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Annotated edit history of AlsaNotes version 22, including all changes. View license author blame.
Rev Author # Line
18 AristotlePagaltzis 1 <b>See also [Alsa5.1Notes].</b>
16 AlastairPorter 2
18 AristotlePagaltzis 3 !!! Application support for [ALSA]
12 SamJansen 4
18 AristotlePagaltzis 5 * There is a version of esd(1) that uses [ALSA] – that means that any app that currently uses esd(1) will be fine. (In [Debian] the [Package] is called <tt>libesd-alsa0</tt>.)
12 SamJansen 6
18 AristotlePagaltzis 7 * [ALSA] has optional support for [OSS] compatibility for older apps that only know about the [OSS]-style sound drivers. To use it, make sure the <tt>snd-pcm-oss</tt> module is loaded. (In Debian, you can just set <tt>startosslayer=true</tt> in <tt>/etc/default/alsa</tt> for the startup scripts to do this for you.)
12 SamJansen 8
15 IanMcDonald 9
18 AristotlePagaltzis 10 !!! Module hints
12 SamJansen 11
18 AristotlePagaltzis 12 * It may be a good idea to make sure you have the <tt>snd-pcm-oss</tt> module if you want backwards-compatibility for older apps (see further below). If you are compiling the modules from source, include <tt>--with-oss=yes</tt> on your <tt>./configure</tt> line.
12 SamJansen 13
18 AristotlePagaltzis 14 * The sound-card on a Thinkpad 600E needs the <tt>snd-cs4236</tt> module, despite the card claiming to be a 46xx (and using a module named cs4232 in the older [OSS] driver series).
12 SamJansen 15
14 JohnMcPherson 16
18 AristotlePagaltzis 17 !!! My sound card doesn't work after an upgrade
12 SamJansen 18
18 AristotlePagaltzis 19 Run <tt>alsaconf</tt>, it will probably fix it.
12 SamJansen 20
21
18 AristotlePagaltzis 22 !!! Not all sound devices work
12 SamJansen 23
18 AristotlePagaltzis 24 If one of your sound devices doesn't work and you get an error similar to <tt>EMU10K1_Audigy: probe of 0000:02:0a.0 failed with error -12</tt> then it might be because the devices are fighting over which sound card number they want to be. To fix this alter the sound card module options (see [Module] page on how to do this). One example of a configuration that works is <tt>options snd-emu10k1 index=-15</tt>. The <tt>index</tt> parameter specifies which card becomes which number, or if negative then it is a bitmask of numbers that it can be autoassigned to. To learn more about this look at the LinuxKernel source file <tt>Documentation/sound/alsa/ALSA-Configuration.txt</tt>
14 JohnMcPherson 25
26
18 AristotlePagaltzis 27 !!! Software Mixing With [ALSA]
19 CraigBox 28
20 AristotlePagaltzis 29 You can get [ALSA] to do software mixing for you without having to resort to something like esd(1). This is done via the dmix plugin and as [documented on the ALSA wiki | http://alsa.opensrc.org/index.php?page=DmixPlugin]. As of 1.0.9rc2, this is configured out of the box for the vast majority of consumer sound chipsets. (The first [Ubuntu] version to benefit from this was Breezy.)
12 SamJansen 30
20 AristotlePagaltzis 31 If you have an earlier version, after you get [ALSA] going, you need to put the following in a <tt>.asoundrc</tt> file in your home directory.
12 SamJansen 32
17 IanMcDonald 33 <verbatim>
18 AristotlePagaltzis 34 # .asoundrc file. Put this in your home directory.
12 SamJansen 35
18 AristotlePagaltzis 36 pcm.mixed {
37 type dmix
38 ipc_key 123456 # Any unique value
39 ipc_key_add_uid true # No idea...
40 slave {
41 pcm "hw:0,0"
42 # Apparently for OSS emulation device, you have to set the period
43 # and the buffer sizes in powers of two.
44 period_time 0
45 period_size 1024 # must be power of 2
46 buffer_size 4096 # ditto
47 rate 44100
48 }
12 SamJansen 49
18 AristotlePagaltzis 50 # bindings are cool. This says, that only the first
51 # two channels are to be used by dmix, which is enough for
52 # (most) oss apps and also lets multichannel chios work
53 # much faster:
12 SamJansen 54
18 AristotlePagaltzis 55 bindings {
56 0 0 # from 0 => to 0
57 1 1 # from 1 => to 1
58 }
59 }
12 SamJansen 60
18 AristotlePagaltzis 61 pcm.!default {
62 type plug
63 slave.pcm mixed
64 }
12 SamJansen 65
18 AristotlePagaltzis 66 pcm.dsp0 {
67 type plug
68 slave.pcm mixed
69 }
12 SamJansen 70
18 AristotlePagaltzis 71 pcm.mixer0 {
72 type hw
73 card 0
74 }
17 IanMcDonald 75 </verbatim>
12 SamJansen 76
18 AristotlePagaltzis 77 There are some problems with this. First of all, [OSS] [Kernel] emulation won’t go through this layer. For an [OSS]-based application to use this, you need to use the <tt>aoss</tt> helper utility. Also, for [SDL] based applications (usually games) to use this, you will want the EnvironmentVariable <tt>AUDIODEV</tt> to be set to <tt>default</tt>, ie. <tt>export AUDIODEV=default</tt>.
21 LawrenceDoliveiro 78
79 !!! Surround-Sound Notes
80
81 Couple of pages that might be useful, at the [ALSA Wiki|http://alsa.opensrc.org/SurroundSound] and [Halfgaar|http://www.halfgaar.net/surround-sound-in-linux], thanks to [Dave Phillips|http://www.linuxjournal.com/node/1000244].
12 SamJansen 82
83
18 AristotlePagaltzis 84 !!! Soundblaster SB16 module
12 SamJansen 85
18 AristotlePagaltzis 86 On my [LinuxKernel2.6] system, I couldn't load the [ALSA] module for the [ISA] SB16 card, no matter what I did. Eventually, I discovered it loaded fine if I disabled the <tt>isapnp</tt> option for the module. Eg in <tt>/etc/modprobe.conf</tt>, I had
12 SamJansen 87
18 AristotlePagaltzis 88 <verbatim>
89 options snd-sb16 isapnp=0
90 </verbatim>
12 SamJansen 91
18 AristotlePagaltzis 92 It seemed to be defaulting to trying to use <tt>isapnp</tt> but that didn't work, whether or not I enabled [Kernel] [ISA] [PnP] support and [BIOS] [PnP] support.
12 SamJansen 93
94
18 AristotlePagaltzis 95 !!! modprobe(8) complains about unresolved symbols in <tt>schedule_work</tt>
12 SamJansen 96
18 AristotlePagaltzis 97 You need to run <tt>touch include/linux/workqueue.h</tt> between <tt>./configure</tt> and <tt>make</tt> on <tt>alsa-driver</tt>.
12 SamJansen 98
18 AristotlePagaltzis 99 If you want to do this while building from [SRPM], do the following:
12 SamJansen 100
18 AristotlePagaltzis 101 Install the [SRPM]:
12 SamJansen 102
18 AristotlePagaltzis 103 <verbatim>
104 rpm -ivh alsa-driver.x.y.z-p.src.rpm
17 IanMcDonald 105 </verbatim>
14 JohnMcPherson 106
18 AristotlePagaltzis 107 Now open the <tt>alsa-driver.x.y.z-p.spec</tt> in the <tt>SPECS/</tt> directory, locate the <tt>%configure</tt> and <tt>make</tt> commands and add the following command between them:
14 JohnMcPherson 108
18 AristotlePagaltzis 109 <verbatim>
110 touch include/linux/workqueue.h
111 </verbatim>
14 JohnMcPherson 112
18 AristotlePagaltzis 113 Finally, [RPM] needs to be told to build the ''spec file'':
14 JohnMcPherson 114
18 AristotlePagaltzis 115 <verbatim>
116 rpmbuild -bb --define 'cards als4000' --target $arch \
117 alsa-driver.x.y.z-p.spec
118 </verbatim>
14 JohnMcPherson 119
18 AristotlePagaltzis 120 You can now install the [RPM]s built in the <tt>RPMS/$arch/</tt> directory.
14 JohnMcPherson 121
122
18 AristotlePagaltzis 123 !!! Compiling [ALSA] on RedHatLinux using the FreshRpms [SRPM]
14 JohnMcPherson 124
18 AristotlePagaltzis 125 You probably want to set up your own <tt>.rpmmacros</b> file first, as per [RPMNotes]. Remember to specify the target architecture and the card (see the [ALSA soundcard matrix | http://www.alsa-project.org/alsa-doc/] to find yours) to compile for, eg.:
14 JohnMcPherson 126
18 AristotlePagaltzis 127 <verbatim>
128 rpmbuild --rebuild alsa-driver.x.y.z-p.src.rpm \
129 --define 'cards als4000' --target $arch
130 </verbatim>
17 IanMcDonald 131
18 AristotlePagaltzis 132 where <tt>$arch</tt> might be <tt>athlon</tt>, f.ex. The [RPM]s will end up in <tt>RPMS/$arch/</tt>, ie f.ex in <tt>RPMS/athlon/</tt>. As with all source builds, you will need to recompile the [SRPM] if you upgrade your [Kernel]; you only need to install the <tt>kernel-module-alsa</tt> [RPM], however.
22 LawrenceDoliveiro 133
134 !!! See also
135 [ALSA configuration notes|http://www.sabi.co.uk/Notes/linuxSoundALSA.html]

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