Bypass alignment in video coding
View Patent ↗In certain aspects, a method and system for encoding a picture of a video including a coding block, and a method and system for decoding a picture of a video including a coding block are provided. In the method for encoding a picture of a video, a coefficient of each position in the coding block to is quantized by a processor to generate a quantization level of the respective position. A high throughput mode is enabled. In the high throughput mode, at least one residual coding bin of the coding block is changed from a context-coded bin to a bypass-coded bin, and bypass bit-alignment is applied. The quantization levels of the coding block are encoded by the processor into a bitstream in the high throughput mode.
1 . A method for encoding a picture of a video, the picture comprising a coding block, the method comprising:
quantizing, by a processor, a coefficient of each position in the coding block to generate a quantization level of the respective position;
enabling a high throughput mode, wherein in the high throughput mode, at least one residual coding bin of the coding block is changed from a context-coded bin to a bypass-coded bin, and bypass bit-alignment is applied to allow shift operation and parallel processing; and
encoding, by the processor, the quantization levels of the coding block into a bitstream in the high throughput mode;
wherein the coding block is a transform block encoded using regular residual coding (RRC), the at least one residual coding bin comprises a coded subblock flag, and the method further comprises:
invoking application of the bypass bit-alignment after a last significant coefficient prefix and before the coded subblock flag.
2 . The method of claim 1 , further comprising setting a value of remaining context-coded bins to be less than a threshold.
3 . The method of claim 2 , wherein the threshold equals 4, and the value of remaining context-coded bins is set to be 0.
4 . The method of claim 1 , wherein
the coding block comprises a plurality of subblocks; and
encoding comprises skipping coding a context-coded bin for each of the subblocks.
5 . The method of claim 1 , further comprising setting a value of a current interval length to be 256 to apply the bypass bit-alignment in the high throughput mode.
6 . A method for decoding a picture of a video, the picture comprising a coding block, the method comprising:
enabling a high throughput mode, wherein in the high throughput mode, at least one residual coding bin of the coding block is changed from a context-coded bin to a bypass-coded bin, and bypass bit-alignment is applied to allow shift operation and parallel processing;
decoding, by a processor, a bitstream to obtain a quantization level of each position in the coding block in the high throughput mode; and
dequantizing, by the processor, the quantization levels of the coding block to generate a coefficient of each position in the coding block;
wherein the coding block is a transform block encoded using regular residual coding (RRC), the at least one residual coding bin comprises a coded subblock flag, and the method further comprises:
invoking application of the bypass bit-alignment after a last significant coefficient prefix and before the coded subblock flag.
7 . The method of claim 6 , wherein a value of remaining context-coded bins is set to be less than a threshold.
8 . The method of claim 7 , wherein the threshold equals 4, and the value of remaining context-coded bins is set to be 0.
9 . The method of claim 6 , wherein
the coding block comprises a plurality of subblocks; and
coding a context-coded bin is skipped for each of the subblocks.
10 . The method of claim 6 , further comprising setting a value of a current interval length to be 256 to apply the bypass bit-alignment in the high throughput mode.
11 . The method of claim 6 , wherein the bitstream is decoded by a shift operation after application of the bypass bit-alignment.
12 . The method of claim 6 , wherein the at least one residual coding bin further comprises a last significant coefficient prefix.
13 . The method of claim 12 , further comprising invoking application of the bypass bit-alignment before the last significant coefficient prefix.
14 . A system for decoding a picture of a video, the picture comprising a coding block, the system comprising:
a memory configured to store instructions; and
a processor coupled to the memory and configured to, upon executing the instructions:
enable a high throughput mode, wherein in the high throughput mode, at least one residual coding bin of the coding block is changed from a context-coded bin to a bypass-coded bin, and bypass bit-alignment is applied to allow shift operation and parallel processing;
decode a bitstream to obtain a quantization level of each position in the coding block in the high throughput mode; and
dequantize the quantization levels of the coding block to generate a coefficient of each position in the coding block;
wherein the coding block is a transform block encoded using regular residual coding (RRC), the at least one residual coding bin comprises a coded subblock flag, and the method further comprises:
invoking application of the bypass bit-alignment after a last significant coefficient prefix and before the coded subblock flag.
15 . The system of claim 14 , wherein a value of remaining context-coded bins is set to be less than a threshold,
wherein the threshold equals 4, and the value of remaining context-coded bins is set to be 0.
16 . The system of claim 14 , wherein
the coding block comprises a plurality of subblocks; and
coding a context-coded bin is skipped for each of the subblocks.
17 . The system of claim 14 , further comprising setting a value of a current interval length to be 256 to apply the bypass bit-alignment in the high throughput mode.
18 . The system of claim 14 , wherein the bitstream is decoded by a shift operation after application of the bypass bit-alignment.
19 . The system of claim 14 , wherein the at least one residual coding bin further comprises a last significant coefficient prefix.
20 . A non-transitory computer-readable storage medium, storing a computer program and a bitstream, wherein the computer program, when executed by a processor, performs the method for encoding the video of claim 1 to generate the bitstream.