Signaling output picture size for reference picture resampling
There is included a method and apparatus comprising computer code configured to cause a processor or processors to perform acquiring an input bitstream comprising metadata and video data, decoding the video data, determining whether the metadata comprises at least one flag signaling at least one component of a picture size of at least one picture of the video data, and signaling, in a case where it is determined that the metadata comprises the at least one flag, a display device to display the at least one picture from the video data according to the at least one flag.
1. A method for video decoding performed by at least one processor, the method comprising:
obtaining coded video data and syntax of the video data;
determining whether a component of metadata of the video data comprises at least one flag signaling at least one component of a picture size of at least one picture of the video data;
determining, in response to determining that the component of the metadata comprises the at least one flag and based on the metadata specifying at least one of a picture width or height with respect to a plurality of pictures, whether any reference picture resampling (RPR) is applied to a picture width or height of a plurality of cropped output pictures of the video data such that each of a plurality of resampled output pictures is to have a constant picture size; and
decoding the video data based on whether the RPR is applied,
wherein whether the RPR is applied to the picture width or height is based on whether the syntax signals whether a cropping parameter, indicated by the at least one flag, is included in or is to be inferred from a sequence parameter set (SPS), and the cropping parameter represents at least one of the constant picture size and a width, in units of luma samples, of an output picture of the RPR.
2. The method for video decoding according to claim 1 , wherein the video data is in a versatile video coding (VVC) format.
3. The method for video decoding according to claim 1 ,
wherein the picture width or height of the picture is a picture width of the picture.
4. The method for video decoding according to claim 1 ,
wherein the picture width or height of the picture is a picture height of the picture.
5. The method for video decoding according to claim 1 , wherein decoding the video data further comprises determining that the RPR is to maintain a width value at a value indicated by the SPS of the video data.
6. The method for video decoding according to claim 1 , wherein decoding the video data further comprises determining that the RPR is to maintain a height value at a value indicated by the SPS of the video data.
7. The method for video decoding according to claim 1 , wherein decoding the video data further comprises determining that each of resampled output pictures of the RPR is to have the constant picture size.
8. A method for video encoding performed by at least one processor, the method comprising:
obtaining video data;
determining whether a component of metadata of the video data is to comprise at least one flag signaling at least one component of a picture size of at least one picture of the video data;
determining, in response to determining that the component of the metadata is to comprise the at least one flag and based on the metadata being determined to specify at least one of a picture width or height with respect to a plurality of pictures, whether any reference picture resampling (RPR) is to be applied to a picture width or height of a plurality of cropped output pictures of the video data such that each of a plurality of resampled output pictures is to have a constant picture size; and
encoding the video data and signaling syntax with the encoded video data;
wherein the syntax signals whether reference picture resampling (RPR) is applied to the picture width or height is based on whether a cropping parameter, to be indicated by the at least one flag, is included in or is to be inferred from a sequence parameter set (SPS), and the cropping parameter represents at least one of a constant picture size and a width, in units of luma samples, of an output picture of the RPR.
9. The method for video encoding according to claim 8 , wherein the video data is in a versatile video coding (VVC) format.
10. The method for video encoding according to claim 8 ,
wherein the picture width or height of the picture is a picture width of the picture.
11. The method for video encoding according to claim 8 ,
wherein the picture width or height of the picture is a picture height of the picture.
12. The method for video encoding according to claim 8 , wherein the syntax signals that the RPR is to maintain a width value at a value indicated by the SPS of the video data.
13. The method for video encoding according to claim 8 , wherein the syntax signals that the RPR is to maintain a height value at a value indicated by the SPS of the video data.
14. The method for video encoding according to claim 8 , wherein the syntax signals that each of resampled output pictures of the RPR is to have the constant picture size.
15. A method of processing visual media data performed by at least one processor, the method comprising:
obtaining at least one of a visual media file and a bitstream of the visual media data;
determining whether a component of metadata of the video data comprises or is to comprise at least one flag signaling at least one component of a picture size of at least one picture of the video data;
determining, in response to determining that the component of the metadata comprises or is to comprise the at least one flag and based on the metadata specifying at least one of a picture width or height with respect to a plurality of pictures, whether any reference picture resampling (RPR) is applied or is to be applied to a picture width or height of a plurality of cropped output pictures of the video data such that each of a plurality of resampled output pictures is to have a constant picture size; and
performing a conversion between the at least one of the visual media file and the bitstream of the visual media data and an other of the visual media file and the bitstream of the visual media data,
wherein bitstream comprises syntax signaling whether reference picture resampling (RPR) is applied to the picture width or height is based on whether a cropping parameter, indicated or to be indicated by the at least one flag, is included in or is to be inferred from a sequence parameter set (SPS), and the cropping parameter represents at least one of a constant picture size and a width, in units of luma samples, of an output picture of the RPR.
16. The method of processing visual media data according to claim 15 , wherein the video data is in a versatile video coding (VVC) format.
17. The method of processing visual media data according to claim 15 ,
wherein the picture width or height of the picture is a picture width of the picture.
18. The method of processing visual media data according to claim 15 ,
wherein the picture width or height of the picture is a picture height of the picture.
19. The method of processing visual media data according to claim 15 , wherein the syntax signals that the RPR is to maintain a width value at a value indicated by the SPS of the video data.
20. The method of processing visual media data according to claim 15 , wherein the syntax signals that the RPR is to maintain a height value at a value indicated by the SPS of the video data.