Capturing audio output

Capturing audio output

[Tarik Reghif]

Hi,

I'm trying to build a program to grab whatever's being played on a computer.
There isn't a recording device that will in all cases pass the audio
being outputed to a recording channel is there?

The idea being, if the user is playing a video, sound file, voice
conversation, etc, whatever goes through the speakers going into my
program.
What I actually want is so it goes out my program instead of the
speakers (but I'm kinda flexible).

Is this possible without delving too much into alsa? (i.e. writing an
app rather than re-writing alsa)

Any ideas would be greatly appreciated,

Cheers

Tarik


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Re: Capturing audio output

[Takashi Iwai]

At Wed, 22 Feb 2006 16:53:22 +0000,
Tarik Reghif wrote:
> 
> Hi,
> 
> I'm trying to build a program to grab whatever's being played on a computer.
> There isn't a recording device that will in all cases pass the audio
> being outputed to a recording channel is there?
> 
> The idea being, if the user is playing a video, sound file, voice
> conversation, etc, whatever goes through the speakers going into my
> program.
> What I actually want is so it goes out my program instead of the
> speakers (but I'm kinda flexible).

If you're using a sound card with ac97 codec chip, you can set "Mix"
as the capture source.  On alsamixer, go to capture view mode via Tab,
choose "Mix", then push space to toggle the capture source.

It's not always a good quality, but easily done without any software
setting.

Some other codecs like HD-audio have similar functions.


> Is this possible without delving too much into alsa? (i.e. writing an
> app rather than re-writing alsa)

A loopback pluging isn't properly implemented yet, unfortunately.


Takashi


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