On Thu, May 21, 2020 at 2:00 PM Martin Storsjö <mar...@martin.st> wrote: > > Oh, indeed, you're right. > > However wrong that is from the mov/mp4 point of view, it may very well be > that AVC intra is supposed to be written like this in mov/mp4 files - but > we'd need a word from somebody who actually knows that case. >
The best way to figure out if a user wants to do AVC Intra muxing would be to either a) require specific codec_tag/muxing mode be set by user or b) attempt to somehow properly check the actual bit stream within `mov_get_h264_codec_tag` to make the selection proper. Right now the system seems to base that if you are doing H.264, and have no codec_tag set already, then `mov_get_h264_codec_tag` attempts to set an AVC Intra codec_tag (which hits TAG_IS_AVCI), which then attempts to mux things in that proprietary way. Currently the check only checks for 10bit 4:2:0/4:2:2 or specific resolutions (which include 1080p and such). And I'm not sure if even the fallback there is a standard codec_tag, since it is not one of those I remember from 14496-15 (although my memory might just be bad). By default, and if the output got written with a standard 14496-15 etc codec_tag, then AVC intra muxing mode should not utilized. And just a note for the record, the logic in `mov_get_h264_codec_tag` seems to already be somewhat imperfect, as I've seen users attempting to encode 10bit H.264 normally into MOV, and one had to force a codec_tag to be avc1 for a non-broken file to be generated (as in, even FFmpeg itself couldn't read the file after muxing with the default selected codec_tag). Just my two cents, Jan _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".