[mythtv-commits] Ticket #9511: [patch] avformat decoder buffer underrun (DVB livetv)

[MythTV]

#9511: [patch] avformat decoder buffer underrun (DVB livetv)
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 Reporter:  Jiri Fojtasek <jiri.fojtasek@…>      |          Owner:  janne
     Type:  Bug Report                           |         Status:  new
 Priority:  critical                             |      Milestone:  unknown
Component:  MythTV - Video Playback              |        Version:  Trunk
 Severity:  high                                 |  Head
 Keywords:                                       |     Resolution:
                                                 |  Ticket locked:  0
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Comment (by Jiri Fojtasek <jiri.fojtasek@…>):

 Replying to [comment:5 markk]:
 > Jiri - I've attached a simple (but not complete fix) for the decoder
 lockup. I've tested this with about 8 hours of livetv here today and it
 has worked very well (i.e. no program transition failures). I did not need
 the eagain patch - so I'm curious whether that is still needed or whether
 it is addressing a different issue.

 Mark,

 Your change is related to one i have tried before with no luck to this
 problem.

 When the avformatdecoder set eof its too late to anything. Any more calls
 to av_read_frame always return -5 (EIO) and the ffmpeg decoder will never
 retry read from the ringbuffer because his internal eof flag is set to 1.
 Its game over until playback crash with "buffers failed". The key log
 message always preceding switchtoprogram and associated decoder failure
 is:
 {{{
 2011-01-22 11:20:03.246
 RingBuf(/var/spool/mythtv/livetv/9008_20110122111500.mpg):
 ReadPriv(..6436, normal): ReadBufAvail() == 0
 }}}

 Have you tried this pause HACK i posted to reproduce this bug ?

 We can made a hack to set ffmpeg's eof flag back to 0 but i do not like
 hacks, and hacking this have beside issues than decoder returning
 incomplette frame (this still doing with v1 patch i posted, in v2 ill post
 soon its fixed) My change to mpegts is clean because eagain is supported
 in ffmpeg high level api.

 Jiri

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Ticket URL: <http://code.mythtv.org/trac/ticket/9511#comment:6>
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