Example asoundrc file

.asoundrc

# Posted at http://dl.dropbox.com/u/18371907/asoundrc
# Info:  http://www.sabi.co.uk/Notes/linuxSoundALSA.html
# Soundcard roundup:  http://forums.gentoo.org/viewtopic-p-4192284.html#4192284

# Show programs currently opening ALSA:
# fuser -fv /dev/snd/* /dev/dsp*

# Show opened settings:
# cat /proc/asound/card0/pcm0p/sub0/hw_params

# Show codec:
# cat /proc/asound/card0/codec#0 | grep Codec
# Codec: Realtek ALC889

# Ignore alsaconf:  http://wiki.debian.org/alsaconf

# Maybe OSS can be compatible with dmix (aoss, alsa-oss):
# https://bbs.archlinux.org/viewtopic.php?pid=981179#p981179
# http://alsa.opensrc.org/Dmix
# http://forums.gentoo.org/viewtopic-t-856668.html
# http://www.knoppix.net/forum/threads/25372-HowTo-ALSA-Dmix-OSS

# dmix - plug:dmix supports 1-8 channels, and does use dmix!
# Whereas surround51 doesn't use dmix
# http://bbs.archlinux.org/viewtopic.php?pid=745946#p745946


# cat /proc/asound/card0/pcm0p/sub0/hw_params

# From https://bugs.launchpad.net/debian/+source/sdl-mixer1.2/+bug/66483
# Not needed.
#defaults.pcm.dmix_max_periods -1

# Seems reasonable quality, low CPU usage
defaults.pcm.rate_converter "speexrate_medium"

# See /usr/share/alsa/pcm/dmix.conf
#defaults.dmix.period_time 0
#defaults.dmix.periods 4
#defaults.pcm.surround51.device "0"

# softvol: https://bbs.archlinux.org/viewtopic.php?id=126789

# Duplicate output to 2 audio devices:
# http://forums.gentoo.org/viewtopic-t-902670.html

# Equalizer:  http://krustev.net/w/articles/Global_equalizer_for_ALSA/


# From https://bugtrack.alsa-project.org/alsa-bug/view.php?id=1853
# Posted at http://bbs.archlinux.org/viewtopic.php?id=95582
# Is a dmix that actually works!
# To prove it, run these commands simultaneously, starting with the first one:
#     speaker-test -c 2 -D default
#     speaker-test -c 6 -D surround51 -t wav
# Reasons why needed:
# https://bbs.archlinux.org/viewtopic.php?pid=1252966#p1252966
pcm.dmixed {
	type asym
	playback.pcm {
		# See plugin:dmix at http://www.alsa-project.org/alsa-doc/alsa-lib/pcm_plugins.html
		type dmix

		# Don't block other users, e.g. the Timidity midi-player daemon
		# http://www.alsa-project.org/alsa-doc/alsa-lib/pcm_plugins.html
		ipc_key_add_uid true

		ipc_key 5678293
		ipc_perm 0660
		ipc_gid audio

		# Don't put the rate here! Otherwise it resets the rate & channels set below, as shown by:  cat /proc/asound/card0/pcm0p/sub0/hw_params
		slave {
			# 2 for stereo, 6 for surround51, 8 for surround71
			channels 6
			pcm {
				# mplayer chooses S32_LE, but others usually S16_LE
				#format S32_LE
				format S16_LE

				# 44100 or 48000
				# 44100 for music, 48000 is compatible with most h/w
				#rate 44100
				rate 48000

				# http://www.alsa-project.org/alsa-doc/alsa-lib/pcm_plugins.html
				# Maybe helps
				nonblock true

				type hw
				card 0
				device 0
				subdevice 0
			}

			# mplayer2 chooses 1024
			# period_size 512 with buffer_size 16384 stops crackling in xmame
			# 320 breaks flash - https://bbs.archlinux.org/viewtopic.php?id=129458
			#period_size 512
			period_size 1024
			#period_size 512

			# 4096 might make sound crackle
			# mplayer2 chooses 8192. Half-Life 2 chooses 16384.
			# If too large, use CONFIG_SND_HDA_PREALLOC_SIZE=2048
			buffer_size 8192
		}
	}
	# apulse (a cut-down replacement for pulseaudio) needs dsnoop
	# https://bbs.archlinux.org/viewtopic.php?id=187258
	capture.pcm "dsnoop"
}



# Playing
#pcm.!default {
#	type asym
#	playback.pcm "upmix_20to51_resample"
#}


# Simple upmixing, from http://forums.bodhilinux.com/index.php?/topic/2493-how-to-51-surround-sound-with-alsa/
#pcm.!default {
#	type plug
#	slave.pcm "surround51"
#	slave.channels 6
#	route_policy duplicate
#}


# Check that e.g. ut2004 still works, if default is redefined.
# Flash, etc. use this "default" entry.
pcm.!default {
	type plug
	# Would need to always output to all 6 channels, so the dmixer actually works if e.g. 6-channel is attempted to be started, while 2-channel is playing.
	slave.pcm "dmixed"
}


pcm.!surround20 {
	type plug
	slave.pcm "dmixed"
}

pcm.!surround40 {
	type plug
	slave.pcm "dmixed"
}

pcm.!surround51 {
	type plug
	slave.pcm "dmixed"
}


pcm.wine {
	type plug
	# Output directly, for performance
	#slave.pcm "hw:0"
	slave.pcm "surround20"
}


# If get error "Slave PCM not usable", then need to use plug:
# If get error "Cannot find rate converter", then install libsamplerate and alsa-plugins

# Lunar Linux:  lin ladspa-bs2b
# listplugins
# analyseplugin bs2b
pcm.bs2b {
	type ladspa
	path "/usr/lib/ladspa"
	plugins {
		0 {
			id 4221  # Bauer stereophonic-to-binaural (4221/bs2b)
			input {
				controls [ 700 6 ]
			}
		}
	}
	# http://bbs.archlinux.org/viewtopic.php?id=95582
	slave.pcm "surround20"
}


# http://quitte.de/dsp/caps.html#Narrower  from caps-plugins
# Alternative to bs2b, for music via headphones
# analyseplugin caps | grep -A14 Narrow
pcm.narrower {
	type ladspa
	path "/usr/lib/ladspa"
	plugins {
		0 {
			id 2595  # Narrower - Stereo image width reduction
			input {
				controls [ 0 0.25 ]
			}
		}
	}
	slave.pcm "surround20"
}


# speaker-test -D headphones -c 2 -t wav
# audacious uses less CPU when running bs2b as a listed plugin, probably because of samplerate_best
# Posted at http://bbs.archlinux.org/viewtopic.php?pid=626573#p626573
pcm.headphones {
	type rate
	slave {
		pcm "plug:bs2b"
		#pcm "plug:narrower"
		#rate 44100
		rate 48000
	}
	#converter "speexrate_medium"

    hint {
        show on
        description "Headphones"
    }
}


# speaker-test -D ch51dup -c 2 -t wav
pcm.ch51dup {
	slave.pcm "surround51"
	slave.channels 6
	type plug

	# Front and rear
	ttable.0.0 0.5
	ttable.1.1 0.5
	ttable.2.2 0.5
	ttable.3.3 0.5

	# Center and LFE
	ttable.4.4 1
	ttable.5.5 1

	# Front left/right to center
	ttable.0.4 0.5
	ttable.1.4 0.5

	# Front left/right to rear
	ttable.0.2 0.5
	ttable.1.3 0.5
}



# From http://marcansoft.com/blog/2009/06/acer-aspire-8930g-linux-audio-support/
# To bring all the 8930g speakers into play.
# Works in mplayer but not audacious - weird!
# Have increased the volume, because mplayer is so quiet.
# speaker-test -D stereo8930 -c 2 -t wav
pcm.stereo8930 {
	type plug
	slave.pcm "surround51"
	slave.channels 6

    hint {
        show on
        description "Stereo speakers 8930g"
    }
	ttable.0.0 1.5
	ttable.1.1 1.5
	ttable.0.2 1.5
	ttable.1.3 1.5
	ttable.0.4 0.3
	ttable.1.4 0.3
	ttable.0.5 1.0
	ttable.1.5 1.0
}



# http://alsa.opensrc.org/SurroundSound
# http://alsa.opensrc.org/Low-pass_filter_for_subwoofer_channel_%28HOWTO%29
# Lunar:  lin ladspa tap-plugins swh-plugins cmt-plugins libsamplerate
# Fedora:  yum install ladspa ladspa-blop-plugins ladspa-caps-plugins ladspa-cmt-plugins ladspa-swh-plugins ladspa-tap-plugins libsamplerate
# Arch Linux:  pacman -S ladspa blop swh-plugins libsamplerate tap-plugins cmt
# For id 1672 - 4 Pole Low-Pass Filter with Resonance (FCRCIA) (1672/lp4pole_fcrcia_oa), install blop-plugins
# listplugins
# analyseplugin cmt
# http://plugin.org.uk/ladspa-swh/docs/ladspa-swh.html
# http://forums.gentoo.org/viewtopic-p-4528619.html#4528619
# speaker-test -D upmix_20to51 -c 2 -t wav
# This is one big & nasty PCM, to stop Skype from querying the individual PCM definitions and then crashing with: Assertion `!snd_interval_empty(i)' failed
pcm.upmix_20to51 {
	# From http://alsa.opensrc.org/Low-pass_filter_for_subwoofer_channel_%28HOWTO%29
	# Set up a third channel for the subwoofer
	type plug
	slave.channels 3
	ttable {
		0.0     1       # left channel
		1.1     1       # right channel
		0.2     0.5     # mix left and right ...
		1.2     0.5     # ... channel for subwoofer
	}

	slave.pcm {
		# Apply subwoofer filter
		type ladspa

		# Set the path to ladspa, to fix this error:
		# Playback open error: -2,No such file or directory
		path "/usr/lib/ladspa"
		channels 3
		plugins {
			0 {
				id 1098  # Identity (Audio) (1098/identity_audio)
				policy duplicate
				input.bindings.0 "Input"
				output.bindings.0 "Output"
			}

			# From http://alsa.opensrc.org/Low-pass_filter_for_subwoofer_channel_%28HOWTO%29
			1 {
				id 1672 # 4 Pole Low-Pass Filter with Resonance (FCRCIA) (1672/lp4pole_fcrcia_oa)
				policy none
				input.bindings.2 "Input"
				output.bindings.2 "Output"
				input {
					controls [ 300 2 ]
				}
			}
		}

		slave.pcm {
			# Final mixing of 6-channel output
			type plug
			slave.channels 6
			ttable {
				0.0     1       # front left
				1.1     1       # front right
				0.2     1       # rear left
				1.3     1       # rear right

				# Front left/right to center
				0.4     0.5
				1.4     0.5

				# Subwoofer, more powerful to compensate for bass-removal from other speakers
				2.5     2
			}
			# This next line needs to be "dmixed" rather than e.g. "surround51" - bizarre
			slave.pcm "dmixed"
		}
	}
}



# Channels are wrong way around in Doom3! This fixes them.
# http://www.linuxforen.de/forums/archive/index.php/t-206470.html
# http://forums.seriouszone.com/showthread.php?t=49869&page=10
# http://forums.gentoo.org/viewtopic-p-4173170.html#4173170
# For Audigy 4
# Weird, Doom3 has crappy sound if I add an alsa rate converter.
# Posted at http://ubuntuforums.org/showthread.php?t=1304228
pcm.doom-surround51 {
	slave.pcm "dmixed"
	slave.channels 6
	type route
	ttable.0.0 1
	ttable.1.1 1
	ttable.2.4 1
	ttable.3.5 1
	ttable.4.2 1
	ttable.5.3 1
}


# Pulseaudio workaround: http://ubuntuforums.org/showthread.php?t=1705760
pcm.doom3-8930g {
	type plug
	slave.pcm {
		type dmix
		ipc_key 1093  # Must be unique
		ipc_key_add_uid false
		ipc_perm 0660
		slave {
			pcm "hw:0,0"
			rate 44100
			channels 2
			#period_time 0
			# period_size was 1024 - maybe 512 is better to stop clicks - not sure
			period_size 1092
			#buffer_time 0
			# Doom 3 wants buffer_size 8192
			# In ~/.doom3/base/autoexec.cfg
			# And ~/.quake4/q4base/autoexec.cfg
			# seta s_alsa_pcm "doom3-8930g"
			buffer_size 8192
		}
	}
}

# From https://bbs.archlinux.org/viewtopic.php?id=99185
# And in ~/.mplayer/config:  ao=alsa:device=movie
# Alternative, in ~/.mplayer/config:  af-add=volnorm=2:0.75
# speaker-test -D movie -c 2 -t wav
pcm.movie {
	type plug
	slave.pcm "ladcomp_compressor"
	slave.channels 6
    hint {
        show on
        description "Movie Volume"
    }
}

pcm.ladcomp_compressor {
	type ladspa
	slave.pcm "ladcomp_limiter"
	path "/usr/lib/ladspa"
	plugins [
		{
			label dysonCompress
			input {
				# peak limit, release time, fast ratio, ratio
				controls [0 1 0.5 0.99]
			}
		}
	]
}

pcm.ladcomp_limiter {
	type ladspa
	slave.pcm "plug:movie8930"
	path "/usr/lib/ladspa"
	plugins [
		{
			label fastLookaheadLimiter
			input {
				# InputGain(Db) -20 -> +20 ; Limit (db) -20 -> 0 ; Release time (s) 0.01 -> 2
				# also possible... 20 0 0.8
				# If movie is too quiet, increase the first number.
				controls [ 5 0 0.8  ]
			}
		}
	]
}

pcm.movie8930 {
	type route
	slave.pcm "dmixed"

	ttable.0.0 1.0
	ttable.1.1 1.0
	ttable.2.2 1.0
	ttable.3.3 1.0
	ttable.4.4 1.0
	ttable.0.5 0.6
	ttable.1.5 0.6
	ttable.4.5 0.6
	ttable.5.5 0.8
}


pcm.downmix_51to20 {
	# From http://www.halfgaar.net/surround-sound-in-linux
	# http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=503839
	type route
	slave.pcm "surround20"

	# Front and rear, at 33% of original signal strength
	ttable.0.0 0.33
	ttable.1.1 0.33
	ttable.2.0 0.33
	ttable.3.1 0.33

	# Center channel routing (routed to front-left and front-right),
	# 6dB gaindrop (gain half of main channels) per channel
	ttable.4.0 0.16
	ttable.4.1 0.16

	# LFE channel routing (routed to front-left and front-right),
	# 6dB gaindrop (gain half of main channels) per channel
	ttable.5.0 0.16
	ttable.5.1 0.16
}


# http://www.freedesktop.org/wiki/Software/PulseAudio/Documentation/User/PerfectSetup/
pcm.pulse {
	type pulse
}

ctl.pulse {
	type pulse
}