ALSA related stuffs

What's New?

What's ALSA?

See ALSA project home page.

SALSA-Lib - Small ALSA Library

SALSA-Lib is a small, light-weight, hot and spicy version of the ALSA library, mainly for embedded systems with limited resources. The library is designed to be source-level compatible with ALSA library API for limited contents. Most of function calls are inlined, and accesses directly to the hardware via system calls. Some components like ALSA sequencer aren't supported, and most of all, the alsa-lib plugins and configurations are completely dropped. Thus, neither dmix nor format conversion is available with SALSA-lib.

HDA-Tools - HD-Audio User-Space Configuarition Tools

HDA-Tools are the programs for setting up the HD-audio driver on user-space. The package includes kernel patches for adding the hwdep hook, and user-space programs for configuration, including module codes for various codec chips.

Some Documents on ALSA

The following documents are found in alsa-kernel/Documentation/DocBook directory, too. The files below are generated from them.

The following one is converted from a plain-text file in alsa-kernel/Documentation directory.

Latency Test Tools for ALSA

The newer version of latency-test tool is available. It's for 2.6 kernel only, and uses RTC as the interrupt source.

About the latency on linux, please refer to this page. I hacked Benno's latency measurement tools for ALSA. Here is the FTP directory above.


My colleague, Werner Fink, extended/fixed Andy's ac3play. You can find the latest version here.


ASeqView - ALSA Sequencer Event Viewer

ASeqView is an ALSA sequencer user-client which works as event viewr. It visualizes received events, e.g. note-on/off, controls, pitch wheels, using bar graphs, as often seen in many sequencer programs. Using this viewer, even a simple command line sequencer like pmidi or playmidi1 becomes a cool one with graphical interface :-)

Another feature of ASeqView is redirection of events. ASeqView can output the received events to subscription ports with some modification like channel mute or pitch change. Since this works as a real-time filter client, such modifications can be applied also in real-time without complexity.

Since the recent version (0.2.3), aseqview includes the piano view support (thanks to Patrick Horn). See the screenshot below.

Virtual Keyboard

This program is originally for AWE32/64 driver on OSS/Free, but it works now on ALSA, too. Start the program with --device alsa option. Then, connect this client to any ALSA port by aconnect utility, for example,

% aconnect 128:0 65:0
Alternatively, you can use --addr 65:0 option to connect directly from vkeybd.

Test / demo programs

Some demo programs for ALSA sequencer. Most of the part has been impelemented in aseqview. I just show this for test only.

Brief Notes about ALSA Sequencer

Some Old Documents



Takashi Iwai; Go to My Home Page