We encounter issue with avplayer in case of EXT-X-DISCONTINUITY misalignment between audio and video produced after insertion of gaps.
The initial objective is to introduce an EXT-X-DISCONTINUITY in audio playlist after some missing segments (EXT-X-GAP) which durations are aligned to video segments durations, to handle irregular audio durations.
Please find below an example of corresponding video and audio playlists:
- video:
#EXTM3U
#EXT-X-VERSION:7
#EXT-X-MEDIA-SEQUENCE:872524632
#EXT-X-INDEPENDENT-SEGMENTS
#EXT-X-TARGETDURATION:2
#USP-X-TIMESTAMP-MAP:MPEGTS=7096045027,LOCAL=2025-05-09T12:38:32.369100Z
#EXT-X-MAP:URI="hls/StreamingBasic-video=979200.m4s"
#EXT-X-PROGRAM-DATE-TIME:2025-05-09T12:38:32.369111Z
#EXTINF:2.002, no desc
hls/StreamingBasic-video=979200-872524632.m4s
#EXTINF:2.002, no desc
hls/StreamingBasic-video=979200-872524633.m4s
#EXTINF:2.002, no desc
hls/StreamingBasic-video=979200-872524634.m4s
#EXTINF:2.002, no desc
hls/StreamingBasic-video=979200-872524635.m4s
#EXTINF:2.002, no desc
hls/StreamingBasic-video=979200-872524636.m4s
## Media sequence discontinuity
#EXT-X-GAP
#EXTINF:2.002, no desc
hls/StreamingBasic-video=979200-872524637.m4s
## Media sequence discontinuity
#EXT-X-GAP
#EXTINF:2.002, no desc
hls/StreamingBasic-video=979200-872524638.m4s
#EXT-X-PROGRAM-DATE-TIME:2025-05-09T12:38:46.383111Z
#EXTINF:2.002, no desc
hls/StreamingBasic-video=979200-872524639.m4s
#EXTINF:2.002, no desc
hls/StreamingBasic-video=979200-872524640.m4s
- audio:
EXTM3U
#EXT-X-VERSION:7
#EXT-X-MEDIA-SEQUENCE:872524632
#EXT-X-INDEPENDENT-SEGMENTS
#EXT-X-TARGETDURATION:2
#USP-X-TIMESTAMP-MAP:MPEGTS=7096045867,LOCAL=2025-05-09T12:38:32.378400Z
#EXT-X-MAP:URI="hls/StreamingBasic-audio_99500_eng=98800.m4s"
#EXT-X-PROGRAM-DATE-TIME:2025-05-09T12:38:32.378444Z
#EXTINF:2.0053, no desc
hls/StreamingBasic-audio_99500_eng=98800-872524632.m4s
#EXTINF:2.0053, no desc
hls/StreamingBasic-audio_99500_eng=98800-872524633.m4s
#EXTINF:2.0053, no desc
hls/StreamingBasic-audio_99500_eng=98800-872524634.m4s
#EXTINF:1.984, no desc
hls/StreamingBasic-audio_99500_eng=98800-872524635.m4s
#EXTINF:2.0053, no desc
hls/StreamingBasic-audio_99500_eng=98800-872524636.m4s
## Media sequence discontinuity
#EXT-X-GAP
#EXTINF:2.002, no desc
hls/StreamingBasic-audio_99500_eng=98800-872524637.m4s
## Media sequence discontinuity
#EXT-X-GAP
#EXTINF:2.002, no desc
hls/StreamingBasic-audio_99500_eng=98800-872524638.m4s
#EXT-X-DISCONTINUITY
#EXT-X-PROGRAM-DATE-TIME:2025-05-09T12:38:46.778444Z
#EXTINF:1.6213, no desc
hls/StreamingBasic-audio_99500_eng=98800-872524639.m4s
#EXTINF:2.0053, no desc
hls/StreamingBasic-audio_99500_eng=98800-872524640.m4s
In this case playback is broken with avplayer.
Is it conformed to Http Live Streaming?
Is it an avplayer bug?
What are the guidelines to handle such gaps?