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