> -----Original Message----- > From: ffmpeg-devel [mailto:ffmpeg-devel-boun...@ffmpeg.org] On Behalf > Of Mark Thompson > Sent: Tuesday, October 10, 2017 6:36 AM > To: ffmpeg-devel@ffmpeg.org > Subject: Re: [FFmpeg-devel] [PATCH 2/6] vaapi: Remove H.264 baseline > profile > > On 09/10/17 22:48, Carl Eugen Hoyos wrote: > > 2017-10-09 13:21 GMT+02:00 wm4 <nfx...@googlemail.com>: > > > >> Shouldn't trying to decode baseline video just fall back to sw decoding? > > > > Given that software doesn't support the specific features of baseline > > either, I don't think this helps. > > I was under the impression the only sane thing to do when reading > > baseline H.264 is printing a warning and continue as if constraint > > baseline was detected. > > At least with software decode we would know that it has failed - an > inconvenient property of many hardware decoders is their reluctance to > report errors usefully or at all. > > Hence the warning on using the ALLOW_PROFILE_MISMATCH flag, which > does allow the attempt to decode baseline profile streams with hardware: > """ > If the stream is actually not supported then the behaviour is undefined, and > may include returning entirely incorrect output while indicating success. > """ > > I think the behaviour we have now with this option to continue if the user > really wants (and is aware of the possible consequences) is correct. >
[Li, Zhong] There advanced features of baseline profile are not supported：FMO, SAO, and Redundant slices. So another way is to check a baseline clip has some of these there features or not (ie, slice_group_number can be check when decoding PPS), If yes, fall back to sw decoding. Else, set the profile to be constrained profile. > Thanks, > > - Mark > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
