[mythtv-users] no audio on some files

[John Pilkington]

On 11/12/10 17:03, Richard Morton wrote:
> myth at myth-server:/var/lib/mythtv/videos/films$  ffmpeg -i "Star Trek 2
> The Wrath of Khan.mkv"
> FFmpeg version SVN-r0.5.1-4:0.5.1-1ubuntu1, Copyright (c) 2000-2009
> Fabrice Bellard, et al.
>    configuration: --extra-version=4:0.5.1-1ubuntu1 --prefix=/usr
> --enable-avfilter --enable-avfilter-lavf --enable-vdpau --enable-bzlib
> --enable-libgsm --enable-libschroedinger --enable-libspeex
> --enable-libtheora --enable-libvorbis --enable-pthreads --enable-zlib
> --disable-stripping --disable-vhook --enable-runtime-cpudetect
> --enable-gpl --enable-postproc --enable-swscale --enable-x11grab
> --enable-libdc1394 --enable-shared --disable-static
>    libavutil     49.15. 0 / 49.15. 0
>    libavcodec    52.20. 1 / 52.20. 1
>    libavformat   52.31. 0 / 52.31. 0
>    libavdevice   52. 1. 0 / 52. 1. 0
>    libavfilter    0. 4. 0 /  0. 4. 0
>    libswscale     0. 7. 1 /  0. 7. 1
>    libpostproc   51. 2. 0 / 51. 2. 0
>    built on Mar  4 2010 12:35:30, gcc: 4.4.3
>
> Seems stream 0 codec frame rate differs from container frame rate:
> 50.00 (50/1) ->  100.00 (100/1)
> Input #0, matroska, from 'Star Trek 2 The Wrath of Khan.mkv':
>    Duration: 01:50:44.81, start: 0.000000, bitrate: N/A
>      Stream #0.0(eng): Video: h264, yuv420p, 704x432, PAR 157:107 DAR
> 6908:2889, 100 tbr, 1k tbn, 50 tbc
>      Stream #0.1: Audio: mp3, 48000 Hz, stereo, s16
> At least one output file must be specified
>
>
>
> looks ok to me, but then again I am no expert... I am going to see if
> I have the original files to see if they are ok, but I think I deleted
> them after I saw they played ok in VLC...
>
> R

Here's the ffmpeg output from a BBC FOUR programme as received:
Input #0, mpegts, from '1009_20101211005600.mpg':
   Duration: 01:11:55.74, start: 51835.297011, bitrate: 5729 kb/s
   Program 1
     Stream #0.0[0xc9]: Video: mpeg2video, yuv420p, 720x576 [PAR 64:45 
DAR 16:9], 15000 kb/s, 25 fps, 25 tbr, 90k tbn, 50 tbc
     Stream #0.1[0x191](eng): Audio: mp2, 48000 Hz, 2 channels, s16, 256 
kb/s
     Stream #0.2[0x192](eng): Audio: mp2, 48000 Hz, 1 channels, s16, 64 kb/s
     Stream #0.3[0x259](eng): Subtitle: dvbsub
     Stream #0.4[0xd1]: Data: [5][0][0][0] / 0x0005

The main audio stream is the 256 kb/s, the 64 kb/s is the audio 
description channel; your output doesn't specify a data rate at all - 
only a sampling rate.  Does that file play in vlc now, or do you mean it 
did before you processed it? :-)  Of course, after I sent the last 
message I realised that I didn't know whether ffmpeg understood mkv; it 
looks as if it probably does, but your output doesn't show an overall 
bitrate either.  Have you compared outputs for playing/mute recordings?