On production systems, having a constant high latency is favored over
dynamically adjusting it in order to optimize for low latency,
because every time a dynamic adjustment happens, there's a glitch.
This adds an option to let the user specify the exact amount of latency
they want.
In USB Audio Class 2 (UAC2) setups, pitch control is handled by
feedback endpoints. The host adjusts its data rate accordingly.
When pitch control is active (pitch_elem), applying the default
delay-locked loop (DLL) bandwidth can lead to instability and
oscillations around the target rate.
This patch adds a new parameter, api.alsa.dll-bandwidth-max, to
configure the maximum DLL bandwidth. It introduces a new field
in the ALSA state to store this value.
By default, it uses SPA_DLL_BW_MAX, but when pitch control is in
use, setting it to a lower value (e.g. 0.02) helps ensure better
stability, based on empirical testing.
Add configuration options for the BAP/PACS sink and source endpoint
location (= channel positions) and context settings.
Although BlueZ associates these with individual endpoints, in the PACS
spec they are actually device-global, so configure directly in monitor
settings.
Parse BAP settings in a single place, and simplify QoS customization a
bit.
Ensure the selected preset gets selected.
For all the BAP codec settings, use device settings instead of global
monitor ones.
When api.alsa.split-enable=true for ACP device, instruct UCM to not
use alsa-lib plugins for SplitPCM devices.
Grab the information from UCM for the intended channel remapping, and
add the splitting information to the nodes emitted.
Session manager can then look at that, and load nodes to do the channel
splitting.
Don't use the api.alsa.soft-mixer option to disable the path selection
but make a new api.alsa.disable-mixer-path.
Disabling the path selection might leave cards unusable after suspend,
so a separate option is a better idea.
See #4311
Collect the list of object properties into a single place.
Group properties in the index based on the object type. Consider
"Monitor" as a separate object type, as it's generally configured
separately.
Add something about Port, Link, and Client properties. Just explain some
of these as they're fairly technical, so just link to API docs.
