On Sat, Apr 11, 2020 at 11:01 PM Jan Ekström <jee...@gmail.com> wrote: > > On Sat, Apr 11, 2020 at 5:49 PM Carl Eugen Hoyos <ceffm...@gmail.com> wrote: > > > > Am Sa., 11. Apr. 2020 um 16:08 Uhr schrieb Jun Zhao <mypopy...@gmail.com>: > > > > > > From: vacinfang <vacinf...@tencent.com> > > > > > > add dolby vision related header > > > > Apart from the name of the header file: > > Could you explain why it is needed? > > > > Is the Dolby Vision metadata not a black box that libavformat > > has to provide to interested decoders? > > > > There's usually two different things: > > 1. Metadata in the file confirming that this is indeed DoVi. This is > what is being parsed. Otherwise the player application has no idea how > to handle DoVi (many of the profiles are actually just re-brands of > already standardized setups, while profiles 5 and I think 7 are the > more interesting ones). > 2. The kind of "black box" (RPU) metadata within NAL units 62. That is > then what (for now) would be passed to a special metadata reader to > enable correct rendering of f.ex. profile 5 clips. > > This patch set enables noting whether a file has the general metadata > from 1. I have seen implementations of 2. around, and we might have a > patch set for it at some point in the near future as we already have > open source code to render the DoVi data w/o the dynamic metadata of > those NAL unit 62 entries (see > https://code.videolan.org/videolan/libplacebo/-/commit/f850fa2839f9b679092e721068a57b0404608bdc > ). > > So to reiterate: > - The container metadata lets a player figure out if the AVStream is > flagged as DoVi and in which profile/level/does it have base|extension > layer contained within it. > - The NAL unit 62 metadata (RPUs) then enable correct rendering in > case of a profile that is not backwards compatible with standard color > spaces. > > Best regards, > Jan Yes, you are right, and thanks given a great details too, in our case, we used FFmpeg libavformat for Dolby Vision MPEG TS/MP4 demuxing, libavformat will parse the profile/level from MPEG TS/MP4 for other decoder ( the decoder is not part of FFmpeg） _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
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