dmix vs alsaplayer [was jackd, zynaddsubfx and iiwusynth]

dmix vs alsaplayer [was jackd, zynaddsubfx and iiwusynth]

[Patrick Shirkey]

Levi Burton wrote:

> Has anyone tried the dmix plugin thats part of alsa rc8?  This looks 
> interesting, but im scared if I install rc8, I will be bitten by that 
> alsa-lib bug again.
> 

I was fscking around with it on Saturday. So far I have managed to use 
multiple instances of aplay but other apps like alsaplayer bork at it. I 
have yet to figure out why but I think I should probably submit a bug 
report somewhere.

I had to remove /dev/dsp otherwise alsaplayer will use the oss drivers.

Both of these commands give the same error.

$ alsaplayer -o alsa -d "plug:'dmix:RATE=44100'" track_8.wav
$ alsaplayer -o alsa -d plug:\'dmix:SLAVE=\"hw:2,1\",RATE=44100\' 
track_8.wav

--------
error on set_period_size (512)
Unavailable hw params:
ACCESS:  RW_INTERLEAVED
FORMAT:  S16_LE
SUBFORMAT:  STD
SAMPLE_BITS: 16
FRAME_BITS: 32
CHANNELS: 2
RATE: 44100
PERIOD_TIME: (125011 125012)
PERIOD_SIZE: 5513
PERIOD_BYTES: 22052
PERIODS: (2 3)
BUFFER_TIME: (371519 371520)
BUFFER_SIZE: 16384
BUFFER_BYTES: 65536
TICK_TIME: ALL
error on set_period_size (1024)
Unavailable hw params:
ACCESS:  RW_INTERLEAVED
FORMAT:  S16_LE
SUBFORMAT:  STD
SAMPLE_BITS: 16
FRAME_BITS: 32
CHANNELS: 2
RATE: 44100
PERIOD_TIME: (125011 125012)
PERIOD_SIZE: 5513
PERIOD_BYTES: 22052
PERIODS: (2 3)
BUFFER_TIME: (371519 371520)
BUFFER_SIZE: 16384
BUFFER_BYTES: 65536
TICK_TIME: ALL
failed to configure output device...trying OSS
error opening /dev/dsp

I could not find a suitable output module on your
system. Make sure they're in "/usr/local/lib/alsaplayer/output/".
Use the -o parameter to select one.

failed to load output plugin (alsa). exitting...
--------

-- 
Patrick Shirkey - Boost Hardware Ltd.
Http://www.boosthardware.com
Http://www.djcj.org - The Linux Audio Users guide
========================================

Being on stage with the band in front of crowds shouting, "Get off! No! 
We want normal music!", I think that was more like acting than anything 
I've ever done.

Goldie, 8 Nov, 2002
The Scotsman



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Re: dmix vs alsaplayer [was jackd, zynaddsubfx and iiwusynth]

[Kai Vehmanen]

On Tue, 4 Mar 2003, Patrick Shirkey wrote:

>> Has anyone tried the dmix plugin thats part of alsa rc8?  This looks 
> I was fscking around with it on Saturday. So far I have managed to use 
> multiple instances of aplay but other apps like alsaplayer bork at it. I 
> have yet to figure out why but I think I should probably submit a bug 
> report somewhere.

I've tried it with ecasound and seems to work just fine. One catch is that 
dmix only supports a certain set of audio format parameters at a time. You 
can change these via asoundrc (or dmix:x,y), but not at run time. Anyway, 
with default dmix installation (on top of snd-intel8x0 hw):

ecasound -i foo.wav -o alsa,dmix -b:4096 &
ecasound -i bar.wav -o alsa,dmix -b:4096

... plays the two files at the same time. -b:4096 is needed because of the 
abovementioned reasons.

> $ alsaplayer -o alsa -d plug:\'dmix:SLAVE=\"hw:2,1\",RATE=44100\' 
> track_8.wav
[...]
> PERIOD_SIZE: 5513
> PERIOD_BYTES: 22052
[...]
> error on set_period_size (1024)
> Unavailable hw params:

Try matching the alsaplayer period_size to the one used by dmix with 
the "-f 22052" alsaplayer option. 

PS Opening dmix in non-interleaved mode produces totally garbled output:
   "ecasound -i foo.wav -f:16,2,44100,n -o alsa,dmix -b:4096"

--
 http://www.eca.cx
 Audio software for Linux!



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Re: dmix vs alsaplayer [was jackd, zynaddsubfx and iiwusynth]

[Jaroslav Kysela]

On Mon, 3 Mar 2003, Kai Vehmanen wrote:

> Try matching the alsaplayer period_size to the one used by dmix with 
> the "-f 22052" alsaplayer option. 

alsaplayer doesn't accept resolution other than multiple of 32 bytes

> 
> PS Opening dmix in non-interleaved mode produces totally garbled output:
>    "ecasound -i foo.wav -f:16,2,44100,n -o alsa,dmix -b:4096"

Works here - using standard stereo device.

						Jaroslav

-----
Jaroslav Kysela <perex@suse.cz>
Linux Kernel Sound Maintainer
ALSA Project, SuSE Labs



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