ALSA 0.9.x Developer documentation - Revision history

EliotBlennerhassett: replace outdated sourceforge cvs link with Hg link

2007-08-12T03:17:08Z

replace outdated sourceforge cvs link with Hg link

← Older revision		Revision as of 03:17, 12 August 2007
Line 8:		Line 8:

	*Click [http://hg-mirror.alsa-project.org/ here to view the code online] - highlighted syntax		*Click [http://hg-mirror.alsa-project.org/ here to view the code online] - highlighted syntax
	*Extra driver/architecture specific information is available in ~~the~~ http://~~cvs~~.~~sourceforge.net/cgi~~-~~bin/viewcvs~~.~~cgi/alsa~~/alsa-kernel/Documentation/ alsa-kernel~~/Documentation dir~~		*Extra driver/architecture specific information is available in [[Matrix:Main\|Vendor and module list]] and [http://hg-mirror.alsa-project.org/alsa-kernel/file/014c234ce690/Documentation/ alsa-kernel source docs (obsolete?)]

EliotBlennerhassett: Delete alsa 0.5 links. Update others to www-old - how relevant are they?

2007-08-12T02:53:30Z

Delete alsa 0.5 links. Update others to www-old - how relevant are they?

← Older revision		Revision as of 02:53, 12 August 2007
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	=== Older documents ===		=== Older documents ===

	The [http://www.alsa-project.org/alsa-doc/alsa-howto ALSA HOWTO/FAQ documentation] tries		The [http://www-old.alsa-project.org/alsa-doc/alsa-howto ALSA HOWTO/FAQ documentation] tries
	to do the ALSA driver installation easier. If you have any ideas or questions		to do the ALSA driver installation easier. If you have any ideas or questions
	regarding this documentation, please, leave a message on		regarding this documentation, please, leave a message on
	the [[Mailing-lists\|alsa-devel at lists.sourceforge.net]] mailing list.		the [[Mailing-lists\|alsa-devel at lists.sourceforge.net]] mailing list.

	The [http://www.alsa-project.org/~valentyn/Alsa-sound-mini-HOWTO.html ALSA-sound-mini-HOWTO]		The [http://www-old.alsa-project.org/~valentyn/Alsa-sound-mini-HOWTO.html ALSA-sound-mini-HOWTO]
	describes the installation of the ALSA sound		describes the installation of the ALSA sound
	drivers for Linux. This HOWTO is also available from the Linux Documentation Project, take		drivers for Linux. This HOWTO is also available from the Linux Documentation Project, take
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	to find your nearest mirror. You can get this HOWTO in various formats:		to find your nearest mirror. You can get this HOWTO in various formats:

	*[http://www.alsa-project.org/~valentyn/Alsa-sound-mini-HOWTO.html HTML (multiple documents)]		*[http://www-old.alsa-project.org/~valentyn/Alsa-sound-mini-HOWTO.html HTML (multiple documents)]
	*[http://www.alsa-project.org/~valentyn/other-formats/Alsa-sound-mini-HOWTO.html HTML (one document)]		*[http://www-old.alsa-project.org/~valentyn/other-formats/Alsa-sound-mini-HOWTO.html HTML (one document)]
	*[http://www.alsa-project.org/~valentyn/other-formats/Alsa-sound-mini-HOWTO.txt plain text]		*[http://www-old.alsa-project.org/~valentyn/other-formats/Alsa-sound-mini-HOWTO.txt plain text]
	*[http://www.alsa-project.org/~valentyn/other-formats/Alsa-sound-mini-HOWTO.sgml sgml source] of the HOWTO is also available.		*[http://www-old.alsa-project.org/~valentyn/other-formats/Alsa-sound-mini-HOWTO.sgml sgml source] of the HOWTO is also available.

			There is also an old [http://www-old.alsa-project.org/~jfulmer/alsa-faq.html ALSA FAQ document] from John Fulmer.
	There is also an old [http://www.alsa-project.org/~jfulmer/alsa-faq.html ALSA FAQ document] from John Fulmer.

	~~== ALSA 0.5.x Developer documentation ==~~

	~~'''N.B. The 0.5.x series is considered deprecated and is no longer supported by ALSA developers'''~~

	~~The [http://www.math.tu-berlin.de/~sbartels/alsa/ ALSA 0.4.0 Developer documentation] describes the internals of the ALSA kernel driver.~~
	~~It is a document for kernel developers and others which want to know more~~
	~~about ALSA internals. It is '''not''' for application programmers.~~
	~~Application programmers should use the ALSA library API found in the alsa-lib~~
	~~package. Incomplete documentation for ALSA 0.5.x API is available in HTML format~~
	~~on [http://www.alsa-project.org/alsa-doc/alsa-lib-old ALSA WWW server] or you~~
	~~may get [http://www.alsa-project.org/~perex/alsa-lib-old/alsa-lib.tgz tarball] for off-line~~
	~~reading~~.

Tiwai at 14:40, 3 August 2007

2007-08-03T14:40:46Z

@@ Line 30: / Line 30: @@
 will have to read the code and reference other applications for more advanced
 info.
 === Older documents ===

Tiwai: Removed old text file, mark alsa-lib API reference more clear

2007-08-03T13:54:52Z

Removed old text file, mark alsa-lib API reference more clear

← Older revision		Revision as of 13:54, 3 August 2007
Line 49:		Line 49:
	applications. The ALSA lib documentation is a valuable developer reference		applications. The ALSA lib documentation is a valuable developer reference
	to the available functions. In many ways it is a tutorial. The latest		to the available functions. In many ways it is a tutorial. The latest
	[http://www.alsa-project.org/alsa-doc/alsa-lib on-~~line documentation~~] ~~is generated from~~		on-line documentation is generated from the alsa-lib CVS sources.
	~~the alsa-lib CVS sources.~~
			*[http://www.alsa-project.org/alsa-doc/alsa-lib/ ALSA-lib API reference]

	You can also generate it yourself. Install the		You can also generate it yourself. Install the
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	*[http://www.alsa-project.org/~iwai/writing-an-alsa-driver/index.html HTML (multiple documents)]		*[http://www.alsa-project.org/~iwai/writing-an-alsa-driver/index.html HTML (multiple documents)]
	*[http://www.alsa-project.org/~iwai/writing-an-alsa-driver.pdf pdf file]		*[http://www.alsa-project.org/~iwai/writing-an-alsa-driver.pdf pdf file]
	*[http://www.alsa-project.org/~iwai/alsa-drivers-writing.txt plain text]
	*[http://www.alsa-project.org/~iwai/writing-an-alsa-driver.sgml The sgml source] is also available		*[http://www.alsa-project.org/~iwai/writing-an-alsa-driver.sgml The sgml source] is also available

Y2kbug: /* Developer tutorials */ Typo

2007-07-22T14:09:30Z

Developer tutorials: Typo

← Older revision		Revision as of 14:09, 22 July 2007
Line 36:		Line 36:
	*[http://equalarea.com/paul/alsa-audio.html Howto use the ALSA API] - Paul Davis has also written a brief explanation.		*[http://equalarea.com/paul/alsa-audio.html Howto use the ALSA API] - Paul Davis has also written a brief explanation.
	*[http://www.alsa-project.org/~frank/alsa-sequencer/ ALSA Sequencer (draft)] - Frank van de Pol's draft on programming the alsa sequencer.		*[http://www.alsa-project.org/~frank/alsa-sequencer/ ALSA Sequencer (draft)] - Frank van de Pol's draft on programming the alsa sequencer.
	*[http://www.alsa-project.org//~iwai/OSS-Emulation.html Kernel OSS-Emulation] - Takashi Iwai has written some notes on how ALSA handles OSS applications.		*[http://www.alsa-project.org/~iwai/OSS-Emulation.html Kernel OSS-Emulation] - Takashi Iwai has written some notes on how ALSA handles OSS applications.
	*[http://www.salleurl.edu/~is04069/Modders/Docs/alsadoc.html Programming ALSA (Espanol)] - David Garcia Garzon has written Spanish docs and tutorials		*[http://www.salleurl.edu/~is04069/Modders/Docs/alsadoc.html Programming ALSA (Espanol)] - David Garcia Garzon has written Spanish docs and tutorials

Soe: New page: == Background Info == The Advanced Linux Sound Architecture comes with a driver API & library API. Our aim is to describe hardware as close as possible in drivers, but in userspace, t...

2007-05-07T23:07:50Z

New page: == Background Info == The Advanced Linux Sound Architecture comes with a driver API & library API. Our aim is to describe hardware as close as possible in drivers, but in userspace, t...

New page

== Background Info ==

The Advanced Linux Sound Architecture comes with a driver API & library API.
Our aim is to describe hardware as close as possible in drivers, but in
userspace, the alsa-lib covers the hardware differences (if required).
It's possible for applications to control all hardware features
(if required).

*Click [http://hg-mirror.alsa-project.org/ here to view the code online] - highlighted syntax
*Extra driver/architecture specific information is available in the http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/alsa/alsa-kernel/Documentation/ alsa-kernel/Documentation dir

'''Q: Why is ALSA more advanced than OSS?'''

*kernel-space supports only h/w-level capabilities
*multi-thread safe design
*transparent use of plugin architecture to handle format,rate,channel cnt and many other conversions
*support for non-interleaved interfaces
*user-space software mixing (dmix)
*user-space "loopback/snoop" capabilities
*merging multiple cards into a single virtual device
*hiding non-ALSA-drivers behind a consistent user-space API (e.g. IEEE1394 drivers, or JACK)
*consistent and generic control API for managing h/w controls
*sufficiently flexible mixer architecture to handle modern audio interfaces fully (rather than reducing them to a simplistic device)
*consistent support for multiple instances of the same card
*linked operations of multiple cards
*and more...

Currently we need developers to write docs on the ctl API. Until then you
will have to read the code and reference other applications for more advanced
info.

== Developer tutorials ==

*[http://www.suse.de/~mana/alsa090_howto.html ALSA 0.9.0 HOWTO] - Dr Matthias Nagorni has writen a comprehensive tutorial for audio application developers.
*[http://equalarea.com/paul/alsa-audio.html Howto use the ALSA API] - Paul Davis has also written a brief explanation.
*[http://www.alsa-project.org/~frank/alsa-sequencer/ ALSA Sequencer (draft)] - Frank van de Pol's draft on programming the alsa sequencer.
*[http://www.alsa-project.org//~iwai/OSS-Emulation.html Kernel OSS-Emulation] - Takashi Iwai has written some notes on how ALSA handles OSS applications.
*[http://www.salleurl.edu/~is04069/Modders/Docs/alsadoc.html Programming ALSA (Espanol)] - David Garcia Garzon has written Spanish docs and tutorials

=== Presentations: ===

*The [http://www.linuxdj.com/audio/lad/eventszkm2003.php LAD meeting] in Karlsruhe, April 2003 provided two presentations (among many) from the core ALSA developers Jaroslav and Takashi. You can view slides and listen to .ogg recordings of the presentations.

== ALSA Library API ==

The ALSA lib api is the interface to the ALSA drivers. Developers need to
use the functions in this api to achieve native ALSA support for their
applications. The ALSA lib documentation is a valuable developer reference
to the available functions. In many ways it is a tutorial. The latest
[http://www.alsa-project.org/alsa-doc/alsa-lib on-line documentation] is generated from
the alsa-lib CVS sources.

You can also generate it yourself. Install the
[http://www.doxygen.org doxygen tool] and type 'make doc' in
the alsa-lib directory.

The currently designed interfaces are listed below:

#Information Interface (/proc/asound)
#Control Interface (/dev/snd/controlCX)
#Mixer Interface (/dev/snd/mixerCXDX)
#PCM Interface (/dev/snd/pcmCXDX)
#Raw MIDI Interface (/dev/snd/midiCXDX)
#Sequencer Interface (/dev/snd/seq)
#Timer Interface (/dev/snd/timer)

== ALSA Driver Documentation ==

Takashi Iwai has written "Writing an ALSA Driver" - a very comprehensive
guide to developing a device driver for ALSA.

The document focuses mainly on the PCI soundcard. In the case of other
device types, the API might be different. However the ALSA kernel API is
consistent so it will be helpful in that context.

*[http://www.alsa-project.org/~iwai/writing-an-alsa-driver/index.html HTML (multiple documents)]
*[http://www.alsa-project.org/~iwai/writing-an-alsa-driver.pdf pdf file]
*[http://www.alsa-project.org/~iwai/alsa-drivers-writing.txt plain text]
*[http://www.alsa-project.org/~iwai/writing-an-alsa-driver.sgml The sgml source] is also available

== ALSA Driver API ==

This document gives a complete rundown of the functions in the alsa-driver API.

*[http://www.alsa-project.org/~iwai/alsa-driver-api/index.html HTML (multiple documents)]
*[http://www.alsa-project.org/~iwai/alsa-driver-api.pdf pdf file]
*[http://www.alsa-project.org/~iwai/alsa-driver-api.sgml The sgml source] is also available

=== Older documents ===

The [http://www.alsa-project.org/alsa-doc/alsa-howto ALSA HOWTO/FAQ documentation] tries
to do the ALSA driver installation easier. If you have any ideas or questions
regarding this documentation, please, leave a message on
the [[Mailing-lists|alsa-devel at lists.sourceforge.net]] mailing list.

The [http://www.alsa-project.org/~valentyn/Alsa-sound-mini-HOWTO.html ALSA-sound-mini-HOWTO]
describes the installation of the ALSA sound
drivers for Linux. This HOWTO is also available from the Linux Documentation Project, take
a look at [http://metalab.unc.edu/LDP/mirrors.html http://metalab.unc.edu/LDP/mirrors.html]
to find your nearest mirror. You can get this HOWTO in various formats:

*[http://www.alsa-project.org/~valentyn/Alsa-sound-mini-HOWTO.html HTML (multiple documents)]
*[http://www.alsa-project.org/~valentyn/other-formats/Alsa-sound-mini-HOWTO.html HTML (one document)]
*[http://www.alsa-project.org/~valentyn/other-formats/Alsa-sound-mini-HOWTO.txt plain text]
*[http://www.alsa-project.org/~valentyn/other-formats/Alsa-sound-mini-HOWTO.sgml sgml source] of the HOWTO is also available.

There is also an old [http://www.alsa-project.org/~jfulmer/alsa-faq.html ALSA FAQ document] from John Fulmer.

== ALSA 0.5.x Developer documentation ==

'''N.B. The 0.5.x series is considered deprecated and is no longer supported by ALSA developers'''

The [http://www.math.tu-berlin.de/~sbartels/alsa/ ALSA 0.4.0 Developer documentation] describes the internals of the ALSA kernel driver.
It is a document for kernel developers and others which want to know more
about ALSA internals. It is '''not''' for application programmers.
Application programmers should use the ALSA library API found in the alsa-lib
package. Incomplete documentation for ALSA 0.5.x API is available in HTML format
on [http://www.alsa-project.org/alsa-doc/alsa-lib-old ALSA WWW server] or you
may get [http://www.alsa-project.org/~perex/alsa-lib-old/alsa-lib.tgz tarball] for off-line
reading.