Re: period/buffer bug on pmac ?

[Takashi Iwai <tiwai@suse.de>]

At Tue, 16 Nov 2004 19:37:39 +0100 (CET),
<danny@mailmij.org> wrote:
> 
> On Mon, 15 Nov 2004, Clemens Ladisch wrote:
> 
> > danny@mailmij.org wrote:
> > > In the process of fixing up the alsa output plugin of bmp a bit I've come
> > > upon a weird problem. The mp3s I was playing played to fast, with a
> > > audible click each few millisecond. This seemed to only happen when the
> > > period size was not a power of 2 (the output plugin used to set
> > > period_time). I've now calculated the period_size myself from the rate and
> > > set it to the nearest power of 2. Which seems to work fine,
> > 
> > There is no general power-of-2 requirement in ALSA.  The pmac driver
> > doesn't set a hardware constraint; if the hardware requires power-of-2
> > periods, it's a bug in the driver.
> > 
> Thanks for the reply!
> I've been hacking around a bit in the driver and think it needs some 
> contraints, although its not (like i first thought) limited to a power of 
> 2. Constraining periods to integer and requiring at least 3 periods seem 
> to fix all issues i have.

That's good to know!

>  However, these requirements sometimes 
> drastically affect the period AND buffersize requested by the app. I play 
> with it a bit more and submit a patch soon. 

Don't forget summary and signed-off-by lines :)


thanks,

Takashi


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