WINEALSA: remove crackling in DirectSound/ALSA combination

[Chris Rankin]

Hi,

I forwarded the original patch to the alsa-devel for comments. See below.

Cheers,
Chris

--- Takashi Iwai <tiwai at suse.de> wrote:
> Date: Thu, 11 Aug 2005 15:12:51 +0200
> From: Takashi Iwai <tiwai at suse.de>
> To: Lee Revell <rlrevell at joe-job.com>
> CC: Chris Rankin <rankincj at yahoo.com>,
> 	alsa-devel at lists.sourceforge.net, a.villacis at palosanto.com
> Subject: Re: [Alsa-devel] ALSA and Wine DirectSound question: Fwd from	wine-patches list
> 
> At Wed, 10 Aug 2005 15:08:45 -0400,
> Lee Revell wrote:
> > 
> > On Wed, 2005-08-10 at 13:14 +0100, Chris Rankin wrote:
> > > I think the Wine developers are seeking enlightenment from an ALSA Guru. (The "World of
> Warcraft"
> > > people seem keen to get this patch working, too ;-).) Can anyone help, please?
> > > 
> > > http://www.winehq.org/hypermail/wine-patches/2005/08/0173.html
> > 
> > This sounds a lot like my theory about what is causing the infamous
> > crackling problem that has been reported with JACK - the ALSA middle
> > layer is consistently returning an incorrect hardware pointer which
> > causes a few samples from the other buffer (assuming a double buffering
> > scheme) to be overwritten.
> 
> If the cracking problem doesn't happen with _snd_pcm_mmap_hw_ptr() and
> happens only with this patch, the problem might be the inaccurate DMA
> position triggered snd_pcm_hw_sync(). 
> 
> Maybe it'd be helpful to put debug outputs comapring both the values
> of _snd_pcm_mmap_hw_ptr() and the emulated hwptr.
> (You should check the values of _snd_pcm_mmap_hw_ptr() before and
>  after snd_pcm_hwsync(), too).
> 
> Or, if the problem is with dmix, it's another story...
> 
> 
> Takashi


		
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