Re: How to read the sound card ?

[Benoit Fouet <benoit.fouet@purplelabs.com>]

Hi,

I think the simpler way is to write a plugin for alsa, which will take
place in the plugin chain, just before outputing the sound.
The last time i did that, you couldn't do it if using softmix (which has
to be directly plugged to hw) but maybe it's possible now...
There is a doc written on how to write an ALSA plugin, that should help
you do that ;)

Regards,

-- Ben


Michaël Todorovic wrote:

>hello,
>I want to read the data on the sound card (to do a fft and other 
>things). I have first tried the capture stream with snd_pcm_readi and 
>everything is working. My problem is that I want to read the sound 
>output (pcm or mixer). For example, I want to read the sound that xmms 
>or mplayer is writing on the sound card. If I just change 
>SND_PCM_STREAM_CAPTURE to SND_PCM_STREAM_PLAYBACK in snd_pcm_open, 
>snd_pcm_readi fails.
>
>So my question is : how can I read the sound output with the alsa-lib ?
>
>Thank you
>
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