[alsa-devel] Beep sound in the end of audio file

[Peter Ujfalusi]

On Wednesday 06 May 2009 17:19:49 ext Todd Fischer wrote:
> Hi,
>
> FWIW: while developing a GSTreamer presentation using a BegleBoard (rev C),
> I noticed the same "tuck" sound.  It also occurs a second or two after the
> GST application exits.  I assumed it was some power management code that
> was disabling the audio codec after it had gone idle, but never looked into
> it.  BeagleBoard also uses TWL4030.
>
> GST command: gst-launch audiotestsrc freq=1000 num-buffers=100 ! alsasink
>
> /proc/version: Linux version 2.6.28-omap1 (ddompe at Aleph) (gcc version 4.3.1
> (GCC) ) #2 Thu Mar 5 08:55:58 CST 2009

The "tuck" is coming from the codec, when it is powered down (in the old 
twl4030 codec found in omap-2.6.28 branch of linux-omap).
But, it still happens with the latest version, when the codec is muted only.
I can observe the "tuck" on Headset output, but not on the PreDrive...
The Headset enable and disable is implemented according to the TRM, but it 
seams that additional tweaking is needed..

-- 
Péter