Opened 10 years ago

Closed 10 years ago

#9120 closed patch (fixed)

smoother play start

Reported by: Mark Spieth Owned by: markk
Priority: minor Milestone: 0.25
Component: MythTV - Video Playback Version: Master Head
Severity: medium Keywords:
Cc: Ticket locked: no


currently on initial AV sync mismatch, AVSync drops or advances frames until stability is reached.

patch comes in 2 parts, independent.

  1. discard any initial audio prior to initial video timecode.
  1. unpause decoder after all subsystems are running. this reduces the initial AV difference by 1/2 sec thus requiring less time to reach sync equilibrium.

Attachments (2)

17-smoother_play_start (3.3 KB) - added by Mark Spieth 10 years ago.
dump prior audio
32-start-play-fast (1020 bytes) - added by Mark Spieth 10 years ago.
reduce startup avsync mismatch

Download all attachments as: .zip

Change History (7)

Changed 10 years ago by Mark Spieth

Attachment: 17-smoother_play_start added

dump prior audio

Changed 10 years ago by Mark Spieth

Attachment: 32-start-play-fast added

reduce startup avsync mismatch

comment:1 Changed 10 years ago by robertm

Status: newassigned

comment:2 Changed 10 years ago by J.Pilk@…

Using 0.24-fixes with dvb-t recording edited by Project-X. Playback start is often messy with several video frames dropped. Go to edit mode, back to start, play,( keys e, PageUp?, e) gives smooth takeup from the intended edit point. Reported

Current version info - Fedora 13 x86_64 latest build from ATrpms installed 25 Jan 2011 MythTV Version : v0.24-118-gec67bfb MythTV Branch : fixes/0.24 Network Protocol : 63 Library API : 0.24.20101129-1 QT Version : 4.6.3

comment:3 Changed 10 years ago by markk

Milestone: unknown0.25
Owner: changed from Janne Grunau to markk
Status: assignedaccepted

Mark - these patches seems reasonable and there are no obvious issues in testing. I was however expecting to see more of an impact. I don't for example see any audio packets being dropped in actual usage - from tv to recordings to dvd and bluray.

Given there have been a number of changes in this area in recent times, can you confirm the patches are still behaving as you expect? (or more accurately, giving the desired benefit)

thanks and regards, Mark

comment:4 Changed 10 years ago by Mark Spieth <>

AvFormatDecoder?: Discard any initial audio packets prior to initial video timecode.

Refs #9120

Signed-off-by: Mark Kendall <mkendall@…>

Changeset: caf431c7c643040fd646345bbb8c41bb3e77ea13

comment:5 Changed 10 years ago by Mark Spieth <>

Resolution: fixed
Status: acceptedclosed

MythPlayer?: Start the decoder paused and unpause it only when ready.

This has a clear benefit on a number of different recordings and sample clips and often completely eliminates the initial av sync adjustment.

Closes #9120

Signed-off-by: Mark Kendall <mkendall@…>

Changeset: 0b1f9d2b96111a8ec27229945b3d397b5c2a5927

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