From: Jaroslav Kysela <perex@perex.cz>
To: "Harsha, Priya" <priya.harsha@intel.com>
Cc: "alsa-devel@alsa-project.org" <alsa-devel@alsa-project.org>
Subject: Re: need help understanding overrun/underrun
Date: Fri, 20 Aug 2010 11:49:32 +0200 (CEST) [thread overview]
Message-ID: <alpine.LNX.2.00.1008201146200.10278@eeebox2.perex-int.cz> (raw)
In-Reply-To: <98769532B4BB14429434178695419EAE0523526CDA@bgsmsx501.gar.corp.intel.com>
On Fri, 20 Aug 2010, Harsha, Priya wrote:
> Hi
>
> I had modified the arecord application to call snd_pcm_writei() with the
> output of snd_pcm_readi(). Basically a loopback.
>
> When we execute, I see the calls return EPIPE (lot of overruns and a few
> underruns). Can anyone help me understand why there are underrun/overrun
> being printed? Is it because of the serial call of reads and writes? Is
> there any issue with the driver I am using? Can you suggest some ways to
> overcome these messages?
You must queue playback with more samples at the beginning (to
setup the output latency) otherwise you get the output underrun
immediatelly. See alsa-lib/test/latency.c for an example.
Jaroslav
-----
Jaroslav Kysela <perex@perex.cz>
Linux Kernel Sound Maintainer
ALSA Project, Red Hat, Inc.
next prev parent reply other threads:[~2010-08-20 9:49 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-20 9:44 need help understanding overrun/underrun Harsha, Priya
2010-08-20 9:49 ` Jaroslav Kysela [this message]
2010-08-24 10:53 ` Harsha, Priya
2010-08-24 12:12 ` Jaroslav Kysela
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