From: Lennart Poettering <mznyfn@0pointer.de>
To: Raymond Yau <superquad.vortex2@gmail.com>
Cc: alsa-devel@alsa-project.org
Subject: Re: safe support for rewind in ALSA
Date: Wed, 17 Feb 2010 16:46:56 +0100 [thread overview]
Message-ID: <20100217154656.GF6891@tango.0pointer.de> (raw)
In-Reply-To: <4f3252891002141903q34144f58n60978e28e65640b4@mail.gmail.com>
On Mon, 15.02.10 11:03, Raymond Yau (superquad.vortex2@gmail.com) wrote:
> For USB case , the driver cannot give accurate hw pointer position , hw
> pointer increase in steps for the current implementation, (i.e. the graph is
> a stepping fuction if you plot the position of hardware pointer against time
> elasped ) .
The granularity of write transfer blocks and of playback pointer
updates is currently not quriable nor configurable in ALSA. We only
have periods which tries to cover both in a way.
For the use in PA it is really important to get better APIs for
this. Ideally both for querying the latency and the transfer
granularityand configuring it, but most importantly for querying it.
This has been discussed before on this mailing list, btw.
Lennart
--
Lennart Poettering Red Hat, Inc.
lennart [at] poettering [dot] net
http://0pointer.net/lennart/ GnuPG 0x1A015CC4
next prev parent reply other threads:[~2010-02-17 15:47 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-01 17:20 safe support for rewind in ALSA pl bossart
2010-02-01 18:00 ` Jaroslav Kysela
2010-02-01 22:40 ` pl bossart
2010-02-03 2:20 ` Raymond Yau
2010-02-03 18:03 ` Kai Vehmanen
2010-02-03 20:52 ` Kai Vehmanen
2010-02-03 22:57 ` pl bossart
2010-02-08 1:22 ` Raymond Yau
2010-02-02 2:53 ` Raymond Yau
2010-02-06 11:59 ` Raymond Yau
2010-02-17 15:30 ` Lennart Poettering
2010-02-18 1:31 ` Raymond Yau
2010-02-18 2:33 ` Lennart Poettering
2010-02-18 3:21 ` Raymond Yau
2010-02-01 18:01 ` Mark Brown
2010-02-01 18:05 ` Jaroslav Kysela
2010-02-01 21:28 ` Kai Vehmanen
2010-02-01 21:54 ` Kai Vehmanen
2010-02-08 22:59 ` Raymond Yau
2010-02-09 20:54 ` Kai Vehmanen
2010-02-10 13:19 ` Raymond Yau
2010-02-10 13:36 ` Clemens Ladisch
2010-02-11 6:52 ` Raymond Yau
2010-02-11 7:20 ` Clemens Ladisch
2010-02-11 7:27 ` Jaroslav Kysela
2010-02-15 3:03 ` Raymond Yau
2010-02-17 15:46 ` Lennart Poettering [this message]
2010-02-21 10:35 ` Kai Vehmanen
2010-02-22 9:07 ` Raymond Yau
[not found] ` <20100221203500.GH31800@tango.0pointer.de>
2010-02-22 19:15 ` semantics of SNDRV_PCM_INFO_BATCH (was: Re: safe support for rewind in ALSA) Kai Vehmanen
2010-02-23 7:02 ` Raymond Yau
2010-02-23 2:37 ` safe support for rewind in ALSA Raymond Yau
2010-02-23 2:44 ` Raymond Yau
2010-02-17 15:42 ` Lennart Poettering
2010-02-21 10:06 ` Kai Vehmanen
[not found] ` <20100221202144.GG31800@tango.0pointer.de>
2010-05-04 2:31 ` Raymond Yau
2010-02-17 15:39 ` Lennart Poettering
2010-02-17 15:36 ` Lennart Poettering
2010-02-17 15:35 ` Lennart Poettering
2010-02-01 22:10 ` Kai Vehmanen
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