[alsa-devel] plug:dmix slows playback

[Jaroslav Kysela]

On Fri, 12 Jun 2009, Steve Langstaff wrote:

>> From: alsa-devel-bounces at alsa-project.org [mailto:alsa-devel-
>> bounces at alsa-project.org] On Behalf Of Jaroslav Kysela
>
>> On Fri, 12 Jun 2009, Steve Langstaff wrote:
>>
>>> Hi All.
>>>
>>> I've got an installation of ALSA (1.0.19 on an embedded device) where
>> using
>>> plug and dmix as my output device slows down playback - voices and
>> tones are
>>> lower in pitch and the playback takes longer than when not using
>> plug:dmix,
>>> e.g.
>>
>> Does 48000Hz 2 channel source work OK with direct device (without dmix)
>> for your hardware?
>
> Yes, I converted the original sample to 48000 Hz, Stereo, and it sounds OK
> when I don't use dmix.
>
> /mnt # time aplay -v ignition48000s.wav

....

> Slave: Hardware PCM card 0 'LM4549' device 0 subdevice 0

>  msbits       : 16

If I remember correctly, this value was 32 in your dmix setup.
Could you try command:

 	aplay -D"plug:'dmix:FORMAT=S16_LE'" <filename>

 						Jaroslav

-----
Jaroslav Kysela <perex at perex.cz>
Linux Kernel Sound Maintainer
ALSA Project, Red Hat, Inc.