Prediction type signaling in video coding
An example method of video processing includes performing a conversion between a video including a video picture including one or more video units and a bitstream representation of the video. The bitstream representation conforms to a format rule that specifies that a first syntax element is included in a header of the video picture indicating allowed prediction types of at least some of the one or more video units in the video picture.
1. A method of processing video data, comprising:
determining, for a conversion between a video comprising a video picture comprising video units and a bitstream of the video, a prediction type of at least one of the video units in the video picture based on one or more syntax elements; and
performing the conversion based on the determination,
wherein the one or more syntax elements are included in a picture header in the bitstream,
wherein the video units are slices, and wherein
the one or more syntax elements comprise a first syntax element indicating whether prediction types of all the slices of the video picture are coded with a first prediction type,
wherein a syntax element indicating a slice type is not included in a slice header in the bitstream when the first syntax element indicates that all the slices of the video picture are I slices.
2. The method of claim 1 , wherein the first prediction type is an intra prediction.
3. The method of claim 1 , wherein the one or more syntax elements conditionally comprise a second syntax element indicating whether at least one of the slices is non-I slice.
4. The method of claim 1 , wherein the conversion includes encoding the video into the bitstream.
5. The method of claim 1 , wherein the conversion includes decoding the video from the bitstream.
6. An apparatus comprising a processor and a non-transitory memory with instructions thereon for processing video data, wherein the instructions upon execution by the processor, cause the processor to:
determine, for a conversion between a video comprising a video picture comprising video units and a bitstream of the video, a prediction type of at least one of the video units in the video picture based on one or more syntax elements; and
perform the conversion based on the determination,
wherein the one or more syntax elements are included in a picture header in the bitstream,
the video units are slices, and
the one or more syntax elements comprise a first syntax element indicating whether prediction types of all the slices of the video picture are coded with a first prediction type,
wherein a syntax element indicating a slice type is not included in a slice header in the bitstream when the first syntax element indicates that all the slices of the video picture are I slices.
7. The apparatus of claim 6 , wherein the first prediction type is an intra prediction.
8. The apparatus of claim 6 , wherein the one or more syntax elements conditionally comprise a second syntax element indicating whether at least one of the slices is non-I slice.
9. A non-transitory computer-readable storage medium storing instructions that cause a processor to:
determine, for a conversion between a video comprising a video picture comprising video units and a bitstream of the video, a prediction type of at least one of the video units in the video picture based on one or more syntax elements; and
perform the conversion based on the determination,
wherein the one or more syntax elements are included in a picture header in the bitstream,
the video units are slices, and
the one or more syntax elements comprise a first syntax element indicating whether prediction types of all the slices of the video picture are coded with a first prediction type,
wherein a syntax element indicating a slice type is not included in a slice header in the bitstream when the first syntax element indicates that all the slices of the video picture are I slices.
10. The non-transitory computer-readable storage medium of claim 9 ,
wherein the first prediction type is an intra prediction; and
wherein the one or more syntax elements conditionally comprise a second syntax element indicating whether at least one of the slices is non-I slice.
11. A non-transitory computer-readable recording medium storing a bitstream of a video which is generated by a method performed by a video processing apparatus, wherein the method comprises:
determining, for the video comprising a video picture comprising video units, a prediction type of at least one of the video units in the video picture based on one or more syntax elements; and
generating the bitstream of the video based on the determination,
wherein the one or more syntax elements are included in a picture header in the bitstream,
the video units are slices, and
the one or more syntax elements comprise a first syntax element indicating whether prediction types of all the slices of the video picture are coded with a first prediction type,
wherein a syntax element indicating a slice type is not included in a slice header in the bitstream when the first syntax element indicates that all the slices of the video picture are I slices.
12. The non-transitory computer-readable recording medium of claim 11 ,
wherein the first prediction type is an intra prediction; and
wherein the one or more syntax elements conditionally comprise a second syntax element indicating whether at least one of the slices is non-I slice.