embodiment of a low complexity updating table with possible parameter variables values of 0, 1, 2, 3, and 4. 
           [0050]      FIG. 30  depicts a fourth exemplary embodiment of a combination logic representation of conditions for updating a parameter variable with possible parameter variables values of 0, 1, 2, 3, and 4. 
           [0051]      FIG. 31  depicts a fifth exemplary embodiment of a low complexity updating table with possible parameter variables values of 0, 1, 2, 3, and 4. 
           [0052]      FIG. 32  depicts a fifth exemplary embodiment of a combination logic representation of conditions for updating a parameter variable with possible parameter variables values of 0, 1, 2, 3, and 4. 
           [0053]      FIG. 33  depicts an exemplary embodiment of computer hardware. 
       
    
    
     DETAILED DESCRIPTION 
       [0054]    In HEVC, an input image, such as a video frame, is broken up into coding units (CUs) that are then identified in code. The CUs are then further broken into sub-units that are coded as will be described subsequently. 
         [0055]    Initially for the coding a quadtree data representation can be used to describe the partition of a large coding unit (LCU)  200 . The quadtree representation can have nodes corresponding to the LCU  200  and CUs  202 . At each node of the quadtree representation, a flag “ 1 ” can be assigned if the LCU  200  or CU  202  is split into four CUs  202 . If the node is not split into CUs  202 , a flag “ 0 ” can be assigned. By way of a non-limiting example, the quadtree representation shown in  FIG. 4  can describe the LCU partition shown in  FIG. 3 , in which the LCU  200  is split into four CUs  202 , and the second CU  202  is split into four smaller CUs  202 . The binary data representation of the quadtree can be a CU split flag that can be coded and transmitted as overhead, along with other data such as a skip mode flag, merge mode flag, and the PU coding mode described subsequently. By way of a non-limiting example, the CU split flag quadtree representation shown in  FIG. 4  can be coded as the binary data representation “10100.” 
         [0056]    At each leaf of the quadtree, the final CUs  202  can be broken up into one or more blocks called prediction units (PUs)  204 . PUs  204  can be square or rectangular. A CU  202  with dimensions of 2N×2N can have one of the four exemplary arrangements of PUs  204  shown in  FIG. 5 , with PUs  204  having dimensions of 2N×2N, 2N×N, N×2N, or N×N. 
         [0057]    A PU can be obtained through spatial or temporal prediction. Temporal prediction is related to inter mode pictures. Spatial prediction relates to intra mode pictures. The PUs  204  of each CU  202  can, thus, be coded in either intra mode or inter mode. Features of coding relating to intra mode and inter mode pictures are described in the paragraphs to follow. 
         [0058]    Intra mode coding can use data from the current input image, without referring to other images, to code an I picture. In intra mode the PUs  204  can be spatially predictive coded. Each PU  204  of a CU  202  can have its own spatial prediction direction. Spatial prediction directions can be horizontal, vertical, 45-degree diagonal, 135 degree diagonal, DC, planar, or any other direction. The spatial prediction direction for the PU  204  can be coded as a syntax element. In some embodiments, brightness information (Luma) and color information (Chroma) for the PU  204  can be predicted separately. In some embodiments, the number of Luma intra prediction modes for 4×4, 8×8, 16×16, 32×32, and 64×64 blocks can be 18, 35, 35, 35, and 4 respectively. In alternate embodiments, the number of Luma intra prediction modes for blocks of any size can be 35. An additional mode can be used for the Chroma intra prediction mode. In some embodiments, the Chroma prediction mode can be called “IntraFromLuma.” 
         [0059]    Inter mode coding can use data from the current input image and one or more reference images to code “P” pictures and/or “B” pictures. In some situations and/or embodiments, inter mode coding can result in higher compression than intra mode coding. In inter mode PUs  204  can be temporally predictive coded, such that each PU  204  of the CU  202  can have one or more motion vectors and one or more associated reference images. Temporal prediction can be performed through a motion estimation operation that searches for a best match prediction for the PU  204  over the associated reference images. The best match prediction can be described by the motion vectors and associated reference images. P pictures use data from the current input image and one or more previous reference images. B pictures use data from the current input image and both previous and subsequent reference images, and can have up to two motion vectors. The motion vectors and reference pictures can be coded in the HEVC bitstream. In some embodiments, the motion vectors can be coded as syntax elements “MV,” and the reference pictures can be coded as syntax elements “refldx.” In some embodiments, inter mode coding can allow both spatial and temporal predictive coding. 
         [0060]      FIG. 6  depicts a block diagram of how a PU  204 , x, can be encoded and/or decoded. At  606  a predicted PU  206 , x′, that is predicted by intra mode at  602  or inter mode at  604 , as described above, can be subtracted from the current PU  204 , x, to obtain a residual PU  208 , e. At  608  the residual PU  208 , e, can be transformed with a block transform into one or more transform units (TUs)  210 , E. Each TU  210  can comprise one or more transform coefficients  212 . In some embodiments, the block transform can be square. In alternate embodiments, the block transform can be non-square. 
         [0061]    As shown in  FIG. 7 , in HEVC, a set of block transforms of different sizes can be performed on a CU  202 , such that some PUs  204  can be divided into smaller TUs  210  and other PUs  204  can have TUs  210  the same size as the PU  204 . Division of CUs  202  and PUs  204  into TUs  210  can be shown by a quadtree representation. By way of a non-limiting example, the quadtree representation shown in  FIG. 8  depicts the arrangement of TUs  210  within the CU  202  shown in  FIG. 7 . 
         [0062]    Referring back to  FIG. 6 , at  610  the transform coefficients  212  of the TU  210 , E, can be quantized into one of a finite number of possible values. In some embodiments, this is a lossy operation in which data lost by quantization may not be recoverable. After the transform coefficients  212  have been quantized, at  612  the quantized transform coefficients  212  can be entropy coded, as discussed below, to obtain the final compression bits  214 . 
         [0063]    At  614  the quantized transform coefficients  212  can be dequantized into dequantized transform coefficients  216  E′. At  616  the dequantized transform coefficients  216  E′ can then be inverse transformed to reconstruct the residual PU  218 , e′. At  618  the reconstructed residual PU  218 , e′, can then be added to a corresponding prediction PU  206 , x′, obtained through either spatial prediction at  602  or temporal prediction at  604 , to obtain a reconstructed PU  220 , x″. At  620  a deblocking filter can be used on reconstructed PUs  220 , x″, to reduce blocking artifacts. At  620  a sample adaptive offset process is also provided that can be conditionally performed to compensate the pixel value offset between reconstructed pixels and original pixels. Further, at  620 , an adaptive loop filter can be conditionally used on the reconstructed PUs  220 , x″, to reduce or minimize coding distortion between input and output images. 
         [0064]    If the reconstructed image is a reference image that will be used for future temporal prediction in inter mode coding, the reconstructed images can be stored in a reference buffer  622 . Intra mode coded images can be a possible point where decoding can begin without needing additional reconstructed images. 
         [0065]    HEVC can use entropy coding schemes during step  612  such as context-based adaptive binary arithmetic coding (CABAC). The coding process for CABAC is shown in  FIG. 9 . At  902 , the position of the last significant transform coefficient of the transform units  210  can be coded. Referring back to  FIG. 6 , the quantized transform coefficients are created by quantizing the TUs  210 . Transform coefficients  212  can be significant or insignificant.  FIG. 10  shows a significance map  1002  of the transform coefficients  212 . Insignificant transform coefficients  212  can have a quantized value of zero, while significant transform coefficients  212  can have a quantized value that is a positive or negative non-zero value. In some embodiments, significant transform coefficients  212  can also be known as non-zero quantized transform coefficients  212 . If a TU  210  comprises one or more significant transform coefficients  212 , the coordinates of the last significant transform coefficient  212  along a forward zig-zag coding scan from the top left corner of the TU  210  to the lower right corner of the TU  210 , as shown in  FIG. 10 , can be coded. In alternate embodiments, the significant transform coefficients  212  can be scanned along an inverse wavefront scan, inverse horizontal scan, inverse vertical scan, or any other scan order. In some embodiments, these coordinates can be coded as the syntax elements “last_significant_coeff_y” and “last_significant_coeff_x.” By way of a non-limiting example,  FIG. 10  depicts the position of the last significant transform  212   b  within a TU  210  which is being coded in block  902  of  FIG. 9 . 
         [0066]    At block  904  in  FIG. 9 , the significance map  1002  can be coded to indicate the positions of each of the significant transform coefficients  212  in the TU  210 . A significance map  1002  can comprise a binary element for each position in the TU  210 . The binary element can be coded as “0” to indicate that the transform coefficient  212  at that position is not significant. The binary element can be coded as “1” to indicate that the transform coefficient  212  at that position is significant. 
         [0067]    The quantized transform coefficients  212  of the TUs  210  can be divided into groups. In some embodiments, the groups can be square blocks of quantized transform coefficients  212  called sub-blocks. The sub-blocks within a TU  210  can be subdivisions of any desired size, such as 4×4 block of 16 quantized transform coefficients  212 . By way of non-limiting examples: an 8×8 TU  210  having 64 quantized transform coefficients  212  can be divided into four 4×4 sub-blocks each having 16 quantized transform coefficients  212 ; a 16×16 TU  210  having 256 quantized transform coefficients  212  can be divided into 16 4×4 sub-blocks each having 16 quantized transform coefficients  212 ; and a 32×32 TU  210  having 1024 quantized transform coefficients  212  can be divided into 64 4×4 sub-blocks each having 16 quantized transform coefficients  212 . In other embodiments, the groups can be subsets. Subsets can comprise 16 quantized transform coefficients  212  that are consecutive along a backwards zig-zag scan. In alternate embodiments, groups can comprise any number of quantized transform coefficients  212  from a TU  210  in any scan order and/or shape. 
         [0068]    Referring back to  FIG. 9  in the last block  906 , each quantized transform coefficient  212  in each group within the TU  210  can be coded into binary values to obtain final compression bits  214  shown in  FIG. 6 , including coding for significant coefficient levels. The absolute value of each quantized transform coefficient  212  can be coded separately from the sign of the quantized transform coefficient  212 .  FIG. 11  illustrates coding steps that deal with taking an absolute value of the quantized transform coefficients. As shown in  FIG. 11 , at  1102  the absolute value of each quantized transform coefficient  212  can be taken to enable obtaining the coefficient level  222  for that quantized transform coefficient  212  at block  1104 . In some embodiments, the positive or negative sign of non-zero coefficient levels  222  can be coded separately. 
         [0069]    The coefficient levels  222  obtained at block  1104  that are expected to occur with a higher frequency can be coded before coefficient levels  222  that are expected to occur with lower frequencies. By way of a non-limiting example, in some embodiments coefficient levels  222  of 0, 1, or 2 can be expected to occur most frequently. Coding the coefficient levels  222  in three parts can identify the most frequently occurring coefficient levels  222 , leaving more complex calculations for the coefficient levels  222  that can be expected to occur less frequently. In some embodiments, this can be done by coding the coefficient levels  222  in three parts. First, the coefficient level  222  of a quantized transform coefficient  212  can be checked to determine whether it is greater than one. If the coefficient level  222  is greater than one, the coefficient level  222  can be checked to determine whether it is greater than two. 
         [0070]    At  1106  in  FIG. 11 , if the coefficient level  222  is greater than two, the coefficient level  222  can be subtracted by a threshold value  224  of three to obtain a symbol  226 . By way of a non-limiting example, in some embodiments, the coefficient level  222  can be coded as three variables: “coeff_abs_level_greater1_flag,” “coeff_abs_level_greater2_flag,” and “coeff_abs_level_minus3.” For quantized transform coefficients  212  with a coefficient level  222  of two or more, “coeff_abs_level_greater_flag” can be set to “1.” If “coeff_abs_level_greater1_flag” is set to “1” and the quantized transform coefficient  212  also has a coefficient level  222  of three or more, “coeff_abs_level_greater2_flag” can be set to “1.” If “coeff_abs_level_greater2_flag” is set to “1,” the threshold value  224  of three can be subtracted from the coefficient level  222  to get the quantized transform coefficient&#39;s symbol  226 , coded as “coeff_abs_level_minus3.” In alternate embodiments, the coefficient level  222  can be coded in a different number of parts, and/or the threshold value  224  can be an integer other than three. 
         [0071]    For the quantized transform coefficients  212  that occur less frequently and have coefficient levels  222  of three or more as determined in the blocks of  FIG. 11 , the quantized transform coefficient&#39;s symbol  226  can be converted to a binary codeword  228  that can be part of the final compression bits  214  generated as shown in  FIG. 6 . The conversion to a binary codeword  228  can be performed with Truncated Rice code alone, or with a combination of Truncated Rice code and exponential-Golomb (Exp-Golomb) code. The Truncated Rice code can obtain a binary codeword  228  based a parameter variable  230  and the symbol  226 . Each symbol  226  can be coded by scanning through each sub-block, subset, or other group within a TU and converting each symbol  226  of the group in order according to the value of the parameter variable  230 , and then moving to the symbols  226  of the next group. In some embodiments, the current scanning position can be denoted by “n.” 
         [0072]    Referring to  FIG. 12  and subsequent figures, the parameter variable  230  can be a global variable that can be updated as each symbol  226  is coded. The parameter variable  230  can control the flatness of the codeword distribution. In some embodiments, the parameter variable  230  can be any integer between 0 and N. By way of a non-limiting example, in some embodiments N can be 3, such that the parameter variable  230  can be 0, 1, 2, or 3. In some embodiments, the parameter variable  230  can be denoted as “cRiceParam” as illustrated in  FIG. 12  as well as  FIG. 13  and subsequent figures. 
         [0073]    Referring still to  FIG. 12 , each parameter variable  230  can have an associated maximum symbol value  232  that denotes the truncation point for the Truncated Rice code. In some embodiments, the maximum symbol value  232  for a particular parameter variable  230  can be denoted as “cTRMax”  232 , as illustrated in  FIG. 12  which depicts an exemplary table of maximum symbol values  232  “cTRMax” for each value of the parameter variable  230  “cRiceParam.” The table of  FIG. 12  is labeled as Table 1, as it provides a first listing of values for the cRiceParam parameter variable  230  relative to the cTRMax maximum value symbols  232 . If the symbol  226  is less than or equal to the maximum symbol value  232  for the current value of the parameter variable  230 , the symbol  226  can be converted into a binary codeword  228  using only Truncated Rice code. If the symbol  226  is greater than the maximum symbol value  232  for the current value of the parameter variable  230 , the binary codeword  228  can be generated using a combination of the Truncated Rice code and Exp-Golomb code, with the Truncated Rice codeword for the maximum symbol value  232  being concatenated with the Exp-Golomb code for the symbol  226  minus the maximum symbol value  232  minus one. By way of a non-limiting example,  FIG. 13  depicts an exemplary table of binary codewords  228  generated based on symbols  226  and parameter variables  230 . Since  FIG. 13  provides a second table listing cRiceParam parameter variables  230  relative to other values, it is labeled as Table 2. 
         [0074]    In some situations and/or embodiments, converting the symbol  226  according to Truncated Rice code with a lower value for the parameter variable  230  can result in a binary codeword  228  having fewer bits than converting the same symbol  226  according to Truncated Rice code with a higher value for the parameter variable  230 . By way of a non-limiting example, as shown by the table depicted in  FIG. 13 , using a parameter variable  230  value of 0 to convert a symbol  226  of 0 can result in the binary codeword  228  of “0” having 1 bit, while using the parameter variable  230  value of 1 to convert the symbol  226  of 0 can result in the binary codeword  228  of “00” having 2 bits. 
         [0075]    In other situations and/or embodiments, converting the symbol  226  according to Truncated Rice code with a higher value for the parameter variable  230  can result in a binary codeword  228  having fewer bits than converting the same symbol  226  according to Truncated Rice code with a lower value for the parameter variable  230 . By way of a non-limiting example, as shown in the table depicted in  FIG. 13 , using a parameter variable  230  value of 0 to convert a symbol  226  of 6 can result in the binary codeword  228  of “1111110” having 7 bits, while using the parameter variable  230  value of 2 to convert the symbol  226  of 6 can result in the binary codeword  228  of “1010” having 4 bits. 
         [0076]    Generally referring to  FIG. 13 , Truncated Rice code with a smaller cRiceParam parameter value  230  can be preferred to code the symbols with smaller codewords, as they need fewer bits to represent. For example, if a symbol  226  has a value of 0, using Truncated Rice code with a cRiceParam parameter value  230  equal to 0, only 1 bit is needed, but 2, 3, or 4 bits are needed when the cRiceParam value is 1, 2, or 3, respectively. If a symbol has a value of 6, using Truncated Rice code with a cRiceParam value equal to 0, 7 bits are needed. But 5, 4, or 4 bits are needed when the cRiceParam value is 1, 2, or 3, respectively. 
         [0077]      FIG. 14  is a flow chart depicting a method for entropy coding the symbols  226 . At  1402 , for each TU  210 , the parameter variable  230  can be initially set to a value of zero. At  1404  the coding system  110  can move to the next symbol  226 . In some situations and/or embodiments, the next symbol  226  can be the first symbol  226  in the first sub-block, subset, or other group within the TU. At  1406 , the symbol  226  can be coded with Truncated Rice and/or Exp-Golomb code using the current value of the parameter variable  230 . At  1408 , the value of the parameter variable  230  can be updated based on the last value of the parameter variable  230  and the value of the last symbol  226  that was coded. In some situations and/or embodiments, the updated value of the parameter variable  230  can be the same as the last value of the parameter variable  230 . In other situations and/or embodiments, the updated value of the parameter variable  230  can be greater than the last value of the parameter variable  230 . The parameter variable  230  can be updated based upon calculations or upon values derived from a table as described herein subsequently. 
         [0078]    At  1410 , after the parameter variable  230  has been updated at  1408 , if any symbols  226  remain uncoded in the sub-block, subset, or other group, the coding system  110  can return to  1404  and move to the next symbol  226  in the group. The next symbol  226  can then be coded at  1406  using the updated value of the parameter variable  230  and the process can repeat for all remaining symbols  226  in the group. If no symbols  226  remain uncoded in the group at  1410 , the coding system  110  can move to the next group at  1412 , return to  1402  and reset the parameter variable  230  to zero, and repeat the process to code the symbols  226  in the next group. In some embodiments, the parameter variable cRiceParam  230  can be reset once per group with an initial “0” value. For a TU with more than one group of quantized transform coefficients  212 , the cRiceParam parameter variable  230  for coeff_abs_level_minus3 symbols  226  can be reset to 0 for each group, which can favor smaller symbol value coding. In other embodiments, the cRiceParam parameter variable  230  can be reset to 0 for each TU and/or each subset, sub-block, or other group of transform coefficients  212 . In still other embodiments, the step of resetting to the parameter variable  230  to zero can be omitted. 
         [0079]    Referring to  FIG. 15  and subsequent figures, the cRiceParam parameter variable  230  can be derived and updated based on a table  1504  as follows. In some embodiments, the parameter variable  230  can be updated by performing a table lookup from a low complexity update table  1504  based on the last value of the parameter variable  230  and the value of the last coded symbol  226 . For a TU sub-block or other group, the cRiceParam  230  can be initially set to 0, and can be updated for each symbol  226  in the group based on the previous value of the parameter variable  230  “cRiceParam” and the value of the symbol  226  “coeff_abs_level_minus3[n−]” according a table, for example the table shown in  FIG. 15 . Because  FIG. 15  shows a third table listing symbol values  226  relative to cRiceParam parameter values  230 , the table is labeled as Table 3. 
         [0080]    Tables 1-3, shown in  FIGS. 12 ,  13 , and  15 , can be used to update the value of the parameter variable  230  as each symbol is scanned and converted into a binary codeword  228 . The Truncated Rice portions of the binary codewords  228  generated with these tables can have a size of up to 12 bits, as can be seen from  FIG. 13 . Because each codeword can potentially have 12 bits, it can take 2 bytes of eight bits each to store each codeword in memory. The total memory needed to store the codewords of Table 2, as shown in  FIG. 12 , would be 294 bytes, based on: 18 bytes used to store the 9 codewords associated with the cRiceParam parameter variable  230  value of 0 in the first column; 44 bytes used to store the 22 codewords associated with the cRiceParam parameter variable  230  value of 1 in the second column; 88 bytes used to store the 44 codewords associated with the cRiceParam parameter variable  230  value of 2 in the third column; and 144 bytes used to store the 72 codewords associated with the cRiceParam parameter variable  230  value of 3 in the fourth column. 
         [0081]    Referring to  FIG. 16  and subsequent figures, in other embodiments binary codewords having a predefined maximum number of bits for the Truncated Rice portion of a codeword  228  can be used to preserve memory space. By way of a non-limiting example, the predefined maximum number of bits for the Truncated Rice portion of the codeword  228  can be set at 8 bits, thereby allowing the Truncated Rice portion of the codeword  228  to be stored in a single byte of 8 bits. In some embodiments, different predefined maximum numbers of bits can be set for codewords  228  that have only a Truncated Rice portion and for codewords  228  that have both Truncated Rice portions and Exp-Golomb portions. By way of a non-limiting example, in some embodiments codewords  228  that have only a Truncated Rice portion can have a maximum of 8 bits; while codewords  228  that have a Truncated Rice portion concatenated with an Exp-Golomb portion can have their Truncated Rice portion capped at 4 bits. The predefined maximum number of bits for the Truncated Rice portion of the codeword  228  can be 8 bits, 7 bits, 5 bits, 4 bits, 3 bits, or any other desired number of bits. 
         [0082]    In some embodiments, generating codewords  228  with a Truncated Rice portion having a predefined maximum number of bits can be achieved by allowing one or more additional values for the “cRiceParam” parameter variable  230  beyond the values listed in Table 1. As stated above, the parameter variable  230  can be any integer between 0 and N. By way of a non-limiting example, in some embodiments N can be 4, such that the parameter variable  230  can be 0, 1, 2, 3, or 4. 
         [0083]    Table 4, as shown in  FIG. 16 , depicts an exemplary table of parameter variables  230  values in relation to their maximum symbol values  232 . In this embodiment, by using maximum symbol values  232  equal to or lower than those shown in Table 1 in combination with an extra possible parameter variable  230  value of 4, the truncation points for the Truncated Rice code can be such that the Truncated Rice portion of the codewords  228  have a maximum of 8 bits. Table 5, as shown in  FIG. 17 , depicts a table of the codewords  228  generated using the maximum symbol values  232  of Table 4. Table 5 includes an additional column when compared to Table 2 due to the inclusion of the additional parameter variable value of 4, as seen in Table 4. 
         [0084]    As can be seen from Table 5, the Truncated Rice portions of the codewords  228  can have eight or fewer bits, such that the Truncated Rice portion can be stored in a single byte. By way of non-limiting examples, as shown in Table 5 in  FIG. 17 , the codeword for a symbol of “4” using a parameter variable value of “0” is “11110,” a 5 bit codeword having only a Truncated Rice portion less than 8 bits. By way of another non-limiting example, the codeword for a symbol of “8” using a parameter variable value of “0” is “11111111, EG0,” a 9 bit codeword having a Truncated Rice portion and an Exp-Golomb portion in which the Truncated Rice portion has the maximum 8 bits. 
         [0085]    In comparison with the 294 bytes needed to store to the Truncated Rice components of the codewords of Table 2, the total memory needed to store the Truncated Rice portions of the codewords of Table 5 is a smaller 181 bytes. Table 5 can be stored in 181 bytes based on: 9 bytes used to store the 9 codewords associated with the cRiceParam parameter variable  230  value of 0 in the first column; 16 bytes used to store the 16 codewords associated with the cRiceParam parameter variable  230  value of 1 in the second column; 28 bytes used to store the 28 codewords associated with the cRiceParam parameter variable 230 value of  2  in the third column; 48 bytes used to store the 48 codewords associated with the cRiceParam parameter variable  230  value of 3 in the fourth column; and 80 bytes used to store the 80 codewords associated with the cRiceParam parameter variable  230  value of 4 in the fifth column. 
         [0086]    As discussed above, in some embodiments a first predefined maximum number of bits can be set for those codewords  228  that have only a Truncated Rice portion, and a second predefined maximum number of bits can be set for those codewords  228  that have only a Truncated Rice portion. Tables 6 and 7 illustrate a non-limiting example in which the predefined maximum number of bits for codewords  228  having only a Truncated Rice portion can be 8 bits, and the predefined number of bits for the Truncated Rice portion of codewords that have the Truncated Rice portion concatenated with an Exp-Golomb portion can be 3 bits. Table 6, as shown in  FIG. 18 , depicts an exemplary table of parameter variables  230  values in relation to their maximum symbol values  232 . Table 7, as shown in  FIG. 19 , depicts a table of the codewords  228  generated using the maximum symbol values  232  of Table 6. In some embodiments a symbol  226  that is less than the maximum symbol value  232  for a particular value of the parameter variable  230  can be converted into a codeword  228  that has only a Truncated Rice portion, and a symbol  226  that is equal to or exceeds the maximum symbol value  232  for that particular value of the parameter variable  230  can be converted into a codeword having both a Truncated Rice portion and an Exp-Golomb portion. In Table 7, codewords  228  having only a Truncated Rice portion do not include a comma, while codewords  228  that have both Truncated Rice and Exp-Golomb portions are shown with the Truncated Rice portion to the left of the comma and the Exp-Golomb portion to the right of the comma. As can be seen from Table 7, the codewords  228  having only Truncated Rice portions have less than the first predefined maximum number of 8 bits, while the codewords  288  having both Truncated Rice and Exp-Golomb portions have the Truncated Rice portion set to “111,” equal to the second predefined maximum number of 3 bits. 
         [0087]      FIG. 20  depicts Table 8, an exemplary embodiment of an updating table  1504  that can be used to generate codewords  228  using the possible values of 0, 1, 2, 3, or 4 for the parameter variable  230 . In some embodiments, referring back to  FIG. 14 , the updating of the parameter variable  230  at  1408  can be determined from a comparison equation  1506  rather than looking up the new value for the parameter variable  230  from a table such as Table 8. In the comparison equation  1506 , it can be determined whether both the last value of the parameter variable  230  and the value of the last coded symbol  226  meet one or more conditions  1502 , as illustrated in  FIG. 21 . In some embodiments, the value of the last coded symbol  226  can be denoted as “coeff_abs_level_minus3[n−]” as it was in Tables 3 and 8. In other embodiments, the value of the last coded symbol  226  can be denoted as “cLastSE” or by any other desired name. The parameter variable  230  can be updated depending on which conditions  1502  are met, and the value of the current symbol  226  can then be coded based on the updated parameter variable  230  using Truncated Rice code and/or Exp-Golomb Code, for example using a table such as Tables 2, 5, or 7. 
         [0088]    In some embodiments, each condition  1502  can comprise two parts, a conditional symbol threshold and a conditional parameter threshold. In these embodiments, the condition  1502  can be met if the value of the symbol  226  is equal to or greater than the conditional symbol threshold and the parameter variable  230  is equal to or greater than the conditional parameter threshold. In alternate embodiments, each condition  1502  can have any number of parts or have any type of condition for either or both the symbol  226  and parameter variable  230 . In some embodiments, the parameter variable  230  can be incremented by one for each condition  1502  that is met. By way of a non-limiting example, an integer of one can be mathematically added to the previous value of the parameter variable  230  for each condition that is satisfied. 
         [0089]    Because an updating table, such as Table 8 shown in  FIG. 20 , can need memory space to store and fetch its data and can require processor cycles to access and use, combination logic such as the comparison equation  1506  of  FIG. 21  can be used perform the comparison in place of an updating table  1504 , as in some embodiments the combination logic can use fewer processor cycles and/or take less memory space. An example of the combination logic representation that determines the updated cRiceParam parameter variable  230  in the place of Table 8 is shown in  FIG. 21 . 
         [0090]      FIG. 22  depicts an alternate embodiment of a method for CABAC coding that depicts steps for processing transform coefficients  212 , similar to that of  FIG. 11 . At step  2202 , the level  222  of the transform coefficients  212  in a subset, sub-block, or other group can be obtained by taking the absolute value of the transform coefficient  212 , similar to steps  1102  and  1104 . At step  2204 , the flags “coeff_abs_level_greater1_flag” and “coeff_abs_level_greater2_flag” can be coded for non-zero coefficients  212  along the beginning of a scan order only until a stopping condition is reached. By way of non-limiting examples, in one scheme the “coeff_abs_level_greater1_flag” can be coded for each quantized transform coefficient  212  in the sub-block, subset, or other group until two quantized transform coefficients  212  having a level  222  greater than 1 are encountered within the group; and the “coeff_abs_level_greater2_flag” can be coded only for the first quantized transform coefficient  212  having a level  222  greater than two and the “coeff_abs_level_greater1_flag” set to “1” in the group. In another scheme, the “coeff_abs_level_greater1_flag” can be coded for the first N quantized transform coefficients  212  having a non-zero absolute value in the sub-block, subset, or other group; and the “coeff_abs_level_greater2_flag” can be coded only for the first quantized transform coefficient  212  having an absolute value greater than 2 and the “coeff_abs_level_greater1_flag” set to “1” in the group. In other schemes, the stopping condition can be set to be any other condition. In some embodiments, the throughput of the CABAC coefficient level coding can be improved by coding these flags until a stopping condition, instead of coding the flags for all transform coefficients  212  in a group, as in the embodiment shown in  FIG. 11 . 
         [0091]    At  2206 , a threshold value  224  can be subtracted from the remaining non-zero quantized transform coefficients  212  to obtain a symbol  226 . In these embodiments, the symbol  226  can be denoted as “coeff_abs_level_remaining ” By way of non-limiting examples, in some embodiments a threshold value  224  of “3” can be subtracted, such that the “coeff_abs_level_remaining” symbol  226  is “coeff_abs_level_minus3,” as discussed above with respect to step  1106 . In other embodiments, a threshold value of “2” can be subtracted such that the “coeff_abs_level_remaining” symbol  226  is “coeff_abs_level_minus2,” or a threshold value of “1” can be subtracted such that the “coeff_abs_level_remaining” symbol  226  is “coeff_abs_level_minus1.” 
         [0092]    After the stopping condition has been reached, the remaining symbols  226  “coeff_abs_level_remaining” in the subset, sub-block, or other group can be converted into binary codewords  228  using the steps shown in  FIG. 14  and/or  FIG. 23 . The conversion of the symbols  226  “coeff_abs_level_remaining” can be based in part on the value of a parameter variable  230  that is updated using a table  1504  or combination logic comparison equation  1506 , as discussed above. As shown in  FIG. 23 , in some embodiments, the value of the parameter variable  230  can be updated according to a syntax element  234  of the last symbol  226  to be converted into a codeword  228  prior to updating the value of the parameter variable  230 . The last syntax element  234  can in some embodiments be denoted as “cLastSE.” In some embodiments, the last syntax element  234  “cLastSE” can be the level  222  of the transform coefficient  212 , for example the absolute value of the transform coefficient  212 . In other embodiments, the last syntax element  234  “cLastSE” can itself be the symbol  226 , for example coeff_abs_level_remaining, coeff_abs_level_minus3, coeff_abs_level_minus2, or coeff_abs_level_minus1. 
         [0093]    At  2302 , the “cRiceParam” parameter variable  230  can be set to an initial value of zero for the subset, sub-block, or other group. At  2304 , the first and/or next symbol  226  on a scan order can be processed. At  2306 , that symbol  226  can be converted into a binary codeword  228  using Trancated Rice and/or Exponential Golomb, according to the value of the parameter variable  230 . For example, the symbol  226  can be converted into a codeword  228  using Tables 2, 5, or 7. 
         [0094]    At  2308 , after each symbol  226  is coded, the value of the “cRiceParam” parameter variable  230  can be updated, based on the value of the parameter variable  230  before the updating, and the value of the syntax element  234  “cLastSE” for the most recently converted symbol  226 . As discussed above, in some embodiments the “cLastSE” last syntax element  234  can be the same as the symbol  226 , while in other embodiments the “cLastSE” last syntax element  234  can be the “coeff_abs_level_remaining” value. By way of a non-limiting example, Table 9, as shown in  FIG. 24 , can be used to update the value of the “cRiceParam” parameter variable  230  using the value of the “cLastSE” last syntax element  234  and the updated value of the parameter variable  230 . If any remaining uncoded symbols in the subset, sub-block, or other group are found at step  2310 , the system can return to  2304 , move to the next symbol  226  in the scan order, and then code that symbol  226  at  2803  according to the updated value of the parameter variable  230  and the value of the “cLastSE” last syntax element  234 . The process can continue until the system moves to the next group of transform coefficients  212  at  2310 , at which time the system returns to step  2302  and the value of the “cRiceParam” variable can be reset to zero. In other embodiments, the cRiceParam parameter variable  230  can be reset to  0  for each TU and/or each subset, sub-block, or other group of transform coefficients  212 . In still other embodiments, the step of resetting to the parameter variable  230  to zero can be omitted. 
         [0095]    The techniques of coding “coeff_abs_level_greater1_flag” and “coeff_abs_level_greater2_flag” only for non-zero coefficients along the beginning of the scan order until a stopping condition is reached, as shown in  FIG. 22 , and converting the remaining “coeff_abs_level_remaining” symbols  226  into binary codewords  228  as shown in  FIG. 23 , can be combined with the technique of increasing the number of possible values for the parameter variable  230 , as shown in  FIGS. 16-19 , so that codewords  228  with a predefined maximum number of bits are used. In some embodiments, the combination of these techniques can offer faster and/or more efficient CABAC coding and/or decoding during step  612 . 
         [0096]    As discussed above tables  1504  and/or combination logic comparison equations  1506  can be used to update the value of the “cRiceParam” parameter variable  230 . By way of a non-limiting example,  FIG. 25  depicts Table 10, a first exemplary embodiment of an updating table  1504  that can be used to update the value of the parameter variable  230  using the “cLastSE” last syntax element  234 , and  FIG. 26  depicts a combination logic representation that can be used to update the value of the parameter variable  230  in the place of Table 10. In  FIG. 26 , the conditional symbol thresholds are set to be equal to or greater than 3, 6, 12, and 24, and the conditional parameter thresholds are respectively set to be equal to zero and equal to or less than 1, 2, and 3. 
         [0097]    As additional non-limiting examples,  FIG. 27  depicts Table 11, a second exemplary embodiment of an updating table  1504  that can be used to update the value of the parameter variable  230  when the two techniques are used in combination, and  FIG. 28  depicts a combination logic representation that can be used to update the value of the parameter variable  230  in the place of Table 11.  FIG. 29  depicts Table 12, a third exemplary embodiment of an updating table  1504  that can be used to update the value of the parameter variable  230  when the two techniques are used in combination, and  FIG. 30  depicts a combination logic representation that can be used to update the value of the parameter variable  230  in the place of Table 12.  FIG. 31  depicts Table 13, a fourth exemplary embodiment of an updating table  1504  that can be used to update the value of the parameter variable  230  when these two techniques are used in combination, and  FIG. 32  depicts a combination logic representation that can be used to update the value of the parameter variable  230  in the place of Table 13. Further, it should be noted that although some previous figures, such as Table 3 shown in  FIG. 15 , Table 8 shown in  FIG. 20 , and the comparison equation  1506  shown in  FIG. 21 , were shown using the symbol  226  “coeff_abs_level_minus3,” in some embodiments they can alternately use the last syntax element  234  “cLastSE” in the place of the symbol  226  to update the value of the parameter variable  230 . 
         [0098]    Although the conversion process has been described in detail above, a specific non-limiting example will now be provided in which “coeff_abs_level_remaining” symbols  226  can be converted into binary codewords  228  using Table 7 shown in  FIG. 19 , and the value of the “cRiceParam” parameter variable  230  can be updated using Table 13 shown in  FIG. 29 . In this example, the parameter variable  230  can initially be set at a value of zero. A transform coefficient  212  with a “coeff_abs_level_remaining” symbol  226  value of 4 can be converted according to Table 7 into the codeword 111,100, which has a Truncated Rice portion “ 111 ” having three bits. Table 13 can then be used to update the value of the “cRiceParam” parameter variable  230 , based on the “cLastSE” last syntax element  234  value of the most recently converted symbol  226 . In this example, the “cLastSE” last syntax element  234  can be set as the symbol  226 , so the “cLastSE” last syntax element  234  can have a value of “4.” Following these values, the parameter variable  230  can be updated from “0,” the value preceding the updating, to a value of “1,” as can be seen from Table 13. In this example, the next “coeff_abs_level_remaining” symbol  226  can have a value of 10, which can be converted into a codeword of “111,1010” using Table 7 with the updated “cRiceParam” parameter variable  230  value of “1.” The symbol&#39;s “cLastSE” last syntax element  234  value of “10” can be used to update the “cRiceParam” parameter variable  230  from “1” to “2” according to Table 13. This process can continue for all remaining “coeff_abs_level_remaining” symbols  226  in the subset, sub-block, or other group of transform coefficients  212 . In other embodiments, a combination logic comparison equation  1506  can be used in place of the table to update the value of the parameter variable  230 . 
         [0099]    The execution of the sequences of instructions required to practice the embodiments may be performed by a computer system  3300  as shown in  FIG. 33 . In an embodiment, execution of the sequences of instructions is performed by a single computer system  3300 . According to other embodiments, two or more computer systems  3300  coupled by a communication link  3315  may perform the sequence of instructions in coordination with one another. Although a description of only one computer system  3300  may be presented herein, it should be understood that any number of computer systems  3300  may be employed. 
         [0100]    A computer system  3300  according to an embodiment will now be described with reference to  FIG. 33 , which is a block diagram of the functional components of a computer system  3300 . As used herein, the term computer system  3300  is broadly used to describe any computing device that can store and independently run one or more programs. 
         [0101]    The computer system  3300  may include a communication interface  3314  coupled to the bus  3306 . The communication interface  3314  provides two-way communication between computer systems  3300 . The communication interface  3314  of a respective computer system  3300  transmits and receives electrical, electromagnetic or optical signals, that include data streams representing various types of signal information, e.g., instructions, messages and data. A communication link  3315  links one computer system  3300  with another computer system  3300 . For example, the communication link  3315  may be a LAN, an integrated services digital network (ISDN) card, a modem, or the Internet. 
         [0102]    A computer system  3300  may transmit and receive messages, data, and instructions, including programs, i.e., application, code, through its respective communication link  3315  and communication interface  3314 . Received program code may be executed by the respective processor(s)  3307  as it is received, and/or stored in the storage device  3310 , or other associated non-volatile media, for later execution. 
         [0103]    In an embodiment, the computer system  3300  operates in conjunction with a data storage system  3331 , e.g., a data storage system  3331  that contains a database  3332  that is readily accessible by the computer system  3300 . The computer system  3300  communicates with the data storage system  3331  through a data interface  3333 . 
         [0104]    Computer system  3300  can include a bus  3306  or other communication mechanism for communicating the instructions, messages and data, collectively, information, and one or more processors  3307  coupled with the bus  3306  for processing information. Computer system  3300  also includes a main memory  3308 , such as a random access memory (RAM) or other dynamic storage device, coupled to the bus  3306  for storing dynamic data and instructions to be executed by the processor(s)  3307 . The computer system  3300  may further include a read only memory (ROM)  3309  or other static storage device coupled to the bus  3306  for storing static data and instructions for the processor(s)  3307 . A storage device  3310 , such as a magnetic disk or optical disk, may also be provided and coupled to the bus  3306  for storing data and instructions for the processor(s)  3307 . 
         [0105]    A computer system  3300  may be coupled via the bus  3306  to a display device  3311 , such as an LCD screen. An input device  3312 , e.g., alphanumeric and other keys, is coupled to the bus  3306  for communicating information and command selections to the processor(s)  3307 . 
         [0106]    According to one embodiment, an individual computer system  3300  performs specific operations by their respective processor(s)  3307  executing one or more sequences of one or more instructions contained in the main memory  3308 . Such instructions may be read into the main memory  3308  from another computer-usable medium, such as the ROM  3309  or the storage device  3310 . Execution of the sequences of instructions contained in the main memory  3308  causes the processor(s)  3307  to perform the processes described herein. In alternative embodiments, hard-wired circuitry may be used in place of or in combination with software instructions. Thus, embodiments are not limited to any specific combination of hardware circuitry and/or software. 
         [0107]    Although the present invention has been described above with particularity, this was merely to teach one of ordinary skill in the art how to make and use the invention. Many additional modifications will fall within the scope of the invention, as that scope is defined by the following claims.