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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 1.81 2008/03/05 09:16:49 nightmorph Exp $ -->
3
2<!DOCTYPE guide SYSTEM "/dtd/guide.dtd"> 4<!DOCTYPE guide SYSTEM "/dtd/guide.dtd">
3 5
4<guide link = "/doc/en/alsa-guide.xml"> 6<guide link="/doc/en/alsa-guide.xml">
5<title>Gentoo Linux ALSA Guide</title> 7<title>Gentoo Linux ALSA Guide</title>
6<author title="Author"><mail link="zu@pandora.be"> 8
7 Vincent Verleye</mail> 9<author title="Author">
10 <mail link="fox2mike@gentoo.org">Shyam Mani</mail>
8</author> 11</author>
9<author title="Author"><mail link="g2boojum@gentoo.org"> 12<author title="Author">
10 Grant Goodyear</mail> 13 <mail link="nightmorph@gentoo.org">Joshua Saddler</mail>
11</author> 14</author>
12<author title="Author"><mail link="agenkin@gentoo.org"> 15<author title="Contributor">
13 Arcady Genkin</mail> 16 <mail link="flameeyes@gentoo.org">Diego Pettenò</mail>
14</author> 17</author>
15<author title="Editor"><mail link="zhen@gentoo.org">
16 John P. Davis</mail>
17</author>
18<author title="Editor"><mail link="swift@gentoo.org">
19 Sven Vermeulen</mail>
20</author>
21<author title="Editor"><mail link="bennyc@gentoo.org">
22 Benny Chuang</mail>
23</author>
24<author title="Editor"><mail link="blubber@gentoo.org">
25 Tiemo Kieft</mail>
26</author>
27 18
19<abstract>
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 -->
28<license/> 25<license/>
29 26
30<abstract>
31This guide will show you how to set up the Advanced Linux Sound Architecture (ALSA) on Gentoo Linux.
32In addition to the Gentoo Linux Desktop Configuration Guide, this guide is supposed to give you more information on this subject. </abstract>
33
34<version>1.3.3</version> 27<version>2.23</version>
35<date>October 9, 2003</date> 28<date>2008-03-05</date>
36 29
37<chapter> 30<chapter>
38<title>Introduction</title> 31<title>Introduction</title>
39<section> 32<section>
40 <title>What is ALSA?</title> 33<title>What is ALSA?</title>
34<body>
35
36<p>
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
41<body> 52</body>
42<p> 53</section>
43The Advanced Linux Sound Architecture (ALSA) is a project to improve the Linux sound subsystem by rewriting 54<section>
44large chunks of it. 55<title>ALSA on Gentoo</title>
45It is anticipated that ALSA will make it into Linux kernel 2.6.x (or 3.x.x -- whichever comes first) as it becomes ready. 56<body>
57
46</p> 58<p>
47 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.
48<p> 66</p>
49ALSA provides audio and MIDI functionality for Linux. 67
50</p> 68<p>
51 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.
52<p> 72</p>
53Quoted from <uri>http://www.alsa-project.org</uri>, ALSA has the following features: 73
54<ul><li> Efficient support for all types of audio interfaces, from consumer soundcards to professional multichannel audio interfaces.</li> 74</body>
55 <li> Fully modularized sound drivers.</li> 75</section>
56 <li> SMP and thread-safe design.</li> 76</chapter>
57 <li> User space library (alsa-lib) to simplify application programming and provide higher level functionality.</li> 77
58 <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>
59</ul> 107</ul>
60There's lots more to ALSA however, like support for Full Duplex playback and recording, multiple soundcard support, 108
61hardware 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
62</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
63</body> 140</body>
64</section>
65<section> 141</section>
66 <title>Why use ALSA?</title> 142<section id="kernel">
67<body> 143<title>Configuring the kernel</title>
68<p>
69If your soundcard is supported by the Linux kernel sound system or the commercial OSS/4Front sound driver system,
70which can be found in all 2.4.x Linux kernels, you could just aswell build <e>those modules</e> for use with your soundcard.
71If you want this, just read through the <uri link="http://www.tldp.org/HOWTO/Sound-HOWTO/index.html">Linux Sound HOWTO</uri>.
72</p>
73<p>
74However, those OSS/4Front drivers have some limitations -- being commercial is one.
75ALSA is an attempt to go beyond these limitations and to do so in an open source fashion.
76ALSA is a fully GPL and LGPL'ed sound driver system, that provides a professional quality system for recording, playback,
77and MIDI sequencing.
78</p>
79</body> 144<body>
80</section> 145
81<section> 146<note>
82 <title>What cards does ALSA support?</title> 147Since the 2005.0 release, Gentoo Linux uses 2.6 as the default kernel. Please
83<body> 148check that your kernel is a 2.6 series kernel. This method will <e>not</e> work
84<p> 149on a 2.4 kernel.
85ALSA tries to support as many (new) cards as possible by providing open-source drivers. 150</note>
86However, some vendors may provide binary-only packages. 151
87</p> 152<p>
88<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.
89<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
90</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
91</body> 241</body>
92</section> 242</section>
93</chapter> 243</chapter>
94 244
95<chapter> 245<chapter>
96<title>Installation</title> 246<title>Configuring/Testing ALSA</title>
97<section> 247<section id="alsa-utilities">
98<title>Gentoo USE flags</title> 248<title>ALSA Utilities</title>
99<body>
100
101<p>
102To compile programs with ALSA-support, be sure to add <e>alsa</e> to
103your USE-variable. However, several tools don't support alsa yet, and
104require OSS. ALSA provides OSS-emulation if you define <e>oss</e> in your
105USE-variable before you start.
106</p>
107
108</body> 249<body>
109</section>
110 250
111<section>
112 <title>Kernel modules</title>
113<body>
114<p>
115Since we're still using 2.4.x kernel sources, we'll have to compile kernel modules and ALSA modules separately. People who are using a 2.5.x kernel can do this from within their kernel configuration, since the ALSA modules are included in the kernel sources and should be built there.
116</p> 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>
117<p> 255</p>
118First we'll make sure that our kernel configuration is ready for use with ALSA. 256
119All 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">
120This will build <c>soundcore.o</c>. 258# <i>emerge alsa-utils</i>
121</p> 259</pre>
122<p> 260
123<note> 261<note>
124Possibly, 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
125However, 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>.
126</note> 266</note>
267
268</body>
269</section>
270<section id="alsa-config">
271<title>Configuration</title>
272<body>
273
127</p> 274<p>
128<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
129If 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
277just letting your kernel automatically setup your sound card for you. Otherwise,
278use <c>alsaconf</c> to configure your card, as shown below.
279</p>
280
281<note>
282Please shut down any programs that <e>might</e> access the sound card while
283running <c>alsaconf</c>.
284</note>
285
130</p> 286<p>
287To configure your sound card just type <c>alsaconf</c> in a shell as root.
288</p>
289
290<pre caption="Invoking alsaconf">
291# <i>alsaconf</i>
131<pre> 292</pre>
132# <i>cd /usr/src/linux</i> 293
133# <i>cp .config ~/</i>
134# <i>make mrproper</i>
135# <i>cp ~/.config .</i>
136# <i>make menuconfig</i>
137</pre>
138<p>
139Now select <e>Sound Card Support</e> as Module (M) and deselect all other sound drivers.
140Exit and say Y to save your kernel configuration.
141After that, build the modules:
142</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.
143<pre> 322</pre>
144# <i>make dep clean</i> 323
145# <i>make modules modules_install</i>
146</pre>
147<p>
148Before installing your new modules, this last line will delete all your previous modules,
149even the ones from a previous ALSA installation.
150</p> 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.
151<p> 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>
379
152<impo> 380<impo>
153This means, whenever you recompile your kernel later on, you MUST recompile <c>alsa-driver</c>. 381If you have issues starting up <c>alsamixer</c> and get errors such as
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.
154</impo> 386</impo>
387
155</p> 388<p>
389This is how the ALSA Mixer <e>might</e> look the first time you open it. Pay
390attention to the Master and PCM channels which both have an MM below them.
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.
156<p> 393</p>
157<note>However, there's no need to reinstall <c>nvidia-kernel</c>, the Nvidia drivers are in a separate directory 394
158in <path>/lib/modules/*/video</path> and won't get deleted by a <c>make modules modules_install</c> 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>
400
401<warn>
402Both Master <e>and</e> PCM need to be unmuted and set to audible volume levels
403if you want to hear some output on your speakers.
404</warn>
405
406<ul>
407 <li>
408 To move between channels, use your left and right arrow keys. (&lt;-
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.
418 </li>
419</ul>
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.
159</note> 425</note>
426
160</p> 427<p>
161</body> 428After you're all done, your ALSA Mixer should look similar to the one below.
162</section> 429Note the 00 instead of the MM and also the volume levels for some optimum
430settings.
431</p>
163 432
433<figure link="/images/docs/alsa-mixerunmuted.png" short="AlsaMixer Unmuted" caption="Alsa Mixer ready to roll"/>
434
435</body>
164<section> 436</section>
165 <title>ALSA modules</title> 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
166<body> 486</body>
487</section>
488<section>
489<title>ALSA and USE</title>
490<body>
167 491
168<p>
169Now it's time to install the ALSA drivers for your soundcard(s). If your soundcard is PCI, you can find out the name
170and type of your soundcard by looking at the output of /proc/pci.
171</p> 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
498</body>
499</section>
500<section>
501<title>Issues?</title>
502<body>
503
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
172<pre> 553</pre>
173# <i>grep audio /proc/pci</i>
174</pre>
175 554
555<!-- TODO: remove this a few months after alsa-driver leaves the tree -->
176 556
177<p>
178<warn>
179If you had a previous sound setup and there are still non-ALSA sound modules loaded, unload them <e>now</e>.
180Check with <c>lsmod</c> and use <c>rmmod</c> to unload all sound-related modules on your system.
181</warn>
182</p> 557<p>
183 558The other most common issue users face is the dreaded "Unknown symbol in module"
559error. An example of the same is shown below.
184<p> 560</p>
185We could simply do an <c>emerge alsa-driver</c> now, this would compile and install <e>all</e> ALSA sound drivers.
186</p>
187<p>
188However, to save some time, lookup the <e>Module Name</e> of your soundcard(s) on the
189<uri link="http://www.alsa-project.org/alsa-doc">ALSA Soundcard Matrix</uri> by following the <e>Details</e> link in the <e>Driver and Docs</e> column in the row of the chipset of your soundcard.
190Mine is <c>snd-emu10k1</c>, since I have an SBlive! soundcard, with the <e>EMU10K1</e> chipset.
191We'll set ALSA_CARDS environment to the value of the module name before emerging (but without the snd prefix), so emerge will only compile the drivers we need.
192</p>
193 561
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 ]
194<pre> 583</pre>
195# <i>env ALSA_CARDS='emu10k1' emerge alsa-driver</i> 584
585<p>
586And when you take a look at <c>dmesg</c> as suggested, you're quite likely to
587see:
196</pre> 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
197<note> 679<note>
198You can also add this value in <path>/etc/make.conf</path>, so when you have to emerge the alsa-driver later on you can just run <c>emerge alsa-driver</c>. 680You will need to copy over SoundFont (SF2) files from your sound card's driver
199For example, like this: <c>echo 'ALSA_CARDS="emu10k1"' >> /etc/make.conf</c> 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.
200</note> 683</note>
201 684
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
202<note> 692<note>
203When you want to install ALSA drivers for more than one soundcard, you could set ALSA_CARDS to a space-separated list 693<path>/mnt</path> paths mentioned in the code listing(s) below will <e>not</e>
204of drivers; like this: <c>env ALSA_CARDS='emu10k1 intel8x0 ens1370' emerge alsa-driver</c> 694be the same in your machine. They are just an example. Please be careful to
695change the path to suit your machine.
205</note> 696</note>
206 697
207<note>If you want to have OSS compatibility, make sure to emerge <i>alsa-oss</i>, it is the ALSA/OSS compatibility 698<pre caption="Loading Soundfonts">
208wrapper. </note> 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>
209 706
210<note>If you plan on recompiling your kernels numerous times, it might
211be adviseable to emerge <c>alsa-driver</c> with <c>--buildpkg</c>. This
212will create a binary package for it. Later, after recompiling your kernel,
213you can just do <c>emerge --usepkg alsa-driver</c> which will install the
214binary package instead of recompiling it completely.</note>
215
216<p>
217After this, the ALSA modules should be installed on your system.
218</p> 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
219</body> 726</body>
220</section>
221<section> 727</section>
222 <title>Configuration of ALSA</title> 728<section id="vsynth">
223<body> 729<title>Virtual Synthesizers</title>
224<p>
225Let's start configuring now to get ALSA working properly.
226We'll need to edit some files, to let our system know about the freshly installed ALSA modules.
227</p>
228
229<p>
230First, install <c>alsa-utils</c> on your system:
231</p>
232
233<pre caption = "Emerging alsa-utils">
234# <i>emerge alsa-utils</i>
235</pre>
236
237<p>
238Hereafter, we need to edit <path>/etc/modules.d/alsa</path>.
239</p>
240<warn>
241There is no need to edit <path>/etc/modules.conf</path>. Instead, always edit files in <path>/etc/modules.d</path>.
242</warn>
243<p>
244Check the ALSA portion <e>at the bottom of the file</e>.
245By tweaking this line you can specify the max number of soundcards you have (generally, just one).
246</p>
247<pre caption="At the bottom of /etc/modules.d/alsa">
248<comment>Set this to the correct number of cards.</comment>
249options snd cards_limit=1
250</pre>
251<p>
252Now we'll specify the sounddriver(s) ALSA should use. In the same file, edit like this:
253</p>
254<pre caption="In /etc/modules.d/alsa">
255## and then run `modules-update' command.
256## Read alsa-driver's INSTALL file in /usr/share/doc for more info.
257##
258## ALSA portion
259alias snd-card-0 snd-emu10k1
260<comment>## If you have more than one, add:</comment>
261## alias snd-card-1 snd-intel8x0
262## alias snd-card-2 snd-ens1370
263## OSS/Free portion
264## alias sound-slot-0 snd-card-0
265## alias sound-slot-1 snd-card-1
266##
267</pre>
268<note>
269If you have more than one soundcard, adjust the <c>cards_limit</c> value and add more snd-card aliases to the file.
270I don't have experience with this, but you can find examples for configurations with two or more soundcards in
271<uri link="http://www.alsa-project.org/alsa-doc/alsa-howto/c1660.htm">Chapter 6</uri>
272of the <uri link="http://www.alsa-project.org/alsa-doc/alsa-howto/alsa-howto.html">ALSA Howto</uri>.
273</note>
274<p>
275Last thing to do in this file, almost at the end, check if these lines are there and uncommented:
276</p>
277<pre caption="Near the end of /etc/modules.d/alsa">
278alias /dev/mixer snd-mixer-oss
279alias /dev/dsp snd-pcm-oss
280alias /dev/midi snd-seq-oss
281</pre>
282<p>
283Now double-check the file <path>/etc/modules.d/alsa</path> and when you're sure everyting is ok, run <c>modules-update</c>.
284<pre>
285# <i>modules-update</i>
286</pre>
287</p>
288<note>
289Running <c>modules-update</c> here will insert the data from <path>/etc/modules.d/alsa</path> into <path>/etc/modules.conf</path>
290</note>
291<p>
292You should also verify that /etc/devfsd.conf has the alsa devices and permissions correctly registered.
293</p>
294<pre caption="/etc/devfsd.conf">
295# ALSA/OSS stuff
296# Comment/change these if you want to change the permissions on
297# the audio devices
298LOOKUP snd MODLOAD ACTION snd
299LOOKUP dsp MODLOAD
300LOOKUP mixer MODLOAD
301LOOKUP midi MODLOAD
302REGISTER sound/.* PERMISSIONS root.audio 660
303REGISTER snd/.* PERMISSIONS root.audio 660
304</pre>
305<note>
306Notice that devfsd.conf sets /dev/sound permissions to be root.audio. Thus, for non-root users to use audio they will have to be part of the audio group.
307</note>
308</body> 730<body>
309</section> 731
310</chapter> 732<p>
311<chapter> 733If your sound card lacks a hardware synthesizer, you could use a virtual one
312<title>Starting ALSA</title> 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>
313<section> 770</section>
314 <title>Adding alsasound to a runlevel</title>
315<body>
316<p>
317First thing to do now, is to make ALSA startup at boottime. Like this:
318<pre>
319# <i>rc-update add alsasound boot</i>
320</pre>
321</p>
322<p>
323<warn>Note that the alsasound script should be added to the "boot" runlevel, not the "default" runlevel.</warn>
324</p>
325</body>
326</section> 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>
327<section> 786</section>
328 <title>Running and unmuting</title>
329<body>
330<p>
331Since we're Linux users, we don't want to reboot. So we'll start the alsasound script manually.
332</p>
333<pre>
334# <i>/etc/init.d/alsasound start</i>
335</pre>
336<p>
337ALSA is running now. If everything is ok, you should be able to see the ALSA modules loaded when running <c>lsmod</c>.
338However, sound won't work yet, because the channels are still muted. We need <c>amixer</c> for this.
339</p>
340<pre caption = "Running amixer">
341# <i>amixer</i>
342</pre>
343<p>
344<warn>
345You shouldn't get this, but <e>if</e> you get an error about "amixer: Mixer attach default error: No such file or directory", you should manually modprobe
346<c>snd-mixer-oss</c> and <c>snd-pcm-oss</c> once. After that run amixer again.
347</warn>
348</p>
349<pre caption="only if you get an error when running amixer">
350# <i>modprobe snd-mixer-oss</i>
351# <i>modprobe snd-pcm-oss</i>
352# <i>amixer</i>
353</pre>
354<p>
355If you got this far, now unmute Master and PCM channels. Some hardware
356even requires you to unmute the center channel or even the surround
357channel.
358</p>
359<p>
360<pre caption = "Unmuting channels">
361# <i>amixer set Master 100 unmute</i>
362# <i>amixer set PCM 100 unmute</i>
363<comment>Only if the above doesn't succeed on its own:</comment>
364# <i>amixer set Center 100 unmute</i>
365# <i>amixer set Surround 100 unmute</i>
366<comment>Test the sound:</comment>
367# <i>aplay $KDEDIR/share/sounds/pop.wav</i> <codenote>(pop.wav is part of KDE)</codenote>
368</pre>
369</p>
370We check to see if sound is working by using the aplay (alsa play) command. If you hear a pop, then sound is indeed working.
371Then, adjust the volume settings to your liking; the ncurses-based <c>alsamixer</c> is a great way to get them "just so".
372<p>
373You may want to emerge <c>alsa-xmms</c> as that will provide ALSA support for XMMS.
374</p>
375When you reboot your system, the <e>alsasound</e> init script will properly save and restore your volume settings.
376</body>
377</section> 787<section>
378</chapter> 788<title>Multiple sound cards</title>
379<chapter> 789<body>
380<title>Final Notes</title> 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>
381<section> 816</section>
382 <title>After kernel-upgrades..</title>
383<body>
384<p>When you ever rebuild your kernel, or upgrade to another kernel, you'll have to rebuild the ALSA modules.</p>
385<p>Although you might have installed <c>alsa-driver</c>, <c>alsa-libs</c> and <c>alsa-utils</c>, only the first will
386have to be installed again, since it will put the alsa modules in
387<path>/lib/modules/*/kernel/sound/pci/</path>.</p>
388<pre caption="needed after each kernel compile">
389# <i>emerge alsa-driver</i>
390</pre>
391</body>
392</section> 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>
393<section> 835</section>
394 <title>/etc/modules.autoload</title>
395<body>
396<p>You won't have to edit this file for use with ALSA. After our <c>rc-update add alsasound boot</c>, our system will
397load the correct modules at startup.</p>
398<p>It's not necessary to add <c>snd-pcm-oss</c> or <c>snd-mixer-oss</c> in this file.
399Check the <uri link="http://www.djcj.org/LAU/guide/alsbook/faq1.html">this FAQ</uri> for more info.</p>
400</body>
401</section> 836<section>
837<title>A big thank you to...</title>
838<body>
402 839
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>
403<section> 847</section>
404<title>Known bugs</title> 848<section>
849<title>References</title>
405<body> 850<body>
406
407<note>
408This guide lags behind on the alsa-development. Chances are these bugs
409are already fixed when you read this.
410</note>
411 851
412<ul> 852<ul>
413<li> 853 <li><uri link="http://www.alsa-project.org/">The ALSA Project</uri></li>
414If you have <b>lots of noise</b> when using <b>oss</b> emulation, add 854 <li><uri link="http://linux-sound.org">Linux Sound/MIDI Software</uri></li>
415<e>options snd-pcm-oss dsp_map=1</e> to
416<path>/etc/modules.d/alsa</path>.
417</li>
418</ul> 855</ul>
419 856
420</body>
421</section>
422
423<section>
424 <title>More links..</title>
425<body>
426<p>
427You could check these for additional info:
428</p>
429<p>
430<ul>
431<li><uri link="http://www.gentoo.org/doc/en/desktop.xml">The Gentoo Linux Desktop Configuration Guide</uri></li>
432<li><uri link="http://www.alsa-project.org">ALSA Project Homepage</uri></li>
433<li><uri link="http://www.alsa-project.org/documentation.php3">ALSA Users Documentation</uri></li>
434<li><uri link="http://www.djcj.org">ALSA Howto's and FAQ's</uri></li>
435<li><uri link="http://tldp.org/HOWTO/Sound-HOWTO/index.html">Linux Sound HOWTO</uri></li>
436<li><uri link="http://linux-sound.org/">Sound and MIDI Software For Linux</uri></li>
437</ul>
438</p>
439</body> 857</body>
440</section> 858</section>
441</chapter> 859</chapter>
442</guide> 860</guide>

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