theora - Jun 2010 - Multi-audio in OGV?

Hi,

I am trying to reencode a video from the European Parliament (WMV)
which has multiple audio tracks for the different languages:

===============================================================================================Debian-50-lenny-32-minimal:/var/www/tmp#
ffmpeg2theora --audiostream 0
VODChapter_20100323_09030000_12350000_Ch04.wmv
[wmv3 @ 0xb7e21b50]Extra data: 8 bits left, value: 0
[wmv3 @ 0xb7e21b50]Extra data: 8 bits left, value: 0
[wmv3 @ 0xb7e21b50]Extra data: 8 bits left, value: 0
Input #0, asf, from 'VODChapter_20100323_09030000_12350000_Ch04.wmv':
  Duration: 03:31:55.2, start: 5.000000, bitrate: 1114 kb/s
    Stream #0.0: Audio: wmav2, 44100 Hz, mono, 32 kb/s
    Stream #0.1: Audio: wmav2, 44100 Hz, mono, 32 kb/s
    Stream #0.2: Audio: wmav2, 44100 Hz, mono, 32 kb/s
    Stream #0.3: Audio: wmav2, 44100 Hz, mono, 32 kb/s
    Stream #0.4: Audio: wmav2, 44100 Hz, mono, 32 kb/s
    Stream #0.5: Audio: wmav2, 44100 Hz, mono, 32 kb/s
    Stream #0.6: Video: wmv3, yuv420p, 512x288 [PAR 0:1 DAR 0:1], 512
kb/s, 25.00 tb(r)
    Stream #0.7: Video: wmv3, yuv420p, 512x288 [PAR 0:1 DAR 0:1], 256
kb/s, 25.00 tb(r)
    Stream #0.8: Audio: wmav2, 44100 Hz, mono, 32 kb/s
    Stream #0.9: Video: wmv3, yuv420p, 256x144 [PAR 0:1 DAR 0:1], 90
kb/s, 25.00 tb(r)
  Using stream #0.0 as audio input
[wmv3 @ 0xb7e21b50]Extra data: 8 bits left, value: 0
  Resize: 512x288
      0:54:34.71 audio: 47kbps video: 470kbps, time remaining: 00:58:08

===============================================================================================
I was wondering if OGV supports multi-audio tracks, howto create such
files, and if the audio track choice is implemented in Chrome/Firefox.

Best,

-- 
Benjamin Henrion <bhenrion at ffii.org>
FFII Brussels - +32-484-566109 - +32-2-4148403
"In July 2005, after several failed attempts to legalise software
patents in Europe, the patent establishment changed its strategy.
Instead of explicitly seeking to sanction the patentability of
software, they are now seeking to create a central European patent
court, which would establish and enforce patentability rules in their
favor, without any possibility of correction by competing courts or
democratically elected legislators."

On 6/25/2010 9:00 AM, Benjamin Henrion wrote:
> I was wondering if OGV supports multi-audio tracks, howto create such
> files, and if the audio track choice is implemented in Chrome/Firefox.
>
There's no support in Firefox for this, but we've talked about adding
it.

--Chris

> I was wondering if OGV supports multi-audio tracks, howto create such
> files, and if the audio track choice is implemented in Chrome/Firefox.
Ogg does support multiple audio tracks. ffmpeg2theora does not.
Your best bet is to do as many encodes as there are languages, with only one
of them including the video, then merge the results.
First command is what you already use.
Second to last commands add --novideo and --audiostream N (N going
through the different audio tracks found by ffmpeg).
Then you end up with a track per language, with the first one also
containing the video.
You can then merge these using oggz-merge, from liboggz, eg:
oggz-merge -o final.ogv first-with-video.ogv language-only-*.ogv


Or you could try looking for other converters with use libogg,
libvorbis, and libtheora (eg, not ffmpeg based encoders, though ffmpeg
based decoders are OK).

Though maybe the EP also has an Ogg format version of this, avoiding
all the conversion hassle ? It'd seem peculiar to use some Windows
specific format only.