[linux-audio-user] Recording Internet Stream, Duplex, Help!?

Frank Barknecht fbar at footils.org
Sat Jan 24 14:38:13 EST 2004

Ed hat gesagt: // Ed wrote:

> OK, after 4 hours on this and enough Googling to break my keyboard, I 
> have to admit defeat.
> What I Want To Do:
>   1. Load a web page containing a Flash Film
>   2. Play the Flash Film
>   3. Record any sound the Flash Film delivers to a WAV file.
>   4. Maybe post-process the WAV into Ogg, MP3, etc.
> What I Have (Hardware + Software):
>   1. SB Audigy

Doesn't the Audigy provide a monitoring device, "capture" or so, that
you can select as source? 

> I can (joyfully!) send the output of amixer if that would help, hope to 
> get a reply on this one soon. In Windows, this is a 5-minute no-brainer. 
> Install Total Recorder, and that's that. I can't imagine that it must be 
> so complex in Linux? First time I've really hit a wall in Linux -- which 
> clearly shows that sound is something which needs to be clarified a 
> *LOT* in Linux. (Having alsamixer start with everything mute is a good 
> example of this!)

Well, silence is a good thing, broken amps and speakers aren't. IIRR
the ALSA docs clearly state that mixer channels are muted. 

Back to the original question: Flash is closed soure, so if flash
doesn't provide a way to save the sound to a file, complains or
feature request should go to Macromedia.

Anyway if you run Mozilla through aoss you can get Flash run through
the ALSA system instead of the OSS emulation. Then it could be
possible to grab this stream with some asoundrc magic. You would
probably need to use some ALSA plugins I'm not that comfortable with,
namely "file". You should test this setup with ALSA software first,
that is use aplay to play a sound that is routed to a "file" plugin.

Put this in ~/.asoundrc:

     type file
     slave.pcm "default"
     file "/tmp/recorder.raw"

Then try "aplay -D totalrecorder some.wav". This will record the audio
output to /tmp/totalrecorder.raw as a raw soundfile. You will need a
converter or an editor which understands opening raw files to make
this useful. 

This should give you a start. Maybe someone with more insight can
complete this example.

For Flash you will then need to use aoss to be able to use the
"totalrecorder" device and you need to redefine pcm.dsp0 as described
in the manpage.

ALSA is an all inclusive package. 

 Frank Barknecht                               _ ______footils.org__

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