View source for Audio conversion (mp3 to ogg)

== ffmpeg ==
Usually ffmpeg takes care of the right library to use for conversion and the following should work:
<syntaxhighlight lang="bash">
ffmpeg -i  file.mp3 file.ogg
</syntaxhighlight>

''However'' there exist different version. On {{SERVER}} version 0.8.17-6 does not convert properly.
<syntaxhighlight lang="bash">
ffmpeg -version
# ffmpeg version 0.8.17-6:0.8.17-1, Copyright (c) 2000-2014 the Libav developers
</syntaxhighlight>

You have to specify the properties in detail to get a functioning ogg-audio file:
<syntaxhighlight lang="bash">
ffmpeg -i  file.mp3 -acodec libvorbis file.ogg # use libvorbis to convert 
ffmpeg -i  file.mp3 -y -acodec libvorbis file.ogg # -y add overwrite mode
ffmpeg -i  file.mp3 -y -qscale:a 8 -acodec libvorbis file.ogg # -qscale:a add quality setting (range: poor 1-10 best)

# use a loop to convert multiple mp3
# ffmpeg version 0.8.17-6:0.8.17-1, Copyright (c) 2000-2014 the Libav developers
# -y overwrite, -acodec audio codec, -qscale:a quality scale for audio
for mp3 in *.mp3;
  do ffmpeg -i "${mp3%.*}.mp3"
  -y \
  -acodec libvorbis \
  -qscale:a 8 \
  "${mp3%.*}.ogg";
done
</syntaxhighlight>

See also [[Selected Linux commands]] for finding files.

=== Information about audio file ===

When an ogg file is converted to <code>flac</code> it does not play natively in Firefox it should be converted using above libvorbis. So the following gets information on the audio file:
 ffprobe "[http://species-id.net/openmedia/File:Corvus_brachyrhynchos_call.ogg Corvus_brachyrhynchos_call.ogg]" 2>&1 | grep --ignore-case 'Stream.*audio'
 #    <span style="color:red;">Stream #0:0: Audio</span>: flac, 22050 Hz, mono, s16

[[Category: Audio]]