Video decoder initialization information signaling

A non-transitory computer readable medium comprising a computer program product for use by a video coding device, the computer program product comprising computer executable instructions stored on the non-transitory computer readable medium such that when executed by a processor cause the video coding device to:

• determine decoder initialization information (DII) for a bitstream, wherein the DII includes data describing a maximum level (MaxLevel) to which all coded video sequences (CVSs) of the bitstream conform and a maximum format that comprises one or more of the following parameters:
• 1) a maximum number of decoded pictures (MaxDecPics) stored in the decoded picture buffer (DPB), 2) a maximum decoded picture width (MaxDecPicW) of all coded pictures in the bitstream, 3) a maximum decoded picture height (MaxDecPicH) of all coded pictures in the bitstream, 4) a maximum colour format (MaxColourFormat) of all coded pictures in the bitstream, and 5) a maximum bit depth (MaxBitdepth) of all coded pictures in the bitstream, wherein the MaxLevel indicates a first maximum DPB size needed for decoding the bitstream, wherein the maximum format indicates a second maximum DPB size, denoted as DPB memory for as maximum format (DpbMemory4MaxFormat), determined by simultaneously setting all parameters of the maximum format to largest values, and wherein the DII further comprises a first indication of whether the DpbMemory4MaxFormat exceeds the first maximum DPB size;
• and
• perform a conversion between a visual media data and a bitstream based on the first indication,
• wherein the DII further comprises a minimum level a decoder should support to decode the bitstream at a maximum format (MinLevel4MaxFormat), and
• wherein the MinLevel4MaxFormat signals a smallest level for which a value of a maximum picture size in luma samples (MaxLumaPs) is greater than or equal to the MaxDecPicW times the MaxDecPicH.

An apparatus for processing 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:
• determine decoder initialization information (DII) for a bitstream, wherein the DII includes data describing a maximum level (MaxLevel) to which all coded video sequences (CVSs) of the bitstream conform and a maximum format that comprises one or more of the following parameters:
• 1) a maximum number of decoded pictures (MaxDecPics) stored in the decoded picture buffer (DPB), 2) a maximum decoded picture width (MaxDecPicW) of all coded pictures in the bitstream, 3) a maximum decoded picture height (MaxDecPicH) of all coded pictures in the bitstream, 4) a maximum colour format (MaxColourFormat) of all coded pictures in the bitstream, and 5) a maximum bit depth (MaxBitdepth) of all coded pictures in the bitstream, wherein the MaxLevel indicates a first maximum DPB size needed for decoding the bitstream, wherein the maximum format indicates a second maximum DPB size, denoted as DPB memory for as maximum format (DpbMemory4MaxFormat), determined by simultaneously setting all parameters of the maximum format to largest values, and wherein the DII further comprises a first indication of whether the DpbMemory4MaxFormat exceeds the first maximum DPB size;
• and
• perform a conversion between a visual media data and a bitstream based on the first indication,
• wherein the DII further comprises a minimum level a decoder should support to decode the bitstream at a maximum format (MinLevel4MaxFormat), and
• wherein the MinLevel4MaxFormat signals a smallest level for which a value of a maximum picture size in luma samples (MaxLumaPs) is greater than or equal to the MaxDecPicW times the MaxDecPicH.