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Groups > comp.os.linux.misc > #7622

Re: video transcoding softeater.

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The Natural Philosopher <tnp@invalid.invalid> wrote:
> On 23/03/13 20:15, Chris Davies wrote:
>> The Natural Philosopher <tnp@invalid.invalid> wrote:
>>> I record TV prtograms. They end up as .m2t files.

>> Providing us your command line and the error that gets spat out would
>> help tremdendously.

> Ok here  you are. Personal details altered
> ffmpeg -i ~/Videos/Robin\ Hood.m2t -ab 128 -ar 44100 -vn Robin\ Hood.mpg
> ffmpeg version 0.8.5-4:0.8.5-0ubuntu0.12.04.1, Copyright (c) 2000-2012 
> the Libav developers
>   built on Jan 24 2013 18:01:36 with gcc 4.6.3
> *** THIS PROGRAM IS DEPRECATED ***
> This program is only provided for compatibility and will be removed in a 
> future release. Please use avconv instead.

I've managed to avoid this deprecation warning so far. But I know that
Debian's also switched to avconv so I guess I'll have to head that way
sooner or later.


> Input #0, mpegts, from '/home/leo/Videos/Robin Hood.m2t':
>   Duration: 02:36:10.37, start: 89877.835300, bitrate: 1850 kb/s
>   Program 27136
>     Stream #0.0[0x2bd]: Video: mpeg2video (Main), yuv420p, 544x576 [PAR 
> 32:17 DAR 16:9], 15000 kb/s, 25.61 fps, 25 tbr, 90k tbn, 50 tbc
>     Stream #0.1[0x2be](eng): Audio: mp2, 48000 Hz, stereo, s16, 128 kb/s
>     Stream #0.2[0x2c0](eng): Audio: mp3, 0 channels, s16 (visual impaired)
>     Stream #0.3[0x2bf](eng): Subtitle: dvbsub

This is the exciting stuff. You're using -vn to strip out the video,
which leaves the two audio channels. You haven't specified which one to
use so ffmpeg maps the first and ignores the second.

> The bitrate parameter is set too low.It takes bits/s as argument, not 
> kbits/s

Ah! You've asked for an audio bitrate of 128 bits/second; you're more
likely to be expecting 128 kbit/sec, so you need "-ab 128k".


> Output #0, mpeg, to 'Robin Hood.mpg':
>   Metadata:
>     encoder         : Lavf53.21.1
>     Stream #0.0(eng): Audio: mp2, 44100 Hz, stereo, s16, 0 kb/s

Your 128 bits/sec audio stream is also shown here ("0 kb/s") ^^


> [NULL @ 0x19cf3c0] Junk in packetate=   3.4kbits/s
>     Last message repeated 1 timesate=   3.4kbits/s
> [mpegts @ 0x19ab9a0] Invalid timestamps stream=0, pts=707, 
> dts=8589924499, size=11045

Not sure about this. I'm hoping for now it'll go away once you fix the
bitrate. If it doesn't please come back here with an update and I'll
dig some more. Most of my stuff doesn't record with errors, though,
so it's tricky for me to test any suggestions.

One of the more helpful ffmpeg pages out there is
http://howto-pages.org/ffmpeg/ which I would strongly recommend you
peruse. (When you have an hour or three.)

Chris

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Thread

video transcoding softeater. The Natural Philosopher <tnp@invalid.invalid> - 2013-03-22 23:14 +0000
  Re: video transcoding softeater. J G Miller <miller@yoyo.ORG> - 2013-03-22 23:56 +0000
    Re: video transcoding softeater. The Natural Philosopher <tnp@invalid.invalid> - 2013-03-23 09:17 +0000
      Re: video transcoding softeater. Johann Klammer <klammerj@NOSPAM.a1.net> - 2013-03-23 13:52 +0100
  Re: video transcoding softeater. Chris Davies <chris-usenet@roaima.co.uk> - 2013-03-23 20:15 +0000
    Re: video transcoding softeater. The Natural Philosopher <tnp@invalid.invalid> - 2013-03-24 10:49 +0000
      Re: video transcoding softeater. SwissCheese <swisscheese@cfl.rr.com> - 2013-03-24 08:31 -0400
        Re: video transcoding softeater. The Natural Philosopher <tnp@invalid.invalid> - 2013-03-24 14:58 +0000
      Re: video transcoding softeater. Chris Davies <chris-usenet@roaima.co.uk> - 2013-03-24 14:29 +0000
        Re: video transcoding softeater. The Natural Philosopher <tnp@invalid.invalid> - 2013-03-24 15:22 +0000
          Re: video transcoding softeater. The Natural Philosopher <tnp@invalid.invalid> - 2013-03-24 15:53 +0000
            Re: video transcoding softeater. The Natural Philosopher <tnp@invalid.invalid> - 2013-03-24 15:58 +0000
              Re: video transcoding softeater. Chris Davies <chris-usenet@roaima.co.uk> - 2013-03-24 16:28 +0000
  Re: video transcoding softeater. faeychild <faeychild@noname.afraid.org> - 2013-03-25 10:00 +1100

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