Opened 3 years ago

Closed 3 years ago

Last modified 3 years ago

#13172 closed Bug Report - General (fixed)

Playback jerky and audio interrupted if adjusting audio sync negative

Reported by: Peter Bennett Owned by: Peter Bennett
Priority: minor Milestone: 30.0
Component: MythTV - Video Playback Version: v29-fixes
Severity: medium Keywords:
Cc: Ticket locked: no


When playing some HD recordings, adjusting the audio sync lower than -100 causes a jerky playback with audio interruptions and video pauses.

It is exacerbated when playing Live TV.

This is caused by insufficient audio being in the buffer at the time the corresponding video frame is played.

This may be related to #12318

Attachments (1)

20171108_#13172_audiosync.patch (2.2 KB) - added by Peter Bennett 3 years ago.
Proposed fix

Download all attachments as: .zip

Change History (7)

comment:1 Changed 3 years ago by Peter Bennett

Attached is a proposed patch. With this patch there is also a setting which can be applied to adjust the amount of audio buffering. "AudioReadAhead" can be set to the number of milliseconds to buffer, so setting for example -O AudioReadAhead=1000 will allow setting a negative audio offset of -1000 milliseconds during playback.

Changed 3 years ago by Peter Bennett

Proposed fix

comment:2 Changed 3 years ago by Peter Bennett

Status: newaccepted

comment:3 Changed 3 years ago by Peter Bennett

See also #12302 which may be the same problem.

comment:4 Changed 3 years ago by Peter Bennett

Milestone: needs_triage30.0

comment:5 Changed 3 years ago by Peter Bennett <pbennett@…>

Resolution: fixed
Status: acceptedclosed

In 7cb7ed9b5e13c1e5d86e22652635f6f7b8f3bc94/mythtv:

Frontend Playback: Add a new setting to address audio stuttering

Replace the "Extra Audio Buffering" checkbox with a millisecond
value. The previous checkbox was a hardcoded 100ms value. If you
are using a negative audio sync adjustment on certain files
you can get audio cutting out unless you increase this value.

Also remove code associated with the "lowbuffers" value that was set
by that checkbox and always use the new setting value.

Fixes #13172

comment:6 Changed 3 years ago by Peter Bennett

Owner: changed from Peter Bennett to Peter Bennett
Note: See TracTickets for help on using tickets.