From alsa-devel-owner@alsa.jcu.cz  Fri Mar 13 19:20:59 1998
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Date: Fri, 13 Mar 1998 13:22:37 -0500
To: alsa-devel@jcu.cz
From: Alan Robinson <ar@vt.edu>
Subject: library/low-level inner workings
In-Reply-To: <35096B06.6EF4@ife.ee.ethz.ch>
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From the api docs:

Low-Level layer supports these formats:

#define SND_PCM_SFMT_MU_LAW             0
#define SND_PCM_SFMT_A_LAW              1
#define SND_PCM_SFMT_IMA_ADPCM          2
#define SND_PCM_SFMT_U8                 3
#define SND_PCM_SFMT_S16_LE             4
#define SND_PCM_SFMT_S16_BE             5
#define SND_PCM_SFMT_S8                 6
#define SND_PCM_SFMT_U16_LE             7
#define SND_PCM_SFMT_U16_BE             8
#define SND_PCM_SFMT_MPEG               9
#define SND_PCM_SFMT_GSM                10

[.....]

My question is, how do you intend to support these formats?  Is there an
already written library out there that can convert those formats into raw
16 or 8 bit data?  Or do you expect to have to write that code too?  Where
I am going with this is that if we are going to need to write the
conversion code (even if it just means reworking somebody else's code) we
ought to put it into a separate library.  Then it could be used by more
than just the driver.  After all, some programs like to be able to modify
audio data directly, and having a nice translation library would make that
task easier.

Just a thought.  Perhaps such an idea already exists?

-- Alan.



