/[gentoo]/xml/htdocs/doc/en/alsa-guide.xml
Gentoo

Contents of /xml/htdocs/doc/en/alsa-guide.xml

Parent Directory Parent Directory | Revision Log Revision Log


Revision 1.89 - (show annotations) (download) (as text)
Sat Feb 23 18:20:55 2013 UTC (13 months, 3 weeks ago) by swift
Branch: MAIN
Changes since 1.88: +4 -10 lines
File MIME type: application/xml
Fix bug #454394 - Update guide to remove 2.6-only references (doc was originally written for 2.4 and 2.6 kernels)

1 <?xml version='1.0' encoding="UTF-8"?>
2 <!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/alsa-guide.xml,v 1.88 2012/07/24 12:12:51 swift Exp $ -->
3
4 <!DOCTYPE guide SYSTEM "/dtd/guide.dtd">
5
6 <guide>
7 <title>Gentoo Linux ALSA Guide</title>
8
9 <author title="Author">
10 <mail link="fox2mike@gentoo.org">Shyam Mani</mail>
11 </author>
12 <author title="Author">
13 <mail link="nightmorph@gentoo.org">Joshua Saddler</mail>
14 </author>
15 <author title="Contributor">
16 <mail link="flameeyes@gentoo.org">Diego Pettenò</mail>
17 </author>
18
19 <abstract>
20 This document helps a user setup ALSA on Gentoo Linux.
21 </abstract>
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 -->
25 <license/>
26
27 <version>6</version>
28 <date>2013-02-23</date>
29
30 <chapter>
31 <title>Introduction</title>
32 <section>
33 <title>What is ALSA?</title>
34 <body>
35
36 <p>
37 ALSA, which stands for <e>Advanced Linux Sound Architecture</e>, provides audio
38 and MIDI (<e>Musical Instrument Digital Interface</e>) functionality to the
39 Linux operating system. ALSA is the default sound subsystem in the 3.x and 2.6
40 kernels, thereby replacing OSS (<e>Open Sound System</e>), which was used in
41 the 2.4 kernels.
42 </p>
43
44 <p>
45 ALSA's main features include efficient support for all types of audio
46 interfaces ranging from consumer sound cards to professional sound
47 equipment, fully modularized drivers, SMP and thread safety, backward
48 compatibility with OSS and a user-space library <c>alsa-lib</c> to make
49 application development a breeze.
50 </p>
51
52 </body>
53 </section>
54 </chapter>
55
56 <chapter>
57 <title>Installing ALSA</title>
58 <section id="lspci">
59 <title>Before you proceed</title>
60 <body>
61
62 <p>
63 First, you need to know what drivers your sound card uses. In most cases, sound
64 cards (onboard and otherwise) are PCI based and <c>lspci</c> will help you in
65 digging out the required information. Please <c>emerge sys-apps/pciutils</c> to
66 get <c>lspci</c>, if you don't have it installed already. In case you have a USB
67 sound card, <c>lsusb</c> from <c>sys-apps/usbutils</c> <e>might</e> be of help.
68 For 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>
88 For ease of use/explanation, we assume the user has a PCI based sound card for
89 the remainder of this guide.
90 </note>
91
92 <p>
93 We 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>
98 0000:00:0a.0 Multimedia audio controller: Creative Labs SB Live! EMU10k1 (rev 06)
99 </pre>
100
101 <p>
102 We now know that the sound card on the machine is a Sound Blaster Live! and the
103 card manufacturer is Creative Labs. Head over to the <uri
104 link="http://bugtrack.alsa-project.org/main/index.php/Matrix:Main">ALSA
105 Soundcard Matrix</uri> page and select Creative Labs from the list. You will
106 be taken to the Creative Labs matrix page where you can see that the SB Live!
107 uses the <c>emu10k1</c> module. That is the information we need for now. If
108 you are interested in detailed information, you can click on the link next to
109 the "Details" and that will take you to the <c>emu10k1</c> specific page.
110 </p>
111
112 <p>
113 If 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
115 guide, we will show you how to set up <uri link="#midi">MIDI support</uri>.
116 </p>
117
118 </body>
119 </section>
120 <section id="kernel">
121 <title>Configuring the kernel</title>
122 <body>
123
124 <p>
125 Let us now configure the kernel to enable ALSA.
126 </p>
127
128 <impo>
129 <c>genkernel</c> users should now run <c>genkernel --menuconfig all</c> and
130 then follow the instructions in <uri link="#doc_chap2_pre3">Kernel Options for
131 ALSA</uri>.
132 </impo>
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>
140 The above example assumes that <path>/usr/src/linux</path> symlink points to
141 the kernel sources you want to use. Please ensure the same before proceeding.
142 </note>
143
144 <p>
145 Now we will look at some of the options we will have to enable in the
146 kernel to ensure proper ALSA support for our sound card.
147 </p>
148
149 <p>
150 Please note that for ease of use, all examples show ALSA built as modules. It
151 is advisable to follow the same as it then allows the use of <c>alsaconf</c>
152 which is a boon when you want to configure your card. Please do <e>not</e> skip
153 the <uri link="#alsa-config">Configuration</uri> section of this document. If
154 you still like to have options built-in, ensure that you make changes to your
155 config accordingly.
156 </p>
157
158 <pre caption="Kernel Options for ALSA">
159 Device 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>
166 Open Sound System ---&gt;
167 &lt; &gt; Open Sound System (DEPRECATED)
168
169 <comment>(Move one step back and enter ALSA)</comment>
170 Advanced 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,
179 you will have one type of device and not more. If you have more than one
180 sound card, please enable them all here.)</comment>
181
182 <comment>(Mostly for testing and development purposes, not needed for normal
183 users unless you know what you are doing.)</comment>
184 Generic devices ---&gt;
185
186 <comment>(For ISA Sound cards)</comment>
187 ISA 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
192 PCI devices)</comment>
193 PCI 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>
202 USB Devices ---&gt;
203 </pre>
204
205 <p>
206 Now that your options are set, you can (re)compile the kernel and ALSA support
207 for your card should be functional once you reboot into the new kernel. Don't
208 forget to update your GRUB configuration to use the newly built kernel.
209 You can now proceed to <uri link="#alsa-utilities">ALSA Utilities</uri> and
210 see if everything is working as it should.
211 </p>
212
213 </body>
214 </section>
215 </chapter>
216
217 <chapter>
218 <title>Configuring/Testing ALSA</title>
219 <section id="alsa-utilities">
220 <title>ALSA Utilities</title>
221 <body>
222
223 <p>
224 <c>alsa-utils</c> forms an integral part of ALSA as it has a truckload of
225 programs that are highly useful, including the ALSA Initscripts. Hence we
226 strongly recommend that you install <c>alsa-utils</c>
227 </p>
228
229 <pre caption="Install alsa-utils">
230 # <i>emerge alsa-utils</i>
231 </pre>
232
233 <note>
234 If you did <e>not</e> compile ALSA as modules, please proceed to the <uri
235 link="#initscript">ALSA Initscript</uri> section. The rest of you need to
236 configure ALSA. This is made very easy by the existence of the <c>alsaconf</c>
237 tool 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
246 <p>
247 Recent versions of <c>udev</c> (<c>>=udev-103</c>) provide some degree of
248 kernel-level autoconfiguration of your sound card. If possible, try to rely on
249 just letting your kernel automatically setup your sound card for you. Otherwise,
250 use <c>alsaconf</c> to configure your card, as shown below.
251 </p>
252
253 <note>
254 Please shut down any programs that <e>might</e> access the sound card while
255 running <c>alsaconf</c>.
256 </note>
257
258 <p>
259 To 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>
267 You will now see a neat menu guided interface that will automatically probe
268 your devices and try to find out your sound card. You will be asked to pick
269 your sound card from a list. Once that's done, it will ask you permission to
270 automatically make required changes to <path>/etc/modprobe.d/alsa.conf</path>.
271 It 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.
273 Once <c>alsaconf</c> exits, you can proceed with setting up the ALSA
274 initscript.
275 </p>
276
277 </body>
278 </section>
279 <section id="initscript">
280 <title>ALSA Initscript</title>
281 <body>
282
283 <p>
284 We're now almost all setup. Whichever method you chose to install ALSA, you'll
285 need to have something load your modules or initialize ALSA and restore your
286 volume settings when your system comes up. The ALSA Initscript handles all of
287 this 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>
297 Next, just check the <path>/etc/conf.d/alsasound</path> file and ensure that
298 SAVE_ON_STOP variable is set to yes. This saves your sound settings when you
299 shutdown your system.
300 </p>
301
302 </body>
303 </section>
304 <section>
305 <title>Audio Group</title>
306 <body>
307
308 <p>
309 Before we move on to testing, there's one last <e>important</e> thing that needs
310 to be setup. Rule of thumb in a *nix OS: Do not run as root unless needed.
311 This applies here as well ;) How? Well, most of the times you should be logged
312 in as a user and would like to listen to music or access your soundcard. For
313 that to happen, you need to be in the "audio" group. At this point, we'll add
314 users to the audio group, so that they won't have any issues when they want to
315 access sound devices. We'll use <c>gpasswd</c> here and you need to be logged in
316 as 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>
322 Adding 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>
332 We've completed all the setups and prerequisites, so let's fire up ALSA. If
333 you ran <c>alsaconf</c>, you can skip this step, since <c>alsaconf</c> already
334 does 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>
342 Now that the required things have been taken care of, we need to check up on
343 the volume as in certain cases, it is muted. We use <c>alsamixer</c> for this
344 purpose.
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>
353 This is how the ALSA Mixer <e>might</e> look the first time you open it. Pay
354 attention to the Master and PCM channels which both have an MM below them.
355 That means they are muted. If you try to play anything with <c>alsamixer</c>
356 in 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>
362 Now, we shall unmute the channels, and set volume levels as needed.
363 </p>
364
365 <warn>
366 Both Master <e>and</e> PCM need to be unmuted and set to audible volume levels
367 if 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>
386 Be careful when setting your Bass and Treble values. 50 is usually a good
387 number for both. Extremely high values of Bass may cause <e>jarring</e>
388 on speakers that are not designed to handle them.
389 </note>
390
391 <p>
392 After you're all done, your ALSA Mixer should look similar to the one below.
393 Note the 00 instead of the MM and also the volume levels for some optimum
394 settings.
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>
406 Finally. Some music. If everything above is perfect, you should now be able to
407 listen to some good music. A quick way to test is to use a command line tool
408 like <c>media-sound/madplay</c>. You could also use something more well known
409 like <c>mpg123</c>. If you are an ogg fan, you could use <c>ogg123</c> provided
410 by <c>media-sound/vorbis-tools</c>. Use any player you are comfortable with. As
411 always, <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>
422 And 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>
427 MPEG 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>
437 Audio Device: Advanced Linux Sound Architecture (ALSA) output
438
439 Playing: Paul Oakenfold - Dread Rock.ogg
440 Ogg Vorbis stream: 2 channel, 44100 Hz
441 Genre: Soundtrack
442 Transcoded: mp3;160
443 Title: Dread Rock
444 Artist: Paul Oakenfold
445 Date: 2003
446 Album: Matrix Reloaded
447 Time: 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>
457 You can now add the <c>alsa</c> use flag to <path>/etc/portage/make.conf</path> to
458 ensure that your applications that support ALSA get built with it. Some
459 architectures 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>
469 If for some reason you're unable to hear sound, the first thing to do would
470 be to check your <uri link="#doc_chap3_pre6">alsamixer</uri> settings. 80% of
471 the issues lie with muted channels or low volume. Also check your Window
472 Manager'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>
477 is your best friend. We shall just take a short look at how much info is made
478 available 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
483 picked up your sound card fine.)</comment>
484 # <i>cat /proc/asound/cards</i>
485 0 [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>
490 Advanced 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>
494 Sound Driver:3.8.1a-980706 (ALSA v1.0.8 emulation code)
495 Kernel: Linux airwolf.zion 2.6.11ac1 #2 Wed May 4 00:35:08 IST 2005 i686
496 Config options: 0
497
498 Installed drivers:
499 Type 10: ALSA emulation
500
501 Card config:
502 Sound Blaster Live! (rev.6, serial:0x80271102) at 0xb800, irq 11
503
504 Audio devices:
505 0: EMU10K1 (DUPLEX)
506
507 Synth devices: NOT ENABLED IN CONFIG
508
509 Midi devices:
510 0: EMU10K1 MPU-401 (UART)
511
512 Timers:
513 7: system timer
514
515 Mixers:
516 0: SigmaTel STAC9721/23
517 </pre>
518
519 <!-- TODO: remove this a few months after alsa-driver leaves the tree -->
520
521 <p>
522 The other most common issue users face is the dreaded "Unknown symbol in module"
523 error. 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 ...
531 WARNING: Error inserting snd_mixer_oss
532 (/lib/modules/2.6.12-gentoo-r6/kernel/sound/core/oss/snd-mixer-oss.ko): Unknown
533 symbol in module, or unknown parameter (see dmesg) FATAL: Error inserting
534 snd_pcm_oss
535 (/lib/modules/2.6.12-gentoo-r6/kernel/sound/core/oss/snd-pcm-oss.ko): Unknown
536 symbol in module, or unknown parameter (see dmesg)
537 [ !! ]
538 * Loading: snd-mixer-oss ...
539 FATAL: Error inserting snd_mixer_oss
540 (/lib/modules/2.6.12-gentoo-r6/kernel/sound/core/oss/snd-mixer-oss.ko): Unknown
541 symbol 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>
550 And when you take a look at <c>dmesg</c> as suggested, you're quite likely to
551 see:
552 </p>
553
554 <pre caption="dmesg output">
555 <comment>(Only relevant portions are shown below)</comment>
556 # <i>dmesg | less</i>
557 ACPI: PCI Interrupt 0000:02:06.0[A] -> Link [APC3] -> GSI 18 (level, low) -> IRQ 209
558 snd_mixer_oss: Unknown symbol snd_unregister_oss_device
559 snd_mixer_oss: Unknown symbol snd_register_oss_device
560 snd_mixer_oss: Unknown symbol snd_mixer_oss_notify_callback
561 snd_mixer_oss: Unknown symbol snd_oss_info_register
562 snd_pcm_oss: Unknown symbol snd_unregister_oss_device
563 snd_pcm_oss: Unknown symbol snd_register_oss_device
564 snd_pcm_oss: Unknown symbol snd_mixer_oss_ioctl_card
565 snd_pcm_oss: Unknown symbol snd_oss_info_register
566 snd_mixer_oss: Unknown symbol snd_unregister_oss_device
567 snd_mixer_oss: Unknown symbol snd_register_oss_device
568 snd_mixer_oss: Unknown symbol snd_mixer_oss_notify_callback
569 snd_mixer_oss: Unknown symbol snd_oss_info_register
570 </pre>
571
572 <p>
573 The above issue is caused when you switch from the <c>alsa-driver</c> to in-kernel
574 ALSA because when you unmerge <c>alsa-driver</c> the module files are config
575 protected and hence get left behind. So, when you switch to in-kernel
576 drivers, running <c>modprobe</c> gives you a mix of <c>alsa-driver</c> and
577 in-kernel modules thus causing the above errors.
578 </p>
579
580 <p>
581 The solution is quite easy. We just need to manually remove the problem causing
582 directory after you unmerge <c>alsa-driver</c>. Be sure to remove the correct
583 kernel 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>
591 Another 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
593 isn't required. Confirm that this is indeed the issue and find out which file
594 is 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>
600 snd: 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>
606 Usually it is a file called <path>alsa</path> with the line <c>options snd
607 device_mode=0666</c>. Remove this line and restart the <c>alsasound</c> service
608 and that should take care of this issue.
609 </p>
610
611 <!-- End of removal notice -->
612
613 </body>
614 </section>
615 </chapter>
616
617 <chapter>
618 <title>Other things ALSA</title>
619 <section id="midi">
620 <title>Setting up MIDI support</title>
621 <body>
622
623 <p>
624 First, check to make sure that you enabled the <c>midi</c> USE flag in
625 <path>/etc/portage/make.conf</path>. If you didn't, go ahead and add it now. You will
626 also need to re-emerge any ALSA packages that use the <c>midi</c> flag, such as
627 <c>alsa-lib</c> and <c>alsa-utils</c>.
628 </p>
629
630 <p>
631 If your sound card is one of those that come with on-board MIDI synthesizers
632 and you would like to listen to some .mid files, you have to install
633 <c>awesfx</c> which is basically a set of utilities for controlling the AWE32
634 driver. We need to install it first. If you don't have a hardware synthesizer,
635 you can use a virtual one. Please see the section on
636 <uri link="#vsynth">Virtual Synthesizers</uri> for more information.
637 </p>
638
639 <pre caption="Installing awesfx">
640 # <i>emerge awesfx</i>
641 </pre>
642
643 <note>
644 You will need to copy over SoundFont (SF2) files from your sound card's driver
645 CD or a Windows installation into <path>/usr/share/sounds/sf2/</path>. For
646 example a sound font file for the Creative SBLive! card would be 8MBGMSFX.SF2.
647 </note>
648
649 <p>
650 After copying over the Soundfont files, we can then play a midi file as shown.
651 You can also add the <c>asfxload</c> command to
652 <path>/etc/conf.d/local.start</path>, so that the sound font is loaded
653 every time the system starts up.
654 </p>
655
656 <note>
657 <path>/mnt</path> paths mentioned in the code listing(s) below will <e>not</e>
658 be the same in your machine. They are just an example. Please be careful to
659 change the path to suit your machine.
660 </note>
661
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>
668 # <i>asfxload /usr/share/sounds/sf2/8MBGMSFX.SF2</i>
669 </pre>
670
671 <p>
672 You 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
674 to play the file on.
675 </p>
676
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>
688 </pre>
689
690 </body>
691 </section>
692 <section id="vsynth">
693 <title>Virtual Synthesizers</title>
694 <body>
695
696 <p>
697 If your sound card lacks a hardware synthesizer, you could use a virtual one
698 like <c>timidity++</c>. Installation is a breeze.
699 </p>
700
701 <pre caption="Installing timidity++">
702 # <i>emerge timidity++</i>
703 </pre>
704
705 <p>
706 For timidity to play sounds, it needs a sound font. Fortunately, the ebuild will
707 install some sound font packages for you. There are a few other font packages
708 available in Portage, such as <c>timidity-freepats</c> and
709 <c>timidity-eawpatches</c>. You can have multiple sound font configurations
710 installed, and you can place your own in <path>/usr/share/timidity/</path>. To
711 switch between different timidity configurations, you should use
712 <c>eselect</c>.
713 </p>
714
715 <pre caption="Changing configurations">
716 # <i>eselect timidity list</i>
717 # <i>eselect timidity set eawpatches</i>
718 </pre>
719
720 <p>
721 Don't forget to add <c>timidity</c> to the default runlevel.
722 </p>
723
724 <pre caption="Adding timidity to the default runlevel">
725 # <i>rc-update add timidity default</i>
726 # <i>/etc/init.d/timidity start</i>
727 </pre>
728
729 <p>
730 You can now try out <uri link="#doc_chap4_pre3">Playing MIDI</uri> files.
731 </p>
732
733 </body>
734 </section>
735 <section>
736 <title>Tools and Firmware</title>
737 <body>
738
739 <p>
740 Some specific sound cards can benefit from certain tools provided by the
741 <c>alsa-tools</c> and <c>alsa-firmware</c> packages. You may install either with
742 a simple <c>emerge</c>.
743 </p>
744
745 <pre caption="Installing ALSA Tools">
746 # <i>emerge alsa-tools</i>
747 </pre>
748
749 </body>
750 </section>
751 <section>
752 <title>Multiple sound cards</title>
753 <body>
754
755 <p>
756 You can have more than one sound card in your system simultaneously, provided
757 that you have built ALSA as modules in your kernel. You just need to specify
758 which should be started first in <path>/etc/modprobe.d/alsa.conf</path>. Your cards
759 are identified by their driver names inside this file. 0 is the first card, 1 is
760 the 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">
764 options snd-emu10k1 index=0
765 options snd-via82xx index=1
766 </pre>
767
768 <p>
769 Or, if you have two cards that use the same driver, you specify them on the same
770 line, using comma-separated numbers. Here's an example for a system with three
771 sound 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">
775 options snd-ymfpci index=0
776 options snd-hda-intel index=1,2
777 </pre>
778
779 </body>
780 </section>
781 <section>
782 <title>Plugins</title>
783 <body>
784
785 <p>
786 You may want to install some plugins for extra functionality.
787 <c>alsa-plugins</c> is a collection of useful plugins, which include: PulseAudio
788 output, a sample rate converter, jack (a low-latency audio server), and an
789 encoder 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
791 installed 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>
805 Everyone who contributed to the earlier version of the Gentoo ALSA Guide:
806 Vincent Verleye, Grant Goodyear, Arcady Genkin, Jeremy Huddleston,
807 John P. Davis, Sven Vermeulen, Benny Chuang, Tiemo Kieft and Erwin.
808 </p>
809
810 </body>
811 </section>
812 <section>
813 <title>References</title>
814 <body>
815
816 <ul>
817 <li><uri link="http://www.alsa-project.org/">The ALSA Project</uri></li>
818 <li><uri link="http://linux-sound.org">Linux Sound/MIDI Software</uri></li>
819 </ul>
820
821 </body>
822 </section>
823 </chapter>
824 </guide>

  ViewVC Help
Powered by ViewVC 1.1.20