Software

Dual-card ALSA Configuration

Sound in Linux can be a pain to get right. Thusly, I’ve attached my (functional) configuration for multiple soundcards in ALSA for reference below:

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# Set default sound card
# Useful so that all settings can be changed to a different card here.
pcm.av710spdif {
	type hw
	card 2
	device 1
}
pcm.realtek {
	type hw
	card 0
#	device 0
}

pcm.!default {
	type plug
	slave.pcm "av710duplex"
}

pcm.monitor {
	type plug
	ttable.0.10 1 # digital mix left
	ttable.1.11 1 # digital mix right
	slave.pcm "av710spdif"
}

# Allow mixing of multiple output streams to this device
pcm.av710output {
	type dmix
	ipc_key 1024
	ipc_perm 0660 # Sound for everybody in your group!
	slave.pcm "av710spdif"
	slave {
	# This stuff provides some fixes for latency issues.
	# buffer_size should be set for your audio chipset.
		format S32_LE
		period_time 0
		period_size 1024
		buffer_size 8192
		rate 44100
	}

	bindings {
		0 0
		1 1
	}
}

# Allow reading from the default device.
# Also known as record or capture.
pcm.av710input {
	type dsnoop
	ipc_key 2048
	slave.pcm "av710spdif"
	slave {
	# This stuff provides some fixes for latency issues.
	# buffer_size should be set for your audio chipset.
		format S32_LE
		period_time 0
		period_size 1024
		buffer_size 8192
		rate 44100
	}

	bindings {
		0 0
		1 1
	}
}

# This is what we want as our default device
# a fully duplex (read/write) audio device.
pcm.av710duplex {
	type asym
	playback.pcm "av710output"
	capture.pcm "av710input"
}

# Allow mixing of multiple output streams to this device
pcm.realtekoutput {
	type dmix
	ipc_key 3096
	ipc_perm 0660 # Sound for everybody in your group!
	slave.pcm "realtek"
	slave {
	# This stuff provides some fixes for latency issues.
	# buffer_size should be set for your audio chipset.
#		format S32_LE
		period_time 0
		period_size 1024
		buffer_size 8192
		rate 44100
	}

	bindings {
		0 0
		1 1
	}
}

# Allow reading from the default device.
# Also known as record or capture.
pcm.realtekinput {
	type dsnoop
	ipc_key 4096
	slave.pcm "realtek"
	slave {
	# This stuff provides some fixes for latency issues.
	# buffer_size should be set for your audio chipset.
#		format S32_LE
		period_time 0
		period_size 1024
		buffer_size 8192
		rate 44100
	}

	bindings {
		0 0
		1 1
	}
}

# This is what we want as our default device
# a fully duplex (read/write) audio device.
pcm.realtekduplex {
	type asym
	playback.pcm "realtekoutput"
	capture.pcm "realtekinput"
}