ffplay with the -ss option to play fmp4 over HLS always results in failure

[luckysk]

Using ffmpeg git master code to play fmp4 over HLS, with -ss option, the playback always fails with the following obvious errors:

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ffplay -ss 17 ​https://lcksk.github.io/test-streams/fmp4_over_hls/index.m3u8

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NULL @ 0x7f588c647240] Invalid NAL unit size (705652795 > 2531).
[NULL @ 0x7f588c647240] missing picture in access unit with size 2535
[NULL @ 0x7f588c647240] Invalid NAL unit size (-1932772363 > 2770).
[NULL @ 0x7f588c647240] missing picture in access unit with size 2774
[NULL @ 0x7f588c647240] Invalid NAL unit size (-330360416 > 15339).
[NULL @ 0x7f588c647240] missing picture in access unit with size 15343
[NULL @ 0x7f588c647240] Invalid NAL unit size (-898925876 > 6201).
[NULL @ 0x7f588c647240] missing picture in access unit with size 6205
[NULL @ 0x7f588c647240] Invalid NAL unit size (-1217661452 > 2892).
[NULL @ 0x7f588c647240] missing picture in access unit with size 2896
[NULL @ 0x7f588c647240] Invalid NAL unit size (-670829996 > 2757).
[NULL @ 0x7f588c647240] missing picture in access unit with size 2761
[NULL @ 0x7f588c647240] Invalid NAL unit size (156497150 > 20840).
[NULL @ 0x7f588c647240] missing picture in access unit with size 20844
[NULL @ 0x7f588c647240] Invalid NAL unit size (-1726862149 > 9178).
[NULL @ 0x7f588c647240] missing picture in access unit with size 9182
[NULL @ 0x7f588c647240] Invalid NAL unit size (-1586106474 > 2988).
[NULL @ 0x7f588c647240] missing picture in access unit with size 2992
[NULL @ 0x7f588c647240] Invalid NAL unit size (-1586106474 > 2988). [47/1919]
[NULL @ 0x7f588c647240] missing picture in access unit with size 2992
[NULL @ 0x7f588c647240] Invalid NAL unit size (-991861552 > 1937).
[NULL @ 0x7f588c647240] missing picture in access unit with size 1941
[NULL @ 0x7f588c647240] Invalid NAL unit size (506020045 > 15496).
[NULL @ 0x7f588c647240] missing picture in access unit with size 15500
[NULL @ 0x7f588c647240] Invalid NAL unit size (1704617837 > 6981).
[NULL @ 0x7f588c647240] missing picture in access unit with size 6985
[NULL @ 0x7f588c647240] Invalid NAL unit size (-781202283 > 2495).
[NULL @ 0x7f588c647240] missing picture in access unit with size 2499
[NULL @ 0x7f588c647240] Invalid NAL unit size (1299206939 > 3109).
[NULL @ 0x7f588c647240] missing picture in access unit with size 3113
[NULL @ 0x7f588c647240] Invalid NAL unit size (-141643905 > 14454).
[NULL @ 0x7f588c647240] missing picture in access unit with size 14458
[NULL @ 0x7f588c647240] Invalid NAL unit size (392010386 > 6523).
[NULL @ 0x7f588c647240] missing picture in access unit with size 6527
[NULL @ 0x7f588c647240] Invalid NAL unit size (664392210 > 2374).
[NULL @ 0x7f588c647240] missing picture in access unit with size 2378
[NULL @ 0x7f588c647240] Invalid NAL unit size (412899187 > 2905).
[NULL @ 0x7f588c647240] missing picture in access unit with size 2909
[NULL @ 0x7f588c647240] Invalid NAL unit size (-724921878 > 19135).
[NULL @ 0x7f588c647240] missing picture in access unit with size 19139
[NULL @ 0x7f588c647240] Invalid NAL unit size (432912219 > 6098).
[NULL @ 0x7f588c647240] missing picture in access unit with size 6102
[NULL @ 0x7f588c647240] Invalid NAL unit size (-1528103377 > 3473).
[NULL @ 0x7f588c647240] missing picture in access unit with size 3477

17s in -ss 17 mentioned above can be replaced with any value within the range (0, duration), which will result in the same issue occurring. If the -ss option is not used, the player can seek to any position without any issues after starting up.

[luckysk]

Similarly, if you use the mpv player with the --start option, you'll hit the same issues. So it looks like the issue isn't really tied to a specific player.

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mpv --msg-level=all=trace --log-file=~/Desktop/mpv_hls_ng.log --start=10 ​https://lcksk.github.io/test-streams/fmp4_over_hls/index.m3u8

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[Balling]

We know: #7359. After #7485 was fixed it broke it.