Techniques For Resource Conservation During Performance Of Intra Block Copy Prediction Searches

1 . A method for image block coding, comprising:

coding blocks of an input image on a block-by-block basis;

decoding the coded blocks; and

storing decoded blocks of the input image in a buffer;

wherein the coding, for a given block, comprises searching for a prediction reference for the given block from within a source region of the buffer and comprises outputting an indication of the prediction reference; wherein the source region is constrained to a first portion of the input image within a predetermined distance of the given block.

2 . The method of claim 1 , further comprising evicting decoded blocks from storage when they are separated from a given block by more than the predetermined distance.

3 . The method of claim 1 , further comprising:

filtering decoded blocks of the input image,

storing filtered blocks of the input image in the buffer, wherein the searching for a prediction reference includes searching among the filtered blocks and is constrained to the first portion of the input image within a predetermined distance of the given block.

4 . The method of claim 1 , wherein the threshold is determined by a height measured from the current block.

5 . The method of claim 1 , wherein the threshold is determined by a block count threshold measured from the current block.

6 . The method of claim 5 , wherein the block count threshold is a count of coding unit (CU) or largest coding unit (LCU) sized blocks.

7 . A method for video decoding, comprising:

decoding coded video data received from a channel on a pixel block-by-pixel block basis, wherein the coded video data includes, for a given pixel block, an indication of a reference pixel block, wherein the decoding comprises predicting the given pixel block from within a source region of a buffer;

storing the decoded pixel blocks in the buffer;

following the decoding of the given pixel block, adjusting the source region to include a first portion of the current image that is closer to the given pixel block than a threshold and to not include a second portion of the current image that is further from the current block than the threshold; and

relinquishing the second portion.

8 . The method of claim 7 , wherein the decoded region is relinquished by freeing it from memory.

9 . The method of claim 7 , further comprising:

filtering the decoded blocks in the second portion; and

storing the filtered blocks in the buffer.

10 . The method of claim 7 , wherein the threshold distance includes a height measured from the current block within the current image.

11 . The method of claim 7 , wherein the threshold distance includes a block count measured from the current block within the current image.

12 . A system for image block coding, comprising a processor and memory, the memory containing instructions that, when executed on the processor, cause the system to at least:

code blocks of an input image on a block-by-block basis;

decode the coded blocks; and

store decoded blocks of the input image in a buffer;

wherein the coding, for a given block, comprises searching for a prediction reference for the given block from within a source region of the buffer and comprises outputting an indication of the prediction reference; wherein the source region is constrained to a first portion of the input image within a predetermined distance of the given block.

13 . The system of claim 12 , further comprising instructions to evict decoded blocks from storage when they are separated from a given block by more than the predetermined distance.

14 . The system of claim 12 , further comprising instructions to:

filter decoded blocks of the input image,

store filtered blocks of the input image in the buffer, wherein the searching for a prediction reference includes searching among the filtered blocks and is constrained to the first portion of the input image within a predetermined distance of the given block.

15 . The system of claim 12 , wherein the threshold is determined by a height measured from the current block.

16 . The system of claim 12 , wherein the threshold is determined by a block count threshold measured from the current block.

17 . The system of claim 16 , wherein the block count threshold is a count of CU or LCU sized blocks.

18 . A system for video decoding, comprising a processor and memory, the memory containing instructions that, when executed on the processor, cause the system to at least:

decode coded video data received from a channel on a pixel block-by-pixel block basis, wherein the coded video data includes, for a given pixel block, an indication of a reference pixel block; wherein the decoding comprises predicting the given pixel block from within a source region of a buffer;

store the decoded pixel blocks in the buffer;

following the decoding of the given pixel block, adjust the source region to include a first portion of the current image that is closer to the given pixel block than a threshold and to not include a second portion of the current image that is further from the current block than the threshold, and

relinquish the second portion.

19 . The system of claim 18 , wherein the decoded region is relinquished by freeing it from memory.

20 . The system of claim 18 , further comprising instructions to:

filter the decoded blocks in the second portion; and

store the filtered blocks in the buffer.

21 . The system of claim 18 , wherein the threshold distance includes a height measured from the current block within the current image.

22 . The system of claim 18 , wherein the threshold distance includes a block count measured from the current block within the current image.