Method and apparatus for implementing reduced memory mode for high-definition television
AssigneeBroadcom Corporation
InventorsSherman (Xuemin) Chen, Jason Demas, Sandeep Bhatia
Life of this patent
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Abstract
A method and apparatus are provided for implementing an enhanced reduced memory mode (RMM) of decoding HDTV MPEG-2 video stream. In one instance, the RMM mode is adaptively enabled with up/down conversion by using the picture-type information. In another instance, the RMM mode is provided by performing anchor-frame compression/decompression by using adaptive DPCM technique with picture-type information. The quantization (PCM) tables are generated using the Lloyd algorithm. Further, the predictor for each pixel is determined by a use of the Graham rule.
Claims51
A video decoding system for receiving a digital bitstream and for decoding the digital bitstream, the system comprising:
- a video decoder for decoding the digital bitstream to generate a plurality of pictures, each picture being associated with a flag for indicating whether or not the picture is to be reduced in size to picture data prior to being stored;
- means for converting one or more pictures to picture data;
- memory comprising a plurality of buffers, the picture being stored in a buffer as the picture data when the associated flag is armed, and the picture being stored in two or more buffers without size reduction when the associated flag is unarmed;
- and
- recovery means for recovering the pictures from the picture data and for providing the pictures to the video decoder for use during decoding of the digital bitstream.
A method of decoding a digital bitstream, the method comprising the steps of:
- decoding the digital bitstream to generate a plurality of pictures, each picture being associated with a flag for indicating whether or not the picture is to be reduced in size to picture data prior to being stored in memory, the memory comprising a plurality of buffers;
- converting one or more pictures to picture data;
- storing the picture in a buffer as the picture data when the associated flag is armed;
- storing the picture in two or more buffers without size reduction when the associated flag is unarmed;
- and
- recovering the pictures from the picture data to be used during decoding of the digital bitstream.
A video decoding system for receiving a digital bitstream and for generating a display video stream by decoding the digital bitstream, the system comprising:
- a video decoder for decoding the encrypted digital bitstream to generate HDTV pictures, the HDTV pictures including one or more anchor pictures;
- a block-based image compressor to compress the anchor pictures in spatial domain using a gain adaptive compression algorithm to generate compressed bits;
- memory for storing the compressed bits;
- and
- a block-based image decompressor to decompress the compressed bits using a gain adaptive decompression algorithm to generate the anchor pictures,
- wherein the decompressed anchor pictures are used during the decoding of the digital bitstream.
A method of generating a display video stream using a digital bitstream, the method comprising the steps of:
- a) decoding the digital bitstream to generate HDTV pictures, the HDTV pictures including one or more anchor pictures;
- b) compressing the anchor pictures in spatial domain using a gain adaptive compression algorithm to generate compressed bits;
- c) storing the compressed bits in memory;
- d) decompressing the compressed bits using a gain adaptive decompression algorithm to generate the anchor pictures;
- and
- e) repeating steps a)-d) using the decompressed anchor pictures during the decoding of the digital bitstream.
Dependencies are inferred from the claim text.