Pulse code modulation technique in video processing

An apparatus for coding video data comprising a processor and a non-transitory memory with instructions thereon, wherein the instructions upon execution by the processor, cause the processor to:

• perform a conversion between a current video unit of a video and a bitstream of the video, wherein the current video unit is a luma video unit;
• and
• apply a filtering process for the current video unit based on a first indication during the conversion, wherein the filtering process is a deblocking filter process;
• wherein one of the first indication and a second indication is used to indicate a usage of a pulse code modulation (PCM) for the current video unit, and the other of the first and the second indications is used to indicate mode information of a multiple reference line based intra prediction (MRLIP) for the current video unit, and wherein whether the second indication is present in the bitstream is related to the first indication,
• wherein, in response to a dual tree partition or a single tree partition being applied, the first indication is a luma indication and is used to indicate the usage of the PCM for the current video unit, and the second indication is used to indicate the mode information of the MRLIP for the current video unit,
• wherein in response to the first indication indicating that the PCM is applied to the current video unit, the second indication is not present in the bitstream, and
• wherein a chroma PCM indication is further used to indicate whether to apply the PCM on at least one chroma component, and no chroma MRLIP indication is used for the at least one chroma component.

A non-transitory computer-readable storage medium storing instructions that cause a processor to:

• perform a conversion between a current video unit of a video and a bitstream of the video, wherein the current video unit is a luma video unit;
• and
• apply a filtering process for the current video unit based on a first indication during the conversion, wherein the filtering process is a deblocking filter process;
• wherein one of the first indication and a second indication is used to indicate a usage of a pulse code modulation (PCM) for the current video unit, and the other of the first and the second indications is used to indicate mode information of a multiple reference line based intra prediction (MRLIP) for the current video unit, and wherein whether the second indication is present in the bitstream is related to the first indication,
• wherein, in response to a dual tree partition or a single tree partition being applied, the first indication is a luma indication and is used to indicate the usage of the PCM for the current video unit, and the second indication is used to indicate the mode information of the MRLIP for the current video unit,
• wherein, in response to the first indication indicating that the PCM is applied to the current video unit, the second indication is not present in the bitstream, and
• wherein a chroma PCM indication is further used to indicate whether to apply the PCM on at least one chroma component, and no chroma MRLIP indication is used for the at least one chroma component.

A non-transitory computer-readable recording medium storing a bitstream which is generated by a method performed by a video processing apparatus, wherein the method comprises:

• generating a bitstream of a video from a current video unit of the video, wherein the current video unit is a luma video unit;
• and
• applying a filtering process for the current video unit based on a first indication during the conversion, wherein the filtering process is a deblocking filter process;
• wherein one of the first indication and a second indication is used to indicate a usage of a pulse code modulation (PCM) for a current video unit, and the other of the first and the second indications is used to indicate mode information of a multiple reference line based intra prediction (MRLIP) for the current video unit, and wherein whether the second indication is present in the bitstream is related to the first indication,
• wherein, in response to a dual tree partition or a single tree partition being applied, the first indication is a luma indication and is used to indicate the usage of the PCM for the current video unit, and the second indication is used to indicate the mode information of the MRLIP for the current video unit,
• wherein, in response to the first indication indicating that the PCM is applied to the current video unit, the second indication is not present in the bitstream, and
• wherein a chroma PCM indication is further used to indicate whether to apply the PCM on at least one chroma component, and no chroma MRLIP indication is used for the at least one chroma component.