Extend MONO_HACK to multi-channel output.
Mono track will have only one channel output on multi-channel devices.
Since ARC++ exposed a 4-channel output device and downmix track in
ChromeOS, we need to add this feature to support mono track sample
expansion.
Add support for both re-sample and non-resample path.
For resample path, we need to add MIXTYPE_STEREOEXPAND in
AudioMixerOps.h since AudioResampler will upmix mono track to stereo
track.
Bug: 120222604
Bug: 112341269
Bug: 117116052
Bug: crbug.com/890560
Test: Play mono tracks without re-sampling on ARC++
Test: Play mono tracks with re-sampling on ARC++
Test: Play normal stereo tracks on ARC++
(cherry picked from commit 9b79e0752e6536c31430aa31838a9de1b7b56f9f)
Change-Id: I51f5914c41dd0196db9c6a2e1a99b44e5d87c0d6
CrOS exposes 4-channel output for ARC++ and mixes samples in CRAS
server to real channel format, but AudioMixer will discard right
channel volume when mixing a 2-channel track to 4-channel output.
This behavior will cause ARC++ fail on Audio Frequency Line Test
in CTS-V since the right channel can't be tested.
The code is also updated to work for 3, 5, 6, 7, 8 canonical output
channel position masks, as well as continue the mono volume
handling for output channel index masks.
Bug: 110551766
Test: Run CTS-V Audio Frequency Line Test
Test: atest mixerops_benchmark
Change-Id: I4c6ee86d30bb8296f0e32f9a17b1135e1313fd64
Split AudioMixer into the base part which doesn't rely on
the framework and can be used in vendor code and the derived part
which is intended to be used by Audioflinger.
Test: A/B compare output from test scripts, manual testing on the phone
Change-Id: I24c390f67f20baa8109902099359ca6e34eebcfd
Judy Hsiao
Mikhail Naganov