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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 1.89 2013/02/23 18:20:55 swift 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>6</version>
44<date>May 18, 2004</date> 28<date>2013-02-23</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.x 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/portage/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>
88First of all, before continuing, make sure your kernel has <e>Sound Card
89Support</e> enabled. If you used <c>genkernel</c> to build your kernel, then
90this is automatically true. Otherwise reconfigure your kernel.
91</p> 124<p>
92 125Let us now configure the kernel to enable ALSA.
93<p> 126</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>
138 127
139<impo> 128<impo>
140Whenever you (re)compile your kernel sources, chances are that the ALSA drivers 129<c>genkernel</c> users should now run <c>genkernel --menuconfig all</c> and
141will be overwritten. It is therefore adviseable to rerun <c>emerge 130then 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 131ALSA</uri>.
143rebooted into the new kernel.
144</impo> 132</impo>
145 133
134<pre caption="Heading over to the source">
135# <i>cd /usr/src/linux</i>
136# <i>make menuconfig</i>
137</pre>
138
139<note>
140The above example assumes that <path>/usr/src/linux</path> symlink points to
141the kernel sources you want to use. Please ensure the same before proceeding.
142</note>
143
144<p>
145Now we will look at some of the options we will have to enable in the
146kernel to ensure proper ALSA support for our sound card.
147</p>
148
149<p>
150Please note that for ease of use, all examples show ALSA built as modules. It
151is advisable to follow the same as it then allows the use of <c>alsaconf</c>
152which is a boon when you want to configure your card. Please do <e>not</e> skip
153the <uri link="#alsa-config">Configuration</uri> section of this document. If
154you still like to have options built-in, ensure that you make changes to your
155config accordingly.
156</p>
157
158<pre caption="Kernel Options for ALSA">
159Device Drivers ---&gt;
160 Sound ---&gt;
161
162<comment>(This needs to be enabled)</comment>
163&lt;M&gt; Sound card support
164
165<comment>(Make sure OSS is disabled)</comment>
166Open Sound System ---&gt;
167 &lt; &gt; Open Sound System (DEPRECATED)
168
169<comment>(Move one step back and enter ALSA)</comment>
170Advanced Linux Sound Architecture ---&gt;
171 &lt;M&gt; Advanced Linux Sound Architecture
172 <comment>(Select this if you want MIDI sequencing and routing)</comment>
173 &lt;M&gt; Sequencer support
174 <comment>(Old style /dev/mixer* and /dev/dsp* support. Recommended.)</comment>
175 &lt;M&gt; OSS Mixer API
176 &lt;M&gt; OSS PCM (digital audio) API
177
178<comment>(You now have a choice of devices to enable support for. Generally,
179you will have one type of device and not more. If you have more than one
180sound card, please enable them all here.)</comment>
181
182<comment>(Mostly for testing and development purposes, not needed for normal
183users unless you know what you are doing.)</comment>
184Generic devices ---&gt;
185
186<comment>(For ISA Sound cards)</comment>
187ISA devices ---&gt;
188<comment>(IF you had the Gravis, you would select this option)</comment>
189 &lt;M&gt; Gravis UltraSound Extreme
190
191<comment>(Move one level back and into PCI devices. Most sound cards today are
192PCI devices)</comment>
193PCI devices ---&gt;
194 <comment>(We now select the emu10k1 driver for our card)</comment>
195 &lt;M&gt; Emu10k1 (SB Live!, Audigy, E-mu APS)
196 <comment>(Or an Intel card would be)</comment>
197 &lt;M&gt; Intel/SiS/nVidia/AMD/ALi AC97 Controller
198 <comment>(Or if you have a VIA Card)</comment>
199 &lt;M&gt; VIA 82C686A/B, 8233/8235 AC97 Controller
200
201<comment>(Move one level back and select in case you have an USB sound card)</comment>
202USB Devices ---&gt;
203</pre>
204
205<p>
206Now that your options are set, you can (re)compile the kernel and ALSA support
207for your card should be functional once you reboot into the new kernel. Don't
208forget to update your GRUB configuration to use the newly built kernel.
209You can now proceed to <uri link="#alsa-utilities">ALSA Utilities</uri> and
210see if everything is working as it should.
211</p>
212
146</body> 213</body>
147</section> 214</section>
215</chapter>
216
217<chapter>
218<title>Configuring/Testing ALSA</title>
148<section id="alsa-utils"> 219<section id="alsa-utilities">
149<title>Installing the ALSA Utils</title> 220<title>ALSA Utilities</title>
150<body> 221<body>
151 222
152<p>
153If you want backwards compatibility with OSS, you need to install
154<c>alsa-oss</c>:
155</p> 223<p>
156 224<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"> 225programs that are highly useful, including the ALSA Initscripts. Hence we
158# <i>emerge alsa-oss</i> 226strongly recommend that you install <c>alsa-utils</c>
159</pre>
160
161<p> 227</p>
162Now install the ALSA Utils on your system (this is mandatory):
163</p>
164 228
165<pre caption="Installing ALSA Utils"> 229<pre caption="Install alsa-utils">
166# <i>emerge alsa-utils</i> 230# <i>emerge alsa-utils</i>
167</pre> 231</pre>
168 232
169<p> 233<note>
170Now that the utils are installed, it is time to configure ALSA... 234If you did <e>not</e> compile ALSA as modules, please proceed to the <uri
235link="#initscript">ALSA Initscript</uri> section. The rest of you need to
236configure ALSA. This is made very easy by the existence of the <c>alsaconf</c>
237tool provided by <c>alsa-utils</c>.
238</note>
239
240</body>
241</section>
242<section id="alsa-config">
243<title>Configuration</title>
244<body>
245
171</p> 246<p>
247Recent versions of <c>udev</c> (<c>>=udev-103</c>) provide some degree of
248kernel-level autoconfiguration of your sound card. If possible, try to rely on
249just letting your kernel automatically setup your sound card for you. Otherwise,
250use <c>alsaconf</c> to configure your card, as shown below.
251</p>
252
253<note>
254Please shut down any programs that <e>might</e> access the sound card while
255running <c>alsaconf</c>.
256</note>
257
258<p>
259To configure your sound card just type <c>alsaconf</c> in a shell as root.
260</p>
261
262<pre caption="Invoking alsaconf">
263# <i>alsaconf</i>
264</pre>
265
266<p>
267You will now see a neat menu guided interface that will automatically probe
268your devices and try to find out your sound card. You will be asked to pick
269your sound card from a list. Once that's done, it will ask you permission to
270automatically make required changes to <path>/etc/modprobe.d/alsa.conf</path>.
271It will then adjust your volume settings to optimum levels, run
272<c>update-modules</c> and start the <path>/etc/init.d/alsasound</path> service.
273Once <c>alsaconf</c> exits, you can proceed with setting up the ALSA
274initscript.
275</p>
276
277</body>
278</section>
279<section id="initscript">
280<title>ALSA Initscript</title>
281<body>
282
283<p>
284We're now almost all setup. Whichever method you chose to install ALSA, you'll
285need to have something load your modules or initialize ALSA and restore your
286volume settings when your system comes up. The ALSA Initscript handles all of
287this for you and is called <c>alsasound</c>. Add it to the boot runlevel.
288</p>
289
290<pre caption="Adding ALSA to the boot runlevel">
291# <i>rc-update add alsasound boot</i>
292 * alsasound added to runlevel boot
293 * rc-update complete.
294</pre>
295
296<p>
297Next, just check the <path>/etc/conf.d/alsasound</path> file and ensure that
298SAVE_ON_STOP variable is set to yes. This saves your sound settings when you
299shutdown your system.
300</p>
301
302</body>
303</section>
304<section>
305<title>Audio Group</title>
306<body>
307
308<p>
309Before we move on to testing, there's one last <e>important</e> thing that needs
310to be setup. Rule of thumb in a *nix OS: Do not run as root unless needed.
311This applies here as well ;) How? Well, most of the times you should be logged
312in as a user and would like to listen to music or access your soundcard. For
313that to happen, you need to be in the "audio" group. At this point, we'll add
314users to the audio group, so that they won't have any issues when they want to
315access sound devices. We'll use <c>gpasswd</c> here and you need to be logged in
316as root for this to work.
317</p>
318
319<pre caption="Adding users to the audio group">
320<comment>(Substitute &lt;username&gt; with your user)</comment>
321# <i>gpasswd -a &lt;username&gt; audio </i>
322Adding user &lt;username&gt; to group audio
323</pre>
324
325</body>
326</section>
327<section>
328<title>Volume Check!</title>
329<body>
330
331<p>
332We've completed all the setups and prerequisites, so let's fire up ALSA. If
333you ran <c>alsaconf</c>, you can skip this step, since <c>alsaconf</c> already
334does this for you.
335</p>
336
337<pre caption="Start the service">
338# <i>/etc/init.d/alsasound start</i>
339</pre>
340
341<p>
342Now that the required things have been taken care of, we need to check up on
343the volume as in certain cases, it is muted. We use <c>alsamixer</c> for this
344purpose.
345</p>
346
347<pre caption="Starting alsamixer">
348<comment>(Opens up a console program. Only required settings are shown)</comment>
349# <i>alsamixer</i>
350</pre>
351
352<p>
353This is how the ALSA Mixer <e>might</e> look the first time you open it. Pay
354attention to the Master and PCM channels which both have an MM below them.
355That means they are muted. If you try to play anything with <c>alsamixer</c>
356in this state, you will not hear anything on your speakers.
357</p>
358
359<figure link="/images/docs/alsa-mixermuted.png" short="AlsaMixer Muted" caption="The Alsa Mixer Main Window, Muted"/>
360
361<p>
362Now, we shall unmute the channels, and set volume levels as needed.
363</p>
364
365<warn>
366Both Master <e>and</e> PCM need to be unmuted and set to audible volume levels
367if you want to hear some output on your speakers.
368</warn>
369
370<ul>
371 <li>
372 To move between channels, use your left and right arrow keys. (&lt;-
373 &amp; -&gt;)
374 </li>
375 <li>
376 To toggle mute, move to the specific channel, for example Master and press
377 the <e>m</e> key on the keyboard.
378 </li>
379 <li>
380 To increase and decrease the volume levels, use the up and down arrow keys
381 respectively.
382 </li>
383</ul>
384
385<note>
386Be careful when setting your Bass and Treble values. 50 is usually a good
387number for both. Extremely high values of Bass may cause <e>jarring</e>
388on speakers that are not designed to handle them.
389</note>
390
391<p>
392After you're all done, your ALSA Mixer should look similar to the one below.
393Note the 00 instead of the MM and also the volume levels for some optimum
394settings.
395</p>
396
397<figure link="/images/docs/alsa-mixerunmuted.png" short="AlsaMixer Unmuted" caption="Alsa Mixer ready to roll"/>
398
399</body>
400</section>
401<section>
402<title>Sound Check!</title>
403<body>
404
405<p>
406Finally. Some music. If everything above is perfect, you should now be able to
407listen to some good music. A quick way to test is to use a command line tool
408like <c>media-sound/madplay</c>. You could also use something more well known
409like <c>mpg123</c>. If you are an ogg fan, you could use <c>ogg123</c> provided
410by <c>media-sound/vorbis-tools</c>. Use any player you are comfortable with. As
411always, <c>emerge</c> what you need.
412</p>
413
414<pre caption="Getting the software">
415<comment>(Install the applications you want)</comment>
416# <i>emerge madplay mpg123</i>
417<comment>(To play .ogg files)</comment>
418# <i>emerge vorbis-tools</i>
419</pre>
420
421<p>
422And then play your favorite sound track...
423</p>
424
425<pre caption="Playing Music">
426# <i>madplay -v /mnt/shyam/Music/Paul\ Oakenfold\ -\ Dread\ Rock.mp3</i>
427MPEG Audio Decoder 0.15.2 (beta) - Copyright (C) 2000-2004 Robert Leslie et al.
428 Title: Dread Rock
429 Artist: Paul Oakenfold
430 Album: Matrix Reloaded
431 Year: 2003
432 Genre: Soundtrack
433 Soundtrack
434 00:04:19 Layer III, 160 kbps, 44100 Hz, joint stereo (MS), no CRC
435
436# <i>ogg123 Paul\ Oakenfold\ -\ Dread\ Rock.ogg</i>
437Audio Device: Advanced Linux Sound Architecture (ALSA) output
438
439Playing: Paul Oakenfold - Dread Rock.ogg
440Ogg Vorbis stream: 2 channel, 44100 Hz
441Genre: Soundtrack
442Transcoded: mp3;160
443Title: Dread Rock
444Artist: Paul Oakenfold
445Date: 2003
446Album: Matrix Reloaded
447Time: 00:11.31 [04:28.75] of 04:40.06 (200.6 kbps) Output Buffer 96.9%
448</pre>
449
450</body>
451</section>
452<section>
453<title>ALSA and USE</title>
454<body>
455
456<p>
457You can now add the <c>alsa</c> use flag to <path>/etc/portage/make.conf</path> to
458ensure that your applications that support ALSA get built with it. Some
459architectures like x86 and amd64 have the flag enabled by default.
460</p>
461
462</body>
463</section>
464<section>
465<title>Issues?</title>
466<body>
467
468<p>
469If for some reason you're unable to hear sound, the first thing to do would
470be to check your <uri link="#doc_chap3_pre6">alsamixer</uri> settings. 80% of
471the issues lie with muted channels or low volume. Also check your Window
472Manager's sound applet and verify that volumes are set to audible levels.
473</p>
474
475<p>
476<path>/proc</path> is your friend. And in this case, <path>/proc/asound</path>
477is your best friend. We shall just take a short look at how much info is made
478available to us there.
479</p>
480
481<pre caption="Fun with /proc/asound">
482<comment>(First and foremost, if /proc/asound/cards shows your card, ALSA has
483picked up your sound card fine.)</comment>
484# <i>cat /proc/asound/cards</i>
4850 [Live ]: EMU10K1 - Sound Blaster Live!
486 Sound Blaster Live! (rev.6, serial:0x80271102) at 0xb800, irq 11
487
488<comment>(This displays the current running ALSA version)</comment>
489# <i>cat /proc/asound/version</i>
490Advanced Linux Sound Architecture Driver Version 1.0.8 (Thu Jan 13 09:39:32 2005 UTC).
491
492<comment>(ALSA OSS emulation details)</comment>
493# <i>cat /proc/asound/oss/sndstat</i>
494Sound Driver:3.8.1a-980706 (ALSA v1.0.8 emulation code)
495Kernel: Linux airwolf.zion 2.6.11ac1 #2 Wed May 4 00:35:08 IST 2005 i686
496Config options: 0
497
498Installed drivers:
499Type 10: ALSA emulation
500
501Card config:
502Sound Blaster Live! (rev.6, serial:0x80271102) at 0xb800, irq 11
503
504Audio devices:
5050: EMU10K1 (DUPLEX)
506
507Synth devices: NOT ENABLED IN CONFIG
508
509Midi devices:
5100: EMU10K1 MPU-401 (UART)
511
512Timers:
5137: system timer
514
515Mixers:
5160: SigmaTel STAC9721/23
517</pre>
518
519<!-- TODO: remove this a few months after alsa-driver leaves the tree -->
520
521<p>
522The other most common issue users face is the dreaded "Unknown symbol in module"
523error. An example of the same is shown below.
524</p>
525
526<pre caption="Unknown Symbol in module error">
527# <i>/etc/init.d/alsasound start</i>
528 * Loading ALSA modules ...
529 * Loading: snd-card-0 ... [ ok ]
530 * Loading: snd-pcm-oss ...
531WARNING: Error inserting snd_mixer_oss
532(/lib/modules/2.6.12-gentoo-r6/kernel/sound/core/oss/snd-mixer-oss.ko): Unknown
533symbol in module, or unknown parameter (see dmesg) FATAL: Error inserting
534snd_pcm_oss
535(/lib/modules/2.6.12-gentoo-r6/kernel/sound/core/oss/snd-pcm-oss.ko): Unknown
536symbol in module, or unknown parameter (see dmesg)
537 [ !! ]
538 * Loading: snd-mixer-oss ...
539FATAL: Error inserting snd_mixer_oss
540(/lib/modules/2.6.12-gentoo-r6/kernel/sound/core/oss/snd-mixer-oss.ko): Unknown
541symbol in module, or unknown parameter (see dmesg)
542 [ !! ]
543 * Loading: snd-seq ... [ ok ]
544 * Loading: snd-emu10k1-synth ... [ ok ]
545 * Loading: snd-seq-midi ... [ ok ]
546 * Restoring Mixer Levels ... [ ok ]
547</pre>
548
549<p>
550And when you take a look at <c>dmesg</c> as suggested, you're quite likely to
551see:
552</p>
553
554<pre caption="dmesg output">
555<comment>(Only relevant portions are shown below)</comment>
556# <i>dmesg | less</i>
557ACPI: PCI Interrupt 0000:02:06.0[A] -> Link [APC3] -> GSI 18 (level, low) -> IRQ 209
558snd_mixer_oss: Unknown symbol snd_unregister_oss_device
559snd_mixer_oss: Unknown symbol snd_register_oss_device
560snd_mixer_oss: Unknown symbol snd_mixer_oss_notify_callback
561snd_mixer_oss: Unknown symbol snd_oss_info_register
562snd_pcm_oss: Unknown symbol snd_unregister_oss_device
563snd_pcm_oss: Unknown symbol snd_register_oss_device
564snd_pcm_oss: Unknown symbol snd_mixer_oss_ioctl_card
565snd_pcm_oss: Unknown symbol snd_oss_info_register
566snd_mixer_oss: Unknown symbol snd_unregister_oss_device
567snd_mixer_oss: Unknown symbol snd_register_oss_device
568snd_mixer_oss: Unknown symbol snd_mixer_oss_notify_callback
569snd_mixer_oss: Unknown symbol snd_oss_info_register
570</pre>
571
572<p>
573The above issue is caused when you switch from the <c>alsa-driver</c> to in-kernel
574ALSA because when you unmerge <c>alsa-driver</c> the module files are config
575protected and hence get left behind. So, when you switch to in-kernel
576drivers, running <c>modprobe</c> gives you a mix of <c>alsa-driver</c> and
577in-kernel modules thus causing the above errors.
578</p>
579
580<p>
581The solution is quite easy. We just need to manually remove the problem causing
582directory after you unmerge <c>alsa-driver</c>. Be sure to remove the correct
583kernel version and not the current one!
584</p>
585
586<pre caption="Removing the alsa-driver modules">
587# <i>rm -rf /lib/modules/$(uname -r)/alsa-driver</i>
588</pre>
589
590<p>
591Another reason for error messages similar to the ones above could be a file in
592<path>/etc/modprobe.d</path> supplying a <c>device_mode</c> parameter when it
593isn't required. Confirm that this is indeed the issue and find out which file
594is the culprit.
595</p>
596
597<pre caption="Confirming and searching for device_mode">
598<comment>(Check dmesg to confirm)</comment>
599# <i>dmesg | grep device_mode</i>
600snd: Unknown parameter `device_mode'
601<comment>(Now, to get to the source of the issue)</comment>
602# <i>grep device_mode /etc/modprobe.d/*</i>
603</pre>
604
605<p>
606Usually it is a file called <path>alsa</path> with the line <c>options snd
607device_mode=0666</c>. Remove this line and restart the <c>alsasound</c> service
608and that should take care of this issue.
609</p>
610
611<!-- End of removal notice -->
172 612
173</body> 613</body>
174</section> 614</section>
175</chapter> 615</chapter>
616
176<chapter> 617<chapter>
177<title>Configuring ALSA</title> 618<title>Other things ALSA</title>
178<section> 619<section id="midi">
179<title>Automatically Loading the Kernel Modules</title> 620<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> 621<body>
207</section>
208<section>
209<title>Verifying the Device Files</title>
210<body>
211 622
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> 623<p>
217 624First, check to make sure that you enabled the <c>midi</c> USE flag in
218<pre caption="/etc/devfsd.conf"> 625<path>/etc/portage/make.conf</path>. If you didn't, go ahead and add it now. You will
219# ALSA/OSS stuff 626also 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 627<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> 628</p>
237To activate ALSA support at boot, add the <c>alsasound</c> init script to the 629
238boot runlevel:
239</p> 630<p>
240 631If your sound card is one of those that come with on-board MIDI synthesizers
241<pre caption="Adding alsasound to the boot runlevel"> 632and you would like to listen to some .mid files, you have to install
242# <i>rc-update add alsasound boot</i> 633<c>awesfx</c> which is basically a set of utilities for controlling the AWE32
243# <i>/etc/init.d/alsasound start</i> 634driver. We need to install it first. If you don't have a hardware synthesizer,
244</pre> 635you can use a virtual one. Please see the section on
245 636<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> 637</p>
253By default, all sound channels are muted. To fix this, run <c>amixer</c>:
254</p>
255 638
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"> 639<pre caption="Installing awesfx">
304# <i>emerge awesfx</i> 640# <i>emerge awesfx</i>
305</pre> 641</pre>
306 642
307<p> 643<note>
308If you have a collection of sound fonts somewhere, place them in 644You 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 645CD or a Windows installation into <path>/usr/share/sounds/sf2/</path>. For
310called <path>8MBGMSFX.SF2</path> or <path>CT4GMSFX.SF2</path>. 646example a sound font file for the Creative SBLive! card would be 8MBGMSFX.SF2.
647</note>
648
311</p> 649<p>
312 650After copying over the Soundfont files, we can then play a midi file as shown.
651You can also add the <c>asfxload</c> command to
652<path>/etc/conf.d/local.start</path>, so that the sound font is loaded
653every time the system starts up.
313<p> 654</p>
314After copying over the sound font, select them using <c>sfxload</c>:
315</p>
316 655
656<note>
657<path>/mnt</path> paths mentioned in the code listing(s) below will <e>not</e>
658be the same in your machine. They are just an example. Please be careful to
659change the path to suit your machine.
660</note>
661
317<pre caption="Loading the sound font"> 662<pre caption="Loading Soundfonts">
663<comment>(First, copy the Soundfont)</comment>
664# <i>cp /mnt/win2k/Program\ Files/CreativeSBLive2k/SFBank/8MBGMSFX.SF2 /usr/share/sounds/sf2/</i>
665<comment>(Or get it from your SoundBlaster CD)</comment>
666# <i>cp /mnt/cdrom/AUDIO/ENGLISH/SFBANK/8MBGMSFX.SF2 /usr/share/sounds/sf2/</i>
667<comment>(We load the specific Soundfont)</comment>
318# <i>sfxload /usr/share/sfbank/8MBGMSFX.SF2</i> 668# <i>asfxload /usr/share/sounds/sf2/8MBGMSFX.SF2</i>
319</pre> 669</pre>
320 670
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> 671<p>
325 672You can now play midi files using a program like <c>aplaymidi</c>. Run
673<c>aplaymidi -l</c> to get a list of available ports and then pick one
674to play the file on.
326<p> 675</p>
327If you can't find soundfonts on your driver CD you can download some online from 676
328<uri>http://www.parabola.demon.co.uk/alsa/awe64.html</uri>. 677<pre caption="Playing MIDI">
678<comment>(Check open ports)</comment>
679# <i>aplaymidi -l</i>
680 Port Client name Port name
681 64:0 EMU10K1 MPU-401 (UART) EMU10K1 MPU-401 (UART)
682 65:0 Emu10k1 WaveTable Emu10k1 Port 0
683 65:1 Emu10k1 WaveTable Emu10k1 Port 1
684 65:2 Emu10k1 WaveTable Emu10k1 Port 2
685 65:3 Emu10k1 WaveTable Emu10k1 Port 3
686<comment>(Pick a port, and play a mid file)</comment>
687# <i> aplaymidi --port=65:0 /mnt/shyam/music/midi/mi2.mid</i>
329</p> 688</pre>
330 689
331</body> 690</body>
332</section>
333<section> 691</section>
692<section id="vsynth">
334<title>Timidity++ Virtual Synthesizer</title> 693<title>Virtual Synthesizers</title>
335<body> 694<body>
336 695
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> 696<p>
697If your sound card lacks a hardware synthesizer, you could use a virtual one
698like <c>timidity++</c>. Installation is a breeze.
699</p>
342 700
343<pre caption="Installing Timidity++"> 701<pre caption="Installing timidity++">
344# <i>emerge timidity++</i> 702# <i>emerge timidity++</i>
345</pre> 703</pre>
346 704
347<p> 705<p>
348A sample configuration file will be installed for you in 706For 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 707install some sound font packages for you. There are a few other font packages
350timidity++ configuration setup yet, you can just use this one. 708available in Portage, such as <c>timidity-freepats</c> and
351</p> 709<c>timidity-eawpatches</c>. You can have multiple sound font configurations
352 710installed, and you can place your own in <path>/usr/share/timidity/</path>. To
353<pre caption="Using the default Timidity++ configuration file"> 711switch between different timidity configurations, you should use
354# <i>cp /usr/share/timidity/config/timidity.cfg /usr/share/timidity</i> 712<c>eselect</c>.
355</pre>
356
357<p> 713</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>
361 714
362<pre caption="Installing timidity-eawpatches"> 715<pre caption="Changing configurations">
716# <i>eselect timidity list</i>
363# <i>emerge timidity-eawpatches</i> 717# <i>eselect timidity set eawpatches</i>
364</pre> 718</pre>
365 719
366<p> 720<p>
367Don't forget to add <c>timidity</c> to the default runlevel. 721Don't forget to add <c>timidity</c> to the default runlevel.
368</p> 722</p>
370<pre caption="Adding timidity to the default runlevel"> 724<pre caption="Adding timidity to the default runlevel">
371# <i>rc-update add timidity default</i> 725# <i>rc-update add timidity default</i>
372# <i>/etc/init.d/timidity start</i> 726# <i>/etc/init.d/timidity start</i>
373</pre> 727</pre>
374 728
729<p>
730You can now try out <uri link="#doc_chap4_pre3">Playing MIDI</uri> files.
731</p>
732
375</body> 733</body>
376</section>
377<section> 734</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> 735<section>
413<title>Tools and Firmware</title> 736<title>Tools and Firmware</title>
414<body> 737<body>
415 738
416<p> 739<p>
417Some specific sound cards can benefit from certain tools provided by the 740Some 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 741<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 742a 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> 743</p>
430 744
431<pre caption="Installing ALSA Tools"> 745<pre caption="Installing ALSA Tools">
432# <i>emerge alsa-tools</i> 746# <i>emerge alsa-tools</i>
433</pre> 747</pre>
434 748
435</body> 749</body>
436</section> 750</section>
437<section> 751<section>
438<title>Activating Joystick Support</title> 752<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> 753<body>
482</section> 754
755<p>
756You can have more than one sound card in your system simultaneously, provided
757that you have built ALSA as modules in your kernel. You just need to specify
758which should be started first in <path>/etc/modprobe.d/alsa.conf</path>. Your cards
759are identified by their driver names inside this file. 0 is the first card, 1 is
760the second, and so on. Here's an example for a system with two sound cards.
761</p>
762
763<pre caption="Two sound cards in /etc/modprobe.d/alsa.conf">
764options snd-emu10k1 index=0
765options snd-via82xx index=1
766</pre>
767
768<p>
769Or, if you have two cards that use the same driver, you specify them on the same
770line, using comma-separated numbers. Here's an example for a system with three
771sound cards, two of which are the same Intel High Definition Audio card.
772</p>
773
774<pre caption="Multiple sound cards in /etc/modprobe.d/alsa.conf">
775options snd-ymfpci index=0
776options snd-hda-intel index=1,2
777</pre>
778
779</body>
483<section> 780</section>
781<section>
782<title>Plugins</title>
783<body>
784
785<p>
786You may want to install some plugins for extra functionality.
787<c>alsa-plugins</c> is a collection of useful plugins, which include: PulseAudio
788output, a sample rate converter, jack (a low-latency audio server), and an
789encoder that lets you output 6-channel audio through digital S/PDIF connections
790(both optical and coaxial). You can choose which of its plugins you want
791installed by adding their USE flags to <path>/etc/portage/package.use</path>.
792</p>
793
794<pre caption="Installing alsa-plugins">
795# <i>emerge -avt alsa-plugins</i>
796</pre>
797
798</body>
799</section>
800<section>
801<title>A big thank you to...</title>
802<body>
803
804<p>
805Everyone who contributed to the earlier version of the Gentoo ALSA Guide:
806Vincent Verleye, Grant Goodyear, Arcady Genkin, Jeremy Huddleston,
807John P. Davis, Sven Vermeulen, Benny Chuang, Tiemo Kieft and Erwin.
808</p>
809
810</body>
811</section>
812<section>
484<title>Resources</title> 813<title>References</title>
485<body> 814<body>
486 815
487<ul> 816<ul>
488 <li><uri link="http://www.alsa-project.org">The ALSA Project</uri></li> 817 <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> 818 <li><uri link="http://linux-sound.org">Linux Sound/MIDI Software</uri></li>
491</ul> 819</ul>
492 820
493</body> 821</body>
494</section> 822</section>

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