[alsa-devel] ALSA SDL VORBIS playback problem

Christian Wolf wolflpz at web.de
Tue Mar 9 19:00:43 CET 2010

libtremor fixed the problem. it seems the arm cpu was to busy with decoding ogg files thru the vorbis/ogg floating point libraries.

therefore i did the following:

1. i downloaded the sources for libtremor from the svn: [http://svn.xiph.org/trunk/Tremor/]
2. cross compiled them for my arm board
3. i also had to cross compile the SDL_mixer library again by adding the parameter "--enable-music-ogg-tremor" to the configure command

These steps finally fixed the buffer underrun problem completely.

Thanks for the help!!!


<53baa24a1003021109xe1c76dekc7f390a2a851df28 at mail.gmail.com>,
 <4B8D6F02.1060608 at emlix.com>
In-Reply-To: <4B8D6F02.1060608 at emlix.com>
Subject: Re: [alsa-devel] ALSA SDL VORBIS playback problem
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-----Urspr=FCngliche Nachricht-----
Von: "Daniel Glöckner" <dg at emlix.com>
Gesendet: 02-Mar-2010 21:03:14
An: Christian Wolf <wolflpz at web.de>
Betreff: Re: [alsa-devel] ALSA SDL VORBIS playback problem

On 03/02/2010 08:09 PM, Alex Austin wrote:
> Basically, see if a straight-up pipe will buffer reasonably. If not, I
> suppose it's remotely possible that this is just a CPU-bound operation an=
> it can't keep up. I can't imagine that's really the case though with that
> CPU.

Libvorbis uses floating point operations while on your AT91SAM9261 you
have a soft-float library (or even worse FPU emulation).

Try the integer only Tremor library linked here:

The API is slightly different (easier), as it can only generate S16_LE


-- =3D

Dipl.-Math. Daniel Gl=3DF6ckner, emlix GmbH, http://www.emlix.com
Fon +49 551 30664-0, Fax -11, Bahnhofsallee 1b, 37081 G=3DF6ttingen, German=
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