id	summary	reporter	owner	description	type	status	priority	milestone	component	version	severity	resolution	keywords	cc	mlocked
11639	Dynamic PMT: Audio lost after transcode	oli.henning@…		"Since a few weeks i have a problem with mythtranscode:
Audio is completly lost after transcoding.
Perhaps this is the same or similar to http://code.mythtv.org/trac/ticket/7118

== Details ==
- Recording with DVB-C
- Problem occurs just on one specific channel: ""ORF 1""  (prime channel of austria).
- Recorded in switzerland, cable-provider ""UPC Cablecom""
- Problem does not occur on every recording - so the problem is not ""stable""
- Just using ""lossless MPEG-2"" transcoding to cut-off commerials.
- No audio- and no video-recompression (so it's quite fast)
- Before the transcoding all audio-channels are present in mythfrontend
- Changes in audio-streams-combinations within recoding is recognized in mythfrontend (e.g. not from the beginning but from somewhere in the middle of the recoding there is an AC3-stream) 

== Example-File to reproduce ==
https://dl.dropboxusercontent.com/u/517875/2109_20130701213000.mpg
I cutted of the first 310'200'000 Bytes. This are exactly 1'650'000 TS-Packets (each 188 Bytes). So this is just the first ~9 minutes of the original recording.
'''Interesting fact''': If the file would be just the first 1'600'000 TS-Packets, then 
{{{mythtranscode}}} will __not__ have the audio-loss-problem. This is the reason why the test-file-to-reproduce has to be so big.

== LOG-Output of mythtranscode ==
{{{
(my_av_print) Input #0, mpegts, from '/mnt/mythtvRecordings/2109_20130701213000.mpg':
(my_av_print)   Duration: N/A, bitrate: N/A
(my_av_print)     Stream #0:0[0x90]: Video: mpeg2video, 90k tbn
(my_av_print)     Stream #0:1[0x91](ger): Audio: mp3, 0 channels
(my_av_print)     Stream #0:2[0x9b](ger): Audio: ac3, 0 channels
(my_av_print)     Stream #0:3[0xae](ger): Subtitle: dvb_teletext
(InitAV) Skipping invalid audio stream: 1
(InitAV) Skipping invalid audio stream: 2
}}}
You can see, that mythtranscode has some problems in identifying the stream-content:
- mythtranscode could not detect the recording-duration (just logs ""N/A"")
- mythtranscode could not detect details of the video-stream (pixel-format, frame-size, frame-rate, ...)
- mythtranscode detected the first audio-stream as beeing ""mp3"". But actually it's a normal ""mp2"" audio-stream (analyzed with avprobe)

To compare: the log of a 'normal' transcoding:
{{{
(my_av_print) Input #0, mpegts, from '/mnt/mythtvRecordings/2102_20130629193300.mpg':
(my_av_print)   Duration: 00:44:56.88, start: 13209.723733, bitrate: 7099 kb/s
(my_av_print)     Stream #0:0[0x50]: Video: mpeg2video (Main), yuv420p, 720x576 [SAR 64:45 DAR 16:9], 15000 kb/s, 25 fps, 25 tbr, 90k tbn, 50 tbc
(my_av_print)     Stream #0:1[0x51](deu): Audio: mp2, 48000 Hz, stereo, s16, 192 kb/s
(my_av_print)     Stream #0:2[0x52](eng): Audio: mp2, 48000 Hz, stereo, s16, 192 kb/s
(my_av_print)     Stream #0:3[0x6e](deu): Data: dvb_vbi
(InitAV) Skipping unsupported codec 2 on stream 3
}}}

On request i can do further investigations. Perhaps you have to name me some analyze-tools."	Bug Report - General	closed	minor	0.27.2	MythTV - Mythtranscode	0.26-fixes	medium	Duplicate	transcode audio		0