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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 1.21 2003/11/23 16:30:50 swift Exp $ --> 2<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/alsa-guide.xml,v 1.81 2008/03/05 09:16:49 nightmorph Exp $ -->
3
3<!DOCTYPE guide SYSTEM "/dtd/guide.dtd"> 4<!DOCTYPE guide SYSTEM "/dtd/guide.dtd">
4 5
5<guide link = "/doc/en/alsa-guide.xml"> 6<guide link="/doc/en/alsa-guide.xml">
6<title>Gentoo Linux ALSA Guide</title> 7<title>Gentoo Linux ALSA Guide</title>
8
7<author title="Author"> 9<author title="Author">
8 <mail link="zu@pandora.be">Vincent Verleye</mail> 10 <mail link="fox2mike@gentoo.org">Shyam Mani</mail>
9</author> 11</author>
10<author title="Author"> 12<author title="Author">
11 <mail link="g2boojum@gentoo.org">Grant Goodyear</mail> 13 <mail link="nightmorph@gentoo.org">Joshua Saddler</mail>
12</author> 14</author>
13<author title="Author"> 15<author title="Contributor">
14 <mail link="agenkin@gentoo.org">Arcady Genkin</mail> 16 <mail link="flameeyes@gentoo.org">Diego Pettenò</mail>
15</author> 17</author>
16<author title="Editor"><!-- zhen@gentoo.org -->
17 John P. Davis
18</author>
19<author title="Editor">
20 <mail link="swift@gentoo.org">Sven Vermeulen</mail>
21</author>
22<author title="Editor">
23 <mail link="bennyc@gentoo.org">Benny Chuang</mail>
24</author>
25<author title="Editor">
26 <mail link="blubber@gentoo.org">Tiemo Kieft</mail>
27</author>
28 18
19<abstract>
20This 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 -->
29<license/> 25<license/>
30 26
31<abstract>
32This guide will show you how to set up the Advanced Linux Sound Architecture
33(ALSA) on Gentoo Linux. In addition to the Gentoo Linux Desktop Configuration
34Guide, this guide is supposed to give you more information on this subject.
35</abstract>
36
37<version>1.3.4</version> 27<version>2.23</version>
38<date>November 23, 2003</date> 28<date>2008-03-05</date>
39 29
40<chapter> 30<chapter>
41<title>Introduction</title> 31<title>Introduction</title>
42<section> 32<section>
43<title>What is ALSA?</title> 33<title>What is ALSA?</title>
44<body> 34<body>
45 35
46<p> 36<p>
47The Advanced Linux Sound Architecture (ALSA) is a project to improve the Linux 37ALSA, which stands for <e>Advanced Linux Sound Architecture</e>, provides
48sound subsystem by rewriting large chunks of it. It is anticipated that ALSA 38audio and MIDI (<e>Musical Instrument Digital Interface</e>) functionality to
49will make it into Linux kernel 2.6.x (or 3.x.x -- whichever comes first) as it 39the Linux operating system. ALSA is the default sound subsystem in the 2.6
50becomes ready. 40kernel thereby replacing OSS (<e>Open Sound System</e>), which was used in the
51</p> 412.4 kernels.
52
53<p> 42</p>
54ALSA provides audio and MIDI functionality for Linux. 43
55</p> 44<p>
56 45ALSA's main features include efficient support for all types of audio
46interfaces ranging from consumer sound cards to professional sound
47equipment, fully modularized drivers, SMP and thread safety, backward
48compatibility with OSS and a user-space library <c>alsa-lib</c> to make
49application development a breeze.
57<p> 50</p>
58Quoted from <uri>http://www.alsa-project.org</uri>, ALSA has the following 51
59features: 52</body>
53</section>
54<section>
55<title>ALSA on Gentoo</title>
56<body>
57
58<p>
59Historically, Gentoo offered two ways to get ALSA up and running: the
60<e>in-kernel</e> driver and the external <c>alsa-driver</c> package. The two
61solutions essentially do the same thing; this made supporting the external
62package extremely difficult and time-consuming. The Gentoo maintainers decided
63to discontinue support for the <c>alsa-driver</c> package, concentrating their
64resources on the ALSA drivers available within the Linux kernel. This guide will
65focus solely on configuring ALSA via the in-kernel driver.
66</p>
67
68<p>
69If you still require the <c>alsa-driver</c> package, please email the <mail
70link="alsa-bugs@gentoo.org">Gentoo ALSA maintainers</mail> with why the
71in-kernel drivers don't work for you. Be sure to include detailed error logs.
72</p>
73
74</body>
75</section>
76</chapter>
77
78<chapter>
79<title>Installing ALSA</title>
80<section id="lspci">
81<title>Before you proceed</title>
82<body>
83
84<p>
85First, you need to know what drivers your sound card uses. In most cases, sound
86cards (onboard and otherwise) are PCI based and <c>lspci</c> will help you in
87digging out the required information. Please <c>emerge sys-apps/pciutils</c> to
88get <c>lspci</c>, if you don't have it installed already. In case you have a USB
89sound card, <c>lsusb</c> from <c>sys-apps/usbutils</c> <e>might</e> be of help.
90For ISA cards, try using <c>sys-apps/isapnptools</c>. Also, the following pages
91<e>may</e> help users with ISA based sound cards:
60</p> 92</p>
61 93
62<ul> 94<ul>
63 <li> 95 <li>
64 Efficient support for all types of audio interfaces, from consumer 96 <uri link="http://www.roestock.demon.co.uk/isapnptools/">The ISAPNPTOOLS
65 soundcards to professional multichannel audio interfaces 97 Page</uri>
66 </li>
67 <li>Fully modularized sound drivers</li>
68 <li>SMP and thread-safe design</li>
69 <li>
70 User space library (alsa-lib) to simplify application programming and
71 provide higher level functionality
72 </li> 98 </li>
73 <li> 99 <li>
74 Support for the older OSS API, providing binary compatibility for most OSS 100 <uri link="http://www2.linuxjournal.com/article/3269">LinuxJournal PnP
75 programs 101 Article</uri>
76 </li> 102 </li>
103 <li>
104 <uri link="http://www.tldp.org/HOWTO/Sound-HOWTO/x320.html">TLDP Sound
105 HowTo</uri>
106 </li>
77</ul> 107</ul>
78 108
79<p> 109<note>
80There's lots more to ALSA however, like support for Full Duplex playback and 110For ease of use/explanation, we assume the user has a PCI based sound card for
81recording, multiple soundcard support, hardware mixing of streams, extensive 111the remainder of this guide.
82mixer capabilities (to support advanced features of new soundcards), ... 112</note>
113
83</p> 114<p>
115We now proceed to find out details about the sound card.
116</p>
84 117
118<pre caption="Soundcard Details">
119# <i>lspci -v | grep -i audio</i>
1200000:00:0a.0 Multimedia audio controller: Creative Labs SB Live! EMU10k1 (rev 06)
121</pre>
122
123<p>
124We now know that the sound card on the machine is a Sound Blaster Live! and the
125card manufacturer is Creative Labs. Head over to the <uri
126link="http://bugtrack.alsa-project.org/main/index.php/Matrix:Main">ALSA
127Soundcard Matrix</uri> page and select Creative Labs from the list. You will
128be taken to the Creative Labs matrix page where you can see that the SB Live!
129uses the <c>emu10k1</c> module. That is the information we need for now. If
130you are interested in detailed information, you can click on the link next to
131the "Details" and that will take you to the <c>emu10k1</c> specific page.
132</p>
133
134<p>
135If you intend to use MIDI, then you should add <c>midi</c> to your USE flags in
136<path>/etc/make.conf</path> before emerging any ALSA packages. Later in the
137guide, we will show you how to set up <uri link="#midi">MIDI support</uri>.
138</p>
139
85</body> 140</body>
86</section>
87<section> 141</section>
88<title>Why use ALSA?</title> 142<section id="kernel">
89<body> 143<title>Configuring the kernel</title>
90
91<p>
92If your soundcard is supported by the Linux kernel sound system or the
93commercial OSS/4Front sound driver system, which can be found in all 2.4.x
94Linux kernels, you could just aswell build <e>those modules</e> for use with
95your soundcard. If you want this, just read through the <uri
96link="http://www.tldp.org/HOWTO/Sound-HOWTO/index.html">Linux Sound HOWTO</uri>.
97</p>
98
99<p>
100However, those OSS/4Front drivers have some limitations -- being commercial is
101one. ALSA is an attempt to go beyond these limitations and to do so in an open
102source fashion. ALSA is a fully GPL and LGPL'ed sound driver system, that
103provides a professional quality system for recording, playback, and MIDI
104sequencing.
105</p>
106
107</body> 144<body>
108</section>
109<section>
110<title>What cards does ALSA support?</title>
111<body>
112 145
113<p> 146<note>
114ALSA tries to support as many (new) cards as possible by providing open-source 147Since the 2005.0 release, Gentoo Linux uses 2.6 as the default kernel. Please
115drivers. However, some vendors may provide binary-only packages. 148check that your kernel is a 2.6 series kernel. This method will <e>not</e> work
149on a 2.4 kernel.
150</note>
151
116</p> 152<p>
117 153Let us now configure the kernel to enable ALSA.
118<p> 154</p>
119To know if your card is supported, you can find a Soundcard Matrix of supported 155
120and not-supported cards here: <uri>http://www.alsa-project.org/alsa-doc/</uri>. 156<impo>
157<c>genkernel</c> users should now run <c>genkernel --menuconfig all</c> and
158then follow the instructions in <uri link="#doc_chap2_pre3">Kernel Options for
159ALSA</uri>.
160</impo>
161
162<pre caption="Heading over to the source">
163# <i>cd /usr/src/linux</i>
164# <i>make menuconfig</i>
165</pre>
166
167<note>
168The above example assumes that <path>/usr/src/linux</path> symlink points to
169the kernel sources you want to use. Please ensure the same before proceeding.
170</note>
171
172<p>
173Now we will look at some of the options we will have to enable in the 2.6
174kernel to ensure proper ALSA support for our sound card.
175</p>
176
177<p>
178Please note that for ease of use, all examples show ALSA built as modules. It
179is advisable to follow the same as it then allows the use of <c>alsaconf</c>
180which is a boon when you want to configure your card. Please do <e>not</e> skip
181the <uri link="#alsa-config">Configuration</uri> section of this document. If
182you still like to have options built-in, ensure that you make changes to your
183config accordingly.
184</p>
185
186<pre caption="Kernel Options for ALSA">
187Device Drivers ---&gt;
188 Sound ---&gt;
189
190<comment>(This needs to be enabled)</comment>
191&lt;M&gt; Sound card support
192
193<comment>(Make sure OSS is disabled)</comment>
194Open Sound System ---&gt;
195 &lt; &gt; Open Sound System (DEPRECATED)
196
197<comment>(Move one step back and enter ALSA)</comment>
198Advanced Linux Sound Architecture ---&gt;
199 &lt;M&gt; Advanced Linux Sound Architecture
200 <comment>(Select this if you want MIDI sequencing and routing)</comment>
201 &lt;M&gt; Sequencer support
202 <comment>(Old style /dev/mixer* and /dev/dsp* support. Recommended.)</comment>
203 &lt;M&gt; OSS Mixer API
204 &lt;M&gt; OSS PCM (digital audio) API
205
206<comment>(You now have a choice of devices to enable support for. Generally,
207you will have one type of device and not more. If you have more than one
208sound card, please enable them all here.)</comment>
209
210<comment>(Mostly for testing and development purposes, not needed for normal
211users unless you know what you are doing.)</comment>
212Generic devices ---&gt;
213
214<comment>(For ISA Sound cards)</comment>
215ISA devices ---&gt;
216<comment>(IF you had the Gravis, you would select this option)</comment>
217 &lt;M&gt; Gravis UltraSound Extreme
218
219<comment>(Move one level back and into PCI devices. Most sound cards today are
220PCI devices)</comment>
221PCI devices ---&gt;
222 <comment>(We now select the emu10k1 driver for our card)</comment>
223 &lt;M&gt; Emu10k1 (SB Live!, Audigy, E-mu APS)
224 <comment>(Or an Intel card would be)</comment>
225 &lt;M&gt; Intel/SiS/nVidia/AMD/ALi AC97 Controller
226 <comment>(Or if you have a VIA Card)</comment>
227 &lt;M&gt; VIA 82C686A/B, 8233/8235 AC97 Controller
228
229<comment>(Move one level back and select in case you have an USB sound card)</comment>
230USB Devices ---&gt;
231</pre>
232
233<p>
234Now that your options are set, you can (re)compile the kernel and ALSA support
235for your card should be functional once you reboot into the new kernel. Don't
236forget to update your GRUB configuration to use the newly built kernel.
237You can now proceed to <uri link="#alsa-utilities">ALSA Utilities</uri> and
238see if everything is working as it should.
121</p> 239</p>
122 240
123</body> 241</body>
124</section> 242</section>
125</chapter> 243</chapter>
126 244
127<chapter> 245<chapter>
128<title>Installation</title> 246<title>Configuring/Testing ALSA</title>
129<section> 247<section id="alsa-utilities">
130<title>Gentoo USE flags</title> 248<title>ALSA Utilities</title>
131<body>
132
133<p>
134To compile programs with ALSA-support, be sure to add <e>alsa</e> to
135your USE-variable. However, several tools don't support alsa yet, and
136require OSS. ALSA provides OSS-emulation if you define <e>oss</e> in your
137USE-variable before you start.
138</p>
139
140</body> 249<body>
141</section>
142<section>
143<title>Kernel modules</title>
144<body>
145 250
146<p>
147Since we're still using 2.4.x kernel sources, we'll have to compile kernel
148modules and ALSA modules separately. People who are using a 2.5.x kernel can
149do this from within their kernel configuration, since the ALSA modules are
150included in the kernel sources and should be built there.
151</p> 251<p>
152 252<c>alsa-utils</c> forms an integral part of ALSA as it has a truckload of
253programs that are highly useful, including the ALSA Initscripts. Hence we
254strongly recommend that you install <c>alsa-utils</c>
153<p> 255</p>
154First we'll make sure that our kernel configuration is ready for use with ALSA. 256
155All you need in your kernel configuration is having Sound Card Support set to 257<pre caption="Install alsa-utils">
156be built as a module (M). This will build <path>soundcore.o</path>. 258# <i>emerge alsa-utils</i>
157</p> 259</pre>
158 260
159<note> 261<note>
160Possibly, this will also work when you built Sound Card Support in the kernel 262If you did <e>not</e> compile ALSA as modules, please proceed to the <uri
161(Y) instead of building it as a module (M). However, the official ALSA 263link="#initscript">ALSA Initscript</uri> section. The rest of you need to
162documentation suggests building it as a module, since ALSA will try loading it. 264configure ALSA. This is made very easy by the existence of the <c>alsaconf</c>
265tool provided by <c>alsa-utils</c>.
163</note> 266</note>
164 267
165<p> 268</body>
166If you already have a working kernel configuration, make sure you remove all 269</section>
167sound drivers (except for Sound Card Support). If you wish to do this without 270<section id="alsa-config">
168having to reboot, you could do like this: 271<title>Configuration</title>
272<body>
273
169</p> 274<p>
170 275Recent versions of <c>udev</c> (<c>>=udev-103</c>) provide some degree of
171<pre caption="Kernel configuration"> 276kernel-level autoconfiguration of your sound card. If possible, try to rely on
172# <i>cd /usr/src/linux</i> 277just letting your kernel automatically setup your sound card for you. Otherwise,
173# <i>cp .config ~/</i> 278use <c>alsaconf</c> to configure your card, as shown below.
174# <i>make mrproper</i>
175# <i>cp ~/.config .</i>
176# <i>make menuconfig</i>
177</pre>
178
179<p> 279</p>
180Now select <e>Sound Card Support</e> as Module (M) and deselect all other sound 280
181drivers. Exit and say Y to save your kernel configuration. After that, build 281<note>
182the modules: 282Please shut down any programs that <e>might</e> access the sound card while
283running <c>alsaconf</c>.
284</note>
285
183</p> 286<p>
184 287To configure your sound card just type <c>alsaconf</c> in a shell as root.
185<pre caption="Kernel compilation">
186# <i>make dep clean</i>
187# <i>make modules modules_install</i>
188</pre>
189
190<p> 288</p>
191Before installing your new modules, this last line will delete all your previous 289
192modules, even the ones from a previous ALSA installation. 290<pre caption="Invoking alsaconf">
291# <i>alsaconf</i>
292</pre>
293
193</p> 294<p>
295You will now see a neat menu guided interface that will automatically probe
296your devices and try to find out your sound card. You will be asked to pick
297your sound card from a list. Once that's done, it will ask you permission to
298automatically make required changes to <path>/etc/modules.d/alsa</path>.
299It will then adjust your volume settings to optimum levels, run
300<c>update-modules</c> and start the <path>/etc/init.d/alsasound</path> service.
301Once <c>alsaconf</c> exits, you can proceed with setting up the ALSA
302initscript.
303</p>
304
305</body>
306</section>
307<section id="initscript">
308<title>ALSA Initscript</title>
309<body>
310
311<p>
312We're now almost all setup. Whichever method you chose to install ALSA, you'll
313need to have something load your modules or initialize ALSA and restore your
314volume settings when your system comes up. The ALSA Initscript handles all of
315this for you and is called <c>alsasound</c>. Add it to the boot runlevel.
316</p>
317
318<pre caption="Adding ALSA to the boot runlevel">
319# <i>rc-update add alsasound boot</i>
320 * alsasound added to runlevel boot
321 * rc-update complete.
322</pre>
323
324<p>
325Next, just check the <path>/etc/conf.d/alsasound</path> file and ensure that
326SAVE_ON_STOP variable is set to yes. This saves your sound settings when you
327shutdown your system.
328</p>
329
330</body>
331</section>
332<section>
333<title>Audio Group</title>
334<body>
335
336<p>
337Before we move on to testing, there's one last <e>important</e> thing that needs
338to be setup. Rule of thumb in a *nix OS: Do not run as root unless needed.
339This applies here as well ;) How? Well, most of the times you should be logged
340in as a user and would like to listen to music or access your soundcard. For
341that to happen, you need to be in the "audio" group. At this point, we'll add
342users to the audio group, so that they won't have any issues when they want to
343access sound devices. We'll use <c>gpasswd</c> here and you need to be logged in
344as root for this to work.
345</p>
346
347<pre caption="Adding users to the audio group">
348<comment>(Substitute &lt;username&gt; with your user)</comment>
349# <i>gpasswd -a &lt;username&gt; audio </i>
350Adding user &lt;username&gt; to group audio
351</pre>
352
353</body>
354</section>
355<section>
356<title>Volume Check!</title>
357<body>
358
359<p>
360We've completed all the setups and prerequisites, so let's fire up ALSA. If
361you ran <c>alsaconf</c>, you can skip this step, since <c>alsaconf</c> already
362does this for you.
363</p>
364
365<pre caption="Start the service">
366# <i>/etc/init.d/alsasound start</i>
367</pre>
368
369<p>
370Now that the required things have been taken care of, we need to check up on
371the volume as in certain cases, it is muted. We use <c>alsamixer</c> for this
372purpose.
373</p>
374
375<pre caption="Starting alsamixer">
376<comment>(Opens up a console program. Only required settings are shown)</comment>
377# <i>alsamixer</i>
378</pre>
194 379
195<impo> 380<impo>
196This means, whenever you recompile your kernel later on, you MUST recompile 381If you have issues starting up <c>alsamixer</c> and get errors such as
197<c>alsa-driver</c>. 382alsamixer: function snd_ctl_open failed for default: No such file or directory,
383this is usually an issue with udev setting up the devices. Run <c>killall
384udevd; udevstart</c> to reload <path>/dev</path> entries and fire up
385<c>alsamixer</c>. It should solve the issue.
198</impo> 386</impo>
199 387
200</body>
201</section>
202<section>
203<title>ALSA modules</title>
204<body>
205
206<p>
207Now it's time to install the ALSA drivers for your soundcard(s). If your
208soundcard is PCI, you can find out the name and type of your soundcard by
209looking at the output of <path>/proc/pci</path>.
210</p> 388<p>
211 389This is how the ALSA Mixer <e>might</e> look the first time you open it. Pay
212<pre caption="Search for soundcard information"> 390attention to the Master and PCM channels which both have an MM below them.
213# <i>grep audio /proc/pci</i> 391That means they are muted. If you try to play anything with <c>alsamixer</c>
392in this state, you will not hear anything on your speakers.
214</pre> 393</p>
394
395<figure link="/images/docs/alsa-mixermuted.png" short="AlsaMixer Muted" caption="The Alsa Mixer Main Window, Muted"/>
396
397<p>
398Now, we shall unmute the channels, and set volume levels as needed.
399</p>
215 400
216<warn> 401<warn>
217If you had a previous sound setup and there are still non-ALSA sound modules 402Both Master <e>and</e> PCM need to be unmuted and set to audible volume levels
218loaded, unload them <e>now</e>. Check with <c>lsmod</c> and use <c>rmmod</c> 403if you want to hear some output on your speakers.
219to unload all sound-related modules on your system.
220</warn> 404</warn>
221
222<p>
223We could simply do an <c>emerge alsa-driver</c> now, this would compile and
224install <e>all</e> ALSA sound drivers.
225</p>
226
227<p>
228However, to save some time, lookup the <e>Module Name</e> of your soundcard(s)
229on the <uri link="http://www.alsa-project.org/alsa-doc">ALSA Soundcard
230Matrix</uri> by following the <e>Details</e> link in the <e>Driver and Docs</e>
231column in the row of the chipset of your soundcard. Mine is <c>snd-emu10k1</c>,
232since I have an SBlive! soundcard, with the <e>EMU10K1</e> chipset. We'll set
233ALSA_CARDS environment to the value of the module name before emerging (but
234without the snd prefix), so emerge will only compile the drivers we need.
235</p>
236
237<pre caption="Compile correct modules">
238# <i>env ALSA_CARDS='emu10k1' emerge alsa-driver</i>
239</pre>
240
241<note>
242You can also add this value in <path>/etc/make.conf</path>, so when you have
243to emerge the alsa-driver later on you can just run <c>emerge alsa-driver</c>.
244For example, like this: <c>echo 'ALSA_CARDS="emu10k1"' >> /etc/make.conf</c>
245</note>
246
247<note>
248When you want to install ALSA drivers for more than one soundcard, you could
249set ALSA_CARDS to a space-separated list of drivers; like this: <c>env
250ALSA_CARDS='emu10k1 intel8x0 ens1370' emerge alsa-driver</c>
251</note>
252
253<note>
254If you want to have OSS compatibility, make sure to emerge <i>alsa-oss</i>, it
255is the ALSA/OSS compatibility wrapper.
256</note>
257
258<note>
259If you plan on recompiling your kernels numerous times, it might
260be adviseable to emerge <c>alsa-driver</c> with <c>--buildpkg</c>. This
261will create a binary package for it. Later, after recompiling your kernel,
262you can just do <c>emerge --usepkg alsa-driver</c> which will install the
263binary package instead of recompiling it completely.
264</note>
265
266<p>
267After this, the ALSA modules should be installed on your system.
268</p>
269
270</body>
271</section>
272<section>
273<title>Configuration of ALSA</title>
274<body>
275
276<p>
277Let's start configuring now to get ALSA working properly. We'll need to edit
278some files, to let our system know about the freshly installed ALSA modules.
279</p>
280
281<p>
282First, install <c>alsa-utils</c> on your system:
283</p>
284
285<pre caption = "Emerging alsa-utils">
286# <i>emerge alsa-utils</i>
287</pre>
288
289<p>
290Hereafter, we need to edit <path>/etc/modules.d/alsa</path>.
291</p>
292
293<warn>
294There is no need to edit <path>/etc/modules.conf</path>. Instead, always edit
295files in <path>/etc/modules.d</path>.
296</warn>
297
298<p>
299Check the ALSA portion <e>at the bottom of the file</e>. By tweaking this line
300you can specify the max number of soundcards you have (generally, just one).
301</p>
302
303<pre caption="At the bottom of /etc/modules.d/alsa">
304<comment>Set this to the correct number of cards.</comment>
305options snd cards_limit=1
306</pre>
307
308<p>
309Now we'll specify the sounddriver(s) ALSA should use. In the same file, edit
310like this:
311</p>
312
313<pre caption="In /etc/modules.d/alsa">
314## and then run `modules-update' command.
315## Read alsa-driver's INSTALL file in /usr/share/doc for more info.
316##
317## ALSA portion
318alias snd-card-0 snd-emu10k1
319<comment>## If you have more than one, add:</comment>
320## alias snd-card-1 snd-intel8x0
321## alias snd-card-2 snd-ens1370
322## OSS/Free portion
323## alias sound-slot-0 snd-card-0
324## alias sound-slot-1 snd-card-1
325##
326</pre>
327
328<note>
329If you have more than one soundcard, adjust the <c>cards_limit</c> value and add
330more snd-card aliases to the file. I don't have experience with this, but you
331can find examples for configurations with two or more soundcards in <uri
332link="http://www.alsa-project.org/alsa-doc/alsa-howto/c1660.htm">Chapter 6</uri>
333of the <uri
334link="http://www.alsa-project.org/alsa-doc/alsa-howto/alsa-howto.html">ALSA
335Howto</uri>.
336</note>
337
338<p>
339Last thing to do in this file, almost at the end, check if these lines are there
340and uncommented:
341</p>
342
343<pre caption="Near the end of /etc/modules.d/alsa">
344alias /dev/mixer snd-mixer-oss
345alias /dev/dsp snd-pcm-oss
346alias /dev/midi snd-seq-oss
347</pre>
348
349<p>
350Now double-check the file <path>/etc/modules.d/alsa</path> and when you're sure
351everyting is ok, run <c>modules-update</c>.
352</p>
353
354<pre caption="Running modules-update">
355# <i>modules-update</i>
356</pre>
357
358<note>
359Running <c>modules-update</c> here will insert the data from
360<path>/etc/modules.d/alsa</path> into <path>/etc/modules.conf</path>
361</note>
362
363<p>
364You should also verify that <path>/etc/devfsd.conf</path> has the alsa devices
365and permissions correctly registered.
366</p>
367
368<pre caption="/etc/devfsd.conf">
369# ALSA/OSS stuff
370# Comment/change these if you want to change the permissions on
371# the audio devices
372LOOKUP snd MODLOAD ACTION snd
373LOOKUP dsp MODLOAD
374LOOKUP mixer MODLOAD
375LOOKUP midi MODLOAD
376REGISTER sound/.* PERMISSIONS root.audio 660
377REGISTER snd/.* PERMISSIONS root.audio 660
378</pre>
379
380<note>
381Notice that devfsd.conf sets <path>/dev/sound</path> permissions to be
382root.audio. Thus, for non-root users to use audio they will have to be part of
383the audio group.
384</note>
385
386</body>
387</section>
388</chapter>
389
390<chapter>
391<title>Starting ALSA</title>
392<section>
393<title>Adding alsasound to a runlevel</title>
394<body>
395
396<p>
397First thing to do now, is to make ALSA startup at boottime. Like this:
398</p>
399
400<pre caption="Add ALSA to the default runlevel">
401# <i>rc-update add alsasound boot</i>
402</pre>
403
404<warn>
405Note that the alsasound script should be added to the "boot" runlevel, not the
406"default" runlevel.
407</warn>
408
409</body>
410</section>
411<section>
412<title>Running and unmuting</title>
413<body>
414
415<p>
416Since we're Linux users, we don't want to reboot. So we'll start the alsasound
417script manually.
418</p>
419
420<pre caption="Starting ALSA">
421# <i>/etc/init.d/alsasound start</i>
422</pre>
423
424<p>
425ALSA is running now. If everything is ok, you should be able to see the ALSA
426modules loaded when running <c>lsmod</c>. However, sound won't work yet,
427because the channels are still muted. We need <c>amixer</c> for this.
428</p>
429
430<pre caption = "Running amixer">
431# <i>amixer</i>
432</pre>
433
434<warn>
435You shouldn't get this, but <e>if</e> you get an error about "amixer: Mixer
436attach default error: No such file or directory", you should manually modprobe
437<c>snd-mixer-oss</c> and <c>snd-pcm-oss</c> once. After that run amixer again.
438</warn>
439
440<pre caption="Only if you get an error when running amixer">
441# <i>modprobe snd-mixer-oss</i>
442# <i>modprobe snd-pcm-oss</i>
443# <i>amixer</i>
444</pre>
445
446<p>
447If you got this far, now unmute Master and PCM channels. Some hardware
448even requires you to unmute the center channel or even the surround
449channel.
450</p>
451
452<pre caption = "Unmuting channels">
453# <i>amixer set Master 100 unmute</i>
454# <i>amixer set PCM 100 unmute</i>
455<comment>Only if the above doesn't succeed on its own:</comment>
456# <i>amixer set Center 100 unmute</i>
457# <i>amixer set Surround 100 unmute</i>
458<comment>Test the sound:</comment>
459# <i>aplay $KDEDIR/share/sounds/pop.wav</i> <codenote>(pop.wav is part of KDE)</codenote>
460</pre>
461
462<p>
463We check to see if sound is working by using the aplay (alsa play) command. If
464you hear a pop, then sound is indeed working. Then, adjust the volume settings
465to your liking; the ncurses-based <c>alsamixer</c> is a great way to get them
466"just so".
467</p>
468
469<p>
470You may want to emerge <c>alsa-xmms</c> as that will provide ALSA support for
471XMMS.
472</p>
473
474<p>
475When you reboot your system, the <c>alsasound</c> init script will properly saveand restore your volume settings.
476</p>
477
478</body>
479</section>
480</chapter>
481
482<chapter>
483<title>Final Notes</title>
484<section>
485<title>After kernel-upgrades..</title>
486<body>
487
488<p>
489When you ever rebuild your kernel, or upgrade to another kernel, you'll have to
490rebuild the ALSA modules.
491</p>
492
493<p>
494Although you might have installed <c>alsa-driver</c>, <c>alsa-libs</c> and
495<c>alsa-utils</c>, only the first will have to be installed again, since it will
496put the alsa modules in <path>/lib/modules/*/kernel/sound/pci/</path>.
497</p>
498
499<pre caption="needed after each kernel compile">
500# <i>emerge alsa-driver</i>
501</pre>
502
503</body>
504</section>
505<section>
506<title>/etc/modules.autoload</title>
507<body>
508
509<p>
510You won't have to edit this file for use with ALSA. After our <c>rc-update add
511alsasound boot</c>, our system will load the correct modules at startup.
512</p>
513
514<p>
515It's not necessary to add <c>snd-pcm-oss</c> or <c>snd-mixer-oss</c> in this
516file. Check the <uri link="http://www.djcj.org/LAU/guide/alsbook/faq1.html">this
517FAQ</uri> for more info.
518</p>
519
520</body>
521</section>
522<section>
523<title>Known bugs</title>
524<body>
525
526<note>
527This guide lags behind on the alsa-development. Chances are these bugs
528are already fixed when you read this.
529</note>
530 405
531<ul> 406<ul>
532 <li> 407 <li>
533 If you have <b>lots of noise</b> when using <b>oss</b> emulation, add 408 To move between channels, use your left and right arrow keys. (&lt;-
534 <e>options snd-pcm-oss dsp_map=1</e> to <path>/etc/modules.d/alsa</path> 409 &amp; -&gt;)
410 </li>
411 <li>
412 To toggle mute, move to the specific channel, for example Master and press
413 the <e>m</e> key on the keyboard.
414 </li>
415 <li>
416 To increase and decrease the volume levels, use the up and down arrow keys
417 respectively.
535 </li> 418 </li>
536</ul> 419</ul>
537 420
421<note>
422Be careful when setting your Bass and Treble values. 50 is usually a good
423number for both. Extremely high values of Bass may cause <e>jarring</e>
424on speakers that are not designed to handle them.
425</note>
426
427<p>
428After you're all done, your ALSA Mixer should look similar to the one below.
429Note the 00 instead of the MM and also the volume levels for some optimum
430settings.
431</p>
432
433<figure link="/images/docs/alsa-mixerunmuted.png" short="AlsaMixer Unmuted" caption="Alsa Mixer ready to roll"/>
434
538</body> 435</body>
539</section>
540<section> 436</section>
541<title>Activating Joystick Support</title>
542<body>
543
544<p>
545If your soundcard has a joystick plug, you might be interested in activating
546joystick support for your soundcard. If so, start by verifying if your soundcard
547driver has a joystick parameter. You can verify this by running <c>modinfo</c>
548against your <path>snd-&lt;your chipset&gt;</path>. For instance, for the
549<c>snd-via82xx</c>:
550</p>
551
552<pre caption="Running modinfo">
553# <i>modinfo snd-via82xx</i>
554filename: /lib/modules/2.4.22-ck2/snd-via82xx.o
555description: "VIA VT82xx audio"
556author: "Jaroslav Kysela &lt;perex@suse.cz&gt;"
557license: "GPL"
558parm: index int array (min = 1, max = 8), description "Index value for VIA 82xx bridge."
559parm: id string array (min = 1, max = 8), description "ID string for VIA 82xx bridge."
560parm: enable int array (min = 1, max = 8), description "Enable audio part of VIA 82xx bridge."
561parm: mpu_port long array (min = 1, max = 8), description "MPU-401 port. (VT82C686x only)"
562<i>parm: joystick int array (min = 1, max = 8), description "Enable joystick. (VT82C686x only)"</i>
563parm: ac97_clock int array (min = 1, max = 8), description "AC'97 codec clock (default 48000Hz)."
564parm: dxs_support int array (min = 1, max = 8), description "Support for DXS channels
565 (0 = auto, 1 = enable, 2 = disable, 3 = 48k only, 4 = no VRA)"
566</pre>
567
568<p>
569If it has the <c>joystick</c> parameter, then append <c>joystick=1</c> to your
570<c>options</c> line in <path>/etc/modules.d/alsa</path>. For instance, for the
571<c>snd-via82xx</c>:
572</p>
573
574<pre caption="Adding the joystick parameter">
575alias snd-card-0 snd-via82xx
576options snd-via82xx joystick=1
577</pre>
578
579</body>
580</section> 437<section>
438<title>Sound Check!</title>
439<body>
440
441<p>
442Finally. Some music. If everything above is perfect, you should now be able to
443listen to some good music. A quick way to test is to use a command line tool
444like <c>media-sound/madplay</c>. You could also use something more well known
445like <c>mpg123</c>. If you are an ogg fan, you could use <c>ogg123</c> provided
446by <c>media-sound/vorbis-tools</c>. Use any player you are comfortable with. As
447always, <c>emerge</c> what you need.
448</p>
449
450<pre caption="Getting the software">
451<comment>(Install the applications you want)</comment>
452# <i>emerge madplay mpg123</i>
453<comment>(To play .ogg files)</comment>
454# <i>emerge vorbis-tools</i>
455</pre>
456
457<p>
458And then play your favorite sound track...
459</p>
460
461<pre caption="Playing Music">
462# <i>madplay -v /mnt/shyam/Music/Paul\ Oakenfold\ -\ Dread\ Rock.mp3</i>
463MPEG Audio Decoder 0.15.2 (beta) - Copyright (C) 2000-2004 Robert Leslie et al.
464 Title: Dread Rock
465 Artist: Paul Oakenfold
466 Album: Matrix Reloaded
467 Year: 2003
468 Genre: Soundtrack
469 Soundtrack
470 00:04:19 Layer III, 160 kbps, 44100 Hz, joint stereo (MS), no CRC
471
472# <i>ogg123 Paul\ Oakenfold\ -\ Dread\ Rock.ogg</i>
473Audio Device: Advanced Linux Sound Architecture (ALSA) output
474
475Playing: Paul Oakenfold - Dread Rock.ogg
476Ogg Vorbis stream: 2 channel, 44100 Hz
477Genre: Soundtrack
478Transcoded: mp3;160
479Title: Dread Rock
480Artist: Paul Oakenfold
481Date: 2003
482Album: Matrix Reloaded
483Time: 00:11.31 [04:28.75] of 04:40.06 (200.6 kbps) Output Buffer 96.9%
484</pre>
485
486</body>
581<section> 487</section>
582<title>More links..</title> 488<section>
489<title>ALSA and USE</title>
490<body>
491
492<p>
493You can now add the <c>alsa</c> use flag to <path>/etc/make.conf</path> to
494ensure that your applications that support ALSA get built with it. Some
495architectures like x86 and amd64 have the flag enabled by default.
496</p>
497
583<body> 498</body>
499</section>
500<section>
501<title>Issues?</title>
502<body>
584 503
585<p>
586You could check these for additional info:
587</p> 504<p>
505If for some reason you're unable to hear sound, the first thing to do would
506be to check your <uri link="#doc_chap3_pre6">alsamixer</uri> settings. 80% of
507the issues lie with muted channels or low volume. Also check your Window
508Manager's sound applet and verify that volumes are set to audible levels.
509</p>
510
511<p>
512<path>/proc</path> is your friend. And in this case, <path>/proc/asound</path>
513is your best friend. We shall just take a short look at how much info is made
514available to us there.
515</p>
516
517<pre caption="Fun with /proc/asound">
518<comment>(First and foremost, if /proc/asound/cards shows your card, ALSA has
519picked up your sound card fine.)</comment>
520# <i>cat /proc/asound/cards</i>
5210 [Live ]: EMU10K1 - Sound Blaster Live!
522 Sound Blaster Live! (rev.6, serial:0x80271102) at 0xb800, irq 11
523
524<comment>(This displays the current running ALSA version)</comment>
525# <i>cat /proc/asound/version</i>
526Advanced Linux Sound Architecture Driver Version 1.0.8 (Thu Jan 13 09:39:32 2005 UTC).
527
528<comment>(ALSA OSS emulation details)</comment>
529# <i>cat /proc/asound/oss/sndstat</i>
530Sound Driver:3.8.1a-980706 (ALSA v1.0.8 emulation code)
531Kernel: Linux airwolf.zion 2.6.11ac1 #2 Wed May 4 00:35:08 IST 2005 i686
532Config options: 0
533
534Installed drivers:
535Type 10: ALSA emulation
536
537Card config:
538Sound Blaster Live! (rev.6, serial:0x80271102) at 0xb800, irq 11
539
540Audio devices:
5410: EMU10K1 (DUPLEX)
542
543Synth devices: NOT ENABLED IN CONFIG
544
545Midi devices:
5460: EMU10K1 MPU-401 (UART)
547
548Timers:
5497: system timer
550
551Mixers:
5520: SigmaTel STAC9721/23
553</pre>
554
555<!-- TODO: remove this a few months after alsa-driver leaves the tree -->
556
557<p>
558The other most common issue users face is the dreaded "Unknown symbol in module"
559error. An example of the same is shown below.
560</p>
561
562<pre caption="Unknown Symbol in module error">
563# <i>/etc/init.d/alsasound start</i>
564 * Loading ALSA modules ...
565 * Loading: snd-card-0 ... [ ok ]
566 * Loading: snd-pcm-oss ...
567WARNING: Error inserting snd_mixer_oss
568(/lib/modules/2.6.12-gentoo-r6/kernel/sound/core/oss/snd-mixer-oss.ko): Unknown
569symbol in module, or unknown parameter (see dmesg) FATAL: Error inserting
570snd_pcm_oss
571(/lib/modules/2.6.12-gentoo-r6/kernel/sound/core/oss/snd-pcm-oss.ko): Unknown
572symbol in module, or unknown parameter (see dmesg)
573 [ !! ]
574 * Loading: snd-mixer-oss ...
575FATAL: Error inserting snd_mixer_oss
576(/lib/modules/2.6.12-gentoo-r6/kernel/sound/core/oss/snd-mixer-oss.ko): Unknown
577symbol in module, or unknown parameter (see dmesg)
578 [ !! ]
579 * Loading: snd-seq ... [ ok ]
580 * Loading: snd-emu10k1-synth ... [ ok ]
581 * Loading: snd-seq-midi ... [ ok ]
582 * Restoring Mixer Levels ... [ ok ]
583</pre>
584
585<p>
586And when you take a look at <c>dmesg</c> as suggested, you're quite likely to
587see:
588</p>
589
590<pre caption="dmesg output">
591<comment>(Only relevant portions are shown below)</comment>
592# <i>dmesg | less</i>
593ACPI: PCI Interrupt 0000:02:06.0[A] -> Link [APC3] -> GSI 18 (level, low) -> IRQ 209
594snd_mixer_oss: Unknown symbol snd_unregister_oss_device
595snd_mixer_oss: Unknown symbol snd_register_oss_device
596snd_mixer_oss: Unknown symbol snd_mixer_oss_notify_callback
597snd_mixer_oss: Unknown symbol snd_oss_info_register
598snd_pcm_oss: Unknown symbol snd_unregister_oss_device
599snd_pcm_oss: Unknown symbol snd_register_oss_device
600snd_pcm_oss: Unknown symbol snd_mixer_oss_ioctl_card
601snd_pcm_oss: Unknown symbol snd_oss_info_register
602snd_mixer_oss: Unknown symbol snd_unregister_oss_device
603snd_mixer_oss: Unknown symbol snd_register_oss_device
604snd_mixer_oss: Unknown symbol snd_mixer_oss_notify_callback
605snd_mixer_oss: Unknown symbol snd_oss_info_register
606</pre>
607
608<p>
609The above issue is caused when you switch from the <c>alsa-driver</c> to in-kernel
610ALSA because when you unmerge <c>alsa-driver</c> the module files are config
611protected and hence get left behind. So, when you switch to in-kernel
612drivers, running <c>modprobe</c> gives you a mix of <c>alsa-driver</c> and
613in-kernel modules thus causing the above errors.
614</p>
615
616<p>
617The solution is quite easy. We just need to manually remove the problem causing
618directory after you unmerge <c>alsa-driver</c>. Be sure to remove the correct
619kernel version and not the current one!
620</p>
621
622<pre caption="Removing the alsa-driver modules">
623# <i>rm -rf /lib/modules/$(uname -r)/alsa-driver</i>
624</pre>
625
626<p>
627Another reason for error messages similar to the ones above could be a file in
628<path>/etc/modules.d</path> supplying a <c>device_mode</c> parameter when it
629isn't required. Confirm that this is indeed the issue and find out which file
630is the culprit.
631</p>
632
633<pre caption="Confirming and searching for device_mode">
634<comment>(Check dmesg to confirm)</comment>
635# <i>dmesg | grep device_mode</i>
636snd: Unknown parameter `device_mode'
637<comment>(Now, to get to the source of the issue)</comment>
638# <i>grep device_mode /etc/modules.d/*</i>
639</pre>
640
641<p>
642Usually it is a file called <path>alsa</path> with the line <c>options snd
643device_mode=0666</c>. Remove this line and restart the <c>alsasound</c> service
644and that should take care of this issue.
645</p>
646
647<!-- End of removal notice -->
648
649</body>
650</section>
651</chapter>
652
653<chapter>
654<title>Other things ALSA</title>
655<section id="midi">
656<title>Setting up MIDI support</title>
657<body>
658
659<p>
660First, check to make sure that you enabled the <c>midi</c> USE flag in
661<path>/etc/make.conf</path>. If you didn't, go ahead and add it now. You will
662also need to re-emerge any ALSA packages that use the <c>midi</c> flag, such as
663<c>alsa-lib</c> and <c>alsa-utils</c>.
664</p>
665
666<p>
667If your sound card is one of those that come with on-board MIDI synthesizers
668and you would like to listen to some .mid files, you have to install
669<c>awesfx</c> which is basically a set of utilities for controlling the AWE32
670driver. We need to install it first. If you don't have a hardware synthesizer,
671you can use a virtual one. Please see the section on
672<uri link="#vsynth">Virtual Synthesizers</uri> for more information.
673</p>
674
675<pre caption="Installing awesfx">
676# <i>emerge awesfx</i>
677</pre>
678
679<note>
680You will need to copy over SoundFont (SF2) files from your sound card's driver
681CD or a Windows installation into <path>/usr/share/sounds/sf2/</path>. For
682example a sound font file for the Creative SBLive! card would be 8MBGMSFX.SF2.
683</note>
684
685<p>
686After copying over the Soundfont files, we can then play a midi file as shown.
687You can also add the <c>asfxload</c> command to
688<path>/etc/conf.d/local.start</path>, so that the sound font is loaded
689every time the system starts up.
690</p>
691
692<note>
693<path>/mnt</path> paths mentioned in the code listing(s) below will <e>not</e>
694be the same in your machine. They are just an example. Please be careful to
695change the path to suit your machine.
696</note>
697
698<pre caption="Loading Soundfonts">
699<comment>(First, copy the Soundfont)</comment>
700# <i>cp /mnt/win2k/Program\ Files/CreativeSBLive2k/SFBank/8MBGMSFX.SF2 /usr/share/sounds/sf2/</i>
701<comment>(Or get it from your SoundBlaster CD)</comment>
702# <i>cp /mnt/cdrom/AUDIO/ENGLISH/SFBANK/8MBGMSFX.SF2 /usr/share/sounds/sf2/</i>
703<comment>(We load the specific Soundfont)</comment>
704# <i>asfxload /usr/share/sounds/sf2/8MBGMSFX.SF2</i>
705</pre>
706
707<p>
708You can now play midi files using a program like <c>aplaymidi</c>. Run
709<c>aplaymidi -l</c> to get a list of available ports and then pick one
710to play the file on.
711</p>
712
713<pre caption="Playing MIDI">
714<comment>(Check open ports)</comment>
715# <i>aplaymidi -l</i>
716 Port Client name Port name
717 64:0 EMU10K1 MPU-401 (UART) EMU10K1 MPU-401 (UART)
718 65:0 Emu10k1 WaveTable Emu10k1 Port 0
719 65:1 Emu10k1 WaveTable Emu10k1 Port 1
720 65:2 Emu10k1 WaveTable Emu10k1 Port 2
721 65:3 Emu10k1 WaveTable Emu10k1 Port 3
722<comment>(Pick a port, and play a mid file)</comment>
723# <i> aplaymidi --port=65:0 /mnt/shyam/music/midi/mi2.mid</i>
724</pre>
725
726</body>
727</section>
728<section id="vsynth">
729<title>Virtual Synthesizers</title>
730<body>
731
732<p>
733If your sound card lacks a hardware synthesizer, you could use a virtual one
734like <c>timidity++</c>. Installation is a breeze.
735</p>
736
737<pre caption="Installing timidity++">
738# <i>emerge timidity++</i>
739</pre>
740
741<p>
742For timidity to play sounds, it needs a sound font. Fortunately, the ebuild will
743install some sound font packages for you. There are a few other font packages
744available in Portage, such as <c>timidity-freepats</c> and
745<c>timidity-eawpatches</c>. You can have multiple sound font configurations
746installed, and you can place your own in <path>/usr/share/timidity/</path>. To
747switch between different timidity configurations, you should use
748<c>eselect</c>.
749</p>
750
751<pre caption="Changing configurations">
752# <i>eselect timidity list</i>
753# <i>eselect timidity set eawpatches</i>
754</pre>
755
756<p>
757Don't forget to add <c>timidity</c> to the default runlevel.
758</p>
759
760<pre caption="Adding timidity to the default runlevel">
761# <i>rc-update add timidity default</i>
762# <i>/etc/init.d/timidity start</i>
763</pre>
764
765<p>
766You can now try out <uri link="#doc_chap4_pre3">Playing MIDI</uri> files.
767</p>
768
769</body>
770</section>
771<section>
772<title>Tools and Firmware</title>
773<body>
774
775<p>
776Some specific sound cards can benefit from certain tools provided by the
777<c>alsa-tools</c> and <c>alsa-firmware</c> packages. You may install either with
778a simple <c>emerge</c>.
779</p>
780
781<pre caption="Installing ALSA Tools">
782# <i>emerge alsa-tools</i>
783</pre>
784
785</body>
786</section>
787<section>
788<title>Multiple sound cards</title>
789<body>
790
791<p>
792You can have more than one sound card in your system simultaneously, provided
793that you have built ALSA as modules in your kernel. You just need to specify
794which should be started first in <path>/etc/modules.d/alsa</path>. Your cards
795are identified by their driver names inside this file. 0 is the first card, 1 is
796the second, and so on. Here's an example for a system with two sound cards.
797</p>
798
799<pre caption="Two sound cards in /etc/modules.d/alsa">
800options snd-emu10k1 index=0
801options snd-via82xx index=1
802</pre>
803
804<p>
805Or, if you have two cards that use the same driver, you specify them on the same
806line, using comma-separated numbers. Here's an example for a system with three
807sound cards, two of which are the same Intel High Definition Audio card.
808</p>
809
810<pre caption="Multiple sound cards in /etc/modules.d/alsa">
811options snd-ymfpci index=0
812options snd-hda-intel index=1,2
813</pre>
814
815</body>
816</section>
817<section>
818<title>Plugins</title>
819<body>
820
821<p>
822You may want to install some plugins for extra functionality.
823<c>alsa-plugins</c> is a collection of useful plugins, which include: PulseAudio
824output, a sample rate converter, jack (a low-latency audio server), and an
825encoder that lets you output 6-channel audio through digital S/PDIF connections
826(both optical and coaxial). You can choose which of its plugins you want
827installed by adding their USE flags to <path>/etc/portage/package.use</path>.
828</p>
829
830<pre caption="Installing alsa-plugins">
831# <i>emerge -avt alsa-plugins</i>
832</pre>
833
834</body>
835</section>
836<section>
837<title>A big thank you to...</title>
838<body>
839
840<p>
841Everyone who contributed to the earlier version of the Gentoo ALSA Guide:
842Vincent Verleye, Grant Goodyear, Arcady Genkin, Jeremy Huddleston,
843John P. Davis, Sven Vermeulen, Benny Chuang, Tiemo Kieft and Erwin.
844</p>
845
846</body>
847</section>
848<section>
849<title>References</title>
850<body>
588 851
589<ul> 852<ul>
590 <li>
591 <uri link="http://www.gentoo.org/doc/en/desktop.xml">The Gentoo Linux
592 Desktop Configuration Guide</uri>
593 </li>
594 <li>
595 <uri link="http://www.alsa-project.org">ALSA Project Homepage</uri> 853 <li><uri link="http://www.alsa-project.org/">The ALSA Project</uri></li>
596 </li>
597 <li>
598 <uri link="http://www.alsa-project.org/documentation.php3">ALSA Users
599 Documentation</uri>
600 </li>
601 <li>
602 <uri link="http://www.djcj.org">ALSA Howto's and FAQ's</uri>
603 </li>
604 <li>
605 <uri link="http://tldp.org/HOWTO/Sound-HOWTO/index.html">Linux Sound
606 HOWTO</uri>
607 </li>
608 <li>
609 <uri link="http://linux-sound.org/">Sound and MIDI Software For Linux</uri> 854 <li><uri link="http://linux-sound.org">Linux Sound/MIDI Software</uri></li>
610 </li>
611</ul> 855</ul>
612 856
613</body> 857</body>
614</section> 858</section>
615</chapter> 859</chapter>

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