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From: Clemens Ladisch <clemens@ladisch.de>
To: Patrick Lai <plai@codeaurora.org>
Cc: linux-arm-msm@vger.kernel.org, alsa-devel <alsa-devel@alsa-project.org>
Subject: Re: [alsa-devel] Compressed Audio Playback/Capture through ALSA	framework
Date: Thu, 17 Mar 2011 08:39:33 +0100	[thread overview]
Message-ID: <4D81BAB5.5060204@ladisch.de> (raw)
In-Reply-To: <4D8134C6.30104@codeaurora.org>

Patrick Lai wrote:
> Where can I find user-space code snippet to see how ALSA is configured 
> for IEC958 playback?

Use the ALSA device name "iec958" (or its alias "spdif").
For another than the default sound card, use "iec958:x".

For compressed formats, you have to set the non-audio bit.
Thise device has four parameters AES0..3 for the four bytes
of S/PDIF metainformation.  The non-audio bit can be set by
adding the parameter "AES0=6"; the complete device name then
looks like "spdif:AES0=6" or "spdif:other=parameters,AES0=6"
or "spdif:{ other-parameters ... AES0=6 }".

The try_open_device function of mplayer tries to do this:
http://git.mplayerhq.hu/?p=mplayer;a=blob;hb=HEAD;f=libao2/ao_alsa.c


Regards,
Clemens

  reply	other threads:[~2011-03-17  7:39 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-03-15 18:31 Compressed Audio Playback/Capture through ALSA framework Patrick Lai
2011-03-15 20:40 ` Eliot Blennerhassett
2011-03-15 20:52   ` [alsa-devel] " pl bossart
2011-03-15 23:28   ` Patrick Lai
2011-03-16  7:21     ` [alsa-devel] " Clemens Ladisch
2011-03-16  7:23     ` Jaroslav Kysela
2011-03-16 22:08     ` Patrick Lai
2011-03-17  7:39       ` Clemens Ladisch [this message]
2011-03-16 10:38 ` [alsa-devel] " Mark Brown
2011-03-16 10:59   ` Koul, Vinod
2011-03-16 11:56     ` Mark Brown
2011-03-16 12:17       ` Koul, Vinod
2011-03-16 17:52       ` pl bossart
2011-03-16 17:53         ` Mark Brown
2011-03-16 18:00           ` pl bossart
2011-03-16 18:08             ` Mark Brown
2011-03-17  2:21               ` Koul, Vinod
2011-03-17  5:00                 ` Patrick Lai
2011-03-17 11:54                   ` Mark Brown
2011-03-17 14:27                     ` pl bossart
2011-03-17 18:25                       ` Mark Brown
2011-03-17 19:16                         ` [alsa-devel] " pl bossart
2011-03-17 20:16                           ` Mark Brown
2011-03-17 21:19                             ` Patrick Lai
2011-03-17 21:25                               ` Mark Brown
2011-03-18 16:03                             ` pl bossart
2011-03-22 13:01                               ` Mark Brown
2011-03-17  5:32           ` Asus E35M1-M Pro and Realtek AL887-VD - no love from ALSA for Sourround Wojciech Myrda
2011-03-17 21:55             ` Paul Menzel
2011-03-20 10:13               ` Wojciech Myrda
2011-03-18  2:22     ` Compressed Audio Playback/Capture through ALSA framework Raymond Yau

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