Takashi Iwai wrote:
At Fri, 19 May 2006 21:17:45 +0000 (UTC),
Gerald Grabner wrote:
Takashi Iwai <tiwai <at> suse.de> writes:
At Mon, 15 May 2006 12:06:47 +0200,
I wrote:
At Sat, 13 May 2006 13:06:51 +0200,
Gerald Grabner wrote:
Hi,
I'm experimenting with the ALSA PCM API and was wondering whether
there is a simple way to exit a record loop by stopping the pcm, but
without loosing pending frames.
Initially, I was thinking of something like this, where I would call
snd_pcm_drop(pcm) from some other thread:
while ( true )
{
r = snd_pcm_readi (pcm, data, frames);
fwrite (data, 2, 2*r, file);
if ( r != frames )
break;
}
However, snd_pcm_drain(pcm) doesn't work here; the loop continues.
snd_pcm_drop(pcm) breaks the loop, but pending frames are lost, and
r=-EBADFD.
Is there an easy way to stop snd_pcm_readi in a way that I can
retrieve the residual frames? Do I need to set any parameters for
that purpose?
If you're using hw or plughw, it's likely a bug in alsa-driver.
Try the patch below.
Actually the patch was also wrong. snd_pcm_drain() shouldn't wait for
the capture streams. So, the patch becomes pretty simple like below.
I'll commit it to HG repo.
Takashi
diff -r 44d28ed5d3d5 core/pcm_native.c
--- a/core/pcm_native.c Wed May 17 11:26:39 2006 +0200
+++ b/core/pcm_native.c Wed May 17 17:07:17 2006 +0200
<at> <at> -1469,8 +1469,6 <at> <at> static int snd_pcm_drain(
struct snd_pcm_
}
}
up_read(&snd_pcm_link_rwsem);
- if (! num_drecs)
- goto _error;
snd_pcm_stream_lock_irq(substream);
/* resume pause */
Hi Takashi,
there seems to be some problem with this patch (the short one). After
recompiling the kernel (and my application), my application doesn't
exit and I can't kill it anymore. The pcm device is kind of lost. See
below for the /var/log/messages entry.
Hmm, according the error message below, I suspect it's something
different since the patch isn't so intrusive.
Could you test again after reverting the patched part?
After recompiling the kernel with the original source, the problem
disappeared.
Gerald
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