Announcement for alsa-gobject v0.1.0 release

Takashi Sakamoto o-takashi at sakamocchi.jp
Tue Jun 23 11:32:39 CEST 2020


Hi,

This is an announcement for the first official release of alsa-gobject
project, addressed in Audio Mini Conference 2018[1]. The release is
available in below URL.

 * https://github.com/alsa-project/alsa-gobject/releases/tag/v0.1.0

The release includes below libraries to operate corresponding character
devices of Linux Sound subsystem (=Advanced Linux Sound Architecture,
a.k.a ALSA)[2]:

 * libalsactl0
 * libalsatimer0
 * libalsaseq0
 * libalsahwdep0
 * libalsarawmidi0

The libraries are also compatible with gobject-introspection (g-i)[3] to
produce gir files:

 * ALSACtl-0.0
 * ALSATimer-0.0
 * ALSASeq-0.0
 * ALSAHwdep-0.0
 * ALSARawmidi-0.0

Any language binding for g-i can handle the gir files to use the the
libraries. For example, PyGObject[4] is available as dynamic g-i loader in
Python 3 runtime, and some Python 3 sample scripts are available in
`samples` directory.

 * https://github.com/alsa-project/alsa-gobject/tree/master/samples

Rust FFI/Safe API crates are provided in alsa-gobject-rs, automatically
generated by gtk-rs/gir[5]. Its README includes code snippet.

 * https://github.com/alsa-project/alsa-gobject-rs

Documentation is available in below URLs. They're auto-generated by
gtk-doc[6] with function annotations:

 * https://alsa-project.github.io/alsa-gobject-docs/

As a design note, the libraries provide API to execute system calls directly
to ALSA core implementation in kernel land. The libraries produce minimal set
of API, and delegate enhanced features to application side. They perform like
'glue' code between application and in-kernel functionalities. This makes it
easy to write test code for the in-kernel functionalities as well as to write 
ehhanced features by each language.

The libraries have no dependency on alsa-lib[7]. The alsa-lib includes own
software features such as configuration space with plug-in system. Although
the plug-in system is useful to add sample operating feature into PCM
interface, it's not necessarily useful for the other interfaces. Furthermore
it's better design to implement enhanced software features in user library and
user application side, instead of common library side. For the above points,
alsa-gobject produces languag bindings different from the existent ones[8][9].

In the release, PCM interface is not supported yet because the 'glue' is
already provided by the other projects; GStreamer[10], PortAudio[11], SDL[12],
and so on. They mostly satisfy the demand, therefore the support is judged not
to be so urgent. It's planned to support PCM interfaces in future release as
'ALSAPcm-0.0'.

Compress-Offload interface is not supported as well because it's difficult to
buy free test device in market as of 2020.

[1] https://www.alsa-project.org/wiki/Miniconf_2018#GObject_introspection
[2] http://www.alsa-project.org/
[3] https://gi.readthedocs.io/
[4] https://pygobject.readthedocs.io/
[5] https://github.com/gtk-rs/gir
[6] https://developer.gnome.org/gtk-doc-manual/
[7] https://git.alsa-project.org/?p=alsa-lib.git;a=summary
[8] https://git.alsa-project.org/?p=alsa-python.git;a=summary
[9] https://github.com/diwic/alsa-rs/
[10] https://gstreamer.freedesktop.org/bindings/
[11] http://www.portaudio.com/
[12] https://www.libsdl.org/languages.php

Regards


Takashi Sakamoto


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