[FFmpeg-user] Audio drift on HLS stream

[George Daramouskas]

Here is how I invoke ffmpeg:

`ffmpeg -use_wallclock_as_timestamps 1 -i srt://
0.0.0.0:9002?mode=listener&passphrase=$pwd&latency=120&pbkeylen=32 -map 0:v
-map 0:a -hls_list_size 0 -master_pl_name stream2.m3u8  -strftime 1
-hls_segment_filename /core/data/stream2/%Y%m%d/segment-%s.m4s
-strftime_mkdir 1 -hls_segment_type fmp4 -hls_flags append_list
-hls_playlist_type event -dts_delta_threshold 1 -c copy -copyts -bsf:a
aac_adtstoasc -map_channel 0.1.0? /core/data/stream2.m3u8`

I need use_wallclock_as_timestamps because I am having some long running
streams (weeks) and I need to know when there exist discontinuities. Also,
I would expect that the `-copyts` would not be necessary but apparently it
is as if I do not use it the timestamps start from zero.

My issue:

after a day or so I get audio drifting from the video when I view the m3u8
from multiple hls players, ffplay seems to working fine. It happens when
both I setup ffmpeg as a caller and listener. It happens with both mpegts
and fmp4 and it happens when I remove -c copy and enc/dec. I have used
multiple releases on ffmpeg from 4.4 onwards till 7.1. Playing the fmp4
directly the audio drift is not happening, it only happens when you play
through m3u8 and with multiple players (quicktime, shaka, hls.js)

I would appreciate any pointers as to what might be causing this.

Thank you

--
George Daramouskas | Software Development
*CUTTING*EDGE /
90 Victoria St, West End, QLD, 4101
*E* gdaramouskas at cuttingedge.com.au | *W* www.cuttingedge.com.au

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