[MPlayer-users] Trouble with realtime transcoding

[Giacomo Comes]

On Thu, Sep 13, 2007 at 01:40:35PM +0400, wwwadmin wrote:
> I try to transcode aac stream to mp3, but i have trouble: when mplayer
> out sound to soundcard, all works fine, but when I try to send
> raw-output to lame, encoding work with a jerks: mplayer recieve some
> portion of a stream (~2sec) and freeze (~0.5sec), and it's repeated and
> repeated. I use construction "mplayer->lame->ezstream" to send encoded
> mp3 stream to icecast, and in freeze time i listen noise. I try to use
> -cache and -cache-min with no effect. Where is a bug?
> 
> Command line: 
> mplayer -playlist /tmp/radio/drum.m3u -ac faad -demuxer aac -vc
> null -vo null -cache 256 -cache-min 40 -ao
> pcm:nowaveheader:file=/dev/stdout | lame --silent -q 0 -b 128 - - |
> ezstream -c /usr/local/etc/ez_drum.xml

I assume that the cache you specify is big enough to permit a smoot
playback. If not a stop is normal.

Apart from that, you can use the command line in this way in order to
feed properly the raw audio stream to lame (requires bash or a bourne
compatible shell):

mplayer <options> -vc null -vo null \
  -ao pcm:nowaveheader:file=/dev/fd/4 4>&1 >&2 | lame <options> ....

For even faster decoding replace -vc null with -vc dummy.
-vc dummy may not work all the times, but in this case it should.

Ciao
Giacomo