ALSA, which stands for
ALSA's main features include efficient support for all types of audio
interfaces ranging from consumer soundcards to professional sound
equipment, fully modularized drivers, SMP and thread safety, backward
compatibility with OSS and a user-space library
One of Gentoo's main strengths lie in giving the user maximum control over how a system is installed/configured. ALSA on Gentoo follows the same principle. There are two ways you can get ALSA support up and running on your system. We shall look at them in detail in the next chapter.
The two options are :
We shall take a peek into both before finally deciding on one.
If you were to use ALSA provided by the kernel, the following are the pros and cons :
Kernel ALSA | Pros and Cons |
---|---|
+ | |
+ | |
- |
And, if you were to use alsa-driver,
alsa-driver | Pros and Cons |
---|---|
+ | |
- | |
- |
The main difference between using
Whichever method of install you choose, you need to know what drivers your
soundcard uses.
# lspci -v | grep -i audio 0000:00:0a.0 Multimedia audio controller: Creative Labs SB Live! EMU10k1 (rev 06)
We now know that the soundcard on the machine is a Sound Blaster Live! and
the card manufacturer is Creative Labs. Head over to the
If you're a person who likes to keep things simple like I do, then this is the way to go.
Let us now configure the kernel to enable ALSA.
# cd /usr/src/linux # make menuconfig
Now we will look at some of the options we will have to enable in the 2.6 kernel to ensure proper ALSA support for our soundcard
Device Drivers ---> Sound --->(This needs to be enabled) <M> Sound card support(Make sure OSS is disabled) Open Sound System ---> < > Open Sound System (DEPRECATED)(Move one step back and enter ALSA) Advanced Linux Sound Architecture ---> <M> Advanced Linux Sound Architecture(Select this if you want MIDI sequencing and routing) <M> Sequencer support(Old style /dev/mixer* and /dev/dsp* support. Recommended.) <M> OSS Mixer API <M> OSS PCM (digital audio) API(You now have a choice of devices to enable support for. Generally, you will have one type of device and not more. If you have more than one soundcard, please enable them all here.) (Mostly for testing and development purposes, not needed for normal users unless you know what you are doing.) Generic devices --->(For ISA Sound cards) ISA devices --->(IF you had the Gravis, you would select this option) <M> Gravis UltraSound Extreme(Move one level back and into PCI devices. Most soundcards today are PCI devices) PCI devices --->(We now select the emu10k1 driver for our card) <M> Emu10k1 (SB Live!, Audigy, E-mu APS)(Or an Intel card would be) <M> Intel/SiS/nVidia/AMD/ALi AC97 Controller(Or if you have a VIA Card) <M> VIA 82C686A/B, 8233/8235 AC97 Controller(Move one level back and select in case you have an USB sound card) USB Devices --->
Now that your options are set, you can (re)compile the kernel and ALSA support
for your card should be functional once you reboot into the new kernel.
You can now proceed to
So you've decided to go the
If you don't have an idea of what drivers your soundcard might need, please
take a look at the
(For one soundcard) ALSA_CARDS="emu10k1"(For more than one, seperate names with spaces) ALSA_CARDS="emu10k1 via82xx"
If you have compiled your kernel and want to use
(Assuming the linux symlink points to the correct kernel) # cd /usr/src/linux # grep SOUND .config(1. is true) CONFIG_SOUND=y(2. is true) CONFIG_SOUND_PRIME is not set # grep SND .config(and 3. is true) CONFIG_SND is not set
Now all you have to do is type the magic words...and no, its not abracadabra.
# emerge alsa-driver
# emerge alsa-utils
The easiest way to configure your soundcard is to run
# alsaconf
You will now see a neat menu guided interface that will automatically probe
your devices and try to find out your soundcard. You will be asked to pick
your soundcard from a list. Once that's done, it will ask you permission to
automatically make required changes to
We're now almost all setup. Whichever method you chose to install ALSA, you'll
need to have something load your modules or initialize ALSA and restore your
volume settings when your system comes up. The ALSA Initscript handles all of
this for you and is called
# rc-update add alsasound default * alsasound added to runlevel default * rc-update complete.
Next, just check the
We've completed all the setups and pre-requisites, so let's fire up ALSA. If
you ran
(Modular Kernels) # /etc/init.d/alsasound start * Loading ALSA modules ... * Loading: snd-card-0 ... [ ok ] * Loading: snd-pcm-oss ... [ ok ] * Loading: snd-seq ... [ ok ] * Loading: snd-emu10k1-synth ... [ ok ] * Loading: snd-seq-midi ... [ ok ] * Restoring Mixer Levels ... [ ok ](ALSA compiled in) # /etc/init.d/alsasound start * Loading ALSA modules ... * Restoring Mixer Levels ... [ ok ]
Now that the required things have been take care of, we need to check up on
the volume as in certain cases, it is muted. We use
(Opens up a console program. Only required settings are shown) # alsamixer
This is how the ALSA Mixer
Now, we shall unmute the channels, and set volume levels as needed.
After you're all done, your ALSA Mixer should look similar to the one below. Note the 00 instead of the MM and also the volume levels for some optimum settings.
Finally. Some music. If everything above is perfect, you should be able to now
listen to some good music. A quick way to test is to use a command line tool
like
(Get any, or get all) # emerge madplay # emerge mpg123 # emerge xmms(To play .ogg files) # emerge vorbis-tools
And then play your favorite soundtrack...
# madplay -v /mnt/shyam/Music/Paul\ Oakenfold\ -\ Dread\ Rock.mp3 MPEG Audio Decoder 0.15.2 (beta) - Copyright (C) 2000-2004 Robert Leslie et al. Title: Dread Rock Artist: Paul Oakenfold Album: Matrix Reloaded Year: 2003 Genre: Soundtrack Soundtrack 00:04:19 Layer III, 160 kbps, 44100 Hz, joint stereo (MS), no CRC # ogg123 Paul\ Oakenfold\ -\ Dread\ Rock.ogg Audio Device: Advanced Linux Sound Architecture (ALSA) output Playing: Paul Oakenfold - Dread Rock.ogg Ogg Vorbis stream: 2 channel, 44100 Hz Genre: Soundtrack Transcoded: mp3;160 Title: Dread Rock Artist: Paul Oakenfold Date: 2003 Album: Matrix Reloaded Time: 00:11.31 [04:28.75] of 04:40.06 (200.6 kbps) Output Buffer 96.9%
If for some reason you're unable to hear sound, the first thing to do would
be to check your
(First and foremost, if /proc/asound/cards shows your card, ALSA has picked up your sound card fine.) # cat /proc/asound/cards 0 [Live ]: EMU10K1 - Sound Blaster Live! Sound Blaster Live! (rev.6, serial:0x80271102) at 0xb800, irq 11(If you run ALSA off the kernel like I do and wonder how far behind you are from alsa-driver, this displays current running ALSA version) # cat /proc/asound/version Advanced Linux Sound Architecture Driver Version 1.0.8 (Thu Jan 13 09:39:32 2005 UTC).(ALSA OSS emulation details) # cat /proc/asound/oss/sndstat Sound Driver:3.8.1a-980706 (ALSA v1.0.8 emulation code) Kernel: Linux airwolf.zion 2.6.11ac1 #2 Wed May 4 00:35:08 IST 2005 i686 Config options: 0 Installed drivers: Type 10: ALSA emulation Card config: Sound Blaster Live! (rev.6, serial:0x80271102) at 0xb800, irq 11 Audio devices: 0: EMU10K1 (DUPLEX) Synth devices: NOT ENABLED IN CONFIG Midi devices: 0: EMU10K1 MPU-401 (UART) Timers: 7: system timer Mixers: 0: SigmaTel STAC9721/23
If your soundcard is one of those that come with onboard MIDI synthesizers and
you would like to listen to some .mid files, you have to install
# emerge awesfx
After copying over the Soundfont files, we can then play a midi file as shown.
You can also add the
(First, copy the Soundfont) # cp /mnt/win2k/Program\ Files/CreativeSBLive2k/SFBank/8MBGMSFX.SF2 /usr/share/sounds/sf2/(We load the specific Soundfont) # asfxload /usr/share/sounds/sf2/8MBGMSFX.SF2
You can now play midi files using a program like
(Check open ports) # aplaymidi -l Port Client name Port name 64:0 EMU10K1 MPU-401 (UART) EMU10K1 MPU-401 (UART) 65:0 Emu10k1 WaveTable Emu10k1 Port 0 65:1 Emu10k1 WaveTable Emu10k1 Port 1 65:2 Emu10k1 WaveTable Emu10k1 Port 2 65:3 Emu10k1 WaveTable Emu10k1 Port 3(Pick a port, and play a mid file) # aplaymidi --port=65:0 /mnt/shyam/music/midi/mi2.mid
If your soundcard lacks a hardware synthesizer, you could use a virtual one
like
# emerge timidity++
For timidity to play sounds, it needs a soundfont. If you do not have any,
install
# emerge timidity-eawpatches # timidity-update -g -s eawpatches(or) # emerge timidity-shompatches # timidity-update -g -s shompatches
Don't forget to add
# rc-update add timidity default # /etc/init.d/timidity start
You can now try out
Some specific sound cards can benefit from certain tools provided by the
ALSA_TOOLS="as10k1 ac3dec"
If the ALSA_TOOLS variable is not set, all available tools will be built.
Now, install the
# emerge alsa-tools
Everyone who contributed to the earlier version of the Gentoo ALSA Guide: Vincent Verleye, Grant Goodyear, Arcady Genkin, Jeremy Huddleston, John P. Davis, Sven Vermeulen, Benny Chuang, Tiemo Kieft and Erwin.