Method and apparatus of encoding original video picture

A method of encoding an original video picture comprising pre-Sample Adaptive Offset (PSAO) vertical filtering using a first combination of PSAO parameters and PSAO horizontal filtering using a second combination of PSAO parameters intended to be applied on video picture data,

• wherein the first combinations of PSAO parameters and the second combinations of PSAO parameters are selected jointly by minimizing a delta cost defined as a linear combination of a delta distortion and a delta rate calculated for a couple of a first candidate combination of PSAO parameters and a second candidate combination of PSAO parameters,
• the delta distortion equals to a difference between a first distortion and a second distortion,
• the first distortion being defined as a cumulative difference between pixels of a reference video picture derived from the original video picture and pixels of an output video picture obtained after having applied a deblocking vertical filtering followed by the PSAO vertical filtering using the first candidate combination of PSAO parameters followed by a deblocking horizontal filtering followed by the PSAO horizontal filtering using the second candidate combination of PSAO parameters to an input video picture,
• the second distortion being defined as a cumulative difference between pixels of the reference video picture and pixels of an output video picture obtained after having applied the vertical deblocking filtering and the horizontal deblocking filtering to the input video picture without applying the PSAO vertical filtering and the PSAO horizontal filtering,
• and
• the delta rate representing a number of bits required to encode syntax elements relative to the PSAO vertical filtering using the first candidate combination of PSAO parameters and the PSAO horizontal filtering using the second candidate combination of PSAO parameters.

An apparatus of encoding an original video picture, comprising:

• a processor;
• and
• a memory storing instructions executable by the processor,
• wherein the processor is configured to perform:
• pre-Sample Adaptive Offset (PSAO) vertical filtering using a first combination of PSAO parameters and PSAO horizontal filtering using a second combination of PSAO parameters intended to be applied on video picture data,
• wherein the first combinations of PSAO parameters and the second combinations of PSAO parameters are selected jointly by minimizing a delta cost defined as a linear combination of a delta distortion and a delta rate calculated for a couple of a first candidate combination of PSAO parameters and a second candidate combination of PSAO parameters,
• the delta distortion equals to a difference between a first distortion and a second distortion,
• the first distortion being defined as a cumulative difference between pixels of a reference video picture derived from the original video picture and pixels of an output video picture obtained after having applied a deblocking vertical filtering followed by the PSAO vertical filtering using the first candidate combination of PSAO parameters followed by a deblocking horizontal filtering followed by the PSAO horizontal filtering using the second candidate combination of PSAO parameters to an input video picture,
• the second distortion being defined as a cumulative difference between pixels of the reference video picture and pixels of an output video picture obtained after having applied the vertical deblocking filtering and the horizontal deblocking filtering to the input video picture without applying the PSAO vertical filtering and the PSAO horizontal filtering,
• and
• the delta rate representing a number of bits required to encode syntax elements relative to the PSAO vertical filtering using the first candidate combination of PSAO parameters and the PSAO horizontal filtering using the second candidate combination of PSAO parameters.

A non-transitory storage medium carrying instructions that, when executed by a processor, cause the processor to perform a method of encoding an original video picture comprising pre-Sample Adaptive Offset (PSAO) vertical filtering using a first combination of PSAO parameters and PSAO horizontal filtering using a second combination of PSAO parameters intended to be applied on video picture data,

• wherein the first combinations of PSAO parameters and the second combinations of PSAO parameters are selected jointly by minimizing a delta cost defined as a linear combination of a delta distortion and a delta rate calculated for a couple of a first candidate combination of PSAO parameters and a second candidate combination of PSAO parameters,
• the delta distortion equals to a difference between a first distortion and a second distortion,
• the first distortion being defined as a cumulative difference between pixels of a reference video picture derived from the original video picture and pixels of an output video picture obtained after having applied a deblocking vertical filtering followed by the PSAO vertical filtering using the first candidate combination of PSAO parameters followed by a deblocking horizontal filtering followed by the PSAO horizontal filtering using the second candidate combination of PSAO parameters to an input video picture,
• the second distortion being defined as a cumulative difference between pixels of the reference video picture and pixels of an output video picture obtained after having applied the vertical deblocking filtering and the horizontal deblocking filtering to the input video picture without applying the PSAO vertical filtering and the PSAO horizontal filtering,
• and
• the delta rate representing a number of bits required to encode syntax elements relative to the PSAO vertical filtering using the first candidate combination of PSAO parameters and the PSAO horizontal filtering using the second candidate combination of PSAO parameters.