[mythtv-commits] Ticket #12852: Adjust Audio Sync causes stutter and slowdown

MythTV noreply at mythtv.org
Tue Aug 9 22:33:46 UTC 2016

#12852: Adjust Audio Sync causes stutter and slowdown
 Reporter:  pbennett                 |          Owner:  jyavenard
     Type:  Bug Report - General     |         Status:  new
 Priority:  minor                    |      Milestone:  unknown
Component:  MythTV - Video Playback  |        Version:  Master Head
 Severity:  medium                   |     Resolution:
 Keywords:                           |  Ticket locked:  0

Comment (by markspieth):

 My understanding of the causes and effects are:
  * AVSync uses spare capacity in audio buffer or video buffers. If video
 buffers is set low, you cant go too far in the negative direction.
  * all video streams (esp from DVB-T) have different A/V PTS (DTS?)
 lags/offsets. This puts more strain on AVSync buffering requirements.
  * higher B frame numbers increases the buffering requirements due to
 lookahead required and thus the apparent PTS offsets between.
  * The number of video buffers allocated can make a difference to the
 achievable negative audio delay achievable.

 These features impact the play startup behaviour whether audio is present
 and video needs to catch up or vice versa as AVSync gets the data needed
 to do its job.

Ticket URL: <https://code.mythtv.org/trac/ticket/12852#comment:4>
MythTV <http://www.mythtv.org>
MythTV Media Center

More information about the mythtv-commits mailing list