Video decoding system having a programmable variable-length decoder

A video decoding system comprising:

• a decoder processor configured to perform decoding functions on a video data stream;
• a first variable-length decoding accelerator coupled to the decoder processor and configured to perform variable-length decoding operations on variable-length code in the video data stream, wherein the first variable-length decoding accelerator is configured by the decoder processor to decode variable-length codes according to any of a plurality of different decoding formats selected by the decoder processor based at least in part on a coding format of the variable video data stream, wherein the first variable-length decoding accelerator is configured to use for the selected decoding format a variable-length coding table of a plurality of different variable-length coding tables stored in memory that respectively correspond to the plurality of different decoding formats;
• and
• a second variable-length decoding accelerator coupled to the decoder processor and configured to perform variable-length decoding operations on variable-length code in the video data stream.

A video decoding system comprising:

• a decoder processor configured to perform decoding functions on a video data
• stream;
• a variable-length decoding accelerator coupled to the decoder processor and configured to perform variable-length decoding operations on a variable-length code in the video data stream;
• wherein the variable-length decoding accelerator is configured by the decoder processor to decode a variable-length code according to any of a plurality of different decoding formats selected by the decoder processor based at least in part on a coding format of the video data stream;
• and
• wherein the variable-length decoding accelerator is configured to use for the selected decoding format a variable-length coding table of a plurality of different variable-length coding tables stored in memory that respectively correspond to the plurality of different decoding formats.

A method, comprising:

• receiving, by a first variable-length decoding accelerator, a first macroblock data element in a video data stream from a decoder processor, the first macroblock data element comprising a first macroblock header and first coefficient data;
• receiving, by a second variable-length decoding accelerator, a second macroblock data element in the video data stream from the decoder processor, the second macroblock data element comprising a second macroblock header and second coefficient data;
• decoding, by the second variable-length decoding accelerator during a stage of decoding, the second coefficient data after decoding the second macroblock header;
• and
• decoding, by the first variable-length decoding accelerator during the stage of decoding, the first macroblock header while the second variable-length decoding accelerator decodes the second coefficient data.

A method, comprising:

• receiving, by a video processing system, video data of a first coding format;
• configuring, by a decoder processor, a variable-length decoding accelerator of the video processing system to use a first variable-length coding table based at least in part on the first coding format;
• decoding the video data of the first coding format by the variable-length decoding accelerator;
• receiving, by the video processing system, video data of a second coding format differing from the first coding format;
• configuring, by the decoder processor, the variable-length decoding accelerator to use a second variable length coding table that is different from the first variable-length coding table based at least in part on the second coding format;
• and
• decoding the video data of the second coding format by the variable-length decoding accelerator.