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

Mike Ryan mythtv at redmar.com
Mon Jul 4 09:10:39 EDT 2005


Nick

Thanks for that. I think that may be it:
[root at amdpvr ~]# ~/ffmpeg/ffmpeg -y -i
/mythtv/recordings/1008_20050630200000_20050630210000.nuv -bitexact -f psp -s
320x240 -r 29.97 -b 512 -acodec aac -ac 2 -ar 24000 -ab 32 -map 0:0 -map 0:2
/mythtv/video/M4V10003.MP4
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 #0.2 -> #0.1

Unfortunately, I won't know until I get home and copy it over to the PSP.
Strange how this only happens for Channel 4.

Cheers

Mike

Quoting Nick Rout <nick at rout.co.nz>:

> I think you need to be looking at the -map: option for ffmpeg, although
> from the documentation I can't figure out exactly how to use it.
>
> http://ffmpeg.sourceforge.net/ffmpeg-doc.html
>
> On Sun,  3 Jul 2005 14:28:21 +0100
> Mike Ryan wrote:
>
>> 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
>> _______________________________________________
>> mythtv-users mailing list
>> mythtv-users at mythtv.org
>> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
>
> --
> Nick Rout
>
>




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