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1	<?xml version='1.0' encoding="UTF-8"?>	1	<?xml version='1.0' encoding="UTF-8"?>
		2	<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/alsa-guide.xml,v 1.73 2007/02/17 19:03:36 nightmorph Exp $ -->
		3
2	<!DOCTYPE guide SYSTEM "/dtd/guide.dtd">	4	<!DOCTYPE guide SYSTEM "/dtd/guide.dtd">
3		5
4	<guide link = "/doc/en/alsa-guide.xml">	6	<guide link="/doc/en/alsa-guide.xml">
5	<title>Gentoo Linux ALSA Guide</title>	7	<title>Gentoo Linux ALSA Guide</title>
6	<author title="Author"><mail link="zu@pandora.be">	8
7	Vincent Verleye</mail>	9	<author title="Author">
		10	<mail link="fox2mike@gentoo.org">Shyam Mani</mail>
8	</author>	11	</author>
9	<author title="Author"><mail link="g2boojum@gentoo.org">	12	<author title="Author">
10	Grant Goodyear</mail>	13	<mail link="nightmorph@gentoo.org">Joshua Saddler</mail>
11	</author>	14	</author>
12	<author title="Author"><mail link="agenkin@gentoo.org">	15	<author title="Contributor">
13	Arcady Genkin</mail>	16	<mail link="flameeyes@gentoo.org">Diego Pettenò</mail>
14	</author>	17	</author>
15	<author title="Editor"><mail link="zhen@gentoo.org">
16	John P. Davis</mail>
17	</author>
18	<author title="Editor"><mail link="swift@gentoo.org">
19	Sven Vermeulen</mail>
20	</author>
21	<author title="Editor"><mail link="bennyc@gentoo.org">
22	Benny Chuang</mail>
23	</author>
24	<author title="Editor"><mail link="blubber@gentoo.org">
25	Tiemo Kieft</mail>
26	</author>
27		18
		19	<abstract>
		20	This document helps a user setup ALSA on Gentoo Linux.
		21	</abstract>
		22
		23	<!-- The content of this document is licensed under the CC-BY-SA license -->
		24	<!-- See http://creativecommons.org/licenses/by-sa/2.5 -->
28	<license/>	25	<license/>
29		26
30	<abstract>
31	This guide will show you how to set up the Advanced Linux Sound Architecture (ALSA) on Gentoo Linux.
32	In addition to the Gentoo Linux Desktop Configuration Guide, this guide is supposed to give you more information on this subject. </abstract>
33
34	<version>1.3.3</version>	27	<version>2.17</version>
35	<date>October 9, 2003</date>	28	<date>2007-02-17</date>
36		29
37	<chapter>	30	<chapter>
38	<title>Introduction</title>	31	<title>Introduction</title>
39	<section>	32	<section>
40	<title>What is ALSA?</title>	33	<title>What is ALSA?</title>
		34	<body>
		35
		36	<p>
		37	ALSA, which stands for <e>Advanced Linux Sound Architecture</e>, provides
		38	audio and MIDI (<e>Musical Instrument Digital Interface</e>) functionality to
		39	the Linux operating system. ALSA is the default sound subsystem in the 2.6
		40	kernel thereby replacing OSS (<e>Open Sound System</e>), which was used in the
		41	2.4 kernels.
		42	</p>
		43
		44	<p>
		45	ALSA's main features include efficient support for all types of audio
		46	interfaces ranging from consumer sound cards to professional sound
		47	equipment, fully modularized drivers, SMP and thread safety, backward
		48	compatibility with OSS and a user-space library <c>alsa-lib</c> to make
		49	application development a breeze.
		50	</p>
		51
41	<body>	52	</body>
42	<p>	53	</section>
43	The Advanced Linux Sound Architecture (ALSA) is a project to improve the Linux sound subsystem by rewriting	54	<section>
44	large chunks of it.	55	<title>ALSA on Gentoo</title>
45	It is anticipated that ALSA will make it into Linux kernel 2.6.x (or 3.x.x -- whichever comes first) as it becomes ready.	56	<body>
		57
46	</p>	58	<p>
47		59	One of Gentoo's main strengths lies in giving the user maximum control over
		60	how a system is installed/configured. ALSA on Gentoo follows the same
		61	principle. There are two ways you can get ALSA support up and running on your
		62	system. We shall look at them in detail in the next chapter.
48	<p>	63	</p>
49	ALSA provides audio and MIDI functionality for Linux.	64
		65	</body>
		66	</section>
		67	</chapter>
		68
		69	<chapter>
		70	<title>Installing ALSA</title>
		71	<section>
		72	<title>Options</title>
		73	<body>
		74
		75	<warn>
		76	The methods shown below are mutually exclusive. You cannot have ALSA compiled
		77	in your kernel and use <c>media-sound/alsa-driver</c>. It <e>will</e> fail.
		78	</warn>
		79
50	</p>	80	<p>
51		81	The two options are :
52	<p>	82	</p>
53	Quoted from <uri>http://www.alsa-project.org</uri>, ALSA has the following features:	83
54	<ul><li> Efficient support for all types of audio interfaces, from consumer soundcards to professional multichannel audio interfaces.</li>	84	<ol>
55	<li> Fully modularized sound drivers.</li>	85	<li>Use ALSA provided by your kernel.</li>
56	<li> SMP and thread-safe design.</li>	86	<li>Use Gentoo's <c>media-sound/alsa-driver</c> package.</li>
57	<li> User space library (alsa-lib) to simplify application programming and provide higher level functionality.</li>	87	</ol>
58	<li> Support for the older OSS API, providing binary compatibility for most OSS programs.</li>	88
		89	<p>
		90	The in-kernel drivers and the <c>alsa-driver</c> package can vary a little; it's
		91	possible that features and fixes found in one might not yet be incorporated into
		92	the other. The upstream developers are aware of this, but the two drivers are
		93	effectively separate branches of the ALSA project; they are not entirely
		94	identical. You should be aware that they might function slightly differently, so
		95	if one doesn't work for you, try the other! We shall take a peek into both
		96	before finally deciding on one.
		97	</p>
		98
		99	<p>
		100	If you were to use ALSA provided by the kernel, the following are the pros and
		101	cons :
		102	</p>
		103
		104	<table>
		105	<tr>
		106	<th>Kernel ALSA</th>
		107	<th>Pros and Cons</th>
		108	</tr>
		109	<tr>
		110	<th>+</th>
		111	<ti>
		112	No need to emerge yet another package; drivers are integrated into kernel.
		113	</ti>
		114	</tr>
		115	<tr>
		116	<th>+</th>
		117	<ti>One shot solution, no repeating emerges.</ti>
		118	</tr>
		119	<tr>
		120	<th>-</th>
		121	<ti>Might be a slightly different version than <c>alsa-driver</c>.</ti>
		122	</tr>
		123	</table>
		124
		125	<p>
		126	And, if you were to use alsa-driver,
		127	</p>
		128
		129	<table>
		130	<tr>
		131	<th>alsa-driver</th>
		132	<th>Pros and Cons</th>
		133	</tr>
		134	<tr>
		135	<th>+</th>
		136	<ti>Possibly the latest drivers from the ALSA Project.</ti>
		137	</tr>
		138	<tr>
		139	<th>+</th>
		140	<ti>Useful if you intend to develop audio drivers.</ti>
		141	</tr>
		142	<tr>
		143	<th>-</th>
		144	<ti>Every kernel recompile requires a re-emerge of <c>alsa-driver</c>.</ti>
		145	</tr>
		146	<tr>
		147	<th>-</th>
		148	<ti>Needs certain kernel config options disabled to work correctly.</ti>
		149	</tr>
		150	</table>
		151
		152	</body>
		153	</section>
		154	<section>
		155	<title>So...</title>
		156	<body>
		157
		158	<p>
		159	The differences between <c>alsa-driver</c> and the in-kernel ALSA drivers are
		160	quite subtle, as mentioned earlier. Since there are not any huge differences,
		161	this guide will go through the process of using the ALSA provided by the kernel
		162	<e>first</e> for ease of use. However, if you run into problems, try switching
		163	to <c>alsa-driver</c>. Before reporting any sound related issues to <uri
		164	link="https://bugs.gentoo.org">Gentoo Bugzilla</uri>, please try to reproduce
		165	them using <c>alsa-driver</c> and file the bug report no matter what the
		166	result.
		167	</p>
		168
		169	</body>
		170	</section>
		171	<section id="lspci">
		172	<title>Before you proceed</title>
		173	<body>
		174
		175	<p>
		176	Whichever method of install you choose, you need to know what drivers your
		177	sound card uses. In most cases, sound cards (onboard and otherwise) are PCI
		178	based and <c>lspci</c> will help you in digging out the required information.
		179	Please <c>emerge sys-apps/pciutils</c> to get <c>lspci</c>, if you don't have it
		180	installed already. In case you have a USB sound card, <c>lsusb</c> from
		181	<c>sys-apps/usbutils</c> <e>might</e> be of help. For ISA cards, try using
		182	<c>sys-apps/isapnptools</c>. Also, the following pages <e>may</e> help users
		183	with ISA based sound cards.
		184	</p>
		185
		186	<ul>
		187	<li>
		188	<uri link="http://www.roestock.demon.co.uk/isapnptools/">The ISAPNPTOOLS
		189	Page</uri>
		190	</li>
		191	<li>
		192	<uri link="http://www2.linuxjournal.com/article/3269">LinuxJournal PnP
		193	Article</uri>
		194	</li>
		195	<li>
		196	<uri link="http://www.tldp.org/HOWTO/Sound-HOWTO/x320.html">TLDP Sound
		197	HowTo</uri>
		198	</li>
59	</ul>	199	</ul>
60	There's lots more to ALSA however, like support for Full Duplex playback and recording, multiple soundcard support,	200
61	hardware mixing of streams, extensive mixer capabilities (to support advanced features of new soundcards), ...	201	<note>
		202	For ease of use/explanation, we assume the user has a PCI based sound card for
		203	the remainder of this guide.
		204	</note>
		205
62	</p>	206	<p>
		207	We now proceed to find out details about the sound card.
		208	</p>
		209
		210	<pre caption="Soundcard Details">
		211	# <i>lspci -v \| grep -i audio</i>
		212	0000:00:0a.0 Multimedia audio controller: Creative Labs SB Live! EMU10k1 (rev 06)
		213	</pre>
		214
		215	<p>
		216	We now know that the sound card on the machine is a Sound Blaster Live! and
		217	the card manufacturer is Creative Labs. Head over to the
		218	<uri link="http://www.alsa-project.org/alsa-doc/"> ALSA Soundcard Matrix</uri>
		219	page and select Creative Labs from the drop down menu. You will be taken to
		220	the Creative Labs matrix page where you can see that the SB Live! uses the
		221	<c>emu10k1</c> module. That is the information we need for now. If you are
		222	interested in detailed information, you can click on the link next to the
		223	"Details" and that will take you to the <c>emu10k1</c> specific page.
		224	</p>
		225
		226	<p>
		227	If you intend to use MIDI, then you should add <c>midi</c> to your USE flags in
		228	<path>/etc/make.conf</path> before emerging any ALSA packages. Later in the
		229	guide, we will show you how to set up <uri link="#midi">MIDI support</uri>.
		230	</p>
		231
		232	<pre caption="MIDI support in /etc/make.conf">
		233	<comment>(If you want MIDI support)</comment>
		234	USE="midi"
		235
		236	<comment>(If you don't need MIDI)</comment>
		237	USE="-midi"
		238	</pre>
		239
63	</body>	240	</body>
64	</section>
65	<section>	241	</section>
66	<title>Why use ALSA?</title>	242	<section id="kernel">
67	<body>	243	<title>Using ALSA provided by your Kernel</title>
68	<p>
69	If your soundcard is supported by the Linux kernel sound system or the commercial OSS/4Front sound driver system,
70	which can be found in all 2.4.x Linux kernels, you could just aswell build <e>those modules</e> for use with your soundcard.
71	If you want this, just read through the <uri link="http://www.tldp.org/HOWTO/Sound-HOWTO/index.html">Linux Sound HOWTO</uri>.
72	</p>
73	<p>
74	However, those OSS/4Front drivers have some limitations -- being commercial is one.
75	ALSA is an attempt to go beyond these limitations and to do so in an open source fashion.
76	ALSA is a fully GPL and LGPL'ed sound driver system, that provides a professional quality system for recording, playback,
77	and MIDI sequencing.
78	</p>
79	</body>	244	<body>
80	</section>	245
		246	<p>
		247	If you're a person who likes to keep things simple like I do, then this is
		248	the way to go.
		249	</p>
		250
		251	<note>
		252	Since the 2005.0 release, Gentoo Linux uses 2.6 as the default kernel. Unless
		253	you are specifically using the 2.4 profile, <c>gentoo-sources</c> will be a
		254	2.6 kernel on <e>most</e> architectures. Please check that your kernel is a
		255	2.6 series kernel. This method will <e>not</e> work on a 2.4 kernel.
		256	</note>
		257
		258	<p>
		259	Let us now configure the kernel to enable ALSA.
		260	</p>
		261
		262	<impo>
		263	<c>genkernel</c> users should now run <c>genkernel --menuconfig all</c> and
		264	then follow the instructions in <uri link="#doc_chap2_pre3">Kernel Options for
		265	ALSA</uri>.
		266	</impo>
		267
		268	<pre caption="Heading over to the source">
		269	# <i>cd /usr/src/linux</i>
		270	# <i>make menuconfig</i>
		271	</pre>
		272
		273	<note>
		274	The above example assumes that <path>/usr/src/linux</path> symlink points to
		275	the kernel sources you want to use. Please ensure the same before proceeding.
		276	</note>
		277
		278	<p>
		279	Now we will look at some of the options we will have to enable in the 2.6
		280	kernel to ensure proper ALSA support for our sound card.
		281	</p>
		282
		283	<p>
		284	Please note that for ease of use, all examples show ALSA built as modules. It
		285	is advisable to follow the same as it then allows the use of <c>alsaconf</c>
		286	which is a boon when you want to configure your card. Please do <e>not</e> skip
		287	the <uri link="#alsa-config">Configuration</uri> section of this document. If
		288	you still like to have options built-in, ensure that you make changes to your
		289	config accordingly.
		290	</p>
		291
		292	<pre caption="Kernel Options for ALSA">
		293	Device Drivers --->
		294	Sound --->
		295
		296	<comment>(This needs to be enabled)</comment>
		297	<M> Sound card support
		298
		299	<comment>(Make sure OSS is disabled)</comment>
		300	Open Sound System --->
		301	< > Open Sound System (DEPRECATED)
		302
		303	<comment>(Move one step back and enter ALSA)</comment>
		304	Advanced Linux Sound Architecture --->
		305	<M> Advanced Linux Sound Architecture
		306	<comment>(Select this if you want MIDI sequencing and routing)</comment>
		307	<M> Sequencer support
		308	<comment>(Old style /dev/mixer* and /dev/dsp* support. Recommended.)</comment>
		309	<M> OSS Mixer API
		310	<M> OSS PCM (digital audio) API
		311
		312	<comment>(You now have a choice of devices to enable support for. Generally,
		313	you will have one type of device and not more. If you have more than one
		314	sound card, please enable them all here.)</comment>
		315
		316	<comment>(Mostly for testing and development purposes, not needed for normal
		317	users unless you know what you are doing.)</comment>
		318	Generic devices --->
		319
		320	<comment>(For ISA Sound cards)</comment>
		321	ISA devices --->
		322	<comment>(IF you had the Gravis, you would select this option)</comment>
		323	<M> Gravis UltraSound Extreme
		324
		325	<comment>(Move one level back and into PCI devices. Most sound cards today are
		326	PCI devices)</comment>
		327	PCI devices --->
		328	<comment>(We now select the emu10k1 driver for our card)</comment>
		329	<M> Emu10k1 (SB Live!, Audigy, E-mu APS)
		330	<comment>(Or an Intel card would be)</comment>
		331	<M> Intel/SiS/nVidia/AMD/ALi AC97 Controller
		332	<comment>(Or if you have a VIA Card)</comment>
		333	<M> VIA 82C686A/B, 8233/8235 AC97 Controller
		334
		335	<comment>(Move one level back and select in case you have an USB sound card)</comment>
		336	USB Devices --->
		337	</pre>
		338
		339	<p>
		340	Now that your options are set, you can (re)compile the kernel and ALSA support
		341	for your card should be functional once you reboot into the new kernel. Don't
		342	forget to update your GRUB configuration to use the newly built kernel.
		343	You can now proceed to <uri link="#alsa-utilities">ALSA Utilities</uri> and
		344	see if everything is working as it should.
		345	</p>
		346
		347	</body>
81	<section>	348	</section>
82	<title>What cards does ALSA support?</title>	349	<section id="alsa-driver">
		350	<title>Using the ALSA Driver package</title>
83	<body>	351	<body>
84	<p>	352
85	ALSA tries to support as many (new) cards as possible by providing open-source drivers.
86	However, some vendors may provide binary-only packages.
87	</p>	353	<p>
88	<p>To know if your card is supported, you can find a Soundcard Matrix of supported and not-supported cards here:	354	So you've decided to go the <c>alsa-driver</c> way. Let's get started then.
89	<uri>http://www.alsa-project.org/alsa-doc/</uri>.	355	There are a few minor things to be done to ensure only the drivers for your
		356	sound card are compiled. Although this is not really necessary, it cuts down
		357	on the unnecessary drivers that will be compiled otherwise.
		358	</p>
		359
90	</p>	360	<p>
		361	If you don't have an idea of what drivers your sound card might need, please
		362	take a look at the <uri link="#lspci">lspci</uri> section of this guide. Once
		363	you have your driver name (<c>emu10k1</c> in our example), edit
		364	<path>/etc/make.conf</path> and add a variable, <c>ALSA_CARDS</c>.
		365	</p>
		366
		367	<pre caption="Adding ALSA_CARDS to make.conf">
		368	<comment>(For one sound card)</comment>
		369	ALSA_CARDS="emu10k1"
		370	<comment>(For more than one, separate names with spaces)</comment>
		371	ALSA_CARDS="emu10k1 via82xx"
		372	</pre>
		373
		374	<p>
		375	If you have compiled your kernel and want to use <c>alsa-driver</c>, please
		376	ensure the following before proceeding, else <c>alsa-driver</c> is likely to
		377	fail. The next code listing gives you one way of performing the checks.
		378	</p>
		379
		380	<note>
		381	<c>genkernel</c> users can proceed with <uri link="#doc_chap2_pre6">Installing
		382	alsa-driver</uri> as their configuration is in sync with the one shown below by
		383	default.
		384	</note>
		385
		386	<ol>
		387	<li>
		388	<c>CONFIG_SOUND</c> is set. (Basic Sound support enabled)
		389	</li>
		390	<li>
		391	<c>CONFIG_SOUND_PRIME</c> is not set. (In-built OSS support disabled)
		392	</li>
		393	<li>
		394	<c>CONFIG_SND</c> is not set. (In-built ALSA support disabled)
		395	</li>
		396	<li>
		397	<path>/usr/src/linux</path> points to the kernel you want ALSA working on.
		398	</li>
		399	</ol>
		400
		401	<pre caption=".config checks">
		402	<comment>(Assuming the linux symlink points to the correct kernel)</comment>
		403	# <i>cd /usr/src/linux</i>
		404	# <i>grep SOUND .config</i>
		405	<comment>(1. is true)</comment>
		406	CONFIG_SOUND=y
		407	<comment>(2. is true)</comment>
		408	CONFIG_SOUND_PRIME is not set
		409	# <i>grep SND .config</i>
		410	<comment>(and 3. is true)</comment>
		411	CONFIG_SND is not set
		412	</pre>
		413
		414	<p>
		415	Now all you have to do is type the magic words... and no, it's not abracadabra.
		416	</p>
		417
		418	<pre caption="Installing alsa-driver">
		419	# <i>emerge alsa-driver</i>
		420	</pre>
		421
		422	<impo>
		423	Please note that you will have to run <c>emerge alsa-driver</c> after every
		424	kernel (re)compile, as the earlier drivers are deleted. To make this task
		425	easier, you may want to emerge the <c>module-rebuild</c> package, which will
		426	keep track of module packages and rebuild them for you. First run
		427	<c>module-rebuild populate</c> to create the list, and then after every kernel
		428	(re)compile, you just run <c>module-rebuild rebuild</c>, and your external
		429	modules will be rebuilt.
		430	</impo>
		431
91	</body>	432	</body>
92	</section>	433	</section>
93	</chapter>	434	</chapter>
94		435
95	<chapter>	436	<chapter>
96	<title>Installation</title>	437	<title>Configuring/Testing ALSA</title>
97	<section>	438	<section id="alsa-utilities">
98	<title>Gentoo USE flags</title>	439	<title>ALSA Utilities</title>
99	<body>
100
101	<p>
102	To compile programs with ALSA-support, be sure to add <e>alsa</e> to
103	your USE-variable. However, several tools don't support alsa yet, and
104	require OSS. ALSA provides OSS-emulation if you define <e>oss</e> in your
105	USE-variable before you start.
106	</p>
107
108	</body>	440	<body>
109	</section>
110		441
111	<section>
112	<title>Kernel modules</title>
113	<body>
114	<p>
115	Since we're still using 2.4.x kernel sources, we'll have to compile kernel modules and ALSA modules separately. People who are using a 2.5.x kernel can do this from within their kernel configuration, since the ALSA modules are included in the kernel sources and should be built there.
116	</p>	442	<p>
		443	<c>alsa-utils</c> forms an integral part of ALSA as it has a truckload of
		444	programs that are highly useful, including the ALSA Initscripts. Hence we
		445	strongly recommend that you install <c>alsa-utils</c>
117	<p>	446	</p>
118	First we'll make sure that our kernel configuration is ready for use with ALSA.	447
119	All you need in your kernel configuration is having Sound Card Support set to be built as a module (M).	448	<pre caption="Install alsa-utils">
120	This will build <c>soundcore.o</c>.	449	# <i>emerge alsa-utils</i>
121	</p>	450	</pre>
122	<p>	451
123	<note>	452	<note>
124	Possibly, this will also work when you built Sound Card Support in the kernel (Y) instead of building it as a module (M).	453	If you activated ALSA in your <uri link="#kernel">kernel</uri> <e>and</e> did
125	However, the official ALSA documentation suggests building it as a module, since ALSA will try loading it.	454	not compile ALSA as modules, please proceed to the
		455	<uri link="#initscript">ALSA Initscript</uri> section. The rest of you need
		456	to configure ALSA. This is made very easy by the existence of the
		457	<c>alsaconf</c> tool provided by <c>alsa-utils</c>.
126	</note>	458	</note>
		459
		460	</body>
		461	</section>
		462	<section id="alsa-config">
		463	<title>Configuration</title>
		464	<body>
		465
127	</p>	466	<p>
128	<p>If you already have a working kernel configuration, make sure you remove all sound drivers (except for Sound Card Support).	467	Recent versions of <c>udev</c> (<c>>=udev-103</c>) provide some degree of
129	If you wish to do this without having to reboot, you could do like this:	468	kernel-level autoconfiguration of your sound card. If possible, try to rely on
		469	just letting your kernel automatically setup your sound card for you. Otherwise,
		470	use <c>alsaconf</c> to configure your card, as shown below.
		471	</p>
		472
		473	<note>
		474	Please shut down any programs that <e>might</e> access the sound card while
		475	running <c>alsaconf</c>.
		476	</note>
		477
130	</p>	478	<p>
		479	Another way to configure your sound card is to run <c>alsaconf</c>. Just type
		480	<c>alsaconf</c> in a shell as root.
		481	</p>
		482
		483	<pre caption="Invoking alsaconf">
		484	# <i>alsaconf</i>
131	<pre>	485	</pre>
132	# <i>cd /usr/src/linux</i>	486
133	# <i>cp .config ~/</i>
134	# <i>make mrproper</i>
135	# <i>cp ~/.config .</i>
136	# <i>make menuconfig</i>
137	</pre>
138	<p>
139	Now select <e>Sound Card Support</e> as Module (M) and deselect all other sound drivers.
140	Exit and say Y to save your kernel configuration.
141	After that, build the modules:
142	</p>	487	<p>
		488	You will now see a neat menu guided interface that will automatically probe
		489	your devices and try to find out your sound card. You will be asked to pick
		490	your sound card from a list. Once that's done, it will ask you permission to
		491	automatically make required changes to <path>/etc/modules.d/alsa</path>.
		492	It will then adjust your volume settings to optimum levels, run
		493	<c>modules-update</c> and start the <path>/etc/init.d/alsasound</path> service.
		494	Once <c>alsaconf</c> exits, you can proceed with setting up the ALSA
		495	initscript.
		496	</p>
		497
		498	</body>
		499	</section>
		500	<section id="initscript">
		501	<title>ALSA Initscript</title>
		502	<body>
		503
		504	<p>
		505	We're now almost all setup. Whichever method you chose to install ALSA, you'll
		506	need to have something load your modules or initialize ALSA and restore your
		507	volume settings when your system comes up. The ALSA Initscript handles all of
		508	this for you and is called <c>alsasound</c>. Add it to the boot runlevel.
		509	</p>
		510
		511	<pre caption="Adding ALSA to the boot runlevel">
		512	# <i>rc-update add alsasound boot</i>
		513	* alsasound added to runlevel boot
		514	* rc-update complete.
143	<pre>	515	</pre>
144	# <i>make dep clean</i>	516
145	# <i>make modules modules_install</i>
146	</pre>
147	<p>
148	Before installing your new modules, this last line will delete all your previous modules,
149	even the ones from a previous ALSA installation.
150	</p>	517	<p>
		518	Next, just check the <path>/etc/conf.d/alsasound</path> file and ensure that
		519	SAVE_ON_STOP variable is set to yes. This saves your sound settings when you
		520	shutdown your system.
151	<p>	521	</p>
		522
		523	</body>
		524	</section>
		525	<section>
		526	<title>Audio Group</title>
		527	<body>
		528
		529	<p>
		530	Before we move on to testing, there's one last <e>important</e> thing that needs
		531	to be setup. Rule of thumb in a *nix OS : Do not run as root unless needed.
		532	This applies here as well ;) How? Well, most of the times you should be logged
		533	in as a user and would like to listen to music or access your soundcard. For
		534	that to happen, you need to be in the "audio" group. At this point, we'll add
		535	users to the audio group, so that they won't have any issues when they want to
		536	access sound devices. We'll use <c>gpasswd</c> here and you need to be logged in
		537	as root for this to work.
		538	</p>
		539
		540	<pre caption="Adding users to the audio group">
		541	<comment>(Substitute <username> with your user)</comment>
		542	# <i>gpasswd -a <username> audio </i>
		543	Adding user <username> to group audio
		544	</pre>
		545
		546	</body>
		547	</section>
		548	<section>
		549	<title>Volume Check!</title>
		550	<body>
		551
		552	<p>
		553	We've completed all the setups and prerequisites, so let's fire up ALSA. If
		554	you ran <c>alsaconf</c>, you can skip this step, since <c>alsaconf</c> already
		555	does this for you.
		556	</p>
		557
		558	<pre caption="Start the service">
		559	# <i>/etc/init.d/alsasound start</i>
		560	</pre>
		561
		562	<p>
		563	Now that the required things have been taken care of, we need to check up on
		564	the volume as in certain cases, it is muted. We use <c>alsamixer</c> for this
		565	purpose.
		566	</p>
		567
		568	<pre caption="Starting alsamixer">
		569	<comment>(Opens up a console program. Only required settings are shown)</comment>
		570	# <i>alsamixer</i>
		571	</pre>
		572
152	<impo>	573	<impo>
153	This means, whenever you recompile your kernel later on, you MUST recompile <c>alsa-driver</c>.	574	If you have issues starting up <c>alsamixer</c> and get errors such as
		575	alsamixer: function snd_ctl_open failed for default: No such file or directory,
		576	this is usually an issue with udev setting up the devices. Run <c>killall
		577	udevd; udevstart</c> to reload <path>/dev</path> entries and fire up
		578	<c>alsamixer</c>. It should solve the issue.
154	</impo>	579	</impo>
		580
155	</p>	581	<p>
		582	This is how the ALSA Mixer <e>might</e> look the first time you open it. Pay
		583	attention to the Master and PCM channels which both have an MM below them.
		584	That means they are muted. If you try to play anything with <c>alsamixer</c>
		585	in this state, you will not hear anything on your speakers.
156	<p>	586	</p>
157	<note>However, there's no need to reinstall <c>nvidia-kernel</c>, the Nvidia drivers are in a separate directory	587
158	in <path>/lib/modules/*/video</path> and won't get deleted by a <c>make modules modules_install</c>	588	<figure link="/images/docs/alsa-mixermuted.png" short="AlsaMixer Muted" caption="The Alsa Mixer Main Window, Muted"/>
		589
		590	<p>
		591	Now, we shall unmute the channels, and set volume levels as needed.
		592	</p>
		593
		594	<warn>
		595	Both Master <e>and</e> PCM need to be unmuted and set to audible volume levels
		596	if you want to hear some output on your speakers.
		597	</warn>
		598
		599	<ul>
		600	<li>
		601	To move between channels, use your left and right arrow keys. (<-
		602	& ->)
		603	</li>
		604	<li>
		605	To toggle mute, move to the specific channel, for example Master and press
		606	the <e>m</e> key on the keyboard.
		607	</li>
		608	<li>
		609	To increase and decrease the volume levels, use the up and down arrow keys
		610	respectively.
		611	</li>
		612	</ul>
		613
		614	<note>
		615	Be careful when setting your Bass and Treble values. 50 is usually a good
		616	number for both. Extremely high values of Bass may cause <e>jarring</e>
		617	on speakers that are not designed to handle them.
159	</note>	618	</note>
		619
160	</p>	620	<p>
161	</body>	621	After you're all done, your ALSA Mixer should look similar to the one below.
162	</section>	622	Note the 00 instead of the MM and also the volume levels for some optimum
		623	settings.
		624	</p>
163		625
		626	<figure link="/images/docs/alsa-mixerunmuted.png" short="AlsaMixer Unmuted" caption="Alsa Mixer ready to roll"/>
		627
		628	</body>
164	<section>	629	</section>
165	<title>ALSA modules</title>	630	<section>
		631	<title>Sound Check!</title>
		632	<body>
		633
		634	<p>
		635	Finally. Some music. If everything above is perfect, you should now be able to
		636	listen to some good music. A quick way to test is to use a command line tool
		637	like <c>media-sound/madplay</c>. You could also use something more well known
		638	like <c>mpg123</c>. If you are an ogg fan, you could use <c>ogg123</c> provided
		639	by <c>media-sound/vorbis-tools</c>. Use any player you are comfortable with. As
		640	always, <c>emerge</c> what you need.
		641	</p>
		642
		643	<pre caption="Getting the software">
		644	<comment>(Install the applications you want)</comment>
		645	# <i>emerge madplay mpg123</i>
		646	<comment>(To play .ogg files)</comment>
		647	# <i>emerge vorbis-tools</i>
		648	</pre>
		649
		650	<p>
		651	And then play your favorite sound track...
		652	</p>
		653
		654	<pre caption="Playing Music">
		655	# <i>madplay -v /mnt/shyam/Music/Paul\ Oakenfold\ -\ Dread\ Rock.mp3</i>
		656	MPEG Audio Decoder 0.15.2 (beta) - Copyright (C) 2000-2004 Robert Leslie et al.
		657	Title: Dread Rock
		658	Artist: Paul Oakenfold
		659	Album: Matrix Reloaded
		660	Year: 2003
		661	Genre: Soundtrack
		662	Soundtrack
		663	00:04:19 Layer III, 160 kbps, 44100 Hz, joint stereo (MS), no CRC
		664
		665	# <i>ogg123 Paul\ Oakenfold\ -\ Dread\ Rock.ogg</i>
		666	Audio Device: Advanced Linux Sound Architecture (ALSA) output
		667
		668	Playing: Paul Oakenfold - Dread Rock.ogg
		669	Ogg Vorbis stream: 2 channel, 44100 Hz
		670	Genre: Soundtrack
		671	Transcoded: mp3;160
		672	Title: Dread Rock
		673	Artist: Paul Oakenfold
		674	Date: 2003
		675	Album: Matrix Reloaded
		676	Time: 00:11.31 [04:28.75] of 04:40.06 (200.6 kbps) Output Buffer 96.9%
		677	</pre>
		678
166	<body>	679	</body>
		680	</section>
		681	<section>
		682	<title>ALSA and USE</title>
		683	<body>
167		684
168	<p>
169	Now it's time to install the ALSA drivers for your soundcard(s). If your soundcard is PCI, you can find out the name
170	and type of your soundcard by looking at the output of /proc/pci.
171	</p>	685	<p>
		686	You can now add the <c>alsa</c> use flag to <path>/etc/make.conf</path> to
		687	ensure that your applications that support ALSA get built with it. Some
		688	architectures like x86 and amd64 have the flag enabled by default.
		689	</p>
		690
		691	</body>
		692	</section>
		693	<section>
		694	<title>Issues?</title>
		695	<body>
		696
		697	<p>
		698	If for some reason you're unable to hear sound, the first thing to do would
		699	be to check your <uri link="#doc_chap3_pre6">alsamixer</uri> settings. 80% of
		700	the issues lie with muted channels or low volume. Also check your Window
		701	Manager's sound applet and verify that volumes are set to audible levels.
		702	</p>
		703
		704	<p>
		705	<path>/proc</path> is your friend. And in this case, <path>/proc/asound</path>
		706	is your best friend. We shall just take a short look at how much info is made
		707	available to us there.
		708	</p>
		709
		710	<pre caption="Fun with /proc/asound">
		711	<comment>(First and foremost, if /proc/asound/cards shows your card, ALSA has
		712	picked up your sound card fine.)</comment>
		713	# <i>cat /proc/asound/cards</i>
		714	0 [Live ]: EMU10K1 - Sound Blaster Live!
		715	Sound Blaster Live! (rev.6, serial:0x80271102) at 0xb800, irq 11
		716
		717	<comment>(If you run ALSA off the kernel like I do and wonder how far behind
		718	you are from alsa-driver, this displays current running ALSA version)</comment>
		719	# <i>cat /proc/asound/version</i>
		720	Advanced Linux Sound Architecture Driver Version 1.0.8 (Thu Jan 13 09:39:32 2005 UTC).
		721
		722	<comment>(ALSA OSS emulation details)</comment>
		723	# <i>cat /proc/asound/oss/sndstat</i>
		724	Sound Driver:3.8.1a-980706 (ALSA v1.0.8 emulation code)
		725	Kernel: Linux airwolf.zion 2.6.11ac1 #2 Wed May 4 00:35:08 IST 2005 i686
		726	Config options: 0
		727
		728	Installed drivers:
		729	Type 10: ALSA emulation
		730
		731	Card config:
		732	Sound Blaster Live! (rev.6, serial:0x80271102) at 0xb800, irq 11
		733
		734	Audio devices:
		735	0: EMU10K1 (DUPLEX)
		736
		737	Synth devices: NOT ENABLED IN CONFIG
		738
		739	Midi devices:
		740	0: EMU10K1 MPU-401 (UART)
		741
		742	Timers:
		743	7: system timer
		744
		745	Mixers:
		746	0: SigmaTel STAC9721/23
172	<pre>	747	</pre>
173	# <i>grep audio /proc/pci</i>
174	</pre>
175		748
176
177	<p>
178	<warn>
179	If you had a previous sound setup and there are still non-ALSA sound modules loaded, unload them <e>now</e>.
180	Check with <c>lsmod</c> and use <c>rmmod</c> to unload all sound-related modules on your system.
181	</warn>
182	</p>	749	<p>
183		750	The other most common issue users face is the dreaded "Unknown symbol in module"
		751	error. An example of the same is shown below.
184	<p>	752	</p>
185	We could simply do an <c>emerge alsa-driver</c> now, this would compile and install <e>all</e> ALSA sound drivers.
186	</p>
187	<p>
188	However, to save some time, lookup the <e>Module Name</e> of your soundcard(s) on the
189	<uri link="http://www.alsa-project.org/alsa-doc">ALSA Soundcard Matrix</uri> by following the <e>Details</e> link in the <e>Driver and Docs</e> column in the row of the chipset of your soundcard.
190	Mine is <c>snd-emu10k1</c>, since I have an SBlive! soundcard, with the <e>EMU10K1</e> chipset.
191	We'll set ALSA_CARDS environment to the value of the module name before emerging (but without the snd prefix), so emerge will only compile the drivers we need.
192	</p>
193		753
		754	<pre caption="Unknown Symbol in module error">
		755	# <i>/etc/init.d/alsasound start</i>
		756	* Loading ALSA modules ...
		757	* Loading: snd-card-0 ... [ ok ]
		758	* Loading: snd-pcm-oss ...
		759	WARNING: Error inserting snd_mixer_oss
		760	(/lib/modules/2.6.12-gentoo-r6/kernel/sound/core/oss/snd-mixer-oss.ko): Unknown
		761	symbol in module, or unknown parameter (see dmesg) FATAL: Error inserting
		762	snd_pcm_oss
		763	(/lib/modules/2.6.12-gentoo-r6/kernel/sound/core/oss/snd-pcm-oss.ko): Unknown
		764	symbol in module, or unknown parameter (see dmesg)
		765	[ !! ]
		766	* Loading: snd-mixer-oss ...
		767	FATAL: Error inserting snd_mixer_oss
		768	(/lib/modules/2.6.12-gentoo-r6/kernel/sound/core/oss/snd-mixer-oss.ko): Unknown
		769	symbol in module, or unknown parameter (see dmesg)
		770	[ !! ]
		771	* Loading: snd-seq ... [ ok ]
		772	* Loading: snd-emu10k1-synth ... [ ok ]
		773	* Loading: snd-seq-midi ... [ ok ]
		774	* Restoring Mixer Levels ... [ ok ]
194	<pre>	775	</pre>
195	# <i>env ALSA_CARDS='emu10k1' emerge alsa-driver</i>	776
		777	<p>
		778	And when you take a look at <c>dmesg</c> as suggested, you're quite likely to
		779	see:
196	</pre>	780	</p>
		781
		782	<pre caption="dmesg output">
		783	<comment>(Only relevant portions are shown below)</comment>
		784	# <i>dmesg \| less</i>
		785	ACPI: PCI Interrupt 0000:02:06.0[A] -> Link [APC3] -> GSI 18 (level, low) -> IRQ 209
		786	snd_mixer_oss: Unknown symbol snd_unregister_oss_device
		787	snd_mixer_oss: Unknown symbol snd_register_oss_device
		788	snd_mixer_oss: Unknown symbol snd_mixer_oss_notify_callback
		789	snd_mixer_oss: Unknown symbol snd_oss_info_register
		790	snd_pcm_oss: Unknown symbol snd_unregister_oss_device
		791	snd_pcm_oss: Unknown symbol snd_register_oss_device
		792	snd_pcm_oss: Unknown symbol snd_mixer_oss_ioctl_card
		793	snd_pcm_oss: Unknown symbol snd_oss_info_register
		794	snd_mixer_oss: Unknown symbol snd_unregister_oss_device
		795	snd_mixer_oss: Unknown symbol snd_register_oss_device
		796	snd_mixer_oss: Unknown symbol snd_mixer_oss_notify_callback
		797	snd_mixer_oss: Unknown symbol snd_oss_info_register
		798	</pre>
		799
		800	<p>
		801	The above issue is caused when you switch from <c>alsa-driver</c> to in-kernel
		802	ALSA because when you unmerge <c>alsa-driver</c> the module files are config
		803	protected and hence get left behind. So, when you switch to in-kernel
		804	drivers, running <c>modprobe</c> gives you a mix of <c>alsa-driver</c> and
		805	in-kernel modules thus causing the above errors.
		806	</p>
		807
		808	<p>
		809	The solution is quite easy. We just need to manually remove the problem causing
		810	directory after you unmerge <c>alsa-driver</c>. Be sure to remove the correct
		811	kernel version and not the current one!
		812	</p>
		813
		814	<pre caption="Removing the alsa-driver modules">
		815	# <i>rm -rf /lib/modules/$(uname -r)/alsa-driver</i>
		816	</pre>
		817
		818	<p>
		819	Another reason for error messages similar to the ones above could be a file in
		820	<path>/etc/modules.d</path> supplying a <c>device_mode</c> parameter when it
		821	isn't required. Confirm that this is indeed the issue and find out which file
		822	is the culprit.
		823	</p>
		824
		825	<pre caption="Confirming and searching for device_mode">
		826	<comment>(Check dmesg to confirm)</comment>
		827	# <i>dmesg \| grep device_mode</i>
		828	snd: Unknown parameter `device_mode'
		829	<comment>(Now, to get to the source of the issue)</comment>
		830	# <i>grep device_mode /etc/modules.d/*</i>
		831	</pre>
		832
		833	<p>
		834	Usually it is a file called <path>alsa</path> with the line <c>options snd
		835	device_mode=0666</c>. Remove this line and restart the alsasound service and
		836	that should take care of this issue.
		837	</p>
		838
		839	</body>
		840	</section>
		841	</chapter>
		842
		843	<chapter>
		844	<title>Other things ALSA</title>
		845	<section id="midi">
		846	<title>Setting up MIDI support</title>
		847	<body>
		848
		849	<p>
		850	First, check to make sure that you enabled the <c>midi</c> USE flag in
		851	<path>/etc/make.conf</path>.
		852	</p>
		853
		854	<pre caption="MIDI support in /etc/make.conf">
		855	USE="midi"
		856	</pre>
		857
		858	<p>
		859	If you didn't previously enable <c>midi</c>, go ahead and add it to
		860	<path>/etc/make.conf</path> now. You will also need to re-emerge any ALSA
		861	packages that use the <c>midi</c> flag, such as <c>alsa-lib</c>,
		862	<c>alsa-utils</c>, and <c>alsa-driver</c>.
		863	</p>
		864
		865	<p>
		866	If your sound card is one of those that come with on-board MIDI synthesizers
		867	and you would like to listen to some .mid files, you have to install
		868	<c>awesfx</c> which is basically a set of utilities for controlling the AWE32
		869	driver. We need to install it first. If you don't have a hardware synthesizer,
		870	you can use a virtual one. Please see the section on
		871	<uri link="#vsynth">Virtual Synthesizers</uri> for more information.
		872	</p>
		873
		874	<pre caption="Installing awesfx">
		875	# <i>emerge awesfx</i>
		876	</pre>
		877
197	<note>	878	<note>
198	You can also add this value in <path>/etc/make.conf</path>, so when you have to emerge the alsa-driver later on you can just run <c>emerge alsa-driver</c>.	879	You will need to copy over SoundFont (SF2) files from your sound card's driver
199	For example, like this: <c>echo 'ALSA_CARDS="emu10k1"' >> /etc/make.conf</c>	880	CD or a Windows installation into <path>/usr/share/sounds/sf2/</path>. For
		881	example a sound font file for the Creative SBLive! card would be 8MBGMSFX.SF2.
200	</note>	882	</note>
201		883
		884	<p>
		885	After copying over the Soundfont files, we can then play a midi file as shown.
		886	You can also add the <c>asfxload</c> command to
		887	<path>/etc/conf.d/local.start</path>, so that the sound font is loaded
		888	every time the system starts up.
		889	</p>
		890
202	<note>	891	<note>
203	When you want to install ALSA drivers for more than one soundcard, you could set ALSA_CARDS to a space-separated list	892	<path>/mnt</path> paths mentioned in the code listing(s) below will <e>not</e>
204	of drivers; like this: <c>env ALSA_CARDS='emu10k1 intel8x0 ens1370' emerge alsa-driver</c>	893	be the same in your machine. They are just an example. Please be careful to
		894	change the path to suit your machine.
205	</note>	895	</note>
206		896
207	<note>If you want to have OSS compatibility, make sure to emerge <i>alsa-oss</i>, it is the ALSA/OSS compatibility	897	<pre caption="Loading Soundfonts">
208	wrapper. </note>	898	<comment>(First, copy the Soundfont)</comment>
		899	# <i>cp /mnt/win2k/Program\ Files/CreativeSBLive2k/SFBank/8MBGMSFX.SF2 /usr/share/sounds/sf2/</i>
		900	<comment>(Or get it from your SoundBlaster CD)</comment>
		901	# <i>cp /mnt/cdrom/AUDIO/ENGLISH/SFBANK/8MBGMSFX.SF2 /usr/share/sounds/sf2/</i>
		902	<comment>(We load the specific Soundfont)</comment>
		903	# <i>asfxload /usr/share/sounds/sf2/8MBGMSFX.SF2</i>
		904	</pre>
209		905
210	<note>If you plan on recompiling your kernels numerous times, it might
211	be adviseable to emerge <c>alsa-driver</c> with <c>--buildpkg</c>. This
212	will create a binary package for it. Later, after recompiling your kernel,
213	you can just do <c>emerge --usepkg alsa-driver</c> which will install the
214	binary package instead of recompiling it completely.</note>
215
216	<p>
217	After this, the ALSA modules should be installed on your system.
218	</p>	906	<p>
		907	You can now play midi files using a program like <c>aplaymidi</c>. Run
		908	<c>aplaymidi -l</c> to get a list of available ports and then pick one
		909	to play the file on.
		910	</p>
		911
		912	<pre caption="Playing MIDI">
		913	<comment>(Check open ports)</comment>
		914	# <i>aplaymidi -l</i>
		915	Port Client name Port name
		916	64:0 EMU10K1 MPU-401 (UART) EMU10K1 MPU-401 (UART)
		917	65:0 Emu10k1 WaveTable Emu10k1 Port 0
		918	65:1 Emu10k1 WaveTable Emu10k1 Port 1
		919	65:2 Emu10k1 WaveTable Emu10k1 Port 2
		920	65:3 Emu10k1 WaveTable Emu10k1 Port 3
		921	<comment>(Pick a port, and play a mid file)</comment>
		922	# <i> aplaymidi --port=65:0 /mnt/shyam/music/midi/mi2.mid</i>
		923	</pre>
		924
219	</body>	925	</body>
220	</section>
221	<section>	926	</section>
222	<title>Configuration of ALSA</title>	927	<section id="vsynth">
223	<body>	928	<title>Virtual Synthesizers</title>
224	<p>
225	Let's start configuring now to get ALSA working properly.
226	We'll need to edit some files, to let our system know about the freshly installed ALSA modules.
227	</p>
228
229	<p>
230	First, install <c>alsa-utils</c> on your system:
231	</p>
232
233	<pre caption = "Emerging alsa-utils">
234	# <i>emerge alsa-utils</i>
235	</pre>
236
237	<p>
238	Hereafter, we need to edit <path>/etc/modules.d/alsa</path>.
239	</p>
240	<warn>
241	There is no need to edit <path>/etc/modules.conf</path>. Instead, always edit files in <path>/etc/modules.d</path>.
242	</warn>
243	<p>
244	Check the ALSA portion <e>at the bottom of the file</e>.
245	By tweaking this line you can specify the max number of soundcards you have (generally, just one).
246	</p>
247	<pre caption="At the bottom of /etc/modules.d/alsa">
248	<comment>Set this to the correct number of cards.</comment>
249	options snd cards_limit=1
250	</pre>
251	<p>
252	Now we'll specify the sounddriver(s) ALSA should use. In the same file, edit like this:
253	</p>
254	<pre caption="In /etc/modules.d/alsa">
255	## and then run `modules-update' command.
256	## Read alsa-driver's INSTALL file in /usr/share/doc for more info.
257	##
258	## ALSA portion
259	alias snd-card-0 snd-emu10k1
260	<comment>## If you have more than one, add:</comment>
261	## alias snd-card-1 snd-intel8x0
262	## alias snd-card-2 snd-ens1370
263	## OSS/Free portion
264	## alias sound-slot-0 snd-card-0
265	## alias sound-slot-1 snd-card-1
266	##
267	</pre>
268	<note>
269	If you have more than one soundcard, adjust the <c>cards_limit</c> value and add more snd-card aliases to the file.
270	I don't have experience with this, but you can find examples for configurations with two or more soundcards in
271	<uri link="http://www.alsa-project.org/alsa-doc/alsa-howto/c1660.htm">Chapter 6</uri>
272	of the <uri link="http://www.alsa-project.org/alsa-doc/alsa-howto/alsa-howto.html">ALSA Howto</uri>.
273	</note>
274	<p>
275	Last thing to do in this file, almost at the end, check if these lines are there and uncommented:
276	</p>
277	<pre caption="Near the end of /etc/modules.d/alsa">
278	alias /dev/mixer snd-mixer-oss
279	alias /dev/dsp snd-pcm-oss
280	alias /dev/midi snd-seq-oss
281	</pre>
282	<p>
283	Now double-check the file <path>/etc/modules.d/alsa</path> and when you're sure everyting is ok, run <c>modules-update</c>.
284	<pre>
285	# <i>modules-update</i>
286	</pre>
287	</p>
288	<note>
289	Running <c>modules-update</c> here will insert the data from <path>/etc/modules.d/alsa</path> into <path>/etc/modules.conf</path>
290	</note>
291	<p>
292	You should also verify that /etc/devfsd.conf has the alsa devices and permissions correctly registered.
293	</p>
294	<pre caption="/etc/devfsd.conf">
295	# ALSA/OSS stuff
296	# Comment/change these if you want to change the permissions on
297	# the audio devices
298	LOOKUP snd MODLOAD ACTION snd
299	LOOKUP dsp MODLOAD
300	LOOKUP mixer MODLOAD
301	LOOKUP midi MODLOAD
302	REGISTER sound/.* PERMISSIONS root.audio 660
303	REGISTER snd/.* PERMISSIONS root.audio 660
304	</pre>
305	<note>
306	Notice that devfsd.conf sets /dev/sound permissions to be root.audio. Thus, for non-root users to use audio they will have to be part of the audio group.
307	</note>
308	</body>	929	<body>
309	</section>	930
310	</chapter>	931	<p>
311	<chapter>	932	If your sound card lacks a hardware synthesizer, you could use a virtual one
312	<title>Starting ALSA</title>	933	like <c>timidity++</c>. Installation is a breeze.
		934	</p>
		935
		936	<pre caption="Installing timidity++">
		937	# <i>emerge timidity++</i>
		938	</pre>
		939
		940	<p>
		941	For timidity to play sounds, it needs a sound font. Fortunately, the ebuild will
		942	install some sound font packages for you. There are a few other font packages
		943	available in Portage, such as <c>timidity-freepats</c> and
		944	<c>timidity-eawpatches</c>. You can have multiple sound font configurations
		945	installed, and you can place your own in <path>/usr/share/timidity/</path>. To
		946	switch between different timidity configurations, you should use
		947	<c>eselect</c>.
		948	</p>
		949
		950	<pre caption="Changing configurations">
		951	# <i>eselect timidity list</i>
		952	# <i>eselect timidity set eawpatches</i>
		953	</pre>
		954
		955	<p>
		956	Don't forget to add <c>timidity</c> to the default runlevel.
		957	</p>
		958
		959	<pre caption="Adding timidity to the default runlevel">
		960	# <i>rc-update add timidity default</i>
		961	# <i>/etc/init.d/timidity start</i>
		962	</pre>
		963
		964	<p>
		965	You can now try out <uri link="#doc_chap4_pre3">Playing MIDI</uri> files.
		966	</p>
		967
		968	</body>
313	<section>	969	</section>
314	<title>Adding alsasound to a runlevel</title>
315	<body>
316	<p>
317	First thing to do now, is to make ALSA startup at boottime. Like this:
318	<pre>
319	# <i>rc-update add alsasound boot</i>
320	</pre>
321	</p>
322	<p>
323	<warn>Note that the alsasound script should be added to the "boot" runlevel, not the "default" runlevel.</warn>
324	</p>
325	</body>
326	</section>	970	<section>
		971	<title>Tools and Firmware</title>
		972	<body>
		973
		974	<p>
		975	Some specific sound cards can benefit from certain tools provided by the
		976	<c>alsa-tools</c> and <c>alsa-firmware</c> packages. You may install either with
		977	a simple <c>emerge</c>.
		978	</p>
		979
		980	<pre caption="Installing ALSA Tools">
		981	# <i>emerge alsa-tools</i>
		982	</pre>
		983
		984	</body>
327	<section>	985	</section>
328	<title>Running and unmuting</title>
329	<body>
330	<p>
331	Since we're Linux users, we don't want to reboot. So we'll start the alsasound script manually.
332	</p>
333	<pre>
334	# <i>/etc/init.d/alsasound start</i>
335	</pre>
336	<p>
337	ALSA is running now. If everything is ok, you should be able to see the ALSA modules loaded when running <c>lsmod</c>.
338	However, sound won't work yet, because the channels are still muted. We need <c>amixer</c> for this.
339	</p>
340	<pre caption = "Running amixer">
341	# <i>amixer</i>
342	</pre>
343	<p>
344	<warn>
345	You shouldn't get this, but <e>if</e> you get an error about "amixer: Mixer attach default error: No such file or directory", you should manually modprobe
346	<c>snd-mixer-oss</c> and <c>snd-pcm-oss</c> once. After that run amixer again.
347	</warn>
348	</p>
349	<pre caption="only if you get an error when running amixer">
350	# <i>modprobe snd-mixer-oss</i>
351	# <i>modprobe snd-pcm-oss</i>
352	# <i>amixer</i>
353	</pre>
354	<p>
355	If you got this far, now unmute Master and PCM channels. Some hardware
356	even requires you to unmute the center channel or even the surround
357	channel.
358	</p>
359	<p>
360	<pre caption = "Unmuting channels">
361	# <i>amixer set Master 100 unmute</i>
362	# <i>amixer set PCM 100 unmute</i>
363	<comment>Only if the above doesn't succeed on its own:</comment>
364	# <i>amixer set Center 100 unmute</i>
365	# <i>amixer set Surround 100 unmute</i>
366	<comment>Test the sound:</comment>
367	# <i>aplay $KDEDIR/share/sounds/pop.wav</i> <codenote>(pop.wav is part of KDE)</codenote>
368	</pre>
369	</p>
370	We check to see if sound is working by using the aplay (alsa play) command. If you hear a pop, then sound is indeed working.
371	Then, adjust the volume settings to your liking; the ncurses-based <c>alsamixer</c> is a great way to get them "just so".
372	<p>
373	You may want to emerge <c>alsa-xmms</c> as that will provide ALSA support for XMMS.
374	</p>
375	When you reboot your system, the <e>alsasound</e> init script will properly save and restore your volume settings.
376	</body>
377	</section>	986	<section>
378	</chapter>	987	<title>Multiple sound cards</title>
379	<chapter>	988	<body>
380	<title>Final Notes</title>	989
		990	<p>
		991	You can more than one sound card in your system simultaneously, provided that
		992	you have built ALSA as modules in your kernel (or have installed
		993	<c>alsa-driver</c> instead). You just need to specify which should be started
		994	first in <path>/etc/modules.d/alsa</path>. Your cards are identified by their
		995	driver names inside this file. 0 is the first card, 1 is the second, and so on.
		996	Here's an example for a system with two sound cards.
		997	</p>
		998
		999	<pre caption="Two sound cards in /etc/modules.d/alsa">
		1000	options snd-emu10k1 index=0
		1001	options snd-via82xx index=1
		1002	</pre>
		1003
		1004	<p>
		1005	Or, if you have two cards that use the same driver, you specify them on the same
		1006	line, using comma-separated numbers. Here's an example for a system with three
		1007	sound cards, two of which are the same Intel High Definition Audio card.
		1008	</p>
		1009
		1010	<pre caption="Multiple sound cards in /etc/modules.d/alsa">
		1011	options snd-ymfpci index=0
		1012	options snd-hda-intel index=1,2
		1013	</pre>
		1014
		1015	</body>
381	<section>	1016	</section>
382	<title>After kernel-upgrades..</title>
383	<body>
384	<p>When you ever rebuild your kernel, or upgrade to another kernel, you'll have to rebuild the ALSA modules.</p>
385	<p>Although you might have installed <c>alsa-driver</c>, <c>alsa-libs</c> and <c>alsa-utils</c>, only the first will
386	have to be installed again, since it will put the alsa modules in
387	<path>/lib/modules/*/kernel/sound/pci/</path>.</p>
388	<pre caption="needed after each kernel compile">
389	# <i>emerge alsa-driver</i>
390	</pre>
391	</body>
392	</section>	1017	<section>
		1018	<title>Plugins</title>
		1019	<body>
		1020
		1021	<p>
		1022	You may want to install some plugins for extra functionality.
		1023	<c>alsa-plugins</c> is a collection of useful plugins, which include: PulseAudio
		1024	output, a sample rate converter, jack (a low-latency audio server), and an
		1025	encoder that lets you output 6-channel audio through digital S/PDIF connections
		1026	(both optical and coaxial). You can choose which of its plugins you want
		1027	installed by adding their USE flags to <path>/etc/portage/package.use</path>.
		1028	</p>
		1029
		1030	<pre caption="Installing alsa-plugins">
		1031	# <i>emerge -avt alsa-plugins</i>
		1032	</pre>
		1033
		1034	</body>
393	<section>	1035	</section>
394	<title>/etc/modules.autoload</title>
395	<body>
396	<p>You won't have to edit this file for use with ALSA. After our <c>rc-update add alsasound boot</c>, our system will
397	load the correct modules at startup.</p>
398	<p>It's not necessary to add <c>snd-pcm-oss</c> or <c>snd-mixer-oss</c> in this file.
399	Check the <uri link="http://www.djcj.org/LAU/guide/alsbook/faq1.html">this FAQ</uri> for more info.</p>
400	</body>
401	</section>	1036	<section>
		1037	<title>A big thank you to...</title>
		1038	<body>
402		1039
		1040	<p>
		1041	Everyone who contributed to the earlier version of the Gentoo ALSA Guide:
		1042	Vincent Verleye, Grant Goodyear, Arcady Genkin, Jeremy Huddleston,
		1043	John P. Davis, Sven Vermeulen, Benny Chuang, Tiemo Kieft and Erwin.
		1044	</p>
		1045
		1046	</body>
403	<section>	1047	</section>
404	<title>Known bugs</title>	1048	<section>
		1049	<title>References</title>
405	<body>	1050	<body>
406
407	<note>
408	This guide lags behind on the alsa-development. Chances are these bugs
409	are already fixed when you read this.
410	</note>
411		1051
412	<ul>	1052	<ul>
413	<li>	1053	<li><uri link="http://www.alsa-project.org/">The ALSA Project</uri></li>
414	If you have <b>lots of noise</b> when using <b>oss</b> emulation, add	1054	<li><uri link="http://linux-sound.org">Linux Sound/MIDI Software</uri></li>
415	<e>options snd-pcm-oss dsp_map=1</e> to
416	<path>/etc/modules.d/alsa</path>.
417	</li>
418	</ul>	1055	</ul>
419		1056
420	</body>
421	</section>
422
423	<section>
424	<title>More links..</title>
425	<body>
426	<p>
427	You could check these for additional info:
428	</p>
429	<p>
430	<ul>
431	<li><uri link="http://www.gentoo.org/doc/en/desktop.xml">The Gentoo Linux Desktop Configuration Guide</uri></li>
432	<li><uri link="http://www.alsa-project.org">ALSA Project Homepage</uri></li>
433	<li><uri link="http://www.alsa-project.org/documentation.php3">ALSA Users Documentation</uri></li>
434	<li><uri link="http://www.djcj.org">ALSA Howto's and FAQ's</uri></li>
435	<li><uri link="http://tldp.org/HOWTO/Sound-HOWTO/index.html">Linux Sound HOWTO</uri></li>
436	<li><uri link="http://linux-sound.org/">Sound and MIDI Software For Linux</uri></li>
437	</ul>
438	</p>
439	</body>	1057	</body>
440	</section>	1058	</section>
441	</chapter>	1059	</chapter>
442	</guide>	1060	</guide>

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