On Sun, Feb 5, 2023 at 6:33 PM Marton Balint <c...@passwd.hu> wrote: > Your code duplicates AUD-s if they are already present and sps is also > added: > > if original packet had > [AUD][IDR] > it will become > [AUD][SPS][PPS][AUD][IDR]. > > Regards, > Marton
Hi Marton, You're right, this is not compliant. The H.264 spec (section 7.4.1.2.3) is clear about this, it says: - There should be at most one AUD per access unit - Each access unit should include a picture. (We can't produce a fake "access unit" to carry the SPS and PPS alone; that's not allowed.) - When AUD is present, it should be the first NAL in the access unit. (We can't just prepend SPS and PPS ahead of the AUD.) Perhaps you knew all this; I am just learning. :-) So if the original packet has [AUD][IDR], then we should produce [AUD][SPS][PPS][IDR]. And if the original packet has [SEI][AUD][IDR], then we should produce [AUD][SPS][PPS][SEI][IDR] -- chopping out the original AUD, and then inserting the prefix with the new AUD. Tests show x264 producing the [SEI][AUD][IDR] sequence, despite it being contrary to the spec's recommendation that AUD should be first. Does that seem like the correct handling? If so I'll post a v2 patch for it. Thanks again. John _______________________________________________ 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".
