[mythtv-users] Mythtranscode FIFO stopping mid transcode without error

Wed Dec 4 12:37:19 UTC 2013

Starting a new thread but related to the later part of the previous discussion here:  http://www.gossamer-threads.com/lists/engine?do=post_view_flat;post=554180;page=1;mh=-1;list=mythtv;sb=post_latest_reply;so=ASC

Essentially I am not having a trouble free run with Mythtranscode in FIFO mode as an alternative to the standard Mythtranscode output.

The symptoms are that on about 1-in-5 to 1-in-8 attempts Mythtranscode just stops at a random point in the transcode process. No warnings or errors or anything just stops as if end of file reached. FFMPEG accordingly also assumes that its the end of the file and ends happily but of course only the first chunk of the recording is processed.

I turned on debug all logging in mythtranscode (extract below) but there just doesn't seem to be anything wrong it just stops (at different points in the file in consecutive runs). It seems to happen more often in longer recordings, most of the 20-30min shows go through without a problem.

I'm guessing either underflow or overflow of the pipes (probably overflow because FFMPEG is only processing at some 10-30fps depending on the recording and that would probably make sense why the problem happens more on longer files (more time for the pipe to fill and overflow)). It also seems to happen more often when other things are happening as well like commflagging which probably slows FFMPEG down more than it slows mythtranscode.

Any suggestions on where to look or what to try would be greatly appreciated. Can I temporarily increase the size of the pipes to see if overflow is the problem? I see in the earlier stage of the log that I get to video(129) and audio(35) for 'allocating additonal buffer' but those messages all occur within the first few minutes and the below failure occurred after nearly 30min. 

On the first run of the below file it got through about 60000 odd frames. As per below on the second run it only got through 22630. Should be some 125000 frames total.

2013-12-04 22:26:02.983160 I  AFD: video timecode 1377715080 15307945 15307945 15307905
2013-12-04 22:26:02.983293 E  AFD: VBI: Unknown descriptor: 153
2013-12-04 22:26:02.983301 E  AFD: VBI: Unknown descriptor: 44
2013-12-04 22:26:02.983420 E  AFD: VBI: Unknown descriptor: 153
2013-12-04 22:26:02.983426 E  AFD: VBI: Unknown descriptor: 44
2013-12-04 22:26:02.983567 E  AFD: VBI: Unknown descriptor: 153
2013-12-04 22:26:02.983573 E  AFD: VBI: Unknown descriptor: 44
2013-12-04 22:26:02.983671 E  AFD: VBI: Unknown descriptor: 153
2013-12-04 22:26:02.983677 E  AFD: VBI: Unknown descriptor: 44
2013-12-04 22:26:02.983957 I  AFD: audio timecode 1377721051 1377721051 15308011 15308043
2013-12-04 22:26:02.984149 I  AFD: audio timecode 1377723931 1377723931 15308043 15308075
2013-12-04 22:26:02.997569 I  AFD: video timecode 1377718680 15307985 15307985 15307945
2013-12-04 22:26:02.997833 I  AFD: audio timecode 1377726811 1377726811 15308075 15308107
2013-12-04 22:26:03.008844 I  AFD: video timecode 1377722280 15308025 15308025 15307985
2013-12-04 22:26:03.009107 I  AFD: audio timecode 1377729691 1377729691 15308107 15308139
2013-12-04 22:26:03.021429 I  AFD: video timecode 1377725880 15308065 15308065 15308025
2013-12-04 22:26:03.021693 I  AFD: audio timecode 1377732571 1377732571 15308139 15308171
2013-12-04 22:26:03.325289 I  MythSocket(ffffffffacd157b8:25): read  <- 25 83      BACKEND_MESSAGE[]:[]UPDATE_FILE_SIZE 1010 2013-12-04T09:57:00Z 38...
2013-12-04 22:26:03.325302 I  MythEvent: UPDATE_FILE_SIZE 1010 2013-12-04T09:57:00Z 3804171916
frame=22615 fps= 14 q=28.0 size=  244810kB time=00:15:02.68 bitrate=2221.7kbits/s    ^Mframe=22623 fps= 14 q=28.0 size=  244957kB time=00:15:03.00 bitrate=2222.2kbits/s    ^Mframe=22630 fps= 14 q=28.0 size=  245042kB time=00:15:03.71 bitrate=2221.3kbits/s    ^M2013-12-04 22:26:04.417472 I  Player(0): StopPlaying - begin
2013-12-04 22:26:04.421602 I  Player(0): Decoder thread exiting.
2013-12-04 22:26:04.421742 I  Player(0): Exited decoder loop.
2013-12-04 22:26:04.456300 I  ~VideoOutputNull()
2013-12-04 22:26:04.485281 I  Player(0): StopPlaying - end
2013-12-04 22:26:04.496733 N  Transcoding /media/fs4/recordings/1090_20131204012700.mpg done
2013-12-04 22:26:04.496778 I  Waiting for threads to exit.
2013-12-04 22:26:04.551131 I  MythSocket(ffffffffacd15810:23): write -> 23 61      MESSAGE[]:[]MASTER_UPDATE_PROG_INFO 1090 2013-12-04T01:27:00Z
2013-12-04 22:26:04.551442 I  MythSocket(ffffffffacd15810:23): read  <- 23 2       OK
2013-12-04 22:26:04.554783 I  MythSocket(ffffffffacd157b8:25): read  <- 25 769     BACKEND_MESSAGE[]:[]RECORDING_LIST_CHANGE UPDATE[]:[]Swallows And...
2013-12-04 22:26:04.554807 I  MythEvent: RECORDING_LIST_CHANGE UPDATE

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