[mythtv-users] Problem using ffmpeg to transcode a DVB-T recording

[Mike Ryan]

Hi

I use ffmpeg to transcode my dvb-t recordings to watch on a PSP and I'm in the
UK. Everything works fine apart from anything I record from Channel 4. For some
reason, there is no sound when I play it back on the PSP. I believe the problem
is that ffmpeg seems to think there's two sound channels - it's selecting the
primary one. Playback on MythTV is no problem. Here's a sample of the output
from
ffmpeg:

ffmpeg version 0.4.9-pre1, build 4756, Copyright (c) 2000-2004 Fabrice Bellard
  configuration:  --enable-faac
  built on Jun 17 2005 16:02:27, gcc: 3.4.3 20050227 (Red Hat 3.4.3-22.fc3)
Input #0, mpeg, from
'/mythtv/recordings/1008_20050630200000_20050630210000.nuv':
  Duration: 00:59:55.1, start: 1697.474022, bitrate: 2893 kb/s
  Stream #0.0[0x1e0]: Video: mpeg2video, yuv420p, 704x576, 25.00 fps, 10000 kb/s
  Stream #0.1[0x1c1]: Audio: mp2, 48000 Hz, mono, 64 kb/s
  Stream #0.2[0x1c0]: Audio: mp2, 48000 Hz, stereo, 192 kb/s
Output #0, psp, to '/mythtv/video/M4V10003.MP4':
  Stream #0.0: Video: mpeg4, yuv420p, 320x240, 29.97 fps, q=2-31, 512 kb/s
  Stream #0.1: Audio: aac, 24000 Hz, stereo, 32 kb/s
Stream mapping:
  Stream #0.0 -> #0.0
  Stream #0.1 -> #0.1

For any other channel, the larger bitrate audio channel comes first, ie:
Input #0, mpeg, from
'/mythtv/recordings/1073_20050628191500_20050628195800.nuv':
  Duration: 00:42:54.5, start: 16393.593167, bitrate: 3053 kb/s
  Stream #0.0[0x1e0]: Video: mpeg2video, yuv420p, 720x576, 25.00 fps, 15000 kb/s
  Stream #0.1[0x1c0]: Audio: mp2, 48000 Hz, stereo, 256 kb/s
  Stream #0.2[0x1c1]: Audio: mp2, 48000 Hz, mono, 56 kb/s

Any got any ideas how I either
1: Tell ffmpeg to select the second audio input channel
or
2: Get myth to record with the larger audio channel first (if this makes sense)

Thanks in advance for any help

Regards

Mike