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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 1.81 2008/03/05 09:16:49 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 link="/doc/en/alsa-guide.xml">
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>2.23</version>
44<date>May 18, 2004</date> 28<date>2008-03-05</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
54development of a high-quality Linux sound subsystem. It has replaced OSS 38audio and MIDI (<e>Musical Instrument Digital Interface</e>) functionality to
55(<e>Open Sound System</e>) as default sound subsystem in the 2.6 kernel series. 39the Linux operating system. ALSA is the default sound subsystem in the 2.6
56</p> 40kernel thereby replacing OSS (<e>Open Sound System</e>), which was used in the
57 412.4 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.
50</p>
51
52</body>
53</section>
54<section>
55<title>ALSA on Gentoo</title>
56<body>
57
58<p>
59Historically, Gentoo offered two ways to get ALSA up and running: the
60<e>in-kernel</e> driver and the external <c>alsa-driver</c> package. The two
61solutions essentially do the same thing; this made supporting the external
62package extremely difficult and time-consuming. The Gentoo maintainers decided
63to discontinue support for the <c>alsa-driver</c> package, concentrating their
64resources on the ALSA drivers available within the Linux kernel. This guide will
65focus solely on configuring ALSA via the in-kernel driver.
66</p>
67
68<p>
69If you still require the <c>alsa-driver</c> package, please email the <mail
70link="alsa-bugs@gentoo.org">Gentoo ALSA maintainers</mail> with why the
71in-kernel drivers don't work for you. Be sure to include detailed error logs.
63</p> 72</p>
64 73
65</body> 74</body>
66</section> 75</section>
67</chapter> 76</chapter>
77
68<chapter> 78<chapter>
69<title>Installing ALSA</title> 79<title>Installing ALSA</title>
80<section id="lspci">
81<title>Before you proceed</title>
82<body>
83
84<p>
85First, you need to know what drivers your sound card uses. In most cases, sound
86cards (onboard and otherwise) are PCI based and <c>lspci</c> will help you in
87digging out the required information. Please <c>emerge sys-apps/pciutils</c> to
88get <c>lspci</c>, if you don't have it installed already. In case you have a USB
89sound card, <c>lsusb</c> from <c>sys-apps/usbutils</c> <e>might</e> be of help.
90For ISA cards, try using <c>sys-apps/isapnptools</c>. Also, the following pages
91<e>may</e> help users with ISA based sound cards:
92</p>
93
94<ul>
95 <li>
96 <uri link="http://www.roestock.demon.co.uk/isapnptools/">The ISAPNPTOOLS
97 Page</uri>
98 </li>
99 <li>
100 <uri link="http://www2.linuxjournal.com/article/3269">LinuxJournal PnP
101 Article</uri>
102 </li>
103 <li>
104 <uri link="http://www.tldp.org/HOWTO/Sound-HOWTO/x320.html">TLDP Sound
105 HowTo</uri>
106 </li>
107</ul>
108
109<note>
110For ease of use/explanation, we assume the user has a PCI based sound card for
111the remainder of this guide.
112</note>
113
114<p>
115We now proceed to find out details about the sound card.
116</p>
117
118<pre caption="Soundcard Details">
119# <i>lspci -v | grep -i audio</i>
1200000:00:0a.0 Multimedia audio controller: Creative Labs SB Live! EMU10k1 (rev 06)
121</pre>
122
123<p>
124We now know that the sound card on the machine is a Sound Blaster Live! and the
125card manufacturer is Creative Labs. Head over to the <uri
126link="http://bugtrack.alsa-project.org/main/index.php/Matrix:Main">ALSA
127Soundcard Matrix</uri> page and select Creative Labs from the list. You will
128be taken to the Creative Labs matrix page where you can see that the SB Live!
129uses the <c>emu10k1</c> module. That is the information we need for now. If
130you are interested in detailed information, you can click on the link next to
131the "Details" and that will take you to the <c>emu10k1</c> specific page.
132</p>
133
134<p>
135If you intend to use MIDI, then you should add <c>midi</c> to your USE flags in
136<path>/etc/make.conf</path> before emerging any ALSA packages. Later in the
137guide, we will show you how to set up <uri link="#midi">MIDI support</uri>.
138</p>
139
140</body>
70<section> 141</section>
71<title>USE Flags</title> 142<section id="kernel">
72<body> 143<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> 144<body>
82</section>
83<section>
84<title>Kernel Modules</title>
85<body>
86 145
87<p> 146<note>
88First of all, before continuing, make sure your kernel has <e>Sound Card 147Since 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 148check that your kernel is a 2.6 series kernel. This method will <e>not</e> work
90this is automatically true. Otherwise reconfigure your kernel. 149on a 2.4 kernel.
150</note>
151
91</p> 152<p>
92 153Let us now configure the kernel to enable ALSA.
93<p> 154</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>
138 155
139<impo> 156<impo>
140Whenever you (re)compile your kernel sources, chances are that the ALSA drivers 157<c>genkernel</c> users should now run <c>genkernel --menuconfig all</c> and
141will be overwritten. It is therefore adviseable to rerun <c>emerge 158then 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 159ALSA</uri>.
143rebooted into the new kernel.
144</impo> 160</impo>
145 161
162<pre caption="Heading over to the source">
163# <i>cd /usr/src/linux</i>
164# <i>make menuconfig</i>
165</pre>
166
167<note>
168The above example assumes that <path>/usr/src/linux</path> symlink points to
169the kernel sources you want to use. Please ensure the same before proceeding.
170</note>
171
172<p>
173Now we will look at some of the options we will have to enable in the 2.6
174kernel to ensure proper ALSA support for our sound card.
175</p>
176
177<p>
178Please note that for ease of use, all examples show ALSA built as modules. It
179is advisable to follow the same as it then allows the use of <c>alsaconf</c>
180which is a boon when you want to configure your card. Please do <e>not</e> skip
181the <uri link="#alsa-config">Configuration</uri> section of this document. If
182you still like to have options built-in, ensure that you make changes to your
183config accordingly.
184</p>
185
186<pre caption="Kernel Options for ALSA">
187Device Drivers ---&gt;
188 Sound ---&gt;
189
190<comment>(This needs to be enabled)</comment>
191&lt;M&gt; Sound card support
192
193<comment>(Make sure OSS is disabled)</comment>
194Open Sound System ---&gt;
195 &lt; &gt; Open Sound System (DEPRECATED)
196
197<comment>(Move one step back and enter ALSA)</comment>
198Advanced Linux Sound Architecture ---&gt;
199 &lt;M&gt; Advanced Linux Sound Architecture
200 <comment>(Select this if you want MIDI sequencing and routing)</comment>
201 &lt;M&gt; Sequencer support
202 <comment>(Old style /dev/mixer* and /dev/dsp* support. Recommended.)</comment>
203 &lt;M&gt; OSS Mixer API
204 &lt;M&gt; OSS PCM (digital audio) API
205
206<comment>(You now have a choice of devices to enable support for. Generally,
207you will have one type of device and not more. If you have more than one
208sound card, please enable them all here.)</comment>
209
210<comment>(Mostly for testing and development purposes, not needed for normal
211users unless you know what you are doing.)</comment>
212Generic devices ---&gt;
213
214<comment>(For ISA Sound cards)</comment>
215ISA devices ---&gt;
216<comment>(IF you had the Gravis, you would select this option)</comment>
217 &lt;M&gt; Gravis UltraSound Extreme
218
219<comment>(Move one level back and into PCI devices. Most sound cards today are
220PCI devices)</comment>
221PCI devices ---&gt;
222 <comment>(We now select the emu10k1 driver for our card)</comment>
223 &lt;M&gt; Emu10k1 (SB Live!, Audigy, E-mu APS)
224 <comment>(Or an Intel card would be)</comment>
225 &lt;M&gt; Intel/SiS/nVidia/AMD/ALi AC97 Controller
226 <comment>(Or if you have a VIA Card)</comment>
227 &lt;M&gt; VIA 82C686A/B, 8233/8235 AC97 Controller
228
229<comment>(Move one level back and select in case you have an USB sound card)</comment>
230USB Devices ---&gt;
231</pre>
232
233<p>
234Now that your options are set, you can (re)compile the kernel and ALSA support
235for your card should be functional once you reboot into the new kernel. Don't
236forget to update your GRUB configuration to use the newly built kernel.
237You can now proceed to <uri link="#alsa-utilities">ALSA Utilities</uri> and
238see if everything is working as it should.
239</p>
240
146</body> 241</body>
147</section> 242</section>
243</chapter>
244
245<chapter>
246<title>Configuring/Testing ALSA</title>
148<section id="alsa-utils"> 247<section id="alsa-utilities">
149<title>Installing the ALSA Utils</title> 248<title>ALSA Utilities</title>
150<body> 249<body>
151 250
152<p>
153If you want backwards compatibility with OSS, you need to install
154<c>alsa-oss</c>:
155</p> 251<p>
156 252<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"> 253programs that are highly useful, including the ALSA Initscripts. Hence we
158# <i>emerge alsa-oss</i> 254strongly recommend that you install <c>alsa-utils</c>
159</pre>
160
161<p> 255</p>
162Now install the ALSA Utils on your system (this is mandatory):
163</p>
164 256
165<pre caption="Installing ALSA Utils"> 257<pre caption="Install alsa-utils">
166# <i>emerge alsa-utils</i> 258# <i>emerge alsa-utils</i>
167</pre> 259</pre>
168 260
169<p> 261<note>
170Now that the utils are installed, it is time to configure ALSA... 262If you did <e>not</e> compile ALSA as modules, please proceed to the <uri
263link="#initscript">ALSA Initscript</uri> section. The rest of you need to
264configure ALSA. This is made very easy by the existence of the <c>alsaconf</c>
265tool provided by <c>alsa-utils</c>.
266</note>
267
268</body>
269</section>
270<section id="alsa-config">
271<title>Configuration</title>
272<body>
273
171</p> 274<p>
275Recent versions of <c>udev</c> (<c>>=udev-103</c>) provide some degree of
276kernel-level autoconfiguration of your sound card. If possible, try to rely on
277just letting your kernel automatically setup your sound card for you. Otherwise,
278use <c>alsaconf</c> to configure your card, as shown below.
279</p>
280
281<note>
282Please shut down any programs that <e>might</e> access the sound card while
283running <c>alsaconf</c>.
284</note>
285
286<p>
287To configure your sound card just type <c>alsaconf</c> in a shell as root.
288</p>
289
290<pre caption="Invoking alsaconf">
291# <i>alsaconf</i>
292</pre>
293
294<p>
295You will now see a neat menu guided interface that will automatically probe
296your devices and try to find out your sound card. You will be asked to pick
297your sound card from a list. Once that's done, it will ask you permission to
298automatically make required changes to <path>/etc/modules.d/alsa</path>.
299It will then adjust your volume settings to optimum levels, run
300<c>update-modules</c> and start the <path>/etc/init.d/alsasound</path> service.
301Once <c>alsaconf</c> exits, you can proceed with setting up the ALSA
302initscript.
303</p>
304
305</body>
306</section>
307<section id="initscript">
308<title>ALSA Initscript</title>
309<body>
310
311<p>
312We're now almost all setup. Whichever method you chose to install ALSA, you'll
313need to have something load your modules or initialize ALSA and restore your
314volume settings when your system comes up. The ALSA Initscript handles all of
315this for you and is called <c>alsasound</c>. Add it to the boot runlevel.
316</p>
317
318<pre caption="Adding ALSA to the boot runlevel">
319# <i>rc-update add alsasound boot</i>
320 * alsasound added to runlevel boot
321 * rc-update complete.
322</pre>
323
324<p>
325Next, just check the <path>/etc/conf.d/alsasound</path> file and ensure that
326SAVE_ON_STOP variable is set to yes. This saves your sound settings when you
327shutdown your system.
328</p>
329
330</body>
331</section>
332<section>
333<title>Audio Group</title>
334<body>
335
336<p>
337Before we move on to testing, there's one last <e>important</e> thing that needs
338to be setup. Rule of thumb in a *nix OS: Do not run as root unless needed.
339This applies here as well ;) How? Well, most of the times you should be logged
340in as a user and would like to listen to music or access your soundcard. For
341that to happen, you need to be in the "audio" group. At this point, we'll add
342users to the audio group, so that they won't have any issues when they want to
343access sound devices. We'll use <c>gpasswd</c> here and you need to be logged in
344as root for this to work.
345</p>
346
347<pre caption="Adding users to the audio group">
348<comment>(Substitute &lt;username&gt; with your user)</comment>
349# <i>gpasswd -a &lt;username&gt; audio </i>
350Adding user &lt;username&gt; to group audio
351</pre>
352
353</body>
354</section>
355<section>
356<title>Volume Check!</title>
357<body>
358
359<p>
360We've completed all the setups and prerequisites, so let's fire up ALSA. If
361you ran <c>alsaconf</c>, you can skip this step, since <c>alsaconf</c> already
362does this for you.
363</p>
364
365<pre caption="Start the service">
366# <i>/etc/init.d/alsasound start</i>
367</pre>
368
369<p>
370Now that the required things have been taken care of, we need to check up on
371the volume as in certain cases, it is muted. We use <c>alsamixer</c> for this
372purpose.
373</p>
374
375<pre caption="Starting alsamixer">
376<comment>(Opens up a console program. Only required settings are shown)</comment>
377# <i>alsamixer</i>
378</pre>
379
380<impo>
381If you have issues starting up <c>alsamixer</c> and get errors such as
382alsamixer: function snd_ctl_open failed for default: No such file or directory,
383this is usually an issue with udev setting up the devices. Run <c>killall
384udevd; udevstart</c> to reload <path>/dev</path> entries and fire up
385<c>alsamixer</c>. It should solve the issue.
386</impo>
387
388<p>
389This is how the ALSA Mixer <e>might</e> look the first time you open it. Pay
390attention to the Master and PCM channels which both have an MM below them.
391That means they are muted. If you try to play anything with <c>alsamixer</c>
392in this state, you will not hear anything on your speakers.
393</p>
394
395<figure link="/images/docs/alsa-mixermuted.png" short="AlsaMixer Muted" caption="The Alsa Mixer Main Window, Muted"/>
396
397<p>
398Now, we shall unmute the channels, and set volume levels as needed.
399</p>
400
401<warn>
402Both Master <e>and</e> PCM need to be unmuted and set to audible volume levels
403if you want to hear some output on your speakers.
404</warn>
405
406<ul>
407 <li>
408 To move between channels, use your left and right arrow keys. (&lt;-
409 &amp; -&gt;)
410 </li>
411 <li>
412 To toggle mute, move to the specific channel, for example Master and press
413 the <e>m</e> key on the keyboard.
414 </li>
415 <li>
416 To increase and decrease the volume levels, use the up and down arrow keys
417 respectively.
418 </li>
419</ul>
420
421<note>
422Be careful when setting your Bass and Treble values. 50 is usually a good
423number for both. Extremely high values of Bass may cause <e>jarring</e>
424on speakers that are not designed to handle them.
425</note>
426
427<p>
428After you're all done, your ALSA Mixer should look similar to the one below.
429Note the 00 instead of the MM and also the volume levels for some optimum
430settings.
431</p>
432
433<figure link="/images/docs/alsa-mixerunmuted.png" short="AlsaMixer Unmuted" caption="Alsa Mixer ready to roll"/>
434
435</body>
436</section>
437<section>
438<title>Sound Check!</title>
439<body>
440
441<p>
442Finally. Some music. If everything above is perfect, you should now be able to
443listen to some good music. A quick way to test is to use a command line tool
444like <c>media-sound/madplay</c>. You could also use something more well known
445like <c>mpg123</c>. If you are an ogg fan, you could use <c>ogg123</c> provided
446by <c>media-sound/vorbis-tools</c>. Use any player you are comfortable with. As
447always, <c>emerge</c> what you need.
448</p>
449
450<pre caption="Getting the software">
451<comment>(Install the applications you want)</comment>
452# <i>emerge madplay mpg123</i>
453<comment>(To play .ogg files)</comment>
454# <i>emerge vorbis-tools</i>
455</pre>
456
457<p>
458And then play your favorite sound track...
459</p>
460
461<pre caption="Playing Music">
462# <i>madplay -v /mnt/shyam/Music/Paul\ Oakenfold\ -\ Dread\ Rock.mp3</i>
463MPEG Audio Decoder 0.15.2 (beta) - Copyright (C) 2000-2004 Robert Leslie et al.
464 Title: Dread Rock
465 Artist: Paul Oakenfold
466 Album: Matrix Reloaded
467 Year: 2003
468 Genre: Soundtrack
469 Soundtrack
470 00:04:19 Layer III, 160 kbps, 44100 Hz, joint stereo (MS), no CRC
471
472# <i>ogg123 Paul\ Oakenfold\ -\ Dread\ Rock.ogg</i>
473Audio Device: Advanced Linux Sound Architecture (ALSA) output
474
475Playing: Paul Oakenfold - Dread Rock.ogg
476Ogg Vorbis stream: 2 channel, 44100 Hz
477Genre: Soundtrack
478Transcoded: mp3;160
479Title: Dread Rock
480Artist: Paul Oakenfold
481Date: 2003
482Album: Matrix Reloaded
483Time: 00:11.31 [04:28.75] of 04:40.06 (200.6 kbps) Output Buffer 96.9%
484</pre>
485
486</body>
487</section>
488<section>
489<title>ALSA and USE</title>
490<body>
491
492<p>
493You can now add the <c>alsa</c> use flag to <path>/etc/make.conf</path> to
494ensure that your applications that support ALSA get built with it. Some
495architectures like x86 and amd64 have the flag enabled by default.
496</p>
497
498</body>
499</section>
500<section>
501<title>Issues?</title>
502<body>
503
504<p>
505If for some reason you're unable to hear sound, the first thing to do would
506be to check your <uri link="#doc_chap3_pre6">alsamixer</uri> settings. 80% of
507the issues lie with muted channels or low volume. Also check your Window
508Manager's sound applet and verify that volumes are set to audible levels.
509</p>
510
511<p>
512<path>/proc</path> is your friend. And in this case, <path>/proc/asound</path>
513is your best friend. We shall just take a short look at how much info is made
514available to us there.
515</p>
516
517<pre caption="Fun with /proc/asound">
518<comment>(First and foremost, if /proc/asound/cards shows your card, ALSA has
519picked up your sound card fine.)</comment>
520# <i>cat /proc/asound/cards</i>
5210 [Live ]: EMU10K1 - Sound Blaster Live!
522 Sound Blaster Live! (rev.6, serial:0x80271102) at 0xb800, irq 11
523
524<comment>(This displays the current running ALSA version)</comment>
525# <i>cat /proc/asound/version</i>
526Advanced Linux Sound Architecture Driver Version 1.0.8 (Thu Jan 13 09:39:32 2005 UTC).
527
528<comment>(ALSA OSS emulation details)</comment>
529# <i>cat /proc/asound/oss/sndstat</i>
530Sound Driver:3.8.1a-980706 (ALSA v1.0.8 emulation code)
531Kernel: Linux airwolf.zion 2.6.11ac1 #2 Wed May 4 00:35:08 IST 2005 i686
532Config options: 0
533
534Installed drivers:
535Type 10: ALSA emulation
536
537Card config:
538Sound Blaster Live! (rev.6, serial:0x80271102) at 0xb800, irq 11
539
540Audio devices:
5410: EMU10K1 (DUPLEX)
542
543Synth devices: NOT ENABLED IN CONFIG
544
545Midi devices:
5460: EMU10K1 MPU-401 (UART)
547
548Timers:
5497: system timer
550
551Mixers:
5520: SigmaTel STAC9721/23
553</pre>
554
555<!-- TODO: remove this a few months after alsa-driver leaves the tree -->
556
557<p>
558The other most common issue users face is the dreaded "Unknown symbol in module"
559error. An example of the same is shown below.
560</p>
561
562<pre caption="Unknown Symbol in module error">
563# <i>/etc/init.d/alsasound start</i>
564 * Loading ALSA modules ...
565 * Loading: snd-card-0 ... [ ok ]
566 * Loading: snd-pcm-oss ...
567WARNING: Error inserting snd_mixer_oss
568(/lib/modules/2.6.12-gentoo-r6/kernel/sound/core/oss/snd-mixer-oss.ko): Unknown
569symbol in module, or unknown parameter (see dmesg) FATAL: Error inserting
570snd_pcm_oss
571(/lib/modules/2.6.12-gentoo-r6/kernel/sound/core/oss/snd-pcm-oss.ko): Unknown
572symbol in module, or unknown parameter (see dmesg)
573 [ !! ]
574 * Loading: snd-mixer-oss ...
575FATAL: Error inserting snd_mixer_oss
576(/lib/modules/2.6.12-gentoo-r6/kernel/sound/core/oss/snd-mixer-oss.ko): Unknown
577symbol in module, or unknown parameter (see dmesg)
578 [ !! ]
579 * Loading: snd-seq ... [ ok ]
580 * Loading: snd-emu10k1-synth ... [ ok ]
581 * Loading: snd-seq-midi ... [ ok ]
582 * Restoring Mixer Levels ... [ ok ]
583</pre>
584
585<p>
586And when you take a look at <c>dmesg</c> as suggested, you're quite likely to
587see:
588</p>
589
590<pre caption="dmesg output">
591<comment>(Only relevant portions are shown below)</comment>
592# <i>dmesg | less</i>
593ACPI: PCI Interrupt 0000:02:06.0[A] -> Link [APC3] -> GSI 18 (level, low) -> IRQ 209
594snd_mixer_oss: Unknown symbol snd_unregister_oss_device
595snd_mixer_oss: Unknown symbol snd_register_oss_device
596snd_mixer_oss: Unknown symbol snd_mixer_oss_notify_callback
597snd_mixer_oss: Unknown symbol snd_oss_info_register
598snd_pcm_oss: Unknown symbol snd_unregister_oss_device
599snd_pcm_oss: Unknown symbol snd_register_oss_device
600snd_pcm_oss: Unknown symbol snd_mixer_oss_ioctl_card
601snd_pcm_oss: Unknown symbol snd_oss_info_register
602snd_mixer_oss: Unknown symbol snd_unregister_oss_device
603snd_mixer_oss: Unknown symbol snd_register_oss_device
604snd_mixer_oss: Unknown symbol snd_mixer_oss_notify_callback
605snd_mixer_oss: Unknown symbol snd_oss_info_register
606</pre>
607
608<p>
609The above issue is caused when you switch from the <c>alsa-driver</c> to in-kernel
610ALSA because when you unmerge <c>alsa-driver</c> the module files are config
611protected and hence get left behind. So, when you switch to in-kernel
612drivers, running <c>modprobe</c> gives you a mix of <c>alsa-driver</c> and
613in-kernel modules thus causing the above errors.
614</p>
615
616<p>
617The solution is quite easy. We just need to manually remove the problem causing
618directory after you unmerge <c>alsa-driver</c>. Be sure to remove the correct
619kernel version and not the current one!
620</p>
621
622<pre caption="Removing the alsa-driver modules">
623# <i>rm -rf /lib/modules/$(uname -r)/alsa-driver</i>
624</pre>
625
626<p>
627Another reason for error messages similar to the ones above could be a file in
628<path>/etc/modules.d</path> supplying a <c>device_mode</c> parameter when it
629isn't required. Confirm that this is indeed the issue and find out which file
630is the culprit.
631</p>
632
633<pre caption="Confirming and searching for device_mode">
634<comment>(Check dmesg to confirm)</comment>
635# <i>dmesg | grep device_mode</i>
636snd: Unknown parameter `device_mode'
637<comment>(Now, to get to the source of the issue)</comment>
638# <i>grep device_mode /etc/modules.d/*</i>
639</pre>
640
641<p>
642Usually it is a file called <path>alsa</path> with the line <c>options snd
643device_mode=0666</c>. Remove this line and restart the <c>alsasound</c> service
644and that should take care of this issue.
645</p>
646
647<!-- End of removal notice -->
172 648
173</body> 649</body>
174</section> 650</section>
175</chapter> 651</chapter>
652
176<chapter> 653<chapter>
177<title>Configuring ALSA</title> 654<title>Other things ALSA</title>
178<section> 655<section id="midi">
179<title>Automatically Loading the Kernel Modules</title> 656<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> 657<body>
207</section>
208<section>
209<title>Verifying the Device Files</title>
210<body>
211 658
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> 659<p>
217 660First, check to make sure that you enabled the <c>midi</c> USE flag in
218<pre caption="/etc/devfsd.conf"> 661<path>/etc/make.conf</path>. If you didn't, go ahead and add it now. You will
219# ALSA/OSS stuff 662also 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 663<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> 664</p>
237To activate ALSA support at boot, add the <c>alsasound</c> init script to the 665
238boot runlevel:
239</p> 666<p>
240 667If your sound card is one of those that come with on-board MIDI synthesizers
241<pre caption="Adding alsasound to the boot runlevel"> 668and you would like to listen to some .mid files, you have to install
242# <i>rc-update add alsasound boot</i> 669<c>awesfx</c> which is basically a set of utilities for controlling the AWE32
243# <i>/etc/init.d/alsasound start</i> 670driver. We need to install it first. If you don't have a hardware synthesizer,
244</pre> 671you can use a virtual one. Please see the section on
245 672<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> 673</p>
253By default, all sound channels are muted. To fix this, run <c>amixer</c>:
254</p>
255 674
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"> 675<pre caption="Installing awesfx">
304# <i>emerge awesfx</i> 676# <i>emerge awesfx</i>
305</pre> 677</pre>
306 678
307<p> 679<note>
308If you have a collection of sound fonts somewhere, place them in 680You 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 681CD or a Windows installation into <path>/usr/share/sounds/sf2/</path>. For
310called <path>8MBGMSFX.SF2</path> or <path>CT4GMSFX.SF2</path>. 682example a sound font file for the Creative SBLive! card would be 8MBGMSFX.SF2.
683</note>
684
311</p> 685<p>
312 686After copying over the Soundfont files, we can then play a midi file as shown.
687You can also add the <c>asfxload</c> command to
688<path>/etc/conf.d/local.start</path>, so that the sound font is loaded
689every time the system starts up.
313<p> 690</p>
314After copying over the sound font, select them using <c>sfxload</c>:
315</p>
316 691
692<note>
693<path>/mnt</path> paths mentioned in the code listing(s) below will <e>not</e>
694be the same in your machine. They are just an example. Please be careful to
695change the path to suit your machine.
696</note>
697
317<pre caption="Loading the sound font"> 698<pre caption="Loading Soundfonts">
699<comment>(First, copy the Soundfont)</comment>
700# <i>cp /mnt/win2k/Program\ Files/CreativeSBLive2k/SFBank/8MBGMSFX.SF2 /usr/share/sounds/sf2/</i>
701<comment>(Or get it from your SoundBlaster CD)</comment>
702# <i>cp /mnt/cdrom/AUDIO/ENGLISH/SFBANK/8MBGMSFX.SF2 /usr/share/sounds/sf2/</i>
703<comment>(We load the specific Soundfont)</comment>
318# <i>sfxload /usr/share/sfbank/8MBGMSFX.SF2</i> 704# <i>asfxload /usr/share/sounds/sf2/8MBGMSFX.SF2</i>
319</pre> 705</pre>
320 706
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> 707<p>
325 708You can now play midi files using a program like <c>aplaymidi</c>. Run
709<c>aplaymidi -l</c> to get a list of available ports and then pick one
710to play the file on.
326<p> 711</p>
327If you can't find soundfonts on your driver CD you can download some online from 712
328<uri>http://www.parabola.demon.co.uk/alsa/awe64.html</uri>. 713<pre caption="Playing MIDI">
714<comment>(Check open ports)</comment>
715# <i>aplaymidi -l</i>
716 Port Client name Port name
717 64:0 EMU10K1 MPU-401 (UART) EMU10K1 MPU-401 (UART)
718 65:0 Emu10k1 WaveTable Emu10k1 Port 0
719 65:1 Emu10k1 WaveTable Emu10k1 Port 1
720 65:2 Emu10k1 WaveTable Emu10k1 Port 2
721 65:3 Emu10k1 WaveTable Emu10k1 Port 3
722<comment>(Pick a port, and play a mid file)</comment>
723# <i> aplaymidi --port=65:0 /mnt/shyam/music/midi/mi2.mid</i>
329</p> 724</pre>
330 725
331</body> 726</body>
332</section>
333<section> 727</section>
728<section id="vsynth">
334<title>Timidity++ Virtual Synthesizer</title> 729<title>Virtual Synthesizers</title>
335<body> 730<body>
336 731
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> 732<p>
733If your sound card lacks a hardware synthesizer, you could use a virtual one
734like <c>timidity++</c>. Installation is a breeze.
735</p>
342 736
343<pre caption="Installing Timidity++"> 737<pre caption="Installing timidity++">
344# <i>emerge timidity++</i> 738# <i>emerge timidity++</i>
345</pre> 739</pre>
346 740
347<p> 741<p>
348A sample configuration file will be installed for you in 742For 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 743install some sound font packages for you. There are a few other font packages
350timidity++ configuration setup yet, you can just use this one. 744available in Portage, such as <c>timidity-freepats</c> and
351</p> 745<c>timidity-eawpatches</c>. You can have multiple sound font configurations
352 746installed, and you can place your own in <path>/usr/share/timidity/</path>. To
353<pre caption="Using the default Timidity++ configuration file"> 747switch between different timidity configurations, you should use
354# <i>cp /usr/share/timidity/config/timidity.cfg /usr/share/timidity</i> 748<c>eselect</c>.
355</pre>
356
357<p> 749</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>
361 750
362<pre caption="Installing timidity-eawpatches"> 751<pre caption="Changing configurations">
752# <i>eselect timidity list</i>
363# <i>emerge timidity-eawpatches</i> 753# <i>eselect timidity set eawpatches</i>
364</pre> 754</pre>
365 755
366<p> 756<p>
367Don't forget to add <c>timidity</c> to the default runlevel. 757Don't forget to add <c>timidity</c> to the default runlevel.
368</p> 758</p>
370<pre caption="Adding timidity to the default runlevel"> 760<pre caption="Adding timidity to the default runlevel">
371# <i>rc-update add timidity default</i> 761# <i>rc-update add timidity default</i>
372# <i>/etc/init.d/timidity start</i> 762# <i>/etc/init.d/timidity start</i>
373</pre> 763</pre>
374 764
765<p>
766You can now try out <uri link="#doc_chap4_pre3">Playing MIDI</uri> files.
767</p>
768
375</body> 769</body>
376</section>
377<section> 770</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> 771<section>
413<title>Tools and Firmware</title> 772<title>Tools and Firmware</title>
414<body> 773<body>
415 774
416<p> 775<p>
417Some specific sound cards can benefit from certain tools provided by the 776Some 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 777<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 778a 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> 779</p>
430 780
431<pre caption="Installing ALSA Tools"> 781<pre caption="Installing ALSA Tools">
432# <i>emerge alsa-tools</i> 782# <i>emerge alsa-tools</i>
433</pre> 783</pre>
434 784
435</body> 785</body>
436</section> 786</section>
437<section> 787<section>
438<title>Activating Joystick Support</title> 788<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> 789<body>
482</section> 790
791<p>
792You can have more than one sound card in your system simultaneously, provided
793that you have built ALSA as modules in your kernel. You just need to specify
794which should be started first in <path>/etc/modules.d/alsa</path>. Your cards
795are identified by their driver names inside this file. 0 is the first card, 1 is
796the second, and so on. Here's an example for a system with two sound cards.
797</p>
798
799<pre caption="Two sound cards in /etc/modules.d/alsa">
800options snd-emu10k1 index=0
801options snd-via82xx index=1
802</pre>
803
804<p>
805Or, if you have two cards that use the same driver, you specify them on the same
806line, using comma-separated numbers. Here's an example for a system with three
807sound cards, two of which are the same Intel High Definition Audio card.
808</p>
809
810<pre caption="Multiple sound cards in /etc/modules.d/alsa">
811options snd-ymfpci index=0
812options snd-hda-intel index=1,2
813</pre>
814
815</body>
483<section> 816</section>
817<section>
818<title>Plugins</title>
819<body>
820
821<p>
822You may want to install some plugins for extra functionality.
823<c>alsa-plugins</c> is a collection of useful plugins, which include: PulseAudio
824output, a sample rate converter, jack (a low-latency audio server), and an
825encoder that lets you output 6-channel audio through digital S/PDIF connections
826(both optical and coaxial). You can choose which of its plugins you want
827installed by adding their USE flags to <path>/etc/portage/package.use</path>.
828</p>
829
830<pre caption="Installing alsa-plugins">
831# <i>emerge -avt alsa-plugins</i>
832</pre>
833
834</body>
835</section>
836<section>
837<title>A big thank you to...</title>
838<body>
839
840<p>
841Everyone who contributed to the earlier version of the Gentoo ALSA Guide:
842Vincent Verleye, Grant Goodyear, Arcady Genkin, Jeremy Huddleston,
843John P. Davis, Sven Vermeulen, Benny Chuang, Tiemo Kieft and Erwin.
844</p>
845
846</body>
847</section>
848<section>
484<title>Resources</title> 849<title>References</title>
485<body> 850<body>
486 851
487<ul> 852<ul>
488 <li><uri link="http://www.alsa-project.org">The ALSA Project</uri></li> 853 <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> 854 <li><uri link="http://linux-sound.org">Linux Sound/MIDI Software</uri></li>
491</ul> 855</ul>
492 856
493</body> 857</body>
494</section> 858</section>

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