[mythtv-commits] Ticket #13554: FPS drops to 4 or few per second and audion sync lost when there is transmission corruption

[MythTV]

#13554: FPS drops to 4 or few per second and audion sync lost when there is
transmission corruption
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 Reporter:  bib1963               |          Owner:  (none)
     Type:  Bug Report - General  |         Status:  infoneeded_new
 Priority:  minor                 |      Milestone:  needs_triage
Component:  MythTV - General      |        Version:  Master Head
 Severity:  medium                |     Resolution:
 Keywords:                        |  Ticket locked:  0
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Comment (by bib1963):

 Finally got it to happen with live tv.

 For the A/V issues, it's as if the FE, is saying it is behind and is
 correcting it, without actually doing so, or possible instead of
 subtracting, it adds or vice versa. This happens with recording as well.

 Regardless, there is a total lack of rendezvousing between video & audio.
 It may think there is, but it's does not appear to be actually doing
 anything.

 My system is only a 2C/4T, and it may also be that the cpu's are busy
 doing other things and the FE is not aware.

 For the last 5 minutes of the log, the video went down to around 2FPS. The
 audio played normally.

 I ended up pausing it, then unpausing it, whereupon the video raced
 through to catch up before settling down, but the audio was still
 massively out of sync. This could be caused by the FE getting ahead of the
 data, in that it tries to extract data from the buffer, but the card has
 not yet supplied it.

 At the end of the log, the audio was around 10 seconds ahead of the video.

 Sending the recording though vlc, shows no problems.

 The audio sync issues are also caused by a corrupted transmission.

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Ticket URL: <https://code.mythtv.org/trac/ticket/13554#comment:3>
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