All of lore.kernel.org
 help / color / mirror / Atom feed
* ALSA DMIX support without MMAP ?
@ 2010-01-13  9:46 ANISH KUMAR
  2010-01-13 11:27 ` Mark Brown
  0 siblings, 1 reply; 9+ messages in thread
From: ANISH KUMAR @ 2010-01-13  9:46 UTC (permalink / raw)
  To: alsa-devel@alsa-project.org

Hi,

I am working on android and and in our device we use ALSA.

 I  have enabled dmix support for andoid as by default android doesn't have this plugin enabled and soon will post it in android forum however i have run into some problems.Hoping takashi can help me out on this.

Problem is when i am trying to use dmix plugin i am not getting any sound (logs shown below).Is it because i don't have mmap mode support on my device???

If yes then can't dmix work without mmap mode???   Logs shown below:

Entered s3c24xx_pcm_hw_params,
Entered s3c24xx_pcm_hw_params, line 330
Entered s3c24xx_pcm_mmap
Entered s3c24xx_pcm_prepare
Entered s3c24xx_pcm_enqueue
Entered s3c24xx_pcm_trigger
Entered s3c24xx_pcm_pointer
Entered s3c24xx_pcm_pointer res_value[0]
snd_pcm_update_hw_ptr_pos xun: [0]occured XRUN!

Normal playback and recording is fine if i dont use dmix plugin.During my normal playback and recording i don't use mmap as i preallocate DMA memory  and use them.

Regards,
anish

^ permalink raw reply	[flat|nested] 9+ messages in thread
[parent not found: <0KW800IYGE3P07@ms13.samsung.com>]
* Re: ALSA DMIX support without MMAP ?
@ 2010-01-14 10:30 ANISH KUMAR
  2010-01-14 10:37 ` Jaroslav Kysela
  0 siblings, 1 reply; 9+ messages in thread
From: ANISH KUMAR @ 2010-01-14 10:30 UTC (permalink / raw)
  To: Mark Brown; +Cc: alsa-devel@alsa-project.org

>mmap is supported by the Samsung drivers.

Thanks for this information which i overlooked.
>This looks like the dmix data rates are getting out of sync with what
>the hardware is doing.  Enabling CONFIG_SND_PCM_XRUN_DEBUG will produce
>more diagnostic information from the driver side
I got the problem and after doing the changes DMIX plugin is working very fine.
As you know XRUN was happening and this happening in snd_pcm_update_hw_ptr_post function.
This happened because stop_threshold is increased suddenly(Is it done by dmix? If yes then why ?) ??????
 In normal condtions this would have been fine but in my code i was multiplying it by some amount causing it to wrap around(stop_threshold=0 );Causing XRUN.So i just removed this multiplying factor.
 
One more Rate conversion query:
./alsa_aplay -v -D"plug:'dmix:RATE=44100'" bond.wav
Playing WAVE 'bond.wav' : Unsigned 8 bit, Rate 11025 Hz, Mono
Plug PCM: Rate conversion PCM (44100, sformat=U8)
As you can see bond.wav is sampled at 11025k but when i am playing with Plug PCM there is some noise in the song why????Is rate conversion algoritm not able to resample it properly?
 
If i play with ./alsa_aplay -v -D"plug:'dmix:RATE=11025'" bond.wav then no noise.Probably because no resampling happening?
 
Mark Brown Heartfelt Thanks for your time.

^ permalink raw reply	[flat|nested] 9+ messages in thread
* Re: ALSA DMIX support without MMAP ?
@ 2010-01-15 12:07 ANISH KUMAR
  2010-01-15 13:37 ` Mark Brown
  0 siblings, 1 reply; 9+ messages in thread
From: ANISH KUMAR @ 2010-01-15 12:07 UTC (permalink / raw)
  To: Jaroslav Kysela; +Cc: maniyar, alsa-devel@alsa-project.org, Mark Brown

>For dmix, the stop_threshold should be equal to boundary value, thus XRUN 
>check should never be true. If you got xrun with dmix, something is wrong.
DMIX is working now.

 > but when i am 
> playing with Plug PCM there is some noise in the song why????Is rate 
> conversion algoritm not able to resample it properly?
>The default linear resampler is not very good quality. You may use some 
>sox resamplers from the alsa-plugins package, but they&#39;re more CPU 
>intensive. Check google.

Actually i am working on soc platform(android-S3C6410) and wanted to use DMIX and some good resampler for my software mixing instead of current software mixing and resampling in upper layer(Above alsa-lib).DMIX is working fine but this resampling is causing some jitter.During rate conversion it looks for libasound_module_rate_speexrate.so which i don't have so its using default one causing the jitter.
Can i build this .so file (as current way of alsa-plugin downloading will not work for me)?For sox resampler i guess i need to use differnet .so and corresponding changes in asound.conf file??
Can i get speex or sox  resampler code so that i can build it for my system?????
This code(speex or sox) i guess would have been integrated with alsa-lib so that alsa-lib can call corresponding functions of resampler source code. 
 
 OR simply point me to url as googling is not helping.Everywhere i am getting this "you need to download plugins".This will not work in my case.

^ permalink raw reply	[flat|nested] 9+ messages in thread
* Re: ALSA DMIX support without MMAP ?
@ 2010-01-18  3:25 ANISH KUMAR
  2010-01-18 11:01 ` Mark Brown
  0 siblings, 1 reply; 9+ messages in thread
From: ANISH KUMAR @ 2010-01-18  3:25 UTC (permalink / raw)
  To: Mark Brown
  Cc: MAHAMMADRAFI MANIYAR, alsa-devel@alsa-project.org, lrg, lennart


> Actually i am working on soc platform(android-S3C6410) and wanted to
> use DMIX and some good resampler for my software mixing instead of
> current software mixing and resampling in upper layer(Above
> alsa-lib).DMIX is working fine but this resampling is causing some
> jitter.During rate conversion it looks for
> libasound_module_rate_speexrate.so which i don't have so its using
> default one causing the jitter.
>>Have you considered using PulseAudio for this?

 
Mark thanks for the suggestion and i checked out PulseAudio for my requirements.I found out that i don't need all the things in PulseAudio 
a. I just need good resampling code.Can i just use just the resampler code of pulseaudio(mine is mobile enviroment)?
b. Just want a good mixer at ALSA-LIB level.As of now this is provided by android framework but i want this to be done by ALSA-LIB so that i
    can replace with some good mixer later on(if i find that some other mixer is good).DMIX is providing that but it's not that good.
c.Jaroslav suggested to use sox resamplers but for that to work i have to get the sox resampler code(proper license) and need to build it for my system and link it  
   with corresponding functions of ALSA-LIB so that they can call relevant functions for resampling.As i am working on mobile domain i think i need to do the   
    integration of sox resampler code with ALSA-LIB for that to work??
   or 
   Can i just use the integrated sox library(some .so i guess) and change the asound.conf for using that library??Will this work??
d. I saw some check-ins related to Scenario Manager.As of now scenario manager functionality is also given in Android(we open a differnet
    device and the corresponding hooks for changing the routes dynamically) but i think if it given in alsa-lib switching will be much faster and this 
    will increase the system performance.

^ permalink raw reply	[flat|nested] 9+ messages in thread
end of thread, other threads:[~2010-01-18 11:01 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2010-01-13  9:46 ALSA DMIX support without MMAP ? ANISH KUMAR
2010-01-13 11:27 ` Mark Brown
     [not found] <0KW800IYGE3P07@ms13.samsung.com>
2010-01-14  9:55 ` Mark Brown
  -- strict thread matches above, loose matches on Subject: below --
2010-01-14 10:30 ANISH KUMAR
2010-01-14 10:37 ` Jaroslav Kysela
2010-01-15 12:07 ANISH KUMAR
2010-01-15 13:37 ` Mark Brown
2010-01-18  3:25 ANISH KUMAR
2010-01-18 11:01 ` Mark Brown

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.