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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 1.60 2005/08/30 11:38:02 fox2mike 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">
10 Grant Goodyear</mail>
11</author>
12<author title="Author"><mail link="agenkin@gentoo.org">
13 Arcady Genkin</mail>
14</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 12
13<abstract>
14This document helps a user setup ALSA on Gentoo Linux.
15</abstract>
16
17<!-- The content of this document is licensed under the CC-BY-SA license -->
18<!-- See http://creativecommons.org/licenses/by-sa/2.5 -->
28<license/> 19<license/>
29 20
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> 21<version>2.8</version>
35<date>October 9, 2003</date> 22<date>2005-08-30</date>
36 23
37<chapter> 24<chapter>
38<title>Introduction</title> 25<title>Introduction</title>
39<section> 26<section>
40 <title>What is ALSA?</title> 27<title>What is ALSA?</title>
28<body>
29
30<p>
31ALSA, which stands for <e>Advanced Linux Sound Architecture</e>, provides
32audio and MIDI (<e>Musical Instrument Digital Interface</e>) functionality to
33the Linux operating system. ALSA is the default sound subsystem in the 2.6
34kernel thereby replacing OSS (<e>Open Sound System</e>), which was used in the
352.4 kernels.
36</p>
37
38<p>
39ALSA's main features include efficient support for all types of audio
40interfaces ranging from consumer sound cards to professional sound
41equipment, fully modularized drivers, SMP and thread safety, backward
42compatibility with OSS and a user-space library <c>alsa-lib</c> to make
43application development a breeze.
44</p>
45
41<body> 46</body>
42<p> 47</section>
43The Advanced Linux Sound Architecture (ALSA) is a project to improve the Linux sound subsystem by rewriting 48<section>
44large chunks of it. 49<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. 50<body>
51
46</p> 52<p>
47 53One of Gentoo's main strengths lies in giving the user maximum control over
54how a system is installed/configured. ALSA on Gentoo follows the same
55principle. There are two ways you can get ALSA support up and running on your
56system. We shall look at them in detail in the next chapter.
48<p> 57</p>
49ALSA provides audio and MIDI functionality for Linux. 58
59</body>
60</section>
61</chapter>
62
63<chapter>
64<title>Installing ALSA</title>
65<section>
66<title>Options</title>
67<body>
68
69<warn>
70The methods shown below are mutually exclusive. You cannot have ALSA compiled
71in your kernel and use <c>media-sound/alsa-driver</c>. It <e>will</e> fail.
72</warn>
73
50</p> 74<p>
51 75The two options are :
52<p> 76</p>
53Quoted from <uri>http://www.alsa-project.org</uri>, ALSA has the following features: 77
54<ul><li> Efficient support for all types of audio interfaces, from consumer soundcards to professional multichannel audio interfaces.</li> 78<ol>
55 <li> Fully modularized sound drivers.</li> 79 <li>
56 <li> SMP and thread-safe design.</li> 80 Use ALSA provided by your kernel. This is the preferred/recommended
57 <li> User space library (alsa-lib) to simplify application programming and provide higher level functionality.</li> 81 method.
58 <li> Support for the older OSS API, providing binary compatibility for most OSS programs.</li> 82 </li>
83 <li>
84 Use Gentoo's <c>media-sound/alsa-driver</c> package.
85 </li>
86</ol>
87
88<p>
89We shall take a peek into both before finally deciding on one.
90</p>
91
92<p>
93If you were to use ALSA provided by the kernel, the following are the pros and
94cons :
95</p>
96
97<table>
98<tr>
99 <th>Kernel ALSA</th>
100 <th>Pros and Cons</th>
101</tr>
102<tr>
103 <th>+</th>
104 <ti>Pretty stable as drivers are integrated into kernel.</ti>
105</tr>
106<tr>
107 <th>+</th>
108 <ti>One shot solution, no repeating emerges.</ti>
109</tr>
110<tr>
111 <th>-</th>
112 <ti>Might be a slightly older version than <c>alsa-driver</c>.</ti>
113</tr>
114</table>
115
116<p>
117And, if you were to use alsa-driver,
118</p>
119
120<table>
121<tr>
122 <th>alsa-driver</th>
123 <th>Pros and Cons</th>
124</tr>
125<tr>
126 <th>+</th>
127 <ti>Latest drivers from the ALSA Project.</ti>
128</tr>
129<tr>
130 <th>-</th>
131 <ti>Every kernel recompile requires a re-emerge of <c>alsa-driver</c>.</ti>
132</tr>
133<tr>
134 <th>-</th>
135 <ti>Needs certain kernel config options disabled to work correctly.</ti>
136</tr>
137</table>
138
139</body>
140</section>
141<section>
142<title>So...</title>
143<body>
144
145<p>
146The main difference between using <c>alsa-driver</c> and ALSA that comes with
147the kernel is that <c>alsa-driver</c> is generally more up to date than the
148version in the kernel. Since this does not make any huge difference as
149such, you are encouraged to use the ALSA provided by the kernel for ease of use.
150Before reporting any sound related issues to <uri
151link="https://bugs.gentoo.org">Gentoo Bugzilla</uri>, please try to reproduce
152them using <c>alsa-driver</c> and file the bug report no matter what the
153result.
154</p>
155
156</body>
157</section>
158<section id="lspci">
159<title>Before you proceed</title>
160<body>
161
162<p>
163Whichever method of install you choose, you need to know what drivers your
164sound card uses. In most cases, sound cards (onboard and otherwise) are PCI
165based and <c>lspci</c> will help you in digging out the required information.
166Please <c>emerge sys-apps/pciutils</c> to get <c>lspci</c>, if you don't have it
167installed already. In case you have a USB sound card, <c>lsusb</c> from
168<c>sys-apps/usbutils</c> <e>might</e> be of help. For ISA cards, try using
169<c>sys-apps/isapnptools</c>. Also, the following pages <e>may</e> help users
170with ISA based sound cards.
171</p>
172
173<ul>
174 <li>
175 <uri link="http://www.roestock.demon.co.uk/isapnptools/">The ISAPNPTOOLS
176 Page</uri>
177 </li>
178 <li>
179 <uri link="http://www2.linuxjournal.com/article/3269">LinuxJournal PnP
180 Article</uri>
181 </li>
182 <li>
183 <uri link="http://www.tldp.org/HOWTO/Sound-HOWTO/x320.html">TLDP Sound
184 HowTo</uri>
185 </li>
59</ul> 186</ul>
60There's lots more to ALSA however, like support for Full Duplex playback and recording, multiple soundcard support, 187
61hardware mixing of streams, extensive mixer capabilities (to support advanced features of new soundcards), ... 188<note>
189For ease of use/explanation, we assume the user has a PCI based sound card for
190the remainder of this guide.
191</note>
192
62</p> 193<p>
194We now proceed to find out details about the sound card.
195</p>
196
197<pre caption="Soundcard Details">
198# <i>lspci -v | grep -i audio</i>
1990000:00:0a.0 Multimedia audio controller: Creative Labs SB Live! EMU10k1 (rev 06)
200</pre>
201
202<p>
203We now know that the sound card on the machine is a Sound Blaster Live! and
204the card manufacturer is Creative Labs. Head over to the
205<uri link="http://www.alsa-project.org/alsa-doc/"> ALSA Soundcard Matrix</uri>
206page and select Creative Labs from the drop down menu. You will be taken to
207the Creative Labs matrix page where you can see that the SB Live! uses the
208<c>emu10k1</c> module. That is the information we need for now. If you are
209interested in detailed information, you can click on the link next to the
210"Details" and that will take you to the <c>emu10k1</c> specific page.
211</p>
212
63</body> 213</body>
64</section>
65<section> 214</section>
66 <title>Why use ALSA?</title> 215<section id="kernel">
67<body> 216<title>Using ALSA provided by your 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> 217<body>
80</section> 218
219<p>
220If you're a person who likes to keep things simple like I do, then this is
221the way to go.
222</p>
223
224<note>
225Since the 2005.0 release, Gentoo Linux uses 2.6 as the default kernel. Unless
226you are specifically using the 2.4 profile, <c>gentoo-sources</c> will be a
2272.6 kernel on <e>most</e> architectures. Please check that your kernel is a
2282.6 series kernel. This method will <e>not</e> work on a 2.4 kernel.
229</note>
230
231<p>
232Let us now configure the kernel to enable ALSA.
233</p>
234
235<impo>
236<c>genkernel</c> users should now run <c>genkernel --menuconfig all</c> and then follow
237the instructions in <uri link="#doc_chap2_pre3">Kernel Options for ALSA</uri>.
238</impo>
239
240<pre caption="Heading over to the source">
241# <i>cd /usr/src/linux</i>
242# <i>make menuconfig</i>
243</pre>
244
245<note>
246The above example assumes that <path>/usr/src/linux</path> symlink points to
247the kernel sources you want to use. Please ensure the same before proceeding.
248</note>
249
250<p>
251Now we will look at some of the options we will have to enable in the 2.6
252kernel to ensure proper ALSA support for our sound card.
253</p>
254
255<p>
256Please note that for the sake of ease, all examples show ALSA built as modules.
257It is advisable to follow the same as it then allows the use of <c>alsaconf</c>
258which is a boon when you want to configure your card. Please do <e>not</e> skip the <uri
259link="#alsa-config">Configuration</uri> section of this document. If you still
260like to have options built-in, ensure that you make changes to your config
261accordingly.
262</p>
263
264<pre caption="Kernel Options for ALSA">
265Device Drivers ---&gt;
266 Sound ---&gt;
267
268<comment>(This needs to be enabled)</comment>
269&lt;M&gt; Sound card support
270
271<comment>(Make sure OSS is disabled)</comment>
272Open Sound System ---&gt;
273 &lt; &gt; Open Sound System (DEPRECATED)
274
275<comment>(Move one step back and enter ALSA)</comment>
276Advanced Linux Sound Architecture ---&gt;
277 &lt;M&gt; Advanced Linux Sound Architecture
278 <comment>(Select this if you want MIDI sequencing and routing)</comment>
279 &lt;M&gt; Sequencer support
280 <comment>(Old style /dev/mixer* and /dev/dsp* support. Recommended.)</comment>
281 &lt;M&gt; OSS Mixer API
282 &lt;M&gt; OSS PCM (digital audio) API
283
284<comment>(You now have a choice of devices to enable support for. Generally,
285you will have one type of device and not more. If you have more than one
286sound card, please enable them all here.)</comment>
287
288<comment>(Mostly for testing and development purposes, not needed for normal
289users unless you know what you are doing.)</comment>
290Generic devices ---&gt;
291
292<comment>(For ISA Sound cards)</comment>
293ISA devices ---&gt;
294<comment>(IF you had the Gravis, you would select this option)</comment>
295 &lt;M&gt; Gravis UltraSound Extreme
296
297<comment>(Move one level back and into PCI devices. Most sound cards today are
298PCI devices)</comment>
299PCI devices ---&gt;
300 <comment>(We now select the emu10k1 driver for our card)</comment>
301 &lt;M&gt; Emu10k1 (SB Live!, Audigy, E-mu APS)
302 <comment>(Or an Intel card would be)</comment>
303 &lt;M&gt; Intel/SiS/nVidia/AMD/ALi AC97 Controller
304 <comment>(Or if you have a VIA Card)</comment>
305 &lt;M&gt; VIA 82C686A/B, 8233/8235 AC97 Controller
306
307<comment>(Move one level back and select in case you have an USB sound card)</comment>
308USB Devices ---&gt;
309</pre>
310
311<p>
312Now that your options are set, you can (re)compile the kernel and ALSA support
313for your card should be functional once you reboot into the new kernel.
314You can now proceed to <uri link="#alsa-utilities">ALSA Utilities</uri> and
315see if everything is working as it should.
316</p>
317
318</body>
81<section> 319</section>
82 <title>What cards does ALSA support?</title> 320<section id="alsa-driver">
321<title>Using the ALSA Driver package</title>
83<body> 322<body>
84<p> 323
85ALSA tries to support as many (new) cards as possible by providing open-source drivers.
86However, some vendors may provide binary-only packages.
87</p> 324<p>
88<p>To know if your card is supported, you can find a Soundcard Matrix of supported and not-supported cards here: 325So you've decided to go the <c>alsa-driver</c> way. Let's get started then.
89<uri>http://www.alsa-project.org/alsa-doc/</uri>. 326There are a few minor things to be done to ensure only the drivers for your
327sound card are compiled. Although this is not really necessary, it cuts down
328on the unnecessary drivers that will be compiled otherwise.
329</p>
330
90</p> 331<p>
332If you don't have an idea of what drivers your sound card might need, please
333take a look at the <uri link="#lspci">lspci</uri> section of this guide. Once
334you have your driver name (<c>emu10k1</c> in our example), edit
335<path>/etc/make.conf</path> and add a variable, <c>ALSA_CARDS</c>.
336</p>
337
338<pre caption="Adding ALSA_CARDS to make.conf">
339<comment>(For one sound card)</comment>
340ALSA_CARDS="emu10k1"
341<comment>(For more than one, separate names with spaces)</comment>
342ALSA_CARDS="emu10k1 via82xx"
343</pre>
344
345<p>
346If you have compiled your kernel and want to use <c>alsa-driver</c>, please
347ensure the following before proceeding, else <c>alsa-driver</c> is likely to
348fail. The next code listing gives you one way of performing the checks.
349</p>
350
351<note>
352<c>genkernel</c> users can proceed with <uri link="#doc_chap2_pre6">Installing
353alsa-driver</uri> as their configuration is in sync with the one shown below by
354default.
355</note>
356
357<ol>
358 <li>
359 <c>CONFIG_SOUND</c> is set. (Basic Sound support enabled)
360 </li>
361 <li>
362 <c>CONFIG_SOUND_PRIME</c> is not set. (In-built OSS support disabled)
363 </li>
364 <li>
365 <c>CONFIG_SND</c> is not set. (In-built ALSA support disabled)
366 </li>
367 <li>
368 <path>/usr/src/linux</path> points to the kernel you want ALSA working on.
369 </li>
370</ol>
371
372<pre caption=".config checks">
373<comment>(Assuming the linux symlink points to the correct kernel)</comment>
374# <i>cd /usr/src/linux</i>
375# <i>grep SOUND .config</i>
376<comment>(1. is true)</comment>
377CONFIG_SOUND=y
378<comment>(2. is true)</comment>
379CONFIG_SOUND_PRIME is not set
380# <i>grep SND .config</i>
381<comment>(and 3. is true)</comment>
382CONFIG_SND is not set
383</pre>
384
385<p>
386Now all you have to do is type the magic words... and no, it's not abracadabra.
387</p>
388
389<pre caption="Installing alsa-driver">
390# <i>emerge alsa-driver</i>
391</pre>
392
393<impo>
394Please note that you will have to run <c>emerge alsa-driver</c> after every
395kernel (re)compile, as the earlier drivers are deleted.
396</impo>
397
91</body> 398</body>
92</section> 399</section>
93</chapter> 400</chapter>
94 401
95<chapter> 402<chapter>
96<title>Installation</title> 403<title>Configuring/Testing ALSA</title>
97<section> 404<section id="alsa-utilities">
98<title>Gentoo USE flags</title> 405<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> 406<body>
109</section>
110 407
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> 408<p>
409<c>alsa-utils</c> forms an integral part of ALSA as it has a truckload of
410programs that are highly useful, including the ALSA Initscripts. Hence we
411strongly recommend that you install <c>alsa-utils</c>
117<p> 412</p>
118First we'll make sure that our kernel configuration is ready for use with ALSA. 413
119All you need in your kernel configuration is having Sound Card Support set to be built as a module (M). 414<pre caption="Install alsa-utils">
120This will build <c>soundcore.o</c>. 415# <i>emerge alsa-utils</i>
121</p> 416</pre>
122<p> 417
123<note> 418<note>
124Possibly, this will also work when you built Sound Card Support in the kernel (Y) instead of building it as a module (M). 419If you activated ALSA in your <uri link="#kernel">kernel</uri> <e>and</e> did
125However, the official ALSA documentation suggests building it as a module, since ALSA will try loading it. 420not compile ALSA as modules, please proceed to the
421<uri link="#initscript">ALSA Initscript</uri> section. The rest of you need
422to configure ALSA. This is made very easy by the existence of the
423<c>alsaconf</c> tool provided by <c>alsa-utils</c>.
126</note> 424</note>
425
426</body>
427</section>
428<section id="alsa-config">
429<title>Configuration</title>
430<body>
431
432<note>
433Please shut down any programs that <e>might</e> access the sound card while
434running <c>alsaconf</c>.
435</note>
436
127</p> 437<p>
128<p>If you already have a working kernel configuration, make sure you remove all sound drivers (except for Sound Card Support). 438The easiest way to configure your sound card is to run <c>alsaconf</c>. Just
129If you wish to do this without having to reboot, you could do like this: 439type <c>alsaconf</c> in a shell as root.
130</p> 440</p>
441
442<pre caption="Invoking alsaconf">
443# <i>alsaconf</i>
131<pre> 444</pre>
132# <i>cd /usr/src/linux</i> 445
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> 446<p>
447You will now see a neat menu guided interface that will automatically probe
448your devices and try to find out your sound card. You will be asked to pick
449your sound card from a list. Once that's done, it will ask you permission to
450automatically make required changes to <path>/etc/modules.d/alsa</path>.
451It will then adjust your volume settings to optimum levels, run
452<c>modules-update</c> and start the <path>/etc/init.d/alsasound</path> service.
453Once <c>alsaconf</c> exits, you can proceed with setting up the ALSA initscript.
454</p>
455
456</body>
457</section>
458<section id="initscript">
459<title>ALSA Initscript</title>
460<body>
461
462<p>
463We're now almost all setup. Whichever method you chose to install ALSA, you'll
464need to have something load your modules or initialize ALSA and restore your
465volume settings when your system comes up. The ALSA Initscript handles all of
466this for you and is called <c>alsasound</c>. Add it to the boot runlevel.
467</p>
468
469<pre caption="Adding ALSA to the boot runlevel">
470# <i>rc-update add alsasound boot</i>
471 * alsasound added to runlevel boot
472 * rc-update complete.
143<pre> 473</pre>
144# <i>make dep clean</i> 474
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> 475<p>
476Next, just check the <path>/etc/conf.d/alsasound</path> file and ensure that
477SAVE_ON_STOP variable is set to yes. This saves your sound settings when you
478shutdown your system.
151<p> 479</p>
480
481</body>
482</section>
483<section>
484<title>Audio Group</title>
485<body>
486
487<p>
488Before we move on to testing, there's one last <e>important</e> thing that needs
489to be setup. Rule of thumb in a *nix OS : Do not run as root unless needed.
490This applies here as well ;) How? Well, most of the times you should be logged
491in as a user and would like to listen to music or access your soundcard. For
492that to happen, you need to be in the "audio" group. At this point, we'll add
493users to the audio group, so that they won't have any issues when they want to
494access sound devices. We'll use <c>gpasswd</c> here and you need to be logged in
495as root for this to work.
496</p>
497
498<pre caption="Adding users to the audio group">
499<comment>(Substitute &lt;username&gt; with your user)</comment>
500# <i>gpasswd -a &lt;username&gt; audio </i>
501Adding user &lt;username&gt; to group audio
502</pre>
503
504</body>
505</section>
506<section>
507<title>Volume Check!</title>
508<body>
509
510<p>
511We've completed all the setups and pre-requisites, so let's fire up ALSA. If
512you ran <c>alsaconf</c>, you can skip this step, since <c>alsaconf</c> already
513does this for you.
514</p>
515
516<pre caption="Start the service">
517<comment>(ALSA as modules)</comment>
518# <i>/etc/init.d/alsasound start</i>
519 * Loading ALSA modules ...
520 * Loading: snd-card-0 ... [ ok ]
521 * Loading: snd-pcm-oss ... [ ok ]
522 * Loading: snd-seq ... [ ok ]
523 * Loading: snd-emu10k1-synth ... [ ok ]
524 * Loading: snd-seq-midi ... [ ok ]
525 * Restoring Mixer Levels ... [ ok ]
526<comment>(ALSA compiled in)</comment>
527# <i>/etc/init.d/alsasound start</i>
528 * Loading ALSA modules ...
529 * Restoring Mixer Levels ... [ ok ]
530</pre>
531
532<p>
533Now that the required things have been taken care of, we need to check up on
534the volume as in certain cases, it is muted. We use <c>alsamixer</c> for this
535purpose.
536</p>
537
538<pre caption="Starting alsamixer">
539<comment>(Opens up a console program. Only required settings are shown)</comment>
540# <i>alsamixer</i>
541</pre>
542
152<impo> 543<impo>
153This means, whenever you recompile your kernel later on, you MUST recompile <c>alsa-driver</c>. 544If you have issues starting up <c>alsamixer</c> and get errors such as
545alsamixer: function snd_ctl_open failed for default: No such file or directory,
546this is usually an issue with udev setting up the devices. Run <c>killall
547udevd; udevstart</c> to reload <path>/dev</path> entries and fire up
548<c>alsamixer</c>. It should solve the issue.
154</impo> 549</impo>
550
155</p> 551<p>
552This is how the ALSA Mixer <e>might</e> look the first time you open it. Pay
553attention to the Master and PCM channels which both have an MM below them.
554That means they are muted. If you try to play anything with <c>alsamixer</c>
555in this state, you will not hear anything on your speakers.
156<p> 556</p>
157<note>However, there's no need to reinstall <c>nvidia-kernel</c>, the Nvidia drivers are in a separate directory 557
158in <path>/lib/modules/*/video</path> and won't get deleted by a <c>make modules modules_install</c> 558<figure link="/images/docs/alsa-mixermuted.png" short="AlsaMixer Muted" caption="The Alsa Mixer Main Window, Muted"/>
559
560<p>
561Now, we shall unmute the channels, and set volume levels as needed.
562</p>
563
564<warn>
565Both Master <e>and</e> PCM need to be unmuted and set to audible volume levels
566if you want to hear some output on your speakers.
567</warn>
568
569<ul>
570 <li>
571 To move between channels, use your left and right arrow keys. (&lt;-
572 &amp; -&gt;)
573 </li>
574 <li>
575 To toggle mute, move to the specific channel, for example Master and press
576 the <e>m</e> key on the keyboard.
577 </li>
578 <li>
579 To increase and decrease the volume levels, use the up and down arrow keys
580 respectively.
581 </li>
582</ul>
583
584<note>
585Be careful when setting your Bass and Treble values. 50 is usually a good
586number for both. Extremely high values of Bass may cause <e>jarring</e>
587on speakers that are not designed to handle them.
159</note> 588</note>
589
160</p> 590<p>
161</body> 591After you're all done, your ALSA Mixer should look similar to the one below.
162</section> 592Note the 00 instead of the MM and also the volume levels for some optimum
593settings.
594</p>
163 595
596<figure link="/images/docs/alsa-mixerunmuted.png" short="AlsaMixer Unmuted" caption="Alsa Mixer ready to roll"/>
597
598</body>
164<section> 599</section>
165 <title>ALSA modules</title> 600<section>
601<title>Sound Check!</title>
166<body> 602<body>
167 603
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> 604<p>
605The irritating way to check your soundcard is to see if you can hear static on
606the speakers. This isn't exactly fun, but hey, it tells you the card is
607configured and working.
608</p>
609
610<pre caption="Bring on the static">
611# <i>cat /dev/urandom > /dev/dsp</i>
172<pre> 612</pre>
173# <i>grep audio /proc/pci</i>
174</pre>
175 613
176
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>
183
184<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
194<pre>
195# <i>env ALSA_CARDS='emu10k1' emerge alsa-driver</i>
196</pre>
197<note> 614<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>. 615<path>/dev/dsp</path> is a symlink to <path>/dev/sound/dsp</path> and should be
199For example, like this: <c>echo 'ALSA_CARDS="emu10k1"' >> /etc/make.conf</c> 616automatically created. Try re-directing the output to
617<path>/dev/sound/dsp</path> in case you don't get a "No such file or directory"
618error.
200</note> 619</note>
201 620
621<p>
622You should hear static. Press <c>Ctrl + C</c> to stop. If you don't hear
623anything, now is a good time to go back and check/trace out the issue and
624rectify it.
625</p>
626
627<p>
628Finally. Some music. If everything above is perfect, you should now be able to
629listen to some good music. A quick way to test is to use a command line tool
630like <c>media-sound/madplay</c>. You could also use something more well known
631like <c>mpg123</c> or <c>xmms</c>. If you are an ogg fan, you could use
632<c>ogg123</c> provided by <c>media-sound/vorbis-tools</c>. Use any player you
633are comfortable with. As always, <c>emerge</c> what you need.
634</p>
635
636<pre caption="Getting the software">
637<comment>(Install the applications you want)</comment>
638# <i>emerge madplay mpg123 xmms</i>
639<comment>(To play .ogg files)</comment>
640# <i>emerge vorbis-tools</i>
641</pre>
642
643<p>
644And then play your favorite sound track...
645</p>
646
647<pre caption="Playing Music">
648# <i>madplay -v /mnt/shyam/Music/Paul\ Oakenfold\ -\ Dread\ Rock.mp3</i>
649MPEG Audio Decoder 0.15.2 (beta) - Copyright (C) 2000-2004 Robert Leslie et al.
650 Title: Dread Rock
651 Artist: Paul Oakenfold
652 Album: Matrix Reloaded
653 Year: 2003
654 Genre: Soundtrack
655 Soundtrack
656 00:04:19 Layer III, 160 kbps, 44100 Hz, joint stereo (MS), no CRC
657
658# <i>ogg123 Paul\ Oakenfold\ -\ Dread\ Rock.ogg</i>
659Audio Device: Advanced Linux Sound Architecture (ALSA) output
660
661Playing: Paul Oakenfold - Dread Rock.ogg
662Ogg Vorbis stream: 2 channel, 44100 Hz
663Genre: Soundtrack
664Transcoded: mp3;160
665Title: Dread Rock
666Artist: Paul Oakenfold
667Date: 2003
668Album: Matrix Reloaded
669Time: 00:11.31 [04:28.75] of 04:40.06 (200.6 kbps) Output Buffer 96.9%
670</pre>
671
672</body>
673</section>
674<section>
675<title>ALSA and USE</title>
676<body>
677
678<p>
679You can now add the <c>alsa</c> use flag to <path>/etc/make.conf</path> to
680ensure that your applications that support ALSA get built with it. Some
681architectures like x86 and amd64 have the flag enabled by default.
682</p>
683
684</body>
685</section>
686<section>
687<title>Issues?</title>
688<body>
689
690<p>
691If for some reason you're unable to hear sound, the first thing to do would
692be to check your <uri link="#doc_chap3_pre6">alsamixer</uri> settings. 80% of
693the issues lie with muted channels or low volume. Also check your Window
694Manager's sound applet and verify that volumes are set to audible levels.
695</p>
696
697<p>
698<path>/proc</path> is your friend. And in this case, <path>/proc/asound</path>
699is your best friend. We shall just take a short look at how much info is made
700available to us there.
701</p>
702
703<pre caption="Fun with /proc/asound">
704<comment>(First and foremost, if /proc/asound/cards shows your card, ALSA has
705picked up your sound card fine.)</comment>
706# <i>cat /proc/asound/cards</i>
7070 [Live ]: EMU10K1 - Sound Blaster Live!
708 Sound Blaster Live! (rev.6, serial:0x80271102) at 0xb800, irq 11
709
710<comment>(If you run ALSA off the kernel like I do and wonder how far behind
711you are from alsa-driver, this displays current running ALSA version)</comment>
712# <i>cat /proc/asound/version</i>
713Advanced Linux Sound Architecture Driver Version 1.0.8 (Thu Jan 13 09:39:32 2005 UTC).
714
715<comment>(ALSA OSS emulation details)</comment>
716# <i>cat /proc/asound/oss/sndstat</i>
717Sound Driver:3.8.1a-980706 (ALSA v1.0.8 emulation code)
718Kernel: Linux airwolf.zion 2.6.11ac1 #2 Wed May 4 00:35:08 IST 2005 i686
719Config options: 0
720
721Installed drivers:
722Type 10: ALSA emulation
723
724Card config:
725Sound Blaster Live! (rev.6, serial:0x80271102) at 0xb800, irq 11
726
727Audio devices:
7280: EMU10K1 (DUPLEX)
729
730Synth devices: NOT ENABLED IN CONFIG
731
732Midi devices:
7330: EMU10K1 MPU-401 (UART)
734
735Timers:
7367: system timer
737
738Mixers:
7390: SigmaTel STAC9721/23
740</pre>
741
742</body>
743</section>
744</chapter>
745
746<chapter>
747<title>Other things ALSA</title>
748<section>
749<title>Setting up MIDI support</title>
750<body>
751
752<p>
753If your sound card is one of those that come with on-board MIDI synthesizers
754and you would like to listen to some .mid files, you have to install
755<c>awesfx</c> which is basically a set of utilities for controlling the AWE32
756driver. We need to install it first. If you don't have a hardware synthesizer,
757you can use a virtual one. Please see the section on
758<uri link="#vsynth">Virtual Synthesizers</uri> for more information.
759</p>
760
761<pre caption="Installing awesfx">
762# <i>emerge awesfx</i>
763</pre>
764
202<note> 765<note>
203When you want to install ALSA drivers for more than one soundcard, you could set ALSA_CARDS to a space-separated list 766You will need to copy over SoundFont (SF2) files from your sound card's driver
204of drivers; like this: <c>env ALSA_CARDS='emu10k1 intel8x0 ens1370' emerge alsa-driver</c> 767CD or a Windows installation into <path>/usr/share/sounds/sf2/</path>. For
768example a sound font file for the Creative SBLive! card would be 8MBGMSFX.SF2.
205</note> 769</note>
206 770
207<note>If you want to have OSS compatibility, make sure to emerge <i>alsa-oss</i>, it is the ALSA/OSS compatibility
208wrapper. </note>
209
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> 771<p>
219</body> 772After copying over the Soundfont files, we can then play a midi file as shown.
220</section> 773You can also add the <c>asfxload</c> command to
221<section> 774<path>/etc/conf.d/local.start</path>, so that the sound font is loaded
222 <title>Configuration of ALSA</title> 775every time the system starts up.
223<body>
224<p> 776</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>
228 777
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> 778<note>
269If you have more than one soundcard, adjust the <c>cards_limit</c> value and add more snd-card aliases to the file. 779<path>/mnt</path> paths mentioned in the code listing(s) below will <e>not</e>
270I don't have experience with this, but you can find examples for configurations with two or more soundcards in 780be the same in your machine. They are just an example. Please be careful to
271<uri link="http://www.alsa-project.org/alsa-doc/alsa-howto/c1660.htm">Chapter 6</uri> 781change the path to suit your machine.
272of the <uri link="http://www.alsa-project.org/alsa-doc/alsa-howto/alsa-howto.html">ALSA Howto</uri>.
273</note> 782</note>
274<p> 783
275Last thing to do in this file, almost at the end, check if these lines are there and uncommented: 784<pre caption="Loading Soundfonts">
276</p> 785<comment>(First, copy the Soundfont)</comment>
277<pre caption="Near the end of /etc/modules.d/alsa"> 786# <i>cp /mnt/win2k/Program\ Files/CreativeSBLive2k/SFBank/8MBGMSFX.SF2 /usr/share/sounds/sf2/</i>
278alias /dev/mixer snd-mixer-oss 787<comment>(We load the specific Soundfont)</comment>
279alias /dev/dsp snd-pcm-oss 788# <i>asfxload /usr/share/sounds/sf2/8MBGMSFX.SF2</i>
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> 789</pre>
285# <i>modules-update</i> 790
286</pre>
287</p> 791<p>
288<note> 792You can now play midi files using a program like <c>aplaymidi</c>. Run
289Running <c>modules-update</c> here will insert the data from <path>/etc/modules.d/alsa</path> into <path>/etc/modules.conf</path> 793<c>aplaymidi -l</c> to get a list of available ports and then pick one
290</note> 794to play the file on.
291<p> 795</p>
292You should also verify that /etc/devfsd.conf has the alsa devices and permissions correctly registered. 796
797<pre caption="Playing MIDI">
798<comment>(Check open ports)</comment>
799# <i>aplaymidi -l</i>
800 Port Client name Port name
801 64:0 EMU10K1 MPU-401 (UART) EMU10K1 MPU-401 (UART)
802 65:0 Emu10k1 WaveTable Emu10k1 Port 0
803 65:1 Emu10k1 WaveTable Emu10k1 Port 1
804 65:2 Emu10k1 WaveTable Emu10k1 Port 2
805 65:3 Emu10k1 WaveTable Emu10k1 Port 3
806<comment>(Pick a port, and play a mid file)</comment>
807# <i> aplaymidi --port=65:0 /mnt/shyam/music/midi/mi2.mid</i>
293</p> 808</pre>
294<pre caption="/etc/devfsd.conf"> 809
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> 810</body>
309</section>
310</chapter>
311<chapter>
312<title>Starting ALSA</title>
313<section> 811</section>
314 <title>Adding alsasound to a runlevel</title> 812<section id="vsynth">
315<body> 813<title>Virtual Synthesizers</title>
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> 814<body>
326</section> 815
816<p>
817If your sound card lacks a hardware synthesizer, you could use a virtual one
818like <c>timidity++</c>. Installation is a breeze.
819</p>
820
821<pre caption="Installing timidity++">
822# <i>emerge timidity++</i>
823</pre>
824
825<p>
826For timidity to play sounds, it needs a sound font. If you do not have any,
827install <c>timidity-eawpatches</c> or <c>timidity-shompatches</c> which will
828give you some sound fonts. You can have multiple sound font configurations
829installed, and you can place your own in <path>/usr/share/timidity/</path>.
830To switch between different timidity configurations, you should use the
831<c>timidity-update</c> tool provided in the timidity++ package.
832</p>
833
834<pre caption="Installing sound fonts">
835# <i>emerge timidity-eawpatches</i>
836# <i>timidity-update -g -s eawpatches</i>
837
838<comment>(or)</comment>
839
840# <i>emerge timidity-shompatches</i>
841# <i>timidity-update -g -s shompatches</i>
842</pre>
843
844<p>
845Don't forget to add <c>timidity</c> to the default runlevel.
846</p>
847
848<pre caption="Adding timidity to the default runlevel">
849# <i>rc-update add timidity default</i>
850# <i>/etc/init.d/timidity start</i>
851</pre>
852
853<p>
854You can now try out <uri link="#doc_chap4_pre3">Playing MIDI</uri> files.
855</p>
856
857</body>
327<section> 858</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> 859<section>
378</chapter> 860<title>Tools and Firmware</title>
379<chapter> 861<body>
380<title>Final Notes</title> 862
863<p>
864Some specific sound cards can benefit from certain tools provided by the
865<c>alsa-tools</c> and <c>alsa-firmware</c> packages. If you need
866<c>alsa-tools</c>, be sure to define the ALSA_TOOLS variable in
867<path>/etc/make.conf</path> with the tools you require. For instance:
868</p>
869
870<pre caption="Selecting ALSA Tools in /etc/make.conf">
871ALSA_TOOLS="as10k1 ac3dec"
872</pre>
873
874<p>
875If the ALSA_TOOLS variable is not set, all available tools will be built.
876Now, install the <c>alsa-tools</c> (and/or <c>alsa-firmware</c>) package(s):
877</p>
878
879<pre caption="Installing ALSA Tools">
880# <i>emerge alsa-tools</i>
881</pre>
882
883</body>
381<section> 884</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> 885<section>
886<title>A Big thank you to...</title>
887<body>
888
889<p>
890Everyone who contributed to the earlier version of the Gentoo ALSA Guide:
891Vincent Verleye, Grant Goodyear, Arcady Genkin, Jeremy Huddleston,
892John P. Davis, Sven Vermeulen, Benny Chuang, Tiemo Kieft and Erwin.
893</p>
894
895</body>
393<section> 896</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> 897<section>
402 898<title>References</title>
403<section>
404<title>Known bugs</title>
405<body> 899<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>
411 900
412<ul> 901<ul>
413<li> 902 <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 903 <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> 904</ul>
419 905
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> 906</body>
440</section> 907</section>
441</chapter> 908</chapter>
442</guide> 909</guide>

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