Re: [LAD] ALSA FLoat sample format

From: Erik de Castro Lopo <mle+la@email-addr-hidden-nerd.com>
Date: Thu Aug 16 2007 - 10:52:20 EEST

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Predrag Viceic wrote:

> For some unknown reason, I seem to be unable to set SND_PCM_FORMAT_FLOAT
> format flag when initialising alsa driver. This happens with my both cards
> (on is the laptops AC'97 Audio Controller and the other a similar onboard
> cart)
>
> This line used to work with alsa 0.9 but return an "Invalid argument" error
> with alsa 1.0.14a :
>
> snd_pcm_hw_params_set_format(alsa_pcm_handle, alsa_hwparams,
> SND_PCM_FORMAT_FLOAT_LE)

You probably want SND_PCM_FORMAT_FLOAT (without the _LE at the end)
to specify CPU native float. Using SND_PCM_FORMAT_FLOAT_LE will mean
that your code is almost certain not correct for big endian CPUS.

> Example code at lines 1031-1041 :
> http://cvs.savannah.nongnu.org/viewvc/freecycle/src/soundplayer.cpp?annotate=1.19&root=freecycle

That should probably be fixed as well.

Erik

-- 
-----------------------------------------------------------------
Erik de Castro Lopo
-----------------------------------------------------------------
"These are the finest moments in (post)modern life, when satire is completly
indistinguishable from reality... I usually have to rely on the presidential
elections for such dada." -- frenomulax on Jesux a christian Linux distro.
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Received on Thu Aug 16 12:15:02 2007

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