[Gllug] 3gp players/encoders for nix

[damion.yates at gmail.com]

On Sun, 20 Aug 2006, Adrian McMenamin wrote:

> On Sun, 2006-08-20 at 00:35 +0100, Adrian McMenamin wrote: 
> > 
> > However it is detailed in libavcodec/amr.c but it seems I am
> > without the right support - will keep looking

Sorry yes, amr.c was the file.  Sounds like you got it going okay.

> OK, I guess this is a bit too specific for this list, but I'll ask
> (once) here anyway...
> 
> I have installed the software and rebuilt ffmpeg and it appears to
> recognise the sound format but is still not converting it - I think
> because I need to select a proper audiocodec for flash video...
> 
> adrian at bossclass:~$ ffmpeg -i aine.3gp aine.flv

[snipped]

>   Stream #0.0(jpn): Video: h263, yuv420p, 176x144,  9.58 fps(r)
>   Stream #0.1(jpn): Audio: amr_nb, 8000 Hz, mono
> Output #0, flv, to 'aine.flv':
>   Stream #0.0: Video: flv, yuv420p, 176x144, q=2-31, 200 kb/s,  9.58
> fps(c)
> Stream mapping:
>   Stream #0.0 -> #0.0
> Press [q] to stop encoding
> frame=   75 q=2.0 Lsize=     229kB time=7.8 bitrate= 239.2kbits/s
> video:217kB audio:0kB global headers:0kB muxing overhead 5.389742%
 
It's odd that it's bothering to encode without audio at all, the
'Audio: amr_nb, 8000 Hz, mono' means you've definitely got amr support
which is what you needed.

> I have tried using adpcm_swf as the output audio codec but that
> generates an error...
> 
> Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'aine.3gp':
>   Duration: 00:00:08.2, start: 0.000000, bitrate: 75 kb/s
>   Stream #0.0(jpn): Video: h263, yuv420p, 176x144,  9.58 fps(r)
>   Stream #0.1(jpn): Audio: amr_nb, 8000 Hz, mono
> Output #0, flv, to 'aine.flv':
>   Stream #0.0: Video: flv, yuv420p, 176x144, q=2-31, 200 kb/s,  9.58
> fps(c)
>   Stream #0.1: Audio: adpcm_swf, 8000 Hz, mono, 64 kb/s
> Stream mapping:
>   Stream #0.0 -> #0.0
>   Stream #0.1 -> #0.1

> Error while opening codec for output stream #0.1 - maybe incorrect
> parameters such as bit_rate, rate, width or height
> 
> Any flash gurus know what the proper settings should be?

You should feed ffmpeg a flash file and encode to any other format, it
will then tell you the audio parameters adpcm_swf is looking for so
you can force those in your encode from 3gp.

Also ffmpeg comes with several default profile settings (-target)
which deal with all of the frame rate and audio rate/channel settings
that it needs to convert.  I don't know if there is one for flv, but
I'd recommend checking that out.  My compile is 6months old now and
I've not had a reason to get back in to video editing so you'll need
to investigate, sounds like you've almost got it sorted.

I happened to have a .flv file nabbed from youtube which I converted
to .3gp recently, these are my ffmpeg outputs:

Input #0, flv, from 'ichiban.flv':
  Duration: N/A, bitrate: N/A
  Stream #0.0: Audio: mp3, 22050 Hz, mono
  Stream #0.1: Video: flv, yuv420p, 320x240, 1000.00 fps
Output #0, 3gp, to 'blah.3gp':
  Stream #0.0: Video: h263, yuv420p, 128x96, 15.00 fps, q=2-31, 25kb/s
  Stream #0.1: Audio: amr_nb, 8000 Hz, mono, 6 kb/s

Damion

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Damion Yates - damion.yates at gmail.com
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