Factor out the channel remap matrix code into a separate function.
Keep a pointer to the channel remapping function so we can install custom
functions.
Catch the common mono->stereo remapping case and install a custom, more
optimized function.
Get rid of the liboil dependency and reimplement the liboil functions with an
equivalent C implementation. Note that most of these functions are deprecated in
liboil and that none of them had any optimisations. We can further specialize
our handrolled versions for some extra speedups.
Move the volume code into a separate file with the reference C implementations.
Add a function to retrieve the volume function and one to install a new one.
Make the coding style match the rest of pulseaudio more.
Remove some liboil functions, they seem unoptimized and likely slower than our
handrolled versions here.
According to POSIX getgrnam_r() returns the error code as return value,
and not in errno. Honour that.
Pointed out and inspired by a patch from Ted Percival.
- We now implement a logic where the sink maintains two distinct
volumes: the 'reference' volume which is shown to the users, and the
'real' volume, which is configured to the hardware. The latter is
configured to the max of all streams. Volume changes on sinks are
propagated back to the streams proportional to the reference volume
change. Volume changes on sink inputs are forwarded to the sink by
'pushing' the volume if necessary.
This renames the old 'virtual_volume' to 'real_volume'. The
'reference_volume' is now the one exposed to users.
By this logic the sink volume visible to the user, will always be the
"upper" boundary for everything that is played. Saved/restored stream
volumes are measured relative to this boundary, the factor here is
always < 1.0.
- introduce accuracy for sink volumes, similar to the accuracy we
already have for source volumes.
- other cleanups.
- drop the 'virtual_' prefix from s->virtual_volume since we don't
distuingish between reference and real volumes for sources
- introduce an accuracy for source volumes: if the hardware can control
the volume "close enough" don't necessarily adjust the rest in
software unless it is beyond a certain threshold. This should save a
little bit of CPU at the expensive of a bit of accuracy in volume
handling.
- other minor cleanups
