Method and apparatus for decoding video data
AssigneeLSI Logic Corporation
InventorAdrian Wise
Life of this patent
Estimating the term…
Abstract
In order to reduce memory bandwidth when predicting B-frames from stored anchor frames in an MPEG-2 video decoder, memory access requests (20) to external memory (14) storing anchor frames are selectively suppressed (18) so that only data is accessed which is required for the current data to be displayed. To still further reduce memory bandwidth, a prediction type (frame picture-frame prediction-half pel filtering) which requires a large number of memory requests is approximated to a type (field prediction) which requires half as many memory requests.
Claims24
A video decoder including prediction means for forming predicted frames from anchor frames, the prediction means including memory addressing logic receiving input data from a current bit stream and generating in response thereto memory access requests for data of the anchor frames stored in external memory, and including buffer means and filter means for receiving data from external memory,
- and including memory request suppression means for suppressing unnecessary memory requests, comprising means responsive to the current prediction type being employed, and determining which memory requests from the addressing logic are necessary in order to form the current prediction for display, and which memory requests are to be suppressed for data which will not be used in the current picture data to be displayed.
A method of decoding video including forming predicted frames from anchor frames stored in memory, comprising receiving input data from a current bitstream and accessing in response thereto data of said anchor frames stored in memory in order to generate prediction data, wherein only data of said anchor frames is accessed which is required for the current prediction picture data being displayed.
Dependencies are inferred from the claim text.