Color blending prevention in video coding
A method for color blending prevention in video coding may include selecting, in a mode decision phase of an encoding of a current video frame, to encode an output bitstream in skip mode, wherein the skip mode includes altering encoding of the coding unit by setting luma component transform coefficients for the coding unit to zero, revaluating the selection of the skip mode based on quantized chroma coefficients, the quantized chroma coefficients generated from transformed and quantized residual chroma components, confirming the selection of the skip mode when there are no non-zero quantized chroma coefficients, and revoking the selection of the skip mode when there are non-zero quantized chroma coefficients, wherein the non-zero quantized chroma coefficients are transmitted when the selection of the skip mode is revoked.
1. A method comprising:
selecting, in a mode decision phase of an encoding of a video frame, to encode an output bit stream in skip mode;
setting unquantized luma component transform coefficients for a coding unit of the video frame to zero responsive to selecting the skip mode;
re-evaluating the selection of the skip mode based on quantized chroma coefficients and independent of the unquantized luma component transform coefficients of the coding unit, the quantized chroma coefficients generated from transformed and quantized residual chroma components;
confirming the selection of the skip mode when there are no non-zero quantized chroma coefficients; and
revoking the selection of the skip mode when there are non-zero quantized chroma coefficients, wherein the non-zero quantized chroma coefficients are transmitted for the coding unit when the selection of the skip mode is revoked.
2. The method of claim 1 , further comprising:
calculating a rate distortion optimization (RDO) cost for selecting an optimal intra-mode, inter-mode, merge mode and skip mode.
3. The method of claim 1 , wherein the video frame is a color video frame.
4. The method of claim 1 , further comprising:
suspending setting chroma transform coefficients to zero; and
performing a skip mode decision after transform and quantization of the chroma transform coefficients.
5. The method of claim 1 , the revoking further comprising:
revoking the selection of the skip mode when there is at least one non-zero quantized chroma coefficient in the coding unit after transform and quantization of chroma coefficients.
6. The method of claim 1 , further comprising:
transmitting the non-zero quantized chroma coefficients with Context Adaptive Binary Arithmetic Coding (CABAC).
7. The method of claim 1 , wherein the coding unit is a High Efficient Video Coding (HVEC) coding unit.
8. An integrated circuit comprising circuitry configured to:
select, in a mode decision phase of an encoding of a video frame, to encode an output bit stream in skip mode, wherein the skip mode includes altering encoding of a coding unit of the video frame by setting luma component transform coefficients for the coding unit to zero, the selecting being performed independent of chroma component transform coefficients and independent of other coding modes;
re-evaluate the selection of the skip mode based on quantized chroma coefficients and independent of the luma component transform coefficients, the quantized chroma coefficients generated from transformed and quantized residual chroma components;
confirm the selection of the skip mode when there are no non-zero quantized chroma coefficients; and
revoke the selection of the skip mode when there are non-zero quantized chroma coefficients, wherein the non-zero quantized chroma coefficients are transmitted when the selection of the skip mode is revoked.
9. The integrated circuit of claim 8 further comprising circuitry configured to:
calculate a rate distortion optimization (RDO) cost for selecting an optimal intra-mode, inter-mode, merge mode and skip mode.
10. The integrated circuit of claim 8 wherein the video frame is a color video frame.
11. The integrated circuit of claim 8 further comprising circuitry configured to:
suspend setting chroma transform coefficients to zero; and
perform a skip mode decision after transform and quantization of the chroma transform coefficients.
12. The integrated circuit of claim 8 further comprising circuitry configured to:
revoke the selection of the skip mode when there is at least one non-zero quantized chroma coefficient in the coding unit after transform and quantization of chroma coefficients.
13. The integrated circuit of claim 8 further comprising circuitry configured to:
transmit the non-zero quantized chroma coefficients with Context Adaptive Binary Arithmetic Coding (CABAC).
14. The integrated circuit of claim 8 wherein the coding unit is a High Efficient Video Coding (HVEC) coding unit.
15. A computer program product comprising instructions stored in a non-transitory computer-readable storage medium, the instructions comprising:
instructions to select, in a mode decision phase of an encoding of a current video frame, to encode an output bit stream in skip mode, wherein the skip mode includes altering encoding of a coding unit of the current video frame by setting luma component transform coefficients for the coding unit to zero;
instructions for re-evaluating the selection of the skip mode based on quantized chroma coefficients and independent of the luma component transform coefficients of the coding unit, the quantized chroma coefficients generated from transformed and quantized residual chroma components;
instructions for confirming the selection of the skip mode when there are no non-zero quantized chroma coefficients; and
instructions for revoking the selection of the skip mode when there are non-zero quantized chroma coefficients, wherein the non-zero quantized chroma coefficients used in re-evaluating the selection of the skip mode are transmitted for the coding unit when the selection of the skip mode is revoked.
16. The computer program product of claim 15 , the instructions further comprising:
instructions for calculating a rate distortion optimization (RDO) cost for selecting an optimal intra-mode, inter-mode, merge mode and skip mode.
17. The computer program product of claim 15 , wherein the current video frame is a color video frame.
18. The computer program product of claim 15 , the instructions further comprising:
instructions for suspending setting chroma transform coefficients to zero; and
instructions for performing a skip mode decision after transform and quantization of the chroma transform coefficients.
19. The computer program product of claim 15 , the instructions further comprising:
instructions for transmitting the non-zero quantized chroma coefficients with Context Adaptive Binary Arithmetic Coding (CABAC).
20. The computer program product of claim 15 , wherein the coding unit is a High Efficient Video Coding (HVEC) coding unit.
21. The method of claim 1 , wherein the luma component transform coefficients set to zero are transmitted with the non-zero quantized chroma coefficients when the selection of the skip mode is revoked.