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

Ed lau at frosch.org
Sat Jan 24 12:07:08 EST 2004


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
   2. Alsa kernel drivers, 1.0.0 RC2
   3. Alsa libs, 1.0.0 RC2
   4. Jack, compiled with the above Alsa libs
   5. Ecasound, compiled with the Alsa libs and Jack

What works:

   1. Sound from CD, System beeps, etc. works

What doesn't work:

   1. Alsa: arecord -f cd -o test.wav, when playing an Ogg file, e.g.
   2. Ecasound: ecasound -i:alsahw,0 -o test.wav, when playing an Ogg
      file, e.g.

Am I missing something fundamental here? I can't imagine that this is an 
especially arcane wish, simply wanting to record and play at the same 
time, yet I can't find anything on this which helps. I have played with 
alsamixer for about an hour, but I simply get silence all the time. All 
the 'capture' devices are things like Mic, CD, Line-In, etc., which is, 
obviously, NOT what I want. I simply want to record what I am currently 
hearing -- although I'm testing this with playback of Ogg, actually I 
clearly want to record the sound from the Flash Film mentioned.

I have read the various docs for Alsa, Ecasound and Jack, but I have to 
admit that sound on Linux is *very* confusing. I am not really sure 
whether I'm supposed to be using /dev/dsp, alsahw, or some other arcane 
terminologies -- kernel compilation is easy in comparison! I'm not 
getting any errors, by the way, everything *seems* to work, but when I 
stop playback and check the output, all I hear is dead air.

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!)

Thanks a million if anyone can help: otherwise I'm rebooting into 
Windows for now, since there's no other way of doing this at the moment.


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