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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 1.84 2011/09/04 17:53:40 swift 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>
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 12<author title="Author">
10<author title="Editor"><mail link="zhen@gentoo.org"> 13 <mail link="nightmorph@gentoo.org">Joshua Saddler</mail>
11 John P. Davis</mail>
12</author> 14</author>
15<author title="Contributor">
16 <mail link="flameeyes@gentoo.org">Diego Pettenò</mail>
17</author>
13 18
14<abstract> 19<abstract>
15This guide will show you how to set up the Advanced Linux Sound Architecture (ALSA) on Gentoo Linux. 20This document helps a user setup ALSA on Gentoo Linux.
16In addition to the Gentoo Linux Desktop Configuration Guide, this guide is supposed to give you more information on this subject. </abstract> 21</abstract>
17 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 -->
25<license/>
26
18<version>1.2</version> 27<version>2.25</version>
19<date>09 February 2003</date> 28<date>2009-08-05</date>
20 29
21<chapter> 30<chapter>
22<title>Introduction</title> 31<title>Introduction</title>
23<section> 32<section>
24 <title>What is ALSA?</title> 33<title>What is ALSA?</title>
34<body>
35
36<p>
37ALSA, which stands for <e>Advanced Linux Sound Architecture</e>, provides
38audio and MIDI (<e>Musical Instrument Digital Interface</e>) functionality to
39the Linux operating system. ALSA is the default sound subsystem in the 2.6
40kernel thereby replacing OSS (<e>Open Sound System</e>), which was used in the
412.4 kernels.
42</p>
43
44<p>
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.
50</p>
51
25<body> 52</body>
26<p> 53</section>
27The Advanced Linux Sound Architecture (ALSA) is a project to improve the Linux sound subsystem by rewriting 54<section>
28large chunks of it. 55<title>ALSA on Gentoo</title>
29It 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
30</p> 58<p>
31 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.
32<p> 66</p>
33ALSA provides audio and MIDI functionality for Linux. 67
34</p> 68<p>
35 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.
36<p> 72</p>
37Quoted from <uri>http://www.alsa-project.org</uri>, ALSA has the following features: 73
38<ul><li> Efficient support for all types of audio interfaces, from consumer soundcards to professional multichannel audio interfaces.</li> 74</body>
39 <li> Fully modularized sound drivers.</li> 75</section>
40 <li> SMP and thread-safe design.</li> 76</chapter>
41 <li> User space library (alsa-lib) to simplify application programming and provide higher level functionality.</li> 77
42 <li> Support for the older OSS API, providing binary compatibility for most OSS programs.</li> 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:
92</p>
93
94<ul>
95 <li>
96 <uri link="http://www.roestock.demon.co.uk/isapnptools/">The ISAPNPTOOLS
97 Page</uri>
98 </li>
99 <li>
100 <uri link="http://www2.linuxjournal.com/article/3269">LinuxJournal PnP
101 Article</uri>
102 </li>
103 <li>
104 <uri link="http://www.tldp.org/HOWTO/Sound-HOWTO/x320.html">TLDP Sound
105 HowTo</uri>
106 </li>
43</ul> 107</ul>
44There's lots more to ALSA however, like support for Full Duplex playback and recording, multiple soundcard support, 108
45hardware mixing of streams, extensive mixer capabilities (to support advanced features of new soundcards), ... 109<note>
110For ease of use/explanation, we assume the user has a PCI based sound card for
111the remainder of this guide.
112</note>
113
46</p> 114<p>
115We now proceed to find out details about the sound card.
116</p>
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
47</body> 140</body>
48</section>
49<section> 141</section>
50 <title>Why use ALSA?</title> 142<section id="kernel">
51<body> 143<title>Configuring the kernel</title>
52<p>
53If your soundcard is supported by the Linux kernel sound system or the commercial OSS/4Front sound driver system,
54which can be found in all 2.4.x Linux kernels, you could just aswell build <e>those modules</e> for use with your soundcard.
55If you want this, just read through the <uri link="http://www.tldp.org/HOWTO/Sound-HOWTO/index.html">Linux Sound HOWTO</uri>.
56</p>
57<p>
58However, those OSS/4Front drivers have some limitations -- being commercial is one.
59ALSA is an attempt to go beyond these limitations and to do so in an open source fashion.
60ALSA is a fully GPL and LGPL'ed sound driver system, that provides a professional quality system for recording, playback,
61and MIDI sequencing.
62</p>
63</body> 144<body>
64</section> 145
65<section> 146<note>
66 <title>What cards does ALSA support?</title> 147Since the 2005.0 release, Gentoo Linux uses 2.6 as the default kernel. Please
67<body> 148check that your kernel is a 2.6 series kernel. This method will <e>not</e> work
68<p> 149on a 2.4 kernel.
69ALSA tries to support as many (new) cards as possible by providing open-source drivers. 150</note>
70However, some vendors may provide binary-only packages. 151
71</p> 152<p>
72<p>To know if your card is supported, you can find a Soundcard Matrix of supported and not-supported cards here: 153Let us now configure the kernel to enable ALSA.
73<uri>http://www.alsa-project.org/alsa-doc/</uri>. 154</p>
155
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
74</p> 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.
239</p>
240
75</body> 241</body>
76</section> 242</section>
77</chapter> 243</chapter>
78 244
79<chapter> 245<chapter>
80<title>Installation</title> 246<title>Configuring/Testing ALSA</title>
81<section> 247<section id="alsa-utilities">
82 <title>Kernel modules</title> 248<title>ALSA Utilities</title>
83<body> 249<body>
84<p> 250
85Since we're still using 2.4.x kernel sources, we'll have to compile kernel modules and ALSA modules separately.
86</p> 251<p>
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>
87<p> 255</p>
88First we'll make sure that our kernel configuration is ready for use with ALSA. 256
89All you need in your kernel configuration is having Sound Card Support set to be built as a module (M). 257<pre caption="Install alsa-utils">
90This will build <c>soundcore.o</c>. 258# <i>emerge alsa-utils</i>
91</p> 259</pre>
92<p> 260
93<note> 261<note>
94Possibly, this will also work when you built Sound Card Support in the kernel (Y) instead of building it as a module (M). 262If you did <e>not</e> compile ALSA as modules, please proceed to the <uri
95However, the official ALSA documentation suggests building it as a module, since ALSA will try loading it. 263link="#initscript">ALSA Initscript</uri> section. The rest of you need to
264configure ALSA. This is made very easy by the existence of the <c>alsaconf</c>
265tool provided by <c>alsa-utils</c>.
96</note> 266</note>
267
268</body>
269</section>
270<section id="alsa-config">
271<title>Configuration</title>
272<body>
273
97</p> 274<p>
98<p>If you already have a working kernel configuration, make sure you remove all sound drivers (except for Sound Card Support). 275Recent versions of <c>udev</c> (<c>>=udev-103</c>) provide some degree of
99If you wish to do this without having to reboot, you could do like this: 276kernel-level autoconfiguration of your sound card. If possible, try to rely on
100</p> 277just letting your kernel automatically setup your sound card for you. Otherwise,
101<pre> 278use <c>alsaconf</c> to configure your card, as shown below.
102# <c>cd /usr/src/linux</c>
103# <c>cp .config ~/</c>
104# <c>make mrproper</c>
105# <c>cp ~/.config .</c>
106# <c>make menuconfig</c>
107</pre>
108<p> 279</p>
109Now select <e>Sound Card Support</e> as Module (M) and deselect all other sound drivers. 280
110Exit and say Y to save your kernel configuration. 281<note>
111After that, build the modules: 282Please shut down any programs that <e>might</e> access the sound card while
112</p> 283running <c>alsaconf</c>.
113<pre>
114# <c>make dep clean</c>
115# <c>make modules modules_install</c>
116</pre>
117<p>
118Before installing your new modules, this last line will delete all your previous modules,
119even the ones from a previous ALSA installation.
120</p>
121<p>
122<impo>
123This means, whenever you recompile your kernel later on, you MUST recompile <c>alsa-driver</c>.
124</impo>
125</p>
126<p>
127<note>However, there's no need to reinstall <c>nvidia-kernel</c>, the Nvidia drivers are in a separate directory
128in <path>/lib/modules/*/video</path> and won't get deleted by a <c>make modules modules_install</c>
129</note> 284</note>
285
130</p> 286<p>
131</body> 287To configure your sound card just type <c>alsaconf</c> in a shell as root.
132</section> 288</p>
133 289
290<pre caption="Invoking alsaconf">
291# <i>alsaconf</i>
292</pre>
293
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/modprobe.d/alsa.conf</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>
134<section> 306</section>
135 <title>ALSA modules</title> 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
136<body> 330</body>
331</section>
332<section>
333<title>Audio Group</title>
334<body>
137 335
138<p>
139Now it's time to install the ALSA drivers for your soundcard(s). If your soundcard is PCI, you can find out the name
140and type of your soundcard by looking at the output of /proc/pci
141<pre>#<c>grep audio /proc/pci</c></pre>
142</p> 336<p>
143 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.
144<p> 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>
379
380<p>
381This is how the ALSA Mixer <e>might</e> look the first time you open it. Pay
382attention to the Master and PCM channels which both have an MM below them.
383That means they are muted. If you try to play anything with <c>alsamixer</c>
384in this state, you will not hear anything on your speakers.
385</p>
386
387<figure link="/images/docs/alsa-mixermuted.png" short="AlsaMixer Muted" caption="The Alsa Mixer Main Window, Muted"/>
388
389<p>
390Now, we shall unmute the channels, and set volume levels as needed.
391</p>
392
145<warn> 393<warn>
146If you had a previous sound setup and there are still non-ALSA sound modules loaded, unload them <e>now</e>. 394Both Master <e>and</e> PCM need to be unmuted and set to audible volume levels
147Check with <c>lsmod</c> and use <c>rmmod</c> to unload all sound-related modules on your system. 395if you want to hear some output on your speakers.
148</warn> 396</warn>
149</p>
150 397
151<p> 398<ul>
152We could simply do an <c>emerge alsa-driver</c> now, this would compile and install <e>all</e> ALSA sound drivers. 399 <li>
153</p> 400 To move between channels, use your left and right arrow keys. (&lt;-
154<p> 401 &amp; -&gt;)
155However, to save some time, lookup the <e>Module Name</e> of your soundcard(s) on the 402 </li>
156<uri link="http://www.alsa-project.org/alsa-doc">ALSA Soundcard Matrix</uri> under the <e>Install</e> section. 403 <li>
157Mine is <c>EMU10K1</c>, since I have an SBlive! soundcard. 404 To toggle mute, move to the specific channel, for example Master and press
158We'll set ALSA_CARDS environment to this value before emerging, so emerge will only compile the drivers we need. 405 the <e>m</e> key on the keyboard.
159</p> 406 </li>
407 <li>
408 To increase and decrease the volume levels, use the up and down arrow keys
409 respectively.
410 </li>
411</ul>
160 412
161<p>
162<pre>
163# <c>env ALSA_CARDS='emu10k1' emerge alsa-driver</c>
164</pre>
165</p>
166<p>
167<note> 413<note>
168When you want to install ALSA drivers for more than one soundcard, you could set ALSA_CARDS to a space-separated list 414Be careful when setting your Bass and Treble values. 50 is usually a good
169of drivers; like this: <c>env ALSA_CARDS='emu10k1 intel8x0 ens1370' emerge alsa-driver</c> 415number for both. Extremely high values of Bass may cause <e>jarring</e>
416on speakers that are not designed to handle them.
170</note> 417</note>
171 418
172<note>If you want to have OSS compatibility, make sure to emerge <i>alsa-oss</i>, it is the ALSA/OSS compatibility
173wrapper. </note>
174
175</p> 419<p>
420After you're all done, your ALSA Mixer should look similar to the one below.
421Note the 00 instead of the MM and also the volume levels for some optimum
422settings.
176<p> 423</p>
177After this, the ALSA modules should be installed on your system. 424
178</p> 425<figure link="/images/docs/alsa-mixerunmuted.png" short="AlsaMixer Unmuted" caption="Alsa Mixer ready to roll"/>
426
179</body> 427</body>
180</section>
181<section> 428</section>
182 <title>Configuration of ALSA</title> 429<section>
430<title>Sound Check!</title>
431<body>
432
433<p>
434Finally. Some music. If everything above is perfect, you should now be able to
435listen to some good music. A quick way to test is to use a command line tool
436like <c>media-sound/madplay</c>. You could also use something more well known
437like <c>mpg123</c>. If you are an ogg fan, you could use <c>ogg123</c> provided
438by <c>media-sound/vorbis-tools</c>. Use any player you are comfortable with. As
439always, <c>emerge</c> what you need.
440</p>
441
442<pre caption="Getting the software">
443<comment>(Install the applications you want)</comment>
444# <i>emerge madplay mpg123</i>
445<comment>(To play .ogg files)</comment>
446# <i>emerge vorbis-tools</i>
447</pre>
448
449<p>
450And then play your favorite sound track...
451</p>
452
453<pre caption="Playing Music">
454# <i>madplay -v /mnt/shyam/Music/Paul\ Oakenfold\ -\ Dread\ Rock.mp3</i>
455MPEG Audio Decoder 0.15.2 (beta) - Copyright (C) 2000-2004 Robert Leslie et al.
456 Title: Dread Rock
457 Artist: Paul Oakenfold
458 Album: Matrix Reloaded
459 Year: 2003
460 Genre: Soundtrack
461 Soundtrack
462 00:04:19 Layer III, 160 kbps, 44100 Hz, joint stereo (MS), no CRC
463
464# <i>ogg123 Paul\ Oakenfold\ -\ Dread\ Rock.ogg</i>
465Audio Device: Advanced Linux Sound Architecture (ALSA) output
466
467Playing: Paul Oakenfold - Dread Rock.ogg
468Ogg Vorbis stream: 2 channel, 44100 Hz
469Genre: Soundtrack
470Transcoded: mp3;160
471Title: Dread Rock
472Artist: Paul Oakenfold
473Date: 2003
474Album: Matrix Reloaded
475Time: 00:11.31 [04:28.75] of 04:40.06 (200.6 kbps) Output Buffer 96.9%
476</pre>
477
183<body> 478</body>
184<p> 479</section>
185Let's start configuring now to get ALSA working properly. 480<section>
186We'll need to edit some files, to let our system know about the freshly installed ALSA modules. 481<title>ALSA and USE</title>
482<body>
483
187</p> 484<p>
485You can now add the <c>alsa</c> use flag to <path>/etc/make.conf</path> to
486ensure that your applications that support ALSA get built with it. Some
487architectures like x86 and amd64 have the flag enabled by default.
188<p> 488</p>
189First file to edit is <path>/etc/modules.d/alsa</path>. 489
490</body>
491</section>
492<section>
493<title>Issues?</title>
494<body>
495
190</p> 496<p>
191<warn> 497If for some reason you're unable to hear sound, the first thing to do would
192There is no need to edit <path>/etc/modules.conf</path>. Instead, always edit files in <path>/etc/modules.d</path>. 498be to check your <uri link="#doc_chap3_pre6">alsamixer</uri> settings. 80% of
193</warn> 499the issues lie with muted channels or low volume. Also check your Window
500Manager's sound applet and verify that volumes are set to audible levels.
194<p> 501</p>
195Check the ALSA portion <e>at the bottom of the file</e>. 502
196By tweaking this line you can specify the max number of soundcards you have (generally, just one).
197</p> 503<p>
504<path>/proc</path> is your friend. And in this case, <path>/proc/asound</path>
505is your best friend. We shall just take a short look at how much info is made
506available to us there.
198<p> 507</p>
199<pre caption="At the top of /etc/modules.d/alsa">
200# Alsa 0.9.X kernel modules' configuration file.
201# $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/alsa-guide.xml,v 1.7 2003/02/09 23:27:14 zhen Exp $
202 508
203# ALSA portion 509<pre caption="Fun with /proc/asound">
204alias char-major-116 snd 510<comment>(First and foremost, if /proc/asound/cards shows your card, ALSA has
205<c>options snd major=116 cards_limit=1</c> 511picked up your sound card fine.)</comment>
206# OSS/Free portion 512# <i>cat /proc/asound/cards</i>
207alias char-major-14 soundcore 5130 [Live ]: EMU10K1 - Sound Blaster Live!
514 Sound Blaster Live! (rev.6, serial:0x80271102) at 0xb800, irq 11
208 515
209## 516<comment>(This displays the current running ALSA version)</comment>
210## IMPORTANT: 517# <i>cat /proc/asound/version</i>
518Advanced Linux Sound Architecture Driver Version 1.0.8 (Thu Jan 13 09:39:32 2005 UTC).
519
520<comment>(ALSA OSS emulation details)</comment>
521# <i>cat /proc/asound/oss/sndstat</i>
522Sound Driver:3.8.1a-980706 (ALSA v1.0.8 emulation code)
523Kernel: Linux airwolf.zion 2.6.11ac1 #2 Wed May 4 00:35:08 IST 2005 i686
524Config options: 0
525
526Installed drivers:
527Type 10: ALSA emulation
528
529Card config:
530Sound Blaster Live! (rev.6, serial:0x80271102) at 0xb800, irq 11
531
532Audio devices:
5330: EMU10K1 (DUPLEX)
534
535Synth devices: NOT ENABLED IN CONFIG
536
537Midi devices:
5380: EMU10K1 MPU-401 (UART)
539
540Timers:
5417: system timer
542
543Mixers:
5440: SigmaTel STAC9721/23
211</pre> 545</pre>
546
547<!-- TODO: remove this a few months after alsa-driver leaves the tree -->
548
212</p> 549<p>
550The other most common issue users face is the dreaded "Unknown symbol in module"
551error. An example of the same is shown below.
213<p> 552</p>
214Now we'll specify the sounddriver(s) ALSA should use. In the same file, edit like this: 553
215<pre caption="A bit lower in /etc/modules.d/alsa"> 554<pre caption="Unknown Symbol in module error">
216## and then run `update-modules' command. 555# <i>/etc/init.d/alsasound start</i>
217## Read alsa-driver's INSTALL file in /usr/share/doc for more info. 556 * Loading ALSA modules ...
218## 557 * Loading: snd-card-0 ... [ ok ]
219## ALSA portion 558 * Loading: snd-pcm-oss ...
220<c>alias snd-card-0 snd-emu10k1</c> 559WARNING: Error inserting snd_mixer_oss
221<c>## If you have more than one, add: 560(/lib/modules/2.6.12-gentoo-r6/kernel/sound/core/oss/snd-mixer-oss.ko): Unknown
222## alias snd-card-1 snd-intel8x0 561symbol in module, or unknown parameter (see dmesg) FATAL: Error inserting
223## alias snd-card-2 snd-ens1370</c> 562snd_pcm_oss
224## OSS/Free portion 563(/lib/modules/2.6.12-gentoo-r6/kernel/sound/core/oss/snd-pcm-oss.ko): Unknown
225## alias sound-slot-0 snd-card-0 564symbol in module, or unknown parameter (see dmesg)
226## alias sound-slot-1 snd-card-1 565 [ !! ]
227## 566 * Loading: snd-mixer-oss ...
567FATAL: 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)
570 [ !! ]
571 * Loading: snd-seq ... [ ok ]
572 * Loading: snd-emu10k1-synth ... [ ok ]
573 * Loading: snd-seq-midi ... [ ok ]
574 * Restoring Mixer Levels ... [ ok ]
228</pre> 575</pre>
576
229</p> 577<p>
578And when you take a look at <c>dmesg</c> as suggested, you're quite likely to
579see:
230<p> 580</p>
581
582<pre caption="dmesg output">
583<comment>(Only relevant portions are shown below)</comment>
584# <i>dmesg | less</i>
585ACPI: PCI Interrupt 0000:02:06.0[A] -> Link [APC3] -> GSI 18 (level, low) -> IRQ 209
586snd_mixer_oss: Unknown symbol snd_unregister_oss_device
587snd_mixer_oss: Unknown symbol snd_register_oss_device
588snd_mixer_oss: Unknown symbol snd_mixer_oss_notify_callback
589snd_mixer_oss: Unknown symbol snd_oss_info_register
590snd_pcm_oss: Unknown symbol snd_unregister_oss_device
591snd_pcm_oss: Unknown symbol snd_register_oss_device
592snd_pcm_oss: Unknown symbol snd_mixer_oss_ioctl_card
593snd_pcm_oss: Unknown symbol snd_oss_info_register
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
598</pre>
599
600<p>
601The above issue is caused when you switch from the <c>alsa-driver</c> to in-kernel
602ALSA because when you unmerge <c>alsa-driver</c> the module files are config
603protected and hence get left behind. So, when you switch to in-kernel
604drivers, running <c>modprobe</c> gives you a mix of <c>alsa-driver</c> and
605in-kernel modules thus causing the above errors.
606</p>
607
608<p>
609The solution is quite easy. We just need to manually remove the problem causing
610directory after you unmerge <c>alsa-driver</c>. Be sure to remove the correct
611kernel version and not the current one!
612</p>
613
614<pre caption="Removing the alsa-driver modules">
615# <i>rm -rf /lib/modules/$(uname -r)/alsa-driver</i>
616</pre>
617
618<p>
619Another reason for error messages similar to the ones above could be a file in
620<path>/etc/modprobe.d</path> supplying a <c>device_mode</c> parameter when it
621isn't required. Confirm that this is indeed the issue and find out which file
622is the culprit.
623</p>
624
625<pre caption="Confirming and searching for device_mode">
626<comment>(Check dmesg to confirm)</comment>
627# <i>dmesg | grep device_mode</i>
628snd: Unknown parameter `device_mode'
629<comment>(Now, to get to the source of the issue)</comment>
630# <i>grep device_mode /etc/modprobe.d/*</i>
631</pre>
632
633<p>
634Usually it is a file called <path>alsa</path> with the line <c>options snd
635device_mode=0666</c>. Remove this line and restart the <c>alsasound</c> service
636and that should take care of this issue.
637</p>
638
639<!-- End of removal notice -->
640
641</body>
642</section>
643</chapter>
644
645<chapter>
646<title>Other things ALSA</title>
647<section id="midi">
648<title>Setting up MIDI support</title>
649<body>
650
651<p>
652First, check to make sure that you enabled the <c>midi</c> USE flag in
653<path>/etc/make.conf</path>. If you didn't, go ahead and add it now. You will
654also need to re-emerge any ALSA packages that use the <c>midi</c> flag, such as
655<c>alsa-lib</c> and <c>alsa-utils</c>.
656</p>
657
658<p>
659If your sound card is one of those that come with on-board MIDI synthesizers
660and you would like to listen to some .mid files, you have to install
661<c>awesfx</c> which is basically a set of utilities for controlling the AWE32
662driver. We need to install it first. If you don't have a hardware synthesizer,
663you can use a virtual one. Please see the section on
664<uri link="#vsynth">Virtual Synthesizers</uri> for more information.
665</p>
666
667<pre caption="Installing awesfx">
668# <i>emerge awesfx</i>
669</pre>
670
231<note> 671<note>
232If you have more than one soundcard, adjust the <c>cards_limit</c> value and add more snd-card aliases to the file. 672You will need to copy over SoundFont (SF2) files from your sound card's driver
233I don't have experience with this, but you can find examples for configurations with two or more soundcards in 673CD or a Windows installation into <path>/usr/share/sounds/sf2/</path>. For
234<uri link="http://www.alsa-project.org/alsa-doc/alsa-howto/c1660.htm">Chapter 6</uri> 674example a sound font file for the Creative SBLive! card would be 8MBGMSFX.SF2.
235of the <uri link="http://www.alsa-project.org/alsa-doc/alsa-howto/alsa-howto.html">ALSA Howto</uri>.
236</note> 675</note>
676
237</p> 677<p>
678After copying over the Soundfont files, we can then play a midi file as shown.
679You can also add the <c>asfxload</c> command to
680<path>/etc/conf.d/local.start</path>, so that the sound font is loaded
681every time the system starts up.
238<p> 682</p>
239Last thing to do in this file, at the very bottom, check if these lines are there and uncommented: 683
240<pre caption="at the very bottom of /etc/modules.d/alsa">
241alias /dev/mixer snd-mixer-oss
242alias /dev/dsp snd-pcm-oss
243alias /dev/midi snd-seq-oss
244</pre>
245</p>
246<p>
247Now double-check the file <path>/etc/modules.d/alsa</path> and when you're sure everyting is ok, run <c>update-modules</c>.
248<pre>
249# <c>update-modules</c>
250</pre>
251</p>
252<note> 684<note>
253Running <c>update-modules</c> here will insert the data from <path>/etc/modules.d/alsa</path> into <path>/etc/modules.conf</path> 685<path>/mnt</path> paths mentioned in the code listing(s) below will <e>not</e>
686be the same in your machine. They are just an example. Please be careful to
687change the path to suit your machine.
254</note> 688</note>
255<p> 689
256You should also verify that /etc/devfsd.conf has the alsa devices and permissions correctly registered. 690<pre caption="Loading Soundfonts">
257</p> 691<comment>(First, copy the Soundfont)</comment>
692# <i>cp /mnt/win2k/Program\ Files/CreativeSBLive2k/SFBank/8MBGMSFX.SF2 /usr/share/sounds/sf2/</i>
693<comment>(Or get it from your SoundBlaster CD)</comment>
694# <i>cp /mnt/cdrom/AUDIO/ENGLISH/SFBANK/8MBGMSFX.SF2 /usr/share/sounds/sf2/</i>
695<comment>(We load the specific Soundfont)</comment>
696# <i>asfxload /usr/share/sounds/sf2/8MBGMSFX.SF2</i>
258<pre> 697</pre>
259# nano -w /etc/devfsd.conf 698
699<p>
700You can now play midi files using a program like <c>aplaymidi</c>. Run
701<c>aplaymidi -l</c> to get a list of available ports and then pick one
702to play the file on.
260</pre> 703</p>
704
705<pre caption="Playing MIDI">
706<comment>(Check open ports)</comment>
707# <i>aplaymidi -l</i>
708 Port Client name Port name
709 64:0 EMU10K1 MPU-401 (UART) EMU10K1 MPU-401 (UART)
710 65:0 Emu10k1 WaveTable Emu10k1 Port 0
711 65:1 Emu10k1 WaveTable Emu10k1 Port 1
712 65:2 Emu10k1 WaveTable Emu10k1 Port 2
713 65:3 Emu10k1 WaveTable Emu10k1 Port 3
714<comment>(Pick a port, and play a mid file)</comment>
715# <i> aplaymidi --port=65:0 /mnt/shyam/music/midi/mi2.mid</i>
261<pre> 716</pre>
262# ALSA/OSS stuff 717
263# Comment/change these if you want to change the permissions on
264# the audio devices
265LOOKUP snd MODLOAD ACTION snd
266LOOKUP dsp MODLOAD
267LOOKUP mixer MODLOAD
268LOOKUP midi MODLOAD
269REGISTER sound/.* PERMISSIONS root.audio 660
270REGISTER snd/.* PERMISSIONS root.audio 660
271</pre>
272<note>
273Notice 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.
274</note>
275</body> 718</body>
276</section>
277</chapter>
278<chapter>
279<title>Starting ALSA</title>
280<section> 719</section>
281 <title>Adding alsasound to a runlevel</title> 720<section id="vsynth">
282<body> 721<title>Virtual Synthesizers</title>
283<p>
284First thing to do now, is to make ALSA startup at boottime. Like this:
285<pre>
286# <c>rc-update add alsasound boot</c>
287</pre>
288</p>
289<p>
290<warn>Note that the alsasound script should be added to the "boot" runlevel, not the "default" runlevel.</warn>
291</p>
292</body> 722<body>
293</section> 723
724<p>
725If your sound card lacks a hardware synthesizer, you could use a virtual one
726like <c>timidity++</c>. Installation is a breeze.
727</p>
728
729<pre caption="Installing timidity++">
730# <i>emerge timidity++</i>
731</pre>
732
733<p>
734For timidity to play sounds, it needs a sound font. Fortunately, the ebuild will
735install some sound font packages for you. There are a few other font packages
736available in Portage, such as <c>timidity-freepats</c> and
737<c>timidity-eawpatches</c>. You can have multiple sound font configurations
738installed, and you can place your own in <path>/usr/share/timidity/</path>. To
739switch between different timidity configurations, you should use
740<c>eselect</c>.
741</p>
742
743<pre caption="Changing configurations">
744# <i>eselect timidity list</i>
745# <i>eselect timidity set eawpatches</i>
746</pre>
747
748<p>
749Don't forget to add <c>timidity</c> to the default runlevel.
750</p>
751
752<pre caption="Adding timidity to the default runlevel">
753# <i>rc-update add timidity default</i>
754# <i>/etc/init.d/timidity start</i>
755</pre>
756
757<p>
758You can now try out <uri link="#doc_chap4_pre3">Playing MIDI</uri> files.
759</p>
760
761</body>
294<section> 762</section>
295 <title>Running and unmuting</title>
296<body>
297<p>
298Since we're Linux users, we don't want to reboot. So we'll start the alsasound script manually.
299</p>
300<pre>
301# <c>/etc/init.d/alsasound start</c>
302</pre>
303<p>
304ALSA is running now. If everything is ok, you should be able to see the ALSA modules loaded when running <c>lsmod</c>.
305However, sound won't work yet, because the channels are still muted. We need <c>alsa-utils</c> for this.
306</p>
307<pre>
308# <c>emerge alsa-utils</c>
309# <c>amixer</c>
310</pre>
311<p>
312<warn>
313You 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 insmod
314<c>snd-mixer-oss</c> and <c>snd-pcm-oss</c> once. After that run amixer again.
315</warn>
316</p>
317<pre caption="only if you get an error when running amixer">
318# <c>insmod snd-mixer-oss</c>
319# <c>insmod snd-pcm-oss</c>
320# <c>amixer</c>
321</pre>
322<p>
323If you got this far, now unmute both Master and PCM channels.
324</p>
325<p>
326<pre>
327# <c>amixer set Master 100 unmute</c>
328# <c>amixer set PCM 100 unmute</c>
329# <c>aplay /usr/kde/3/share/sounds/pop.wav</c> <codenote>(pop.wav is part of KDE)</codenote>
330</pre>
331</p>
332We check to see if sound is working by using the aplay (alsa play) command. If you hear a pop, then sound is indeed working.
333Then, adjust the volume settings to your liking; the ncurses-based <c>alsamixer</c> is a great way to get them "just so".
334<p>
335You may want to emerge <c>alsa-xmms</c> as that will provide ALSA support for XMMS.
336</p>
337When you reboot your system, the <e>alsasound</e> init script will properly save and restore your volume settings.
338</body>
339</section> 763<section>
340</chapter> 764<title>Tools and Firmware</title>
341<chapter> 765<body>
342<title>Final Notes</title> 766
767<p>
768Some specific sound cards can benefit from certain tools provided by the
769<c>alsa-tools</c> and <c>alsa-firmware</c> packages. You may install either with
770a simple <c>emerge</c>.
771</p>
772
773<pre caption="Installing ALSA Tools">
774# <i>emerge alsa-tools</i>
775</pre>
776
777</body>
343<section> 778</section>
344 <title>After kernel-upgrades..</title>
345<body>
346<p>When you ever rebuild your kernel, or upgrade to another kernel, you'll have to rebuild the ALSA modules.</p>
347<p>Although you might have installed <c>alsa-driver</c>, <c>alsa-libs</c> and <c>alsa-utils</c>, only the first will
348have to be installed again, since it will put the alsa modules in
349<path>/lib/modules/*/kernel/sound/pci/</path>.</p>
350<pre caption="needed after each kernel compile">
351emerge alsa-driver
352</pre>
353</body>
354</section> 779<section>
780<title>Multiple sound cards</title>
781<body>
782
783<p>
784You can have more than one sound card in your system simultaneously, provided
785that you have built ALSA as modules in your kernel. You just need to specify
786which should be started first in <path>/etc/modprobe.d/alsa.conf</path>. Your cards
787are identified by their driver names inside this file. 0 is the first card, 1 is
788the second, and so on. Here's an example for a system with two sound cards.
789</p>
790
791<pre caption="Two sound cards in /etc/modprobe.d/alsa.conf">
792options snd-emu10k1 index=0
793options snd-via82xx index=1
794</pre>
795
796<p>
797Or, if you have two cards that use the same driver, you specify them on the same
798line, using comma-separated numbers. Here's an example for a system with three
799sound cards, two of which are the same Intel High Definition Audio card.
800</p>
801
802<pre caption="Multiple sound cards in /etc/modprobe.d/alsa.conf">
803options snd-ymfpci index=0
804options snd-hda-intel index=1,2
805</pre>
806
807</body>
355<section> 808</section>
356 <title>/etc/modules.autoload</title>
357<body>
358<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
359load the correct modules at startup.</p>
360<p>It's not necessary to add <c>snd-pcm-oss</c> or <c>snd-mixer-oss</c> in this file.
361Check the <uri link="http://www.djcj.org/LAU/guide/alsbook/faq1.html">this FAQ</uri> for more info.</p>
362</body>
363</section> 809<section>
810<title>Plugins</title>
811<body>
812
813<p>
814You may want to install some plugins for extra functionality.
815<c>alsa-plugins</c> is a collection of useful plugins, which include: PulseAudio
816output, a sample rate converter, jack (a low-latency audio server), and an
817encoder that lets you output 6-channel audio through digital S/PDIF connections
818(both optical and coaxial). You can choose which of its plugins you want
819installed by adding their USE flags to <path>/etc/portage/package.use</path>.
820</p>
821
822<pre caption="Installing alsa-plugins">
823# <i>emerge -avt alsa-plugins</i>
824</pre>
825
826</body>
364<section> 827</section>
365 <title>More links..</title> 828<section>
829<title>A big thank you to...</title>
830<body>
831
832<p>
833Everyone who contributed to the earlier version of the Gentoo ALSA Guide:
834Vincent Verleye, Grant Goodyear, Arcady Genkin, Jeremy Huddleston,
835John P. Davis, Sven Vermeulen, Benny Chuang, Tiemo Kieft and Erwin.
836</p>
837
366<body> 838</body>
367<p> 839</section>
368You could check these for additional info: 840<section>
369</p> 841<title>References</title>
370<p> 842<body>
843
371<ul> 844<ul>
372<li><uri link="http://www.gentoo.org/doc/desktop.html">The Gentoo Linux Desktop Configuration Guide</uri></li>
373<li><uri link="http://www.alsa-project.org">ALSA Project Homepage</uri></li> 845 <li><uri link="http://www.alsa-project.org/">The ALSA Project</uri></li>
374<li><uri link="http://www.alsa-project.org/documentation.php3">ALSA Users Documentation</uri></li>
375<li><uri link="http://www.djcj.org">ALSA Howto's and FAQ's</uri></li>
376<li><uri link="http://tldp.org/HOWTO/Sound-HOWTO/index.html">Linux Sound HOWTO</uri></li>
377<li><uri link="http://linux-sound.org/">Sound and MIDI Software For Linux</uri></li> 846 <li><uri link="http://linux-sound.org">Linux Sound/MIDI Software</uri></li>
378</ul> 847</ul>
379</p> 848
380</body> 849</body>
381</section> 850</section>
382</chapter> 851</chapter>
383</guide> 852</guide>

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