Re: microphone and sound access in Ada

[Adrian Knoth <adi@drcomp.erfurt.thur.de>]

Preben Randhol <randhol+news@pvv.org> wrote:

>> Yes. I proposed that some weeks ago, perhaps we should start. Any further
>> interests?
> I'm in. Although, I have to read up on how to do C bindings first as I
> haven't done this before. I guess GtkAda is a good source for examples
> :-)

I think so, too. Most is pragma Import :)
 
> libao: 
>    Libao is a cross-platform library that allows programs to output PCM
>    audio data to the native audio devices on a wide variety of platforms.
>    It currently supports:
> 
>        * OSS (Open Sound System)
>        * ESD (ESounD)
>        * ALSA (Advanced Linux Sound Architecture)
>        * Sun audio system (used in Solaris, OpenBSD, and NetBSD)
>        * aRts (Analog Realtime Synthesizer) 
> 
> (hope this can do input as well)

Well, libao is a generic audio-output-library. We might want to use it
or simply cat to /dev/audio :) 
 
> libogg:
>    Libogg contains necessary functionality to create, decode, and work with
>    Ogg bitstreams.

This would be important for speex.
 
> libvorbis:
>  * libvorbisenc
> 
>     Libvorbisenc is a convenient API for setting up an encoding
>     environment using libvorbis. Libvorbisenc encapsulates the actions
>     needed to set up the encoder properly.

This is a later issue. Sure encoding is important, but playback might be
in first release, because it's easier.
 
>  * Vorbisfile
>     The Vorbisfile library provides a convenient high-level API for
>     decoding and basic manipulation of all Vorbis I audio streams.

Nice. I guess we can start right here. It is linked against libogg, so
we can neglect a binding to it first:

adi@drcomp:~$ ldd /usr/local/lib/libvorbisfile.so.3.0.0 | grep ogg
        libogg.so.0 => /usr/local/lib/libogg.so.0 (0x40033000)

>     Libvorbisfile is implemented as a layer on top of Xiph.org's
>     reference libogg and libvorbis libraries.

Sure.

It might even be fun to write a binding to the ALSA-API, best case would
be a native kernel-binding. Lutz? On the other hand, a wrapper around
the C-library would work as well.

-- 
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