HEVC fmp4 HLS video produced by ffmpeg is currently unplayable on Apple software (Safari, QuickTime, AVFoundation). This is caused by an empty sdtp atom being erroneously written to the fmp4 init segment. The `has_disposable` flag can be set for a track with B-frames, but the init segment contains no actual frames (track->entry == 0). Writing an sdtp atom in this case is incorrect and causes Apple's parsers to reject the file. This patch fixes the issue by ensuring the sdtp atom is only written if track->entry is non-zero. A similar patch was proposed in November 2023 by Jay Zhang, but it was never merged.
Unified · Split
| @@ -3273,7 +3273,7 @@ static int mov_write_stbl_tag(AVFormatContext *s, AVIOContext *pb, MOVMuxContext · 3272 unmodified lines | ||
| 3273 | 3273 | track->par->codec_tag == MKTAG('r','t','p',' ')) && |
| 3274 | 3274 | track->has_keyframes && track->has_keyframes < track->entry) |
| 3275 | 3275 | mov_write_stss_tag(pb, track, MOV_SYNC_SAMPLE); |
| 3276 | − if (track->par->codec_type == AVMEDIA_TYPE_VIDEO && track->has_disposable) | |
| 3276 | + if (track->par->codec_type == AVMEDIA_TYPE_VIDEO && track->has_disposable && track->entry) | |
| 3277 | 3277 | mov_write_sdtp_tag(pb, track); |
| 3278 | 3278 | if (track->mode == MODE_MOV && track->flags & MOV_TRACK_STPS) |
| 3279 | 3279 | mov_write_stss_tag(pb, track, MOV_PARTIAL_SYNC_SAMPLE); |