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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 1.37 2004/06/15 07:21:07 bennyc Exp $ --> 2<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/alsa-guide.xml,v 1.85 2012/02/13 08:33:31 nightmorph Exp $ -->
3
3<!DOCTYPE guide SYSTEM "/dtd/guide.dtd"> 4<!DOCTYPE guide SYSTEM "/dtd/guide.dtd">
4 5
5<guide link = "/doc/en/alsa-guide.xml"> 6<guide>
6<title>Gentoo Linux ALSA Guide</title> 7<title>Gentoo Linux ALSA Guide</title>
8
7<author title="Author"> 9<author title="Author">
8 <mail link="zu@pandora.be">Vincent Verleye</mail> 10 <mail link="fox2mike@gentoo.org">Shyam Mani</mail>
9</author> 11</author>
10<author title="Author"> 12<author title="Author">
11 <mail link="g2boojum@gentoo.org">Grant Goodyear</mail> 13 <mail link="nightmorph@gentoo.org">Joshua Saddler</mail>
12</author> 14</author>
13<author title="Author"> 15<author title="Contributor">
14 <mail link="agenkin@gentoo.org">Arcady Genkin</mail> 16 <mail link="flameeyes@gentoo.org">Diego Pettenò</mail>
15</author> 17</author>
16<author title="Author">
17 <mail link="eradicator@gentoo.org">Jeremy Huddleston</mail>
18</author>
19<author title="Editor"><!-- zhen@gentoo.org -->
20 John P. Davis
21</author>
22<author title="Editor">
23 <mail link="swift@gentoo.org">Sven Vermeulen</mail>
24</author>
25<author title="Editor">
26 <mail link="bennyc@gentoo.org">Benny Chuang</mail>
27</author>
28<author title="Editor">
29 <mail link="blubber@gentoo.org">Tiemo Kieft</mail>
30</author>
31<author title="Editor">
32 <mail link="erwin@gentoo.org">Erwin</mail>
33</author>
34 18
35<abstract> 19<abstract>
36This guide will show you how to set up the Advanced Linux Sound Architecture 20This document helps a user setup ALSA on Gentoo Linux.
37(ALSA) on Gentoo Linux. In addition to the Gentoo Linux Desktop Configuration
38Guide, this guide is supposed to give you more information on this subject.
39</abstract> 21</abstract>
40 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 -->
41<license/> 25<license/>
42 26
43<version>1.5.0</version> 27<version>3</version>
44<date>May 18, 2004</date> 28<date>2012-02-13</date>
45 29
46<chapter> 30<chapter>
47<title>The Advanced Linux Sound Architecture</title> 31<title>Introduction</title>
48<section> 32<section>
49<title>What is ALSA?</title> 33<title>What is ALSA?</title>
50<body> 34<body>
51 35
52<p> 36<p>
53ALSA is the <e>Advanced Linux Sound Architecture</e>, a project dedicated to the 37ALSA, which stands for <e>Advanced Linux Sound Architecture</e>, provides audio
54development of a high-quality Linux sound subsystem. It has replaced OSS 38and MIDI (<e>Musical Instrument Digital Interface</e>) functionality to the
55(<e>Open Sound System</e>) as default sound subsystem in the 2.6 kernel series. 39Linux operating system. ALSA is the default sound subsystem in the 3.0 and 2.6
56</p> 40kernels, thereby replacing OSS (<e>Open Sound System</e>), which was used in
57 41the 2.4 kernels.
58<p> 42</p>
59ALSA provides efficient support for all types of audio interfaces, is fully 43
60modularized, is SMP and thread-safe and provides a high-quality user space 44<p>
61library called <e>alsa-lib</e> to simplify application programming. It also 45ALSA's main features include efficient support for all types of audio
62provides a backwards compatibility layer with OSS. 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.
63</p> 50</p>
64 51
65</body> 52</body>
66</section> 53</section>
67</chapter> 54</chapter>
55
68<chapter> 56<chapter>
69<title>Installing ALSA</title> 57<title>Installing ALSA</title>
58<section id="lspci">
59<title>Before you proceed</title>
60<body>
61
62<p>
63First, you need to know what drivers your sound card uses. In most cases, sound
64cards (onboard and otherwise) are PCI based and <c>lspci</c> will help you in
65digging out the required information. Please <c>emerge sys-apps/pciutils</c> to
66get <c>lspci</c>, if you don't have it installed already. In case you have a USB
67sound card, <c>lsusb</c> from <c>sys-apps/usbutils</c> <e>might</e> be of help.
68For ISA cards, try using <c>sys-apps/isapnptools</c>. Also, the following pages
69<e>may</e> help users with ISA based sound cards:
70</p>
71
72<ul>
73 <li>
74 <uri link="http://www.roestock.demon.co.uk/isapnptools/">The ISAPNPTOOLS
75 Page</uri>
76 </li>
77 <li>
78 <uri link="http://www2.linuxjournal.com/article/3269">LinuxJournal PnP
79 Article</uri>
80 </li>
81 <li>
82 <uri link="http://www.tldp.org/HOWTO/Sound-HOWTO/x320.html">TLDP Sound
83 HowTo</uri>
84 </li>
85</ul>
86
87<note>
88For ease of use/explanation, we assume the user has a PCI based sound card for
89the remainder of this guide.
90</note>
91
92<p>
93We now proceed to find out details about the sound card.
94</p>
95
96<pre caption="Soundcard Details">
97# <i>lspci -v | grep -i audio</i>
980000:00:0a.0 Multimedia audio controller: Creative Labs SB Live! EMU10k1 (rev 06)
99</pre>
100
101<p>
102We now know that the sound card on the machine is a Sound Blaster Live! and the
103card manufacturer is Creative Labs. Head over to the <uri
104link="http://bugtrack.alsa-project.org/main/index.php/Matrix:Main">ALSA
105Soundcard Matrix</uri> page and select Creative Labs from the list. You will
106be taken to the Creative Labs matrix page where you can see that the SB Live!
107uses the <c>emu10k1</c> module. That is the information we need for now. If
108you are interested in detailed information, you can click on the link next to
109the "Details" and that will take you to the <c>emu10k1</c> specific page.
110</p>
111
112<p>
113If you intend to use MIDI, then you should add <c>midi</c> to your USE flags in
114<path>/etc/make.conf</path> before emerging any ALSA packages. Later in the
115guide, we will show you how to set up <uri link="#midi">MIDI support</uri>.
116</p>
117
118</body>
70<section> 119</section>
71<title>USE Flags</title> 120<section id="kernel">
72<body> 121<title>Configuring the kernel</title>
73
74<p>
75Gentoo provides an <c>alsa</c> USE flag which you should set in
76<path>/etc/make.conf</path> to allow our available packages to compile with
77ALSA support. If you have <c>oss</c> in your USE variable as well, ALSA will
78compile with OSS backward compatibility.
79</p>
80
81</body> 122<body>
82</section>
83<section>
84<title>Kernel Modules</title>
85<body>
86 123
87<p> 124<note>
88First of all, before continuing, make sure your kernel has <e>Sound Card 125Since the 2005.0 release, Gentoo Linux uses 2.6 as the default kernel. Please
89Support</e> enabled. If you used <c>genkernel</c> to build your kernel, then 126check that your kernel is a 2.6 series kernel. This method will <e>not</e> work
90this is automatically true. Otherwise reconfigure your kernel. 127on a 2.4 kernel.
128</note>
129
91</p> 130<p>
92 131Let us now configure the kernel to enable ALSA.
93<p> 132</p>
94If you use a 2.6 kernel you can skip the rest of this section and continue with
95<uri link="#alsa-utils">Installing the ALSA Utils</uri> as 2.6 already has the
96necessary ALSA drivers in it. Of course, don't forget to enable support for the
97sound card you have when configuring your kernel.
98</p>
99
100<p>
101Users of 2.4 kernel sources will have to install the necessary ALSA drivers for
102their soundcard. First find out what soundcard you have. An easy trick is to
103search for "audio" in <path>/proc/pci</path>:
104</p>
105
106<pre caption="Finding out the soundcard type">
107# <i>grep -i audio /proc/pci</i>
108Multimedia audio controller: VIA Technologies, Inc. VT82C686 AC97 Audio
109Controller (rev 64).
110</pre>
111
112<p>
113Now go to the <uri link="http://www.alsa-project.org/alsa-doc">ALSA Soundcard
114Matrix</uri> and search for your soundcard. In the above example you should go
115to the "VIA" manufacturer. You will receive a table with the known chipsets of
116that vendor. The chipset in the above example is "via82c686"; the "Details" link
117then informs me that the driver is called <path>via82xx</path>.
118</p>
119
120<p>
121Based on this information we can now install the <c>alsa-driver</c> for our
122soundcard. First edit <path>/etc/make.conf</path> and <e>add</e> a new option
123called ALSA_CARDS to it. Inside this variable you declare the soundcard driver
124you want to use:
125</p>
126
127<pre caption="Editing /etc/make.conf for ALSA_CARDS">
128ALSA_CARDS="via82xx"
129</pre>
130
131<p>
132Now install <c>alsa-driver</c>:
133</p>
134
135<pre caption="Installing ALSA Drivers">
136# <i>emerge alsa-driver</i>
137</pre>
138 133
139<impo> 134<impo>
140Whenever you (re)compile your kernel sources, chances are that the ALSA drivers 135<c>genkernel</c> users should now run <c>genkernel --menuconfig all</c> and
141will be overwritten. It is therefore adviseable to rerun <c>emerge 136then follow the instructions in <uri link="#doc_chap2_pre3">Kernel Options for
142alsa-driver</c> every time you (re)compile your kernel <e>after</e> having 137ALSA</uri>.
143rebooted into the new kernel.
144</impo> 138</impo>
145 139
140<pre caption="Heading over to the source">
141# <i>cd /usr/src/linux</i>
142# <i>make menuconfig</i>
143</pre>
144
145<note>
146The above example assumes that <path>/usr/src/linux</path> symlink points to
147the kernel sources you want to use. Please ensure the same before proceeding.
148</note>
149
150<p>
151Now we will look at some of the options we will have to enable in the 2.6
152kernel to ensure proper ALSA support for our sound card.
153</p>
154
155<p>
156Please note that for ease of use, all examples show ALSA built as modules. It
157is advisable to follow the same as it then allows the use of <c>alsaconf</c>
158which is a boon when you want to configure your card. Please do <e>not</e> skip
159the <uri link="#alsa-config">Configuration</uri> section of this document. If
160you still like to have options built-in, ensure that you make changes to your
161config accordingly.
162</p>
163
164<pre caption="Kernel Options for ALSA">
165Device Drivers ---&gt;
166 Sound ---&gt;
167
168<comment>(This needs to be enabled)</comment>
169&lt;M&gt; Sound card support
170
171<comment>(Make sure OSS is disabled)</comment>
172Open Sound System ---&gt;
173 &lt; &gt; Open Sound System (DEPRECATED)
174
175<comment>(Move one step back and enter ALSA)</comment>
176Advanced Linux Sound Architecture ---&gt;
177 &lt;M&gt; Advanced Linux Sound Architecture
178 <comment>(Select this if you want MIDI sequencing and routing)</comment>
179 &lt;M&gt; Sequencer support
180 <comment>(Old style /dev/mixer* and /dev/dsp* support. Recommended.)</comment>
181 &lt;M&gt; OSS Mixer API
182 &lt;M&gt; OSS PCM (digital audio) API
183
184<comment>(You now have a choice of devices to enable support for. Generally,
185you will have one type of device and not more. If you have more than one
186sound card, please enable them all here.)</comment>
187
188<comment>(Mostly for testing and development purposes, not needed for normal
189users unless you know what you are doing.)</comment>
190Generic devices ---&gt;
191
192<comment>(For ISA Sound cards)</comment>
193ISA devices ---&gt;
194<comment>(IF you had the Gravis, you would select this option)</comment>
195 &lt;M&gt; Gravis UltraSound Extreme
196
197<comment>(Move one level back and into PCI devices. Most sound cards today are
198PCI devices)</comment>
199PCI devices ---&gt;
200 <comment>(We now select the emu10k1 driver for our card)</comment>
201 &lt;M&gt; Emu10k1 (SB Live!, Audigy, E-mu APS)
202 <comment>(Or an Intel card would be)</comment>
203 &lt;M&gt; Intel/SiS/nVidia/AMD/ALi AC97 Controller
204 <comment>(Or if you have a VIA Card)</comment>
205 &lt;M&gt; VIA 82C686A/B, 8233/8235 AC97 Controller
206
207<comment>(Move one level back and select in case you have an USB sound card)</comment>
208USB Devices ---&gt;
209</pre>
210
211<p>
212Now that your options are set, you can (re)compile the kernel and ALSA support
213for your card should be functional once you reboot into the new kernel. Don't
214forget to update your GRUB configuration to use the newly built kernel.
215You can now proceed to <uri link="#alsa-utilities">ALSA Utilities</uri> and
216see if everything is working as it should.
217</p>
218
146</body> 219</body>
147</section> 220</section>
221</chapter>
222
223<chapter>
224<title>Configuring/Testing ALSA</title>
148<section id="alsa-utils"> 225<section id="alsa-utilities">
149<title>Installing the ALSA Utils</title> 226<title>ALSA Utilities</title>
150<body> 227<body>
151 228
152<p>
153If you want backwards compatibility with OSS, you need to install
154<c>alsa-oss</c>:
155</p> 229<p>
156 230<c>alsa-utils</c> forms an integral part of ALSA as it has a truckload of
157<pre caption="Installing the ALSA OSS compatibility layer"> 231programs that are highly useful, including the ALSA Initscripts. Hence we
158# <i>emerge alsa-oss</i> 232strongly recommend that you install <c>alsa-utils</c>
159</pre>
160
161<p> 233</p>
162Now install the ALSA Utils on your system (this is mandatory):
163</p>
164 234
165<pre caption="Installing ALSA Utils"> 235<pre caption="Install alsa-utils">
166# <i>emerge alsa-utils</i> 236# <i>emerge alsa-utils</i>
167</pre> 237</pre>
168 238
169<p> 239<note>
170Now that the utils are installed, it is time to configure ALSA... 240If you did <e>not</e> compile ALSA as modules, please proceed to the <uri
241link="#initscript">ALSA Initscript</uri> section. The rest of you need to
242configure ALSA. This is made very easy by the existence of the <c>alsaconf</c>
243tool provided by <c>alsa-utils</c>.
244</note>
245
246</body>
247</section>
248<section id="alsa-config">
249<title>Configuration</title>
250<body>
251
171</p> 252<p>
253Recent versions of <c>udev</c> (<c>>=udev-103</c>) provide some degree of
254kernel-level autoconfiguration of your sound card. If possible, try to rely on
255just letting your kernel automatically setup your sound card for you. Otherwise,
256use <c>alsaconf</c> to configure your card, as shown below.
257</p>
258
259<note>
260Please shut down any programs that <e>might</e> access the sound card while
261running <c>alsaconf</c>.
262</note>
263
264<p>
265To configure your sound card just type <c>alsaconf</c> in a shell as root.
266</p>
267
268<pre caption="Invoking alsaconf">
269# <i>alsaconf</i>
270</pre>
271
272<p>
273You will now see a neat menu guided interface that will automatically probe
274your devices and try to find out your sound card. You will be asked to pick
275your sound card from a list. Once that's done, it will ask you permission to
276automatically make required changes to <path>/etc/modprobe.d/alsa.conf</path>.
277It will then adjust your volume settings to optimum levels, run
278<c>update-modules</c> and start the <path>/etc/init.d/alsasound</path> service.
279Once <c>alsaconf</c> exits, you can proceed with setting up the ALSA
280initscript.
281</p>
282
283</body>
284</section>
285<section id="initscript">
286<title>ALSA Initscript</title>
287<body>
288
289<p>
290We're now almost all setup. Whichever method you chose to install ALSA, you'll
291need to have something load your modules or initialize ALSA and restore your
292volume settings when your system comes up. The ALSA Initscript handles all of
293this for you and is called <c>alsasound</c>. Add it to the boot runlevel.
294</p>
295
296<pre caption="Adding ALSA to the boot runlevel">
297# <i>rc-update add alsasound boot</i>
298 * alsasound added to runlevel boot
299 * rc-update complete.
300</pre>
301
302<p>
303Next, just check the <path>/etc/conf.d/alsasound</path> file and ensure that
304SAVE_ON_STOP variable is set to yes. This saves your sound settings when you
305shutdown your system.
306</p>
307
308</body>
309</section>
310<section>
311<title>Audio Group</title>
312<body>
313
314<p>
315Before we move on to testing, there's one last <e>important</e> thing that needs
316to be setup. Rule of thumb in a *nix OS: Do not run as root unless needed.
317This applies here as well ;) How? Well, most of the times you should be logged
318in as a user and would like to listen to music or access your soundcard. For
319that to happen, you need to be in the "audio" group. At this point, we'll add
320users to the audio group, so that they won't have any issues when they want to
321access sound devices. We'll use <c>gpasswd</c> here and you need to be logged in
322as root for this to work.
323</p>
324
325<pre caption="Adding users to the audio group">
326<comment>(Substitute &lt;username&gt; with your user)</comment>
327# <i>gpasswd -a &lt;username&gt; audio </i>
328Adding user &lt;username&gt; to group audio
329</pre>
330
331</body>
332</section>
333<section>
334<title>Volume Check!</title>
335<body>
336
337<p>
338We've completed all the setups and prerequisites, so let's fire up ALSA. If
339you ran <c>alsaconf</c>, you can skip this step, since <c>alsaconf</c> already
340does this for you.
341</p>
342
343<pre caption="Start the service">
344# <i>/etc/init.d/alsasound start</i>
345</pre>
346
347<p>
348Now that the required things have been taken care of, we need to check up on
349the volume as in certain cases, it is muted. We use <c>alsamixer</c> for this
350purpose.
351</p>
352
353<pre caption="Starting alsamixer">
354<comment>(Opens up a console program. Only required settings are shown)</comment>
355# <i>alsamixer</i>
356</pre>
357
358<p>
359This is how the ALSA Mixer <e>might</e> look the first time you open it. Pay
360attention to the Master and PCM channels which both have an MM below them.
361That means they are muted. If you try to play anything with <c>alsamixer</c>
362in this state, you will not hear anything on your speakers.
363</p>
364
365<figure link="/images/docs/alsa-mixermuted.png" short="AlsaMixer Muted" caption="The Alsa Mixer Main Window, Muted"/>
366
367<p>
368Now, we shall unmute the channels, and set volume levels as needed.
369</p>
370
371<warn>
372Both Master <e>and</e> PCM need to be unmuted and set to audible volume levels
373if you want to hear some output on your speakers.
374</warn>
375
376<ul>
377 <li>
378 To move between channels, use your left and right arrow keys. (&lt;-
379 &amp; -&gt;)
380 </li>
381 <li>
382 To toggle mute, move to the specific channel, for example Master and press
383 the <e>m</e> key on the keyboard.
384 </li>
385 <li>
386 To increase and decrease the volume levels, use the up and down arrow keys
387 respectively.
388 </li>
389</ul>
390
391<note>
392Be careful when setting your Bass and Treble values. 50 is usually a good
393number for both. Extremely high values of Bass may cause <e>jarring</e>
394on speakers that are not designed to handle them.
395</note>
396
397<p>
398After you're all done, your ALSA Mixer should look similar to the one below.
399Note the 00 instead of the MM and also the volume levels for some optimum
400settings.
401</p>
402
403<figure link="/images/docs/alsa-mixerunmuted.png" short="AlsaMixer Unmuted" caption="Alsa Mixer ready to roll"/>
404
405</body>
406</section>
407<section>
408<title>Sound Check!</title>
409<body>
410
411<p>
412Finally. Some music. If everything above is perfect, you should now be able to
413listen to some good music. A quick way to test is to use a command line tool
414like <c>media-sound/madplay</c>. You could also use something more well known
415like <c>mpg123</c>. If you are an ogg fan, you could use <c>ogg123</c> provided
416by <c>media-sound/vorbis-tools</c>. Use any player you are comfortable with. As
417always, <c>emerge</c> what you need.
418</p>
419
420<pre caption="Getting the software">
421<comment>(Install the applications you want)</comment>
422# <i>emerge madplay mpg123</i>
423<comment>(To play .ogg files)</comment>
424# <i>emerge vorbis-tools</i>
425</pre>
426
427<p>
428And then play your favorite sound track...
429</p>
430
431<pre caption="Playing Music">
432# <i>madplay -v /mnt/shyam/Music/Paul\ Oakenfold\ -\ Dread\ Rock.mp3</i>
433MPEG Audio Decoder 0.15.2 (beta) - Copyright (C) 2000-2004 Robert Leslie et al.
434 Title: Dread Rock
435 Artist: Paul Oakenfold
436 Album: Matrix Reloaded
437 Year: 2003
438 Genre: Soundtrack
439 Soundtrack
440 00:04:19 Layer III, 160 kbps, 44100 Hz, joint stereo (MS), no CRC
441
442# <i>ogg123 Paul\ Oakenfold\ -\ Dread\ Rock.ogg</i>
443Audio Device: Advanced Linux Sound Architecture (ALSA) output
444
445Playing: Paul Oakenfold - Dread Rock.ogg
446Ogg Vorbis stream: 2 channel, 44100 Hz
447Genre: Soundtrack
448Transcoded: mp3;160
449Title: Dread Rock
450Artist: Paul Oakenfold
451Date: 2003
452Album: Matrix Reloaded
453Time: 00:11.31 [04:28.75] of 04:40.06 (200.6 kbps) Output Buffer 96.9%
454</pre>
455
456</body>
457</section>
458<section>
459<title>ALSA and USE</title>
460<body>
461
462<p>
463You can now add the <c>alsa</c> use flag to <path>/etc/make.conf</path> to
464ensure that your applications that support ALSA get built with it. Some
465architectures like x86 and amd64 have the flag enabled by default.
466</p>
467
468</body>
469</section>
470<section>
471<title>Issues?</title>
472<body>
473
474<p>
475If for some reason you're unable to hear sound, the first thing to do would
476be to check your <uri link="#doc_chap3_pre6">alsamixer</uri> settings. 80% of
477the issues lie with muted channels or low volume. Also check your Window
478Manager's sound applet and verify that volumes are set to audible levels.
479</p>
480
481<p>
482<path>/proc</path> is your friend. And in this case, <path>/proc/asound</path>
483is your best friend. We shall just take a short look at how much info is made
484available to us there.
485</p>
486
487<pre caption="Fun with /proc/asound">
488<comment>(First and foremost, if /proc/asound/cards shows your card, ALSA has
489picked up your sound card fine.)</comment>
490# <i>cat /proc/asound/cards</i>
4910 [Live ]: EMU10K1 - Sound Blaster Live!
492 Sound Blaster Live! (rev.6, serial:0x80271102) at 0xb800, irq 11
493
494<comment>(This displays the current running ALSA version)</comment>
495# <i>cat /proc/asound/version</i>
496Advanced Linux Sound Architecture Driver Version 1.0.8 (Thu Jan 13 09:39:32 2005 UTC).
497
498<comment>(ALSA OSS emulation details)</comment>
499# <i>cat /proc/asound/oss/sndstat</i>
500Sound Driver:3.8.1a-980706 (ALSA v1.0.8 emulation code)
501Kernel: Linux airwolf.zion 2.6.11ac1 #2 Wed May 4 00:35:08 IST 2005 i686
502Config options: 0
503
504Installed drivers:
505Type 10: ALSA emulation
506
507Card config:
508Sound Blaster Live! (rev.6, serial:0x80271102) at 0xb800, irq 11
509
510Audio devices:
5110: EMU10K1 (DUPLEX)
512
513Synth devices: NOT ENABLED IN CONFIG
514
515Midi devices:
5160: EMU10K1 MPU-401 (UART)
517
518Timers:
5197: system timer
520
521Mixers:
5220: SigmaTel STAC9721/23
523</pre>
524
525<!-- TODO: remove this a few months after alsa-driver leaves the tree -->
526
527<p>
528The other most common issue users face is the dreaded "Unknown symbol in module"
529error. An example of the same is shown below.
530</p>
531
532<pre caption="Unknown Symbol in module error">
533# <i>/etc/init.d/alsasound start</i>
534 * Loading ALSA modules ...
535 * Loading: snd-card-0 ... [ ok ]
536 * Loading: snd-pcm-oss ...
537WARNING: Error inserting snd_mixer_oss
538(/lib/modules/2.6.12-gentoo-r6/kernel/sound/core/oss/snd-mixer-oss.ko): Unknown
539symbol in module, or unknown parameter (see dmesg) FATAL: Error inserting
540snd_pcm_oss
541(/lib/modules/2.6.12-gentoo-r6/kernel/sound/core/oss/snd-pcm-oss.ko): Unknown
542symbol in module, or unknown parameter (see dmesg)
543 [ !! ]
544 * Loading: snd-mixer-oss ...
545FATAL: Error inserting snd_mixer_oss
546(/lib/modules/2.6.12-gentoo-r6/kernel/sound/core/oss/snd-mixer-oss.ko): Unknown
547symbol in module, or unknown parameter (see dmesg)
548 [ !! ]
549 * Loading: snd-seq ... [ ok ]
550 * Loading: snd-emu10k1-synth ... [ ok ]
551 * Loading: snd-seq-midi ... [ ok ]
552 * Restoring Mixer Levels ... [ ok ]
553</pre>
554
555<p>
556And when you take a look at <c>dmesg</c> as suggested, you're quite likely to
557see:
558</p>
559
560<pre caption="dmesg output">
561<comment>(Only relevant portions are shown below)</comment>
562# <i>dmesg | less</i>
563ACPI: PCI Interrupt 0000:02:06.0[A] -> Link [APC3] -> GSI 18 (level, low) -> IRQ 209
564snd_mixer_oss: Unknown symbol snd_unregister_oss_device
565snd_mixer_oss: Unknown symbol snd_register_oss_device
566snd_mixer_oss: Unknown symbol snd_mixer_oss_notify_callback
567snd_mixer_oss: Unknown symbol snd_oss_info_register
568snd_pcm_oss: Unknown symbol snd_unregister_oss_device
569snd_pcm_oss: Unknown symbol snd_register_oss_device
570snd_pcm_oss: Unknown symbol snd_mixer_oss_ioctl_card
571snd_pcm_oss: Unknown symbol snd_oss_info_register
572snd_mixer_oss: Unknown symbol snd_unregister_oss_device
573snd_mixer_oss: Unknown symbol snd_register_oss_device
574snd_mixer_oss: Unknown symbol snd_mixer_oss_notify_callback
575snd_mixer_oss: Unknown symbol snd_oss_info_register
576</pre>
577
578<p>
579The above issue is caused when you switch from the <c>alsa-driver</c> to in-kernel
580ALSA because when you unmerge <c>alsa-driver</c> the module files are config
581protected and hence get left behind. So, when you switch to in-kernel
582drivers, running <c>modprobe</c> gives you a mix of <c>alsa-driver</c> and
583in-kernel modules thus causing the above errors.
584</p>
585
586<p>
587The solution is quite easy. We just need to manually remove the problem causing
588directory after you unmerge <c>alsa-driver</c>. Be sure to remove the correct
589kernel version and not the current one!
590</p>
591
592<pre caption="Removing the alsa-driver modules">
593# <i>rm -rf /lib/modules/$(uname -r)/alsa-driver</i>
594</pre>
595
596<p>
597Another reason for error messages similar to the ones above could be a file in
598<path>/etc/modprobe.d</path> supplying a <c>device_mode</c> parameter when it
599isn't required. Confirm that this is indeed the issue and find out which file
600is the culprit.
601</p>
602
603<pre caption="Confirming and searching for device_mode">
604<comment>(Check dmesg to confirm)</comment>
605# <i>dmesg | grep device_mode</i>
606snd: Unknown parameter `device_mode'
607<comment>(Now, to get to the source of the issue)</comment>
608# <i>grep device_mode /etc/modprobe.d/*</i>
609</pre>
610
611<p>
612Usually it is a file called <path>alsa</path> with the line <c>options snd
613device_mode=0666</c>. Remove this line and restart the <c>alsasound</c> service
614and that should take care of this issue.
615</p>
616
617<!-- End of removal notice -->
172 618
173</body> 619</body>
174</section> 620</section>
175</chapter> 621</chapter>
622
176<chapter> 623<chapter>
177<title>Configuring ALSA</title> 624<title>Other things ALSA</title>
178<section> 625<section id="midi">
179<title>Automatically Loading the Kernel Modules</title> 626<title>Setting up MIDI support</title>
180<body>
181
182<p>
183If you use a modular kernel (such as when using <c>genkernel</c>) you have to
184edit <path>/etc/modules.d/alsa</path> so that it activates the necesary modules
185at boot time. For the soundcard in our example:
186</p>
187
188<pre caption="/etc/modules.d/alsa">
189alias snd-card-0 snd-via82xx
190<comment># The following is only needed when you want OSS compatibility</comment>
191alias sound-slot-0 snd-card-0
192alias /dev/mixer snd-mixer-oss
193alias /dev/dsp snd-pcm-oss
194alias /dev/midi snd-seq-oss
195</pre>
196
197<p>
198Now run <c>modules-update</c> to save the changes you made to the
199<path>alsa</path> file into <path>/etc/modules.conf</path>:
200</p>
201
202<pre caption="Running modules-update">
203# <i>modules-update</i>
204</pre>
205
206</body> 627<body>
207</section>
208<section>
209<title>Verifying the Device Files</title>
210<body>
211 628
212<p>
213If you use DevFS (which is the default for Gentoo installations) make sure that
214<path>/etc/devfsd.conf</path> has the ALSA devices and permissions correctly
215registered:
216</p> 629<p>
217 630First, check to make sure that you enabled the <c>midi</c> USE flag in
218<pre caption="/etc/devfsd.conf"> 631<path>/etc/make.conf</path>. If you didn't, go ahead and add it now. You will
219# ALSA/OSS stuff 632also need to re-emerge any ALSA packages that use the <c>midi</c> flag, such as
220# Comment/change these if you want to change the permissions on 633<c>alsa-lib</c> and <c>alsa-utils</c>.
221# the audio devices
222LOOKUP snd MODLOAD ACTION snd
223LOOKUP dsp MODLOAD
224LOOKUP mixer MODLOAD
225LOOKUP midi MODLOAD
226REGISTER sound/.* PERMISSIONS root.audio 660
227REGISTER snd/.* PERMISSIONS root.audio 660
228</pre>
229
230</body>
231</section>
232<section>
233<title>Having ALSA Activated at Boot</title>
234<body>
235
236<p> 634</p>
237To activate ALSA support at boot, add the <c>alsasound</c> init script to the 635
238boot runlevel:
239</p> 636<p>
240 637If your sound card is one of those that come with on-board MIDI synthesizers
241<pre caption="Adding alsasound to the boot runlevel"> 638and you would like to listen to some .mid files, you have to install
242# <i>rc-update add alsasound boot</i> 639<c>awesfx</c> which is basically a set of utilities for controlling the AWE32
243# <i>/etc/init.d/alsasound start</i> 640driver. We need to install it first. If you don't have a hardware synthesizer,
244</pre> 641you can use a virtual one. Please see the section on
245 642<uri link="#vsynth">Virtual Synthesizers</uri> for more information.
246</body>
247</section>
248<section>
249<title>Unmute the Channels</title>
250<body>
251
252<p> 643</p>
253By default, all sound channels are muted. To fix this, run <c>amixer</c>:
254</p>
255 644
256<pre caption="Running amixer">
257# <i>amixer</i>
258</pre>
259
260<p>
261If <c>amixer</c> produces lots of output then you're ready to unmute the
262channels. If you receive an error, doublecheck that your soundcard module is
263started.
264</p>
265
266<p>
267Now unmute the <e>Master</e> and <e>PCM</e> channels. If this isn't sufficient,
268also unmute the <e>Center</e> and <e>Surround</e> channels.
269</p>
270
271<pre caption="Unmuting the sound channels">
272# <i>amixer set Master 100 unmute</i>
273# <i>amixer set PCM 100 unmute</i>
274<comment>(Only if the above isn't sufficient:)</comment>
275# <i>amixer set Center 100 unmute</i>
276# <i>amixer set Surround 100 unmute</i>
277</pre>
278
279<p>
280To check if your sound works, play a wave file (using <c>aplay</c>), mp3 (using
281<c>mpg123</c> or even <c>mplayer</c>) or any other sound file for that matter.
282</p>
283
284<p>
285To fine-tune the sound channel settings you can use the <c>alsamixer</c>
286application.
287</p>
288
289</body>
290</section>
291</chapter>
292<chapter>
293<title>Activating MIDI Support</title>
294<section>
295<title>Installing the Necessary Packages</title>
296<body>
297
298<p>
299Some soundcards come with onboard MIDI synthesizers. To use them, you must first
300install the <c>awesfx</c> package:
301</p>
302
303<pre caption="Installing the awesfx package"> 645<pre caption="Installing awesfx">
304# <i>emerge awesfx</i> 646# <i>emerge awesfx</i>
305</pre> 647</pre>
306 648
307<p> 649<note>
308If you have a collection of sound fonts somewhere, place them in 650You will need to copy over SoundFont (SF2) files from your sound card's driver
309<path>/usr/share/sfbank</path>. For instance, the SBLive has a sound font file 651CD or a Windows installation into <path>/usr/share/sounds/sf2/</path>. For
310called <path>8MBGMSFX.SF2</path> or <path>CT4GMSFX.SF2</path>. 652example a sound font file for the Creative SBLive! card would be 8MBGMSFX.SF2.
653</note>
654
311</p> 655<p>
312 656After copying over the Soundfont files, we can then play a midi file as shown.
657You can also add the <c>asfxload</c> command to
658<path>/etc/conf.d/local.start</path>, so that the sound font is loaded
659every time the system starts up.
313<p> 660</p>
314After copying over the sound font, select them using <c>sfxload</c>:
315</p>
316 661
662<note>
663<path>/mnt</path> paths mentioned in the code listing(s) below will <e>not</e>
664be the same in your machine. They are just an example. Please be careful to
665change the path to suit your machine.
666</note>
667
317<pre caption="Loading the sound font"> 668<pre caption="Loading Soundfonts">
669<comment>(First, copy the Soundfont)</comment>
670# <i>cp /mnt/win2k/Program\ Files/CreativeSBLive2k/SFBank/8MBGMSFX.SF2 /usr/share/sounds/sf2/</i>
671<comment>(Or get it from your SoundBlaster CD)</comment>
672# <i>cp /mnt/cdrom/AUDIO/ENGLISH/SFBANK/8MBGMSFX.SF2 /usr/share/sounds/sf2/</i>
673<comment>(We load the specific Soundfont)</comment>
318# <i>sfxload /usr/share/sfbank/8MBGMSFX.SF2</i> 674# <i>asfxload /usr/share/sounds/sf2/8MBGMSFX.SF2</i>
319</pre> 675</pre>
320 676
321<p>
322You must have this command run every time you boot, so it is adviseable to add
323it to <path>/etc/conf.d/local.start</path> as well.
324</p> 677<p>
325 678You can now play midi files using a program like <c>aplaymidi</c>. Run
679<c>aplaymidi -l</c> to get a list of available ports and then pick one
680to play the file on.
326<p> 681</p>
327If you can't find soundfonts on your driver CD you can download some online from 682
328<uri>http://www.parabola.demon.co.uk/alsa/awe64.html</uri>. 683<pre caption="Playing MIDI">
684<comment>(Check open ports)</comment>
685# <i>aplaymidi -l</i>
686 Port Client name Port name
687 64:0 EMU10K1 MPU-401 (UART) EMU10K1 MPU-401 (UART)
688 65:0 Emu10k1 WaveTable Emu10k1 Port 0
689 65:1 Emu10k1 WaveTable Emu10k1 Port 1
690 65:2 Emu10k1 WaveTable Emu10k1 Port 2
691 65:3 Emu10k1 WaveTable Emu10k1 Port 3
692<comment>(Pick a port, and play a mid file)</comment>
693# <i> aplaymidi --port=65:0 /mnt/shyam/music/midi/mi2.mid</i>
329</p> 694</pre>
330 695
331</body> 696</body>
332</section>
333<section> 697</section>
698<section id="vsynth">
334<title>Timidity++ Virtual Synthesizer</title> 699<title>Virtual Synthesizers</title>
335<body> 700<body>
336 701
337<p>
338If your sound card does not come with a hardware synthesizer (or you don't want
339to use it), you can use <c>timidity++</c> to provide you with a virtual
340synthesizer. Start by emerging this package:
341</p> 702<p>
703If your sound card lacks a hardware synthesizer, you could use a virtual one
704like <c>timidity++</c>. Installation is a breeze.
705</p>
342 706
343<pre caption="Installing Timidity++"> 707<pre caption="Installing timidity++">
344# <i>emerge timidity++</i> 708# <i>emerge timidity++</i>
345</pre> 709</pre>
346 710
347<p> 711<p>
348A sample configuration file will be installed for you in 712For timidity to play sounds, it needs a sound font. Fortunately, the ebuild will
349<path>/usr/share/timidity/config/timidity.cfg</path>. If you don't have a 713install some sound font packages for you. There are a few other font packages
350timidity++ configuration setup yet, you can just use this one. 714available in Portage, such as <c>timidity-freepats</c> and
351</p> 715<c>timidity-eawpatches</c>. You can have multiple sound font configurations
352 716installed, and you can place your own in <path>/usr/share/timidity/</path>. To
353<pre caption="Using the default Timidity++ configuration file"> 717switch between different timidity configurations, you should use
354# <i>cp /usr/share/timidity/config/timidity.cfg /usr/share/timidity</i> 718<c>eselect</c>.
355</pre>
356
357<p> 719</p>
358For timidity to play sounds, it needs a soundfont. If you do not have any,
359install <c>timidity-eawpatches</c> which will give you some soundfonts.
360</p>
361 720
362<pre caption="Installing timidity-eawpatches"> 721<pre caption="Changing configurations">
722# <i>eselect timidity list</i>
363# <i>emerge timidity-eawpatches</i> 723# <i>eselect timidity set eawpatches</i>
364</pre> 724</pre>
365 725
366<p> 726<p>
367Don't forget to add <c>timidity</c> to the default runlevel. 727Don't forget to add <c>timidity</c> to the default runlevel.
368</p> 728</p>
370<pre caption="Adding timidity to the default runlevel"> 730<pre caption="Adding timidity to the default runlevel">
371# <i>rc-update add timidity default</i> 731# <i>rc-update add timidity default</i>
372# <i>/etc/init.d/timidity start</i> 732# <i>/etc/init.d/timidity start</i>
373</pre> 733</pre>
374 734
735<p>
736You can now try out <uri link="#doc_chap4_pre3">Playing MIDI</uri> files.
737</p>
738
375</body> 739</body>
376</section>
377<section> 740</section>
378<title>Testing MIDI Support</title>
379<body>
380
381<p>
382You can use <c>pmidi</c> to test your MIDI configuration:
383</p>
384
385<pre caption="Installing pmidi">
386# <i>emerge pmidi</i>
387</pre>
388
389<p>
390To see what MIDI output ports are available on your system, use the <c>-l</c>
391option:
392</p>
393
394<pre caption="Viewing the MIDI output ports">
395# <i>pmidi -l</i>
396</pre>
397
398<p>
399If all looks fine, try playing a MIDI file to make sure everything works. With
400the <c>-p</c> option you define what MIDI port you want to use.
401</p>
402
403<pre caption="Playing a MIDI file">
404# <i>pmidi -p 65:0 "Final Fantasy 7 - Aerith' Theme.mid"</i>
405</pre>
406
407</body>
408</section>
409</chapter>
410<chapter>
411<title>Final Remarks</title>
412<section> 741<section>
413<title>Tools and Firmware</title> 742<title>Tools and Firmware</title>
414<body> 743<body>
415 744
416<p> 745<p>
417Some specific sound cards can benefit from certain tools provided by the 746Some specific sound cards can benefit from certain tools provided by the
418<c>alsa-tools</c> and <c>alsa-firmware</c> packages. If you need 747<c>alsa-tools</c> and <c>alsa-firmware</c> packages. You may install either with
419<c>alsa-tools</c>, be sure to define the ALSA_TOOLS variable in 748a simple <c>emerge</c>.
420<path>/etc/make.conf</path> with the tools you require. For instance:
421</p>
422
423<pre caption="Selecting ALSA Tools in /etc/make.conf">
424ALSA_TOOLS="as10k1 ac3dec"
425</pre>
426
427<p>
428Then install the <c>alsa-tools</c> (and/or <c>alsa-firmware</c>) package(s):
429</p> 749</p>
430 750
431<pre caption="Installing ALSA Tools"> 751<pre caption="Installing ALSA Tools">
432# <i>emerge alsa-tools</i> 752# <i>emerge alsa-tools</i>
433</pre> 753</pre>
434 754
435</body> 755</body>
436</section> 756</section>
437<section> 757<section>
438<title>Activating Joystick Support</title> 758<title>Multiple sound cards</title>
439<body>
440
441<p>
442If your soundcard has a joystick plug, you might be interested in activating
443joystick support for your soundcard. If so, start by verifying if your soundcard
444driver has a joystick parameter. You can verify this by running <c>modinfo</c>
445against your kernel module. For instance, for the <c>snd-via82xx</c>:
446</p>
447
448<pre caption="Running modinfo">
449# <i>modinfo snd-via82xx</i>
450filename: /lib/modules/2.4.22-ck2/snd-via82xx.o
451description: "VIA VT82xx audio"
452author: "Jaroslav Kysela &lt;perex@suse.cz&gt;"
453license: "GPL"
454parm: index int array (min = 1, max = 8), description "Index value for
455 VIA 82xx bridge."
456parm: id string array (min = 1, max = 8), description "ID string for VIA
457 82xx bridge."
458parm: enable int array (min = 1, max = 8), description "Enable audio part
459 of VIA 82xx bridge."
460parm: mpu_port long array (min = 1, max = 8), description "MPU-401 port.
461 (VT82C686x only)"
462<i>parm: joystick int array (min = 1, max = 8), description "Enable
463 joystick. (VT82C686x only)"</i>
464parm: ac97_clock int array (min = 1, max = 8), description "AC'97 codec
465 clock (default 48000Hz)."
466parm: dxs_support int array (min = 1, max = 8), description "Support for
467 DXS channels (0 = auto, 1 = enable, 2 = disable, 3 = 48k only, 4 =
468 no VRA)
469</pre>
470
471<p>
472If it has the <c>joystick</c> parameter, append <c>joystick=1</c> to your
473<c>options</c> line in <path>/etc/modules.d/alsa</path>. For instance:
474</p>
475
476<pre caption="Adding the joystick parameter">
477alias snd-card-0 snd-via82xx
478options snd-via82xx joystick=1
479</pre>
480
481</body> 759<body>
482</section> 760
761<p>
762You can have more than one sound card in your system simultaneously, provided
763that you have built ALSA as modules in your kernel. You just need to specify
764which should be started first in <path>/etc/modprobe.d/alsa.conf</path>. Your cards
765are identified by their driver names inside this file. 0 is the first card, 1 is
766the second, and so on. Here's an example for a system with two sound cards.
767</p>
768
769<pre caption="Two sound cards in /etc/modprobe.d/alsa.conf">
770options snd-emu10k1 index=0
771options snd-via82xx index=1
772</pre>
773
774<p>
775Or, if you have two cards that use the same driver, you specify them on the same
776line, using comma-separated numbers. Here's an example for a system with three
777sound cards, two of which are the same Intel High Definition Audio card.
778</p>
779
780<pre caption="Multiple sound cards in /etc/modprobe.d/alsa.conf">
781options snd-ymfpci index=0
782options snd-hda-intel index=1,2
783</pre>
784
785</body>
483<section> 786</section>
787<section>
788<title>Plugins</title>
789<body>
790
791<p>
792You may want to install some plugins for extra functionality.
793<c>alsa-plugins</c> is a collection of useful plugins, which include: PulseAudio
794output, a sample rate converter, jack (a low-latency audio server), and an
795encoder that lets you output 6-channel audio through digital S/PDIF connections
796(both optical and coaxial). You can choose which of its plugins you want
797installed by adding their USE flags to <path>/etc/portage/package.use</path>.
798</p>
799
800<pre caption="Installing alsa-plugins">
801# <i>emerge -avt alsa-plugins</i>
802</pre>
803
804</body>
805</section>
806<section>
807<title>A big thank you to...</title>
808<body>
809
810<p>
811Everyone who contributed to the earlier version of the Gentoo ALSA Guide:
812Vincent Verleye, Grant Goodyear, Arcady Genkin, Jeremy Huddleston,
813John P. Davis, Sven Vermeulen, Benny Chuang, Tiemo Kieft and Erwin.
814</p>
815
816</body>
817</section>
818<section>
484<title>Resources</title> 819<title>References</title>
485<body> 820<body>
486 821
487<ul> 822<ul>
488 <li><uri link="http://www.alsa-project.org">The ALSA Project</uri></li> 823 <li><uri link="http://www.alsa-project.org/">The ALSA Project</uri></li>
489 <li><uri link="http://www.djcj.org">ALSA Howto's and FAQs</uri></li>
490 <li><uri link="http://linux-sound.org">Linux Sound/MIDI Software</uri></li> 824 <li><uri link="http://linux-sound.org">Linux Sound/MIDI Software</uri></li>
491</ul> 825</ul>
492 826
493</body> 827</body>
494</section> 828</section>

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