[alsa-devel] trace PCM data from usb bus to alsa lib

[Takashi Iwai]

At Wed, 17 Jun 2009 08:33:15 +0000 (UTC),
ZeroCluo wrote:
> 
> Takashi Iwai <tiwai <at> suse.de> writes:
> 
> > 
> > At Wed, 17 Jun 2009 16:10:26 +0800,
> > Zero Luo wrote:
> > > 
> > > Dear Takashi,
> > >  
> > >    Data from usb dongle is 16K*16 bit PCM data.
> > 
> > And what is the format and channels you are using in alsa-lib?
> > alsa-lib itself can convert formats and channels automatically if needed.
> > 
> > Takashi
> 
> 
>  In alsa-lib ,I set data format as 8K * mulaw .
>         hwparams.format = SND_PCM_FORMAT_MU_LAW;
>         hwparams.rate = 8000;
>         hwparams.channels = 1;
>  Yes,indeed alsa-lib help to convert formats.But before alsa-lib convert pcm 
> data to mulaw,I dumped the src data in snd_pcm_mulaw_encode() which already 
> has no "0000" .

Well, another question is whether the output result is correct.
Did you get broken output or so?


Takashi