commit 3fae037db39ff89707c3a58ef1419229a00ad71d
author Richard Folke Tullberg <richardfolke.tullberg@sony.com> Fri Jan 13 09:04:25 2017 +0100
committer Andy Hung <hunga@google.com> Mon Jan 28 16:21:52 2019 -0800
tree 33087aa031e45fdc65add4ffaaf74e6a7872cf0f
parent 48f59ed61b902f0e6cb7811bd8ee5fa60ab63abe

Add master audio balance

Test: Change Balance through Settings, play audio
Bug: 28390736
Co-author: Ed Savage-Jones <edward.savage-jones@sony.com>
Change-Id: I0169b436ccbaa5628584d9f4954dd7c76d021aae

services/audioflinger/FastMixer.cpp

diff --git a/services/audioflinger/FastMixer.cpp b/services/audioflinger/FastMixer.cpp
index f328577..7c9e15a 100644
--- a/services/audioflinger/FastMixer.cpp
+++ b/services/audioflinger/FastMixer.cpp
@@ -60,7 +60,6 @@
     mSinkChannelCount(FCC_2),
     mMixerBuffer(NULL),
     mMixerBufferSize(0),
-    mMixerBufferFormat(AUDIO_FORMAT_PCM_16_BIT),
     mMixerBufferState(UNDEFINED),
     mFormat(Format_Invalid),
     mSampleRate(0),
@@ -161,6 +160,7 @@
         mOutputSink = current->mOutputSink;
         mOutputSinkGen = current->mOutputSinkGen;
         mSinkChannelMask = current->mSinkChannelMask;
+        mBalance.setChannelMask(mSinkChannelMask);
         if (mOutputSink == NULL) {
             mFormat = Format_Invalid;
             mSampleRate = 0;
@@ -191,10 +191,6 @@
         free(mSinkBuffer);
         mSinkBuffer = NULL;
         if (frameCount > 0 && mSampleRate > 0) {
-            // The mixer produces either 16 bit PCM or float output, select
-            // float output if the HAL supports higher than 16 bit precision.
-            mMixerBufferFormat = mFormat.mFormat == AUDIO_FORMAT_PCM_16_BIT ?
-                    AUDIO_FORMAT_PCM_16_BIT : AUDIO_FORMAT_PCM_FLOAT;
             // FIXME new may block for unbounded time at internal mutex of the heap
             //       implementation; it would be better to have normal mixer allocate for us
             //       to avoid blocking here and to prevent possible priority inversion
@@ -471,6 +467,12 @@
             mono_blend(mMixerBuffer, mMixerBufferFormat, Format_channelCount(mFormat), frameCount,
                     true /*limit*/);
         }
+
+        // Balance must take effect after mono conversion.
+        // mBalance detects zero balance within the class for speed (not needed here).
+        mBalance.setBalance(mMasterBalance.load());
+        mBalance.process((float *)mMixerBuffer, frameCount);
+
         // prepare the buffer used to write to sink
         void *buffer = mSinkBuffer != NULL ? mSinkBuffer : mMixerBuffer;
         if (mFormat.mFormat != mMixerBufferFormat) { // sink format not the same as mixer format