pipewire/spa/plugins/alsa/acp
Stefan Binding 7f07448a80 spa: acp: Allow Volume control which supports mute to be used as a hardware mute
Some devices have a hardware volume control, but not a dedicated
hardware mute control. In some of these cases, the volume control is
described as having a hardware mute when volume is 0. This is described
in the TLV information of the volume control, when the
SNDRV_CTL_TLVD_DB_SCALE_MUTE flag is set in the TLV structure.
If set, alsa-lib will set the minimum dB value to -99999.99dB, which
can be detected inside PipeWire.

PipeWire can then use this hardware volume control to apply hardware
mute, when set.

In order to be able to set volumes and mutes separately, changing the
volume whilst muted will save the value, but not write it to the
hardware. When the device is unmuted, the saved value will be restored.

Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com>
2025-05-05 07:40:29 +00:00
..
acp.c spa: acp: Allow Volume control which supports mute to be used as a hardware mute 2025-05-05 07:40:29 +00:00
acp.h
alsa-mixer.c
alsa-mixer.h spa: acp: Allow Volume control which supports mute to be used as a hardware mute 2025-05-05 07:40:29 +00:00
alsa-ucm.c
alsa-ucm.h
alsa-util.c
alsa-util.h
array.h
card.h
channelmap.h
compat.c
compat.h
conf-parser.c
conf-parser.h
device-port.h
dynarray.h
hashmap.h
idxset.h
llist.h
meson.build
proplist.h
volume.h