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1<?xml version='1.0' encoding="UTF-8"?> 1<?xml version='1.0' encoding="UTF-8"?>
2<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/alsa-guide.xml,v 1.21 2003/11/23 16:30:50 swift Exp $ --> 2
3<!DOCTYPE guide SYSTEM "/dtd/guide.dtd"> 3<!DOCTYPE guide SYSTEM "/dtd/guide.dtd">
4 4
5<guide link = "/doc/en/alsa-guide.xml"> 5<guide link="/doc/en/alsa-guide.xml">
6<title>Gentoo Linux ALSA Guide</title> 6<title>Gentoo Linux ALSA Guide</title>
7
7<author title="Author"> 8<author title="Author">
8 <mail link="zu@pandora.be">Vincent Verleye</mail> 9 <mail link="fox2mike@gmail.com">Shyam Mani</mail>
9</author> 10</author>
10<author title="Author">
11 <mail link="g2boojum@gentoo.org">Grant Goodyear</mail>
12</author>
13<author title="Author">
14 <mail link="agenkin@gentoo.org">Arcady Genkin</mail>
15</author>
16<author title="Editor"><!-- zhen@gentoo.org -->
17 John P. Davis
18</author>
19<author title="Editor">
20 <mail link="swift@gentoo.org">Sven Vermeulen</mail>
21</author>
22<author title="Editor">
23 <mail link="bennyc@gentoo.org">Benny Chuang</mail>
24</author>
25<author title="Editor">
26 <mail link="blubber@gentoo.org">Tiemo Kieft</mail>
27</author>
28 11
12<abstract>
13This document helps a user setup ALSA on Gentoo Linux.
14</abstract>
15
16<!-- The content of this document is licensed under the CC-BY-SA license -->
17<!-- See http://creativecommons.org/licenses/by-sa/2.0 -->
29<license/> 18<license/>
30 19
31<abstract>
32This guide will show you how to set up the Advanced Linux Sound Architecture
33(ALSA) on Gentoo Linux. In addition to the Gentoo Linux Desktop Configuration
34Guide, this guide is supposed to give you more information on this subject.
35</abstract>
36
37<version>1.3.4</version> 20<version>2.0</version>
38<date>November 23, 2003</date> 21<date>2005-06-07</date>
39 22
40<chapter> 23<chapter>
41<title>Introduction</title> 24<title>Introduction</title>
42<section> 25<section>
43<title>What is ALSA?</title> 26<title>What is ALSA?</title>
44<body> 27<body>
45 28
46<p> 29<p>
47The Advanced Linux Sound Architecture (ALSA) is a project to improve the Linux 30ALSA, which stands for <e>Advanced Linux Sound Architecture</e>, provides
48sound subsystem by rewriting large chunks of it. It is anticipated that ALSA 31audio and MIDI (<e>Musical Instrument Digital Interface</e>) functionality to
49will make it into Linux kernel 2.6.x (or 3.x.x -- whichever comes first) as it 32the Linux operating system. ALSA is the default sound subsystem in the 2.6
50becomes ready. 33kernel thereby replacing OSS (<e>Open Sound System</e>), which was used in the
51</p> 342.4 kernels.
52
53<p> 35</p>
54ALSA provides audio and MIDI functionality for Linux. 36
55</p> 37<p>
56 38ALSA's main features include efficient support for all types of audio
39interfaces ranging from consumer sound cards to professional sound
40equipment, fully modularized drivers, SMP and thread safety, backward
41compatibility with OSS and a user-space library <c>alsa-lib</c> to make
42application development a breeze.
57<p> 43</p>
58Quoted from <uri>http://www.alsa-project.org</uri>, ALSA has the following 44
59features: 45</body>
46</section>
47<section>
48<title>ALSA on Gentoo</title>
49<body>
50
60</p> 51<p>
52One of Gentoo's main strengths lies in giving the user maximum control over
53how a system is installed/configured. ALSA on Gentoo follows the same
54principle. There are two ways you can get ALSA support up and running on your
55system. We shall look at them in detail in the next chapter.
56</p>
57
58</body>
59</section>
60</chapter>
61
62<chapter>
63<title>Installing ALSA</title>
64<section>
65<title>Options</title>
66<body>
67
68<warn>
69The methods shown below are mutually exclusive. You cannot have ALSA compiled
70in your kernel and use <c>media-sound/alsa-driver</c>. It <e>will</e> fail.
71</warn>
72
73<impo>
74<c>genkernel</c> users have their config built such a way that the ALSA
75sub-system in the kernel is active. Therefore <c>genkernel</c> users can
76proceed to the <uri link="#alsa-utilities">ALSA Utilities</uri> section
77directly.
78</impo>
79
80<p>
81The two options are :
82</p>
83
84<ol>
85 <li>
86 Use ALSA provided by your kernel. This is the preferred/recommended
87 method.
88 </li>
89 <li>
90 Use Gentoo's <c>media-sound/alsa-driver</c> package.
91 </li>
92</ol>
93
94<p>
95We shall take a peek into both before finally deciding on one.
96</p>
97
98<p>
99If you were to use ALSA provided by the kernel, the following are the pros and
100cons :
101</p>
102
103<table>
104<tr>
105 <th>Kernel ALSA</th>
106 <th>Pros and Cons</th>
107</tr>
108<tr>
109 <th>+</th>
110 <ti>Pretty stable as drivers are integrated into kernel.</ti>
111</tr>
112<tr>
113 <th>+</th>
114 <ti>One shot solution, no repeating emerges.</ti>
115</tr>
116<tr>
117 <th>-</th>
118 <ti>Might be a slightly older version than <c>alsa-driver</c>.</ti>
119</tr>
120</table>
121
122<p>
123And, if you were to use alsa-driver,
124</p>
125
126<table>
127<tr>
128 <th>alsa-driver</th>
129 <th>Pros and Cons</th>
130</tr>
131<tr>
132 <th>+</th>
133 <ti>Latest drivers from the ALSA Project.</ti>
134</tr>
135<tr>
136 <th>-</th>
137 <ti>Every kernel recompile requires a re-emerge of <c>alsa-driver</c>.</ti>
138</tr>
139<tr>
140 <th>-</th>
141 <ti>Needs certain kernel config options disabled to work correctly.</ti>
142</tr>
143</table>
144
145</body>
146</section>
147<section>
148<title>So...</title>
149<body>
150
151<p>
152The main difference between using <c>alsa-driver</c> and ALSA that comes with
153the kernel is that <c>alsa-driver</c> is generally more up to date than the
154version in the kernel. Since this does not make any huge difference as
155such, you are encouraged to use the ALSA provided by the kernel.
156</p>
157
158</body>
159</section>
160<section id="lspci">
161<title>Before you proceed</title>
162<body>
163
164<p>
165Whichever method of install you choose, you need to know what drivers your
166sound card uses. <c>lspci</c> will help you in digging out the required
167information. Please <c>emerge sys-apps/pciutils</c> to get <c>lspci</c>, if
168you don't have it installed already. We now proceed to find out details about
169the sound card.
170</p>
171
172<pre caption="Soundcard Details">
173# <i>lspci -v | grep -i audio</i>
1740000:00:0a.0 Multimedia audio controller: Creative Labs SB Live! EMU10k1 (rev 06)
175</pre>
176
177<p>
178We now know that the sound card on the machine is a Sound Blaster Live! and
179the card manufacturer is Creative Labs. Head over to the
180<uri link="http://www.alsa-project.org/alsa-doc/"> ALSA Soundcard Matrix</uri>
181page and select Creative Labs from the drop down menu. You will be taken to
182the Creative Labs matrix page where you can see that the SB Live! uses the
183<c>emu10k1</c> module. That is the information we need for now. If you are
184interested in detailed information, you can click on the link next to the
185"Details" and that will take you to the <c>emu10k1</c> specific page.
186</p>
187
188</body>
189</section>
190<section id="kernel">
191<title>Using ALSA provided by your Kernel</title>
192<body>
193
194<p>
195If you're a person who likes to keep things simple like I do, then this is
196the way to go.
197</p>
198
199<note>
200Since the 2005.0 release, Gentoo Linux uses 2.6 as the default kernel. Unless
201you are specifically using the 2.4 profile, <c>gentoo-sources</c> will be a
2022.6 kernel on <e>most</e> architectures. Please check that your kernel is a
2032.6 series kernel. This method will <e>not</e> work on a 2.4 kernel.
204</note>
205
206<p>
207Let us now configure the kernel to enable ALSA.
208</p>
209
210<pre caption="Heading over to the source">
211# <i>cd /usr/src/linux</i>
212# <i>make menuconfig</i>
213</pre>
214
215<note>
216The above example assumes that <path>/usr/src/linux</path> symlink points to
217the kernel sources you want to use. Please ensure the same before proceeding.
218</note>
219
220<p>
221Now we will look at some of the options we will have to enable in the 2.6
222kernel to ensure proper ALSA support for our sound card.
223</p>
224
225<note>
226Please note that for the sake of ease, all examples show a modular kernel. It
227is advisable to follow the same. Please do <e>not</e> skip the
228<uri link="#alsa-config">Configuration</uri> section of this document. If
229you still like to have options built-in, ensure that you make changes to your
230config accordingly.
231</note>
232
233<pre caption="Kernel Options for ALSA">
234Device Drivers ---&gt;
235 Sound ---&gt;
236
237<comment>(This needs to be enabled)</comment>
238&lt;M&gt; Sound card support
239
240<comment>(Make sure OSS is disabled)</comment>
241Open Sound System ---&gt;
242 &lt; &gt; Open Sound System (DEPRECATED)
243
244<comment>(Move one step back and enter ALSA)</comment>
245Advanced Linux Sound Architecture ---&gt;
246 &lt;M&gt; Advanced Linux Sound Architecture
247 <comment>(Select this if you want MIDI sequencing and routing)</comment>
248 &lt;M&gt; Sequencer support
249 <comment>(Old style /dev/mixer* and /dev/dsp* support. Recommended.)</comment>
250 &lt;M&gt; OSS Mixer API
251 &lt;M&gt; OSS PCM (digital audio) API
252
253<comment>(You now have a choice of devices to enable support for. Generally,
254you will have one type of device and not more. If you have more than one
255sound card, please enable them all here.)</comment>
256
257<comment>(Mostly for testing and development purposes, not needed for normal
258users unless you know what you are doing.)</comment>
259Generic devices ---&gt;
260
261<comment>(For ISA Sound cards)</comment>
262ISA devices ---&gt;
263<comment>(IF you had the Gravis, you would select this option)</comment>
264 &lt;M&gt; Gravis UltraSound Extreme
265
266<comment>(Move one level back and into PCI devices. Most sound cards today are
267PCI devices)</comment>
268PCI devices ---&gt;
269 <comment>(We now select the emu10k1 driver for our card)</comment>
270 &lt;M&gt; Emu10k1 (SB Live!, Audigy, E-mu APS)
271 <comment>(Or an Intel card would be)</comment>
272 &lt;M&gt; Intel/SiS/nVidia/AMD/ALi AC97 Controller
273 <comment>(Or if you have a VIA Card)</comment>
274 &lt;M&gt; VIA 82C686A/B, 8233/8235 AC97 Controller
275
276<comment>(Move one level back and select in case you have an USB sound card)</comment>
277USB Devices ---&gt;
278</pre>
279
280<p>
281Now that your options are set, you can (re)compile the kernel and ALSA support
282for your card should be functional once you reboot into the new kernel.
283You can now proceed to <uri link="#alsa-utilities">ALSA Utilities</uri> and
284see if everything is working as it should.
285</p>
286
287</body>
288</section>
289<section id="alsa-driver">
290<title>Using the ALSA Driver package</title>
291<body>
292
293<p>
294So you've decided to go the <c>alsa-driver</c> way. Let's get started then.
295There are a few minor things to be done to ensure only the drivers for your
296sound card are compiled. Although this is not really necessary, it cuts down
297on the unnecessary drivers that will be compiled otherwise.
298</p>
299
300<p>
301If you don't have an idea of what drivers your sound card might need, please
302take a look at the <uri link="#lspci">lspci</uri> section of this guide. Once
303you have your driver name (<c>emu10k1</c> in our example), edit
304<path>/etc/make.conf</path> and add a variable, <c>ALSA_CARDS</c>.
305</p>
306
307<pre caption="Adding ALSA_CARDS to make.conf">
308<comment>(For one sound card)</comment>
309ALSA_CARDS="emu10k1"
310<comment>(For more than one, seperate names with spaces)</comment>
311ALSA_CARDS="emu10k1 via82xx"
312</pre>
313
314<p>
315If you have compiled your kernel and want to use <c>alsa-driver</c>, please
316ensure the following before proceeding, else <c>alsa-driver</c> is likely to
317fail. The next code listing gives you one way of performing the checks.
318</p>
319
320<ol>
321 <li>
322 <c>CONFIG_SOUND</c> is set. (Basic Sound support enabled)
323 </li>
324 <li>
325 <c>CONFIG_SOUND_PRIME</c> is not set. (In-built OSS support disabled)
326 </li>
327 <li>
328 <c>CONFIG_SND</c> is not set. (In-built ALSA support disabled)
329 </li>
330 <li>
331 <path>/usr/src/linux</path> points to the kernel you want ALSA working on.
332 </li>
333</ol>
334
335<pre caption=".config checks">
336<comment>(Assuming the linux symlink points to the correct kernel)</comment>
337# <i>cd /usr/src/linux</i>
338# <i>grep SOUND .config</i>
339<comment>(1. is true)</comment>
340CONFIG_SOUND=y
341<comment>(2. is true)</comment>
342CONFIG_SOUND_PRIME is not set
343# <i>grep SND .config</i>
344<comment>(and 3. is true)</comment>
345CONFIG_SND is not set
346</pre>
347
348<p>
349Now all you have to do is type the magic words...and no, its not abracadabra.
350</p>
351
352<pre caption="Installing alsa-driver">
353# <i>emerge alsa-driver</i>
354</pre>
355
356<impo>
357Please note that you will have to run <c>emerge alsa-driver</c> after every
358kernel (re)compile, as the earlier drivers are deleted.
359</impo>
360
361</body>
362</section>
363</chapter>
364
365<chapter>
366<title>Configuring/Testing ALSA</title>
367<section id="alsa-utilities">
368<title>ALSA Utilities</title>
369<body>
370
371<p>
372<c>alsa-utils</c> forms an integral part of ALSA as it has a truckload of
373programs that are highly useful, including the ALSA Initscripts. Hence we
374strongly recommend that you install <c>alsa-utils</c>
375</p>
376
377<pre caption="Install alsa-utils">
378# <i>emerge alsa-utils</i>
379</pre>
380
381<note>
382If you activated ALSA in your <uri link="#kernel">kernel</uri> <e>and</e> did
383not compile ALSA as modules, please proceed to the
384<uri link="#initscript">ALSA Initscript</uri> section. The rest of you need
385to configure ALSA. This is made very easy by the existence of the
386<c>alsaconf</c> tool provided by <c>alsa-utils</c>.
387</note>
388
389</body>
390</section>
391<section id="alsa-config">
392<title>Configuration</title>
393<body>
394
395<note>
396Please shut down any programs that <e>might</e> access the sound card while
397running <c>alsaconf</c>.
398</note>
399
400<p>
401The easiest way to configure your sound card is to run <c>alsaconf</c>. Just
402type <c>alsaconf</c> in a shell as root.
403</p>
404
405<pre caption="Invoking alsaconf">
406# <i>alsaconf</i>
407</pre>
408
409<p>
410You will now see a neat menu guided interface that will automatically probe
411your devices and try to find out your sound card. You will be asked to pick
412your sound card from a list. Once that's done, it will ask you permission to
413automatically make required changes to <path>/etc/modules.d/alsa</path>.
414It will then adjust your volume settings to optimum levels and run
415<c>modules-update</c> and starts the <path>/etc/init.d/alsasound</path>
416service. Once <c>alsaconf</c> exits, you can proceed with setting up the ALSA
417initscript.
418</p>
419
420</body>
421</section>
422<section id="initscript">
423<title>ALSA Initscript</title>
424<body>
425
426<p>
427We're now almost all setup. Whichever method you chose to install ALSA, you'll
428need to have something load your modules or initialize ALSA and restore your
429volume settings when your system comes up. The ALSA Initscript handles all of
430this for you and is called <c>alsasound</c>. Add it to the default run-level.
431</p>
432
433<pre caption="Adding ALSA to default">
434# <i>rc-update add alsasound default</i>
435 * alsasound added to runlevel default
436 * rc-update complete.
437</pre>
438
439<p>
440Next, just check the <path>/etc/conf.d/alsasound</path> file and ensure that
441SAVE_ON_STOP variable is set to yes. This saves your sound settings when you
442shutdown your system.
443</p>
444
445</body>
446</section>
447<section>
448<title>Volume Check!</title>
449<body>
450
451<p>
452We've completed all the setups and pre-requisites, so let's fire up ALSA. If
453you ran <c>alsaconf</c>, you can skip this step, since <c>alsaconf</c> already
454does this for you.
455</p>
456
457<pre caption="Start the service">
458<comment>(Modular Kernels)</comment>
459# <i>/etc/init.d/alsasound start</i>
460 * Loading ALSA modules ...
461 * Loading: snd-card-0 ... [ ok ]
462 * Loading: snd-pcm-oss ... [ ok ]
463 * Loading: snd-seq ... [ ok ]
464 * Loading: snd-emu10k1-synth ... [ ok ]
465 * Loading: snd-seq-midi ... [ ok ]
466 * Restoring Mixer Levels ... [ ok ]
467<comment>(ALSA compiled in)</comment>
468# <i>/etc/init.d/alsasound start</i>
469 * Loading ALSA modules ...
470 * Restoring Mixer Levels ... [ ok ]
471</pre>
472
473<p>
474Now that the required things have been take care of, we need to check up on
475the volume as in certain cases, it is muted. We use <c>alsamixer</c> for this purpose.
476</p>
477
478<pre caption="Starting alsamixer">
479<comment>(Opens up a console program. Only required settings are shown)</comment>
480# <i>alsamixer</i>
481</pre>
482
483<p>
484This is how the ALSA Mixer <e>might</e> look the first time you open it. Pay
485attention to the Master and PCM channels which both have an MM below them.
486That means they are muted. If you try to play anything with <c>alsamixer</c>
487in this state, you will not hear anything on your speakers.
488</p>
489
490<figure link="/images/docs/alsa-mixermuted.png" short="AlsaMixer Muted" caption="The Alsa Mixer Main Window, Muted"/>
491
492<p>
493Now, we shall unmute the channels, and set volume levels as needed.
494</p>
495
496<warn>
497Both Master <e>and</e> PCM need to be unmuted and set to audible volume levels if
498you want to hear some output on your speakers.
499</warn>
61 500
62<ul> 501<ul>
63 <li> 502 <li>
64 Efficient support for all types of audio interfaces, from consumer 503 To move between channels, use your left and right arrow keys. (&lt;-
65 soundcards to professional multichannel audio interfaces 504 &amp; -&gt;)
66 </li>
67 <li>Fully modularized sound drivers</li>
68 <li>SMP and thread-safe design</li>
69 <li>
70 User space library (alsa-lib) to simplify application programming and
71 provide higher level functionality
72 </li> 505 </li>
73 <li> 506 <li>
74 Support for the older OSS API, providing binary compatibility for most OSS 507 To toggle mute, move to the specific channel, for example Master and press
75 programs 508 the <e>m</e> key on the keyboard.
76 </li> 509 </li>
77</ul>
78
79<p>
80There's lots more to ALSA however, like support for Full Duplex playback and
81recording, multiple soundcard support, hardware mixing of streams, extensive
82mixer capabilities (to support advanced features of new soundcards), ...
83</p>
84
85</body>
86</section>
87<section>
88<title>Why use ALSA?</title>
89<body>
90
91<p>
92If your soundcard is supported by the Linux kernel sound system or the
93commercial OSS/4Front sound driver system, which can be found in all 2.4.x
94Linux kernels, you could just aswell build <e>those modules</e> for use with
95your soundcard. If you want this, just read through the <uri
96link="http://www.tldp.org/HOWTO/Sound-HOWTO/index.html">Linux Sound HOWTO</uri>.
97</p>
98
99<p>
100However, those OSS/4Front drivers have some limitations -- being commercial is
101one. ALSA is an attempt to go beyond these limitations and to do so in an open
102source fashion. ALSA is a fully GPL and LGPL'ed sound driver system, that
103provides a professional quality system for recording, playback, and MIDI
104sequencing.
105</p>
106
107</body>
108</section>
109<section>
110<title>What cards does ALSA support?</title>
111<body>
112
113<p>
114ALSA tries to support as many (new) cards as possible by providing open-source
115drivers. However, some vendors may provide binary-only packages.
116</p>
117
118<p>
119To know if your card is supported, you can find a Soundcard Matrix of supported
120and not-supported cards here: <uri>http://www.alsa-project.org/alsa-doc/</uri>.
121</p>
122
123</body>
124</section>
125</chapter>
126
127<chapter>
128<title>Installation</title>
129<section>
130<title>Gentoo USE flags</title>
131<body>
132
133<p>
134To compile programs with ALSA-support, be sure to add <e>alsa</e> to
135your USE-variable. However, several tools don't support alsa yet, and
136require OSS. ALSA provides OSS-emulation if you define <e>oss</e> in your
137USE-variable before you start.
138</p>
139
140</body>
141</section>
142<section>
143<title>Kernel modules</title>
144<body>
145
146<p>
147Since we're still using 2.4.x kernel sources, we'll have to compile kernel
148modules and ALSA modules separately. People who are using a 2.5.x kernel can
149do this from within their kernel configuration, since the ALSA modules are
150included in the kernel sources and should be built there.
151</p>
152
153<p>
154First we'll make sure that our kernel configuration is ready for use with ALSA.
155All you need in your kernel configuration is having Sound Card Support set to
156be built as a module (M). This will build <path>soundcore.o</path>.
157</p>
158
159<note>
160Possibly, this will also work when you built Sound Card Support in the kernel
161(Y) instead of building it as a module (M). However, the official ALSA
162documentation suggests building it as a module, since ALSA will try loading it.
163</note>
164
165<p>
166If you already have a working kernel configuration, make sure you remove all
167sound drivers (except for Sound Card Support). If you wish to do this without
168having to reboot, you could do like this:
169</p>
170
171<pre caption="Kernel configuration">
172# <i>cd /usr/src/linux</i>
173# <i>cp .config ~/</i>
174# <i>make mrproper</i>
175# <i>cp ~/.config .</i>
176# <i>make menuconfig</i>
177</pre>
178
179<p>
180Now select <e>Sound Card Support</e> as Module (M) and deselect all other sound
181drivers. Exit and say Y to save your kernel configuration. After that, build
182the modules:
183</p>
184
185<pre caption="Kernel compilation">
186# <i>make dep clean</i>
187# <i>make modules modules_install</i>
188</pre>
189
190<p>
191Before installing your new modules, this last line will delete all your previous
192modules, even the ones from a previous ALSA installation.
193</p>
194
195<impo>
196This means, whenever you recompile your kernel later on, you MUST recompile
197<c>alsa-driver</c>.
198</impo>
199
200</body>
201</section>
202<section>
203<title>ALSA modules</title>
204<body>
205
206<p>
207Now it's time to install the ALSA drivers for your soundcard(s). If your
208soundcard is PCI, you can find out the name and type of your soundcard by
209looking at the output of <path>/proc/pci</path>.
210</p>
211
212<pre caption="Search for soundcard information">
213# <i>grep audio /proc/pci</i>
214</pre>
215
216<warn>
217If you had a previous sound setup and there are still non-ALSA sound modules
218loaded, unload them <e>now</e>. Check with <c>lsmod</c> and use <c>rmmod</c>
219to unload all sound-related modules on your system.
220</warn>
221
222<p>
223We could simply do an <c>emerge alsa-driver</c> now, this would compile and
224install <e>all</e> ALSA sound drivers.
225</p>
226
227<p>
228However, to save some time, lookup the <e>Module Name</e> of your soundcard(s)
229on the <uri link="http://www.alsa-project.org/alsa-doc">ALSA Soundcard
230Matrix</uri> by following the <e>Details</e> link in the <e>Driver and Docs</e>
231column in the row of the chipset of your soundcard. Mine is <c>snd-emu10k1</c>,
232since I have an SBlive! soundcard, with the <e>EMU10K1</e> chipset. We'll set
233ALSA_CARDS environment to the value of the module name before emerging (but
234without the snd prefix), so emerge will only compile the drivers we need.
235</p>
236
237<pre caption="Compile correct modules">
238# <i>env ALSA_CARDS='emu10k1' emerge alsa-driver</i>
239</pre>
240
241<note>
242You can also add this value in <path>/etc/make.conf</path>, so when you have
243to emerge the alsa-driver later on you can just run <c>emerge alsa-driver</c>.
244For example, like this: <c>echo 'ALSA_CARDS="emu10k1"' >> /etc/make.conf</c>
245</note>
246
247<note>
248When you want to install ALSA drivers for more than one soundcard, you could
249set ALSA_CARDS to a space-separated list of drivers; like this: <c>env
250ALSA_CARDS='emu10k1 intel8x0 ens1370' emerge alsa-driver</c>
251</note>
252
253<note>
254If you want to have OSS compatibility, make sure to emerge <i>alsa-oss</i>, it
255is the ALSA/OSS compatibility wrapper.
256</note>
257
258<note>
259If you plan on recompiling your kernels numerous times, it might
260be adviseable to emerge <c>alsa-driver</c> with <c>--buildpkg</c>. This
261will create a binary package for it. Later, after recompiling your kernel,
262you can just do <c>emerge --usepkg alsa-driver</c> which will install the
263binary package instead of recompiling it completely.
264</note>
265
266<p>
267After this, the ALSA modules should be installed on your system.
268</p>
269
270</body>
271</section>
272<section>
273<title>Configuration of ALSA</title>
274<body>
275
276<p>
277Let's start configuring now to get ALSA working properly. We'll need to edit
278some files, to let our system know about the freshly installed ALSA modules.
279</p>
280
281<p>
282First, install <c>alsa-utils</c> on your system:
283</p>
284
285<pre caption = "Emerging alsa-utils">
286# <i>emerge alsa-utils</i>
287</pre>
288
289<p>
290Hereafter, we need to edit <path>/etc/modules.d/alsa</path>.
291</p>
292
293<warn>
294There is no need to edit <path>/etc/modules.conf</path>. Instead, always edit
295files in <path>/etc/modules.d</path>.
296</warn>
297
298<p>
299Check the ALSA portion <e>at the bottom of the file</e>. By tweaking this line
300you can specify the max number of soundcards you have (generally, just one).
301</p>
302
303<pre caption="At the bottom of /etc/modules.d/alsa">
304<comment>Set this to the correct number of cards.</comment>
305options snd cards_limit=1
306</pre>
307
308<p>
309Now we'll specify the sounddriver(s) ALSA should use. In the same file, edit
310like this:
311</p>
312
313<pre caption="In /etc/modules.d/alsa">
314## and then run `modules-update' command.
315## Read alsa-driver's INSTALL file in /usr/share/doc for more info.
316##
317## ALSA portion
318alias snd-card-0 snd-emu10k1
319<comment>## If you have more than one, add:</comment>
320## alias snd-card-1 snd-intel8x0
321## alias snd-card-2 snd-ens1370
322## OSS/Free portion
323## alias sound-slot-0 snd-card-0
324## alias sound-slot-1 snd-card-1
325##
326</pre>
327
328<note>
329If you have more than one soundcard, adjust the <c>cards_limit</c> value and add
330more snd-card aliases to the file. I don't have experience with this, but you
331can find examples for configurations with two or more soundcards in <uri
332link="http://www.alsa-project.org/alsa-doc/alsa-howto/c1660.htm">Chapter 6</uri>
333of the <uri
334link="http://www.alsa-project.org/alsa-doc/alsa-howto/alsa-howto.html">ALSA
335Howto</uri>.
336</note>
337
338<p>
339Last thing to do in this file, almost at the end, check if these lines are there
340and uncommented:
341</p>
342
343<pre caption="Near the end of /etc/modules.d/alsa">
344alias /dev/mixer snd-mixer-oss
345alias /dev/dsp snd-pcm-oss
346alias /dev/midi snd-seq-oss
347</pre>
348
349<p>
350Now double-check the file <path>/etc/modules.d/alsa</path> and when you're sure
351everyting is ok, run <c>modules-update</c>.
352</p>
353
354<pre caption="Running modules-update">
355# <i>modules-update</i>
356</pre>
357
358<note>
359Running <c>modules-update</c> here will insert the data from
360<path>/etc/modules.d/alsa</path> into <path>/etc/modules.conf</path>
361</note>
362
363<p>
364You should also verify that <path>/etc/devfsd.conf</path> has the alsa devices
365and permissions correctly registered.
366</p>
367
368<pre caption="/etc/devfsd.conf">
369# ALSA/OSS stuff
370# Comment/change these if you want to change the permissions on
371# the audio devices
372LOOKUP snd MODLOAD ACTION snd
373LOOKUP dsp MODLOAD
374LOOKUP mixer MODLOAD
375LOOKUP midi MODLOAD
376REGISTER sound/.* PERMISSIONS root.audio 660
377REGISTER snd/.* PERMISSIONS root.audio 660
378</pre>
379
380<note>
381Notice that devfsd.conf sets <path>/dev/sound</path> permissions to be
382root.audio. Thus, for non-root users to use audio they will have to be part of
383the audio group.
384</note>
385
386</body>
387</section>
388</chapter>
389
390<chapter>
391<title>Starting ALSA</title>
392<section>
393<title>Adding alsasound to a runlevel</title>
394<body>
395
396<p>
397First thing to do now, is to make ALSA startup at boottime. Like this:
398</p>
399
400<pre caption="Add ALSA to the default runlevel">
401# <i>rc-update add alsasound boot</i>
402</pre>
403
404<warn>
405Note that the alsasound script should be added to the "boot" runlevel, not the
406"default" runlevel.
407</warn>
408
409</body>
410</section>
411<section>
412<title>Running and unmuting</title>
413<body>
414
415<p>
416Since we're Linux users, we don't want to reboot. So we'll start the alsasound
417script manually.
418</p>
419
420<pre caption="Starting ALSA">
421# <i>/etc/init.d/alsasound start</i>
422</pre>
423
424<p>
425ALSA is running now. If everything is ok, you should be able to see the ALSA
426modules loaded when running <c>lsmod</c>. However, sound won't work yet,
427because the channels are still muted. We need <c>amixer</c> for this.
428</p>
429
430<pre caption = "Running amixer">
431# <i>amixer</i>
432</pre>
433
434<warn>
435You shouldn't get this, but <e>if</e> you get an error about "amixer: Mixer
436attach default error: No such file or directory", you should manually modprobe
437<c>snd-mixer-oss</c> and <c>snd-pcm-oss</c> once. After that run amixer again.
438</warn>
439
440<pre caption="Only if you get an error when running amixer">
441# <i>modprobe snd-mixer-oss</i>
442# <i>modprobe snd-pcm-oss</i>
443# <i>amixer</i>
444</pre>
445
446<p>
447If you got this far, now unmute Master and PCM channels. Some hardware
448even requires you to unmute the center channel or even the surround
449channel.
450</p>
451
452<pre caption = "Unmuting channels">
453# <i>amixer set Master 100 unmute</i>
454# <i>amixer set PCM 100 unmute</i>
455<comment>Only if the above doesn't succeed on its own:</comment>
456# <i>amixer set Center 100 unmute</i>
457# <i>amixer set Surround 100 unmute</i>
458<comment>Test the sound:</comment>
459# <i>aplay $KDEDIR/share/sounds/pop.wav</i> <codenote>(pop.wav is part of KDE)</codenote>
460</pre>
461
462<p>
463We check to see if sound is working by using the aplay (alsa play) command. If
464you hear a pop, then sound is indeed working. Then, adjust the volume settings
465to your liking; the ncurses-based <c>alsamixer</c> is a great way to get them
466"just so".
467</p>
468
469<p>
470You may want to emerge <c>alsa-xmms</c> as that will provide ALSA support for
471XMMS.
472</p>
473
474<p>
475When you reboot your system, the <c>alsasound</c> init script will properly saveand restore your volume settings.
476</p>
477
478</body>
479</section>
480</chapter>
481
482<chapter>
483<title>Final Notes</title>
484<section>
485<title>After kernel-upgrades..</title>
486<body>
487
488<p>
489When you ever rebuild your kernel, or upgrade to another kernel, you'll have to
490rebuild the ALSA modules.
491</p>
492
493<p>
494Although you might have installed <c>alsa-driver</c>, <c>alsa-libs</c> and
495<c>alsa-utils</c>, only the first will have to be installed again, since it will
496put the alsa modules in <path>/lib/modules/*/kernel/sound/pci/</path>.
497</p>
498
499<pre caption="needed after each kernel compile">
500# <i>emerge alsa-driver</i>
501</pre>
502
503</body>
504</section>
505<section>
506<title>/etc/modules.autoload</title>
507<body>
508
509<p>
510You won't have to edit this file for use with ALSA. After our <c>rc-update add
511alsasound boot</c>, our system will load the correct modules at startup.
512</p>
513
514<p>
515It's not necessary to add <c>snd-pcm-oss</c> or <c>snd-mixer-oss</c> in this
516file. Check the <uri link="http://www.djcj.org/LAU/guide/alsbook/faq1.html">this
517FAQ</uri> for more info.
518</p>
519
520</body>
521</section>
522<section>
523<title>Known bugs</title>
524<body>
525
526<note>
527This guide lags behind on the alsa-development. Chances are these bugs
528are already fixed when you read this.
529</note>
530
531<ul>
532 <li> 510 <li>
533 If you have <b>lots of noise</b> when using <b>oss</b> emulation, add 511 To increase and decrease the volume levels, use the up and down arrow keys
534 <e>options snd-pcm-oss dsp_map=1</e> to <path>/etc/modules.d/alsa</path> 512 respectively.
535 </li> 513 </li>
536</ul> 514</ul>
537 515
516<note>
517Be careful when setting your Bass and Treble values. 50 is usually a good
518number for both. Extremely high values of Bass may cause <e>jarring</e>
519on speakers that are not designed to handle them.
520</note>
521
522<p>
523After you're all done, your ALSA Mixer should look similar to the one below.
524Note the 00 instead of the MM and also the volume levels for some optimum
525settings.
526</p>
527
528<figure link="/images/docs/alsa-mixerunmuted.png" short="AlsaMixer Unmuted" caption="Alsa Mixer ready to roll"/>
529
538</body> 530</body>
539</section>
540<section> 531</section>
541<title>Activating Joystick Support</title>
542<body>
543
544<p>
545If your soundcard has a joystick plug, you might be interested in activating
546joystick support for your soundcard. If so, start by verifying if your soundcard
547driver has a joystick parameter. You can verify this by running <c>modinfo</c>
548against your <path>snd-&lt;your chipset&gt;</path>. For instance, for the
549<c>snd-via82xx</c>:
550</p>
551
552<pre caption="Running modinfo">
553# <i>modinfo snd-via82xx</i>
554filename: /lib/modules/2.4.22-ck2/snd-via82xx.o
555description: "VIA VT82xx audio"
556author: "Jaroslav Kysela &lt;perex@suse.cz&gt;"
557license: "GPL"
558parm: index int array (min = 1, max = 8), description "Index value for VIA 82xx bridge."
559parm: id string array (min = 1, max = 8), description "ID string for VIA 82xx bridge."
560parm: enable int array (min = 1, max = 8), description "Enable audio part of VIA 82xx bridge."
561parm: mpu_port long array (min = 1, max = 8), description "MPU-401 port. (VT82C686x only)"
562<i>parm: joystick int array (min = 1, max = 8), description "Enable joystick. (VT82C686x only)"</i>
563parm: ac97_clock int array (min = 1, max = 8), description "AC'97 codec clock (default 48000Hz)."
564parm: dxs_support int array (min = 1, max = 8), description "Support for DXS channels
565 (0 = auto, 1 = enable, 2 = disable, 3 = 48k only, 4 = no VRA)"
566</pre>
567
568<p>
569If it has the <c>joystick</c> parameter, then append <c>joystick=1</c> to your
570<c>options</c> line in <path>/etc/modules.d/alsa</path>. For instance, for the
571<c>snd-via82xx</c>:
572</p>
573
574<pre caption="Adding the joystick parameter">
575alias snd-card-0 snd-via82xx
576options snd-via82xx joystick=1
577</pre>
578
579</body>
580</section> 532<section>
533<title>Sound Check!</title>
534<body>
535
536<p>
537Finally. Some music. If everything above is perfect, you should be able to now
538listen to some good music. A quick way to test is to use a command line tool
539like <c>media-sound/madplay</c>. You could also use something more well known
540like <c>mpg123</c> or <c>xmms</c>. If you are an ogg fan, you could use
541<c>ogg123</c> provided by <c>media-sound/vorbis-tools</c>. Use any player you
542are comfortable with. As always, <c>emerge</c> what you need.
543</p>
544
545<pre caption="Getting the software">
546<comment>(Install the applications you want)</comment>
547# <i>emerge madplay mpg123 xmms</i>
548<comment>(To play .ogg files)</comment>
549# <i>emerge vorbis-tools</i>
550</pre>
551
552<p>
553And then play your favorite sound track...
554</p>
555
556<pre caption="Playing Music">
557# <i>madplay -v /mnt/shyam/Music/Paul\ Oakenfold\ -\ Dread\ Rock.mp3</i>
558MPEG Audio Decoder 0.15.2 (beta) - Copyright (C) 2000-2004 Robert Leslie et al.
559 Title: Dread Rock
560 Artist: Paul Oakenfold
561 Album: Matrix Reloaded
562 Year: 2003
563 Genre: Soundtrack
564 Soundtrack
565 00:04:19 Layer III, 160 kbps, 44100 Hz, joint stereo (MS), no CRC
566
567# <i>ogg123 Paul\ Oakenfold\ -\ Dread\ Rock.ogg</i>
568Audio Device: Advanced Linux Sound Architecture (ALSA) output
569
570Playing: Paul Oakenfold - Dread Rock.ogg
571Ogg Vorbis stream: 2 channel, 44100 Hz
572Genre: Soundtrack
573Transcoded: mp3;160
574Title: Dread Rock
575Artist: Paul Oakenfold
576Date: 2003
577Album: Matrix Reloaded
578Time: 00:11.31 [04:28.75] of 04:40.06 (200.6 kbps) Output Buffer 96.9%
579</pre>
580
581</body>
581<section> 582</section>
582<title>More links..</title> 583<section>
584<title>Issues?</title>
585<body>
586
587<p>
588If for some reason you're unable to hear sound, the first thing to do would
589be to check your <uri link="#doc_chap3_pre5">alsamixer</uri> settings. 80% of
590the issues lie with muted channels or low volume. Also check your Window
591Manager's sound applet and verify that volumes are set to audible levels.
592</p>
593
594<p>
595<path>/proc</path> is your friend. And in this case, <path>/proc/asound</path>
596is your best friend. We shall just take a short look at how much info is made
597available to us there.
598</p>
599
600<pre caption="Fun with /proc/asound">
601<comment>(First and foremost, if /proc/asound/cards shows your card, ALSA has
602picked up your sound card fine.)</comment>
603# <i>cat /proc/asound/cards</i>
6040 [Live ]: EMU10K1 - Sound Blaster Live!
605 Sound Blaster Live! (rev.6, serial:0x80271102) at 0xb800, irq 11
606
607<comment>(If you run ALSA off the kernel like I do and wonder how far behind
608you are from alsa-driver, this displays current running ALSA version)</comment>
609# <i>cat /proc/asound/version</i>
610Advanced Linux Sound Architecture Driver Version 1.0.8 (Thu Jan 13 09:39:32 2005 UTC).
611
612<comment>(ALSA OSS emulation details)</comment>
613# <i>cat /proc/asound/oss/sndstat</i>
614Sound Driver:3.8.1a-980706 (ALSA v1.0.8 emulation code)
615Kernel: Linux airwolf.zion 2.6.11ac1 #2 Wed May 4 00:35:08 IST 2005 i686
616Config options: 0
617
618Installed drivers:
619Type 10: ALSA emulation
620
621Card config:
622Sound Blaster Live! (rev.6, serial:0x80271102) at 0xb800, irq 11
623
624Audio devices:
6250: EMU10K1 (DUPLEX)
626
627Synth devices: NOT ENABLED IN CONFIG
628
629Midi devices:
6300: EMU10K1 MPU-401 (UART)
631
632Timers:
6337: system timer
634
635Mixers:
6360: SigmaTel STAC9721/23
637</pre>
638
583<body> 639</body>
640</section>
641</chapter>
584 642
585<p> 643<chapter>
586You could check these for additional info: 644<title>Other things ALSA</title>
645<section>
646<title>Setting up MIDI support</title>
647<body>
648
587</p> 649<p>
650If your sound card is one of those that come with on-board MIDI synthesizers
651and you would like to listen to some .mid files, you have to install
652<c>awesfx</c> which is basically a set of utilities for controlling the AWE32
653driver. We need to install it first. If you don't have a hardware synthesizer,
654you can use a virtual one. Please see the section on
655<uri link="#vsynth">Virtual Synthesizers</uri> for more information.
656</p>
657
658<pre caption="Installing awesfx">
659# <i>emerge awesfx</i>
660</pre>
661
662<note>
663You will need to copy over SoundFont (SF2) files from your sound card's driver
664CD or a Windows installation into <path>/usr/share/sounds/sf2/</path>. For
665example a sound font file for the Creative SBLive! card would be 8MBGMSFX.SF2.
666</note>
667
668<p>
669After copying over the Soundfont files, we can then play a midi file as shown.
670You can also add the <c>asfxload</c> command to
671<path>/etc/conf.d/local.start</path>, so that the sound font is loaded
672every time the system starts up.
673</p>
674
675<note>
676<path>/mnt</path> paths mentioned in the code listing(s) below will <e>not</e>
677be the same in your machine. They are just an example. Please be careful to
678change the path to suit your machine.
679</note>
680
681<pre caption="Loading Soundfonts">
682<comment>(First, copy the Soundfont)</comment>
683# <i>cp /mnt/win2k/Program\ Files/CreativeSBLive2k/SFBank/8MBGMSFX.SF2 /usr/share/sounds/sf2/</i>
684<comment>(We load the specific Soundfont)</comment>
685# <i>asfxload /usr/share/sounds/sf2/8MBGMSFX.SF2</i>
686</pre>
687
688<p>
689You can now play midi files using a program like <c>aplaymidi</c>. Run
690<c>aplaymidi -l</c> to get a list of available ports and then pick one
691to play the file on.
692</p>
693
694<pre caption="Playing MIDI">
695<comment>(Check open ports)</comment>
696# <i>aplaymidi -l</i>
697 Port Client name Port name
698 64:0 EMU10K1 MPU-401 (UART) EMU10K1 MPU-401 (UART)
699 65:0 Emu10k1 WaveTable Emu10k1 Port 0
700 65:1 Emu10k1 WaveTable Emu10k1 Port 1
701 65:2 Emu10k1 WaveTable Emu10k1 Port 2
702 65:3 Emu10k1 WaveTable Emu10k1 Port 3
703<comment>(Pick a port, and play a mid file)</comment>
704# <i> aplaymidi --port=65:0 /mnt/shyam/music/midi/mi2.mid</i>
705</pre>
706
707</body>
708</section>
709<section id="vsynth">
710<title>Virtual Synthesizers</title>
711<body>
712
713<p>
714If your sound card lacks a hardware synthesizer, you could use a virtual one
715like <c>timidity++</c>. Installation is a breeze.
716</p>
717
718<pre caption="Installing timidity++">
719# <i>emerge timidity++</i>
720</pre>
721
722<p>
723For timidity to play sounds, it needs a sound font. If you do not have any,
724install <c>timidity-eawpatches</c> or <c>timidity-shompatches</c> which will
725give you some sound fonts. You can have multiple sound font configurations
726installed, and you can place your own in <path>/usr/share/timidity/</path>.
727To switch between different timidity configurations, you should use the
728<e>timidity-update</e> tool provided in the timidity++ package.
729</p>
730
731<pre caption="Installing sound fonts">
732# <i>emerge timidity-eawpatches</i>
733# <i>timidity-update -g -s eawpatches</i>
734
735<comment>(or)</comment>
736
737# <i>emerge timidity-shompatches</i>
738# <i>timidity-update -g -s shompatches</i>
739</pre>
740
741<p>
742Don't forget to add <c>timidity</c> to the default runlevel.
743</p>
744
745<pre caption="Adding timidity to the default runlevel">
746# <i>rc-update add timidity default</i>
747# <i>/etc/init.d/timidity start</i>
748</pre>
749
750<p>
751You can now try out <uri link="#doc_chap4_pre3">Playing MIDI</uri> files.
752</p>
753
754</body>
755</section>
756<section>
757<title>Tools and Firmware</title>
758<body>
759
760<p>
761Some specific sound cards can benefit from certain tools provided by the
762<c>alsa-tools</c> and <c>alsa-firmware</c> packages. If you need
763<c>alsa-tools</c>, be sure to define the ALSA_TOOLS variable in
764<path>/etc/make.conf</path> with the tools you require. For instance:
765</p>
766
767<pre caption="Selecting ALSA Tools in /etc/make.conf">
768ALSA_TOOLS="as10k1 ac3dec"
769</pre>
770
771<p>
772If the ALSA_TOOLS variable is not set, all available tools will be built.
773Now, install the <c>alsa-tools</c> (and/or <c>alsa-firmware</c>) package(s):
774</p>
775
776<pre caption="Installing ALSA Tools">
777# <i>emerge alsa-tools</i>
778</pre>
779
780</body>
781</section>
782<section>
783<title>A Big thank you to...</title>
784<body>
785
786<p>
787Everyone who contributed to the earlier version of the Gentoo ALSA Guide:
788Vincent Verleye, Grant Goodyear, Arcady Genkin, Jeremy Huddleston,
789John P. Davis, Sven Vermeulen, Benny Chuang, Tiemo Kieft and Erwin.
790</p>
791
792</body>
793</section>
794<section>
795<title>References</title>
796<body>
588 797
589<ul> 798<ul>
590 <li>
591 <uri link="http://www.gentoo.org/doc/en/desktop.xml">The Gentoo Linux
592 Desktop Configuration Guide</uri>
593 </li>
594 <li>
595 <uri link="http://www.alsa-project.org">ALSA Project Homepage</uri> 799 <li><uri link="http://www.alsa-project.org/">The ALSA Project</uri></li>
596 </li>
597 <li>
598 <uri link="http://www.alsa-project.org/documentation.php3">ALSA Users
599 Documentation</uri>
600 </li>
601 <li>
602 <uri link="http://www.djcj.org">ALSA Howto's and FAQ's</uri>
603 </li>
604 <li>
605 <uri link="http://tldp.org/HOWTO/Sound-HOWTO/index.html">Linux Sound
606 HOWTO</uri>
607 </li>
608 <li>
609 <uri link="http://linux-sound.org/">Sound and MIDI Software For Linux</uri> 800 <li><uri link="http://linux-sound.org">Linux Sound/MIDI Software</uri></li>
610 </li>
611</ul> 801</ul>
612 802
613</body> 803</body>
614</section> 804</section>
615</chapter> 805</chapter>

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