From: Eliot Blennerhassett <linux@audioscience.com>
To: alsa-devel@alsa-project.org
Subject: Re: How can I make sure the period size is a multiple of 16?
Date: Wed, 05 Sep 2007 12:29:54 +1200 [thread overview]
Message-ID: <200709051229.54852.linux@audioscience.com> (raw)
In-Reply-To: <46DDE137.2070507@freescale.com>
On Wednesday 05 September 2007 10:50:31 Timur Tabi wrote:
> To work around a hardware issue, my ASoC driver requires the period size to
> be a multiple of 16. What is the best way to ensure that?
Well, I was going to refer you to
http://www-old.alsa-project.org/~iwai/writing-an-alsa-driver/index.html
but I just get a blank page today.
Set snd_pcm_hardware.period_bytes_min to 16 or is that 16 * samplesize?
You need to add some constraints to your driver, in the open callback.
E.g.
snd_pcm_hw_constraint_step(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 16);
List of hwparams that can be constrained is in asound.h
List of constraint helpers in pcm.h, or grep for snd_pcm_hw_constraint to see
usage examples.
--
Eliot
next prev parent reply other threads:[~2007-09-05 0:26 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-09-04 22:50 How can I make sure the period size is a multiple of 16? Timur Tabi
2007-09-05 0:29 ` Eliot Blennerhassett [this message]
2007-09-05 9:08 ` Clemens Ladisch
2007-09-05 9:55 ` Trent Piepho
2007-09-05 12:58 ` Takashi Iwai
2007-09-06 17:07 ` Timur Tabi
2007-09-06 17:14 ` Trent Piepho
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