From 0d34354e3e6e70ecce4cbef30d7dc6a1b9bcf328 Mon Sep 17 00:00:00 2001
From: Zhou Song <zhous@codeaurora.org>
Date: Thu, 19 Nov 2015 13:49:18 +0800
Subject: audio: QTI resampler supports for 32 bit input format

Configure QTI resampler as 32 bit input format to avoid
losing precision.

audioflinger: add channel count check to use QTI resampler
Change-Id: I8f76dd82b72a0dd8b77343e77e0d0545e1be2114

CRs-Fixed: 940287
Change-Id: I7e1b8582cd6bb106ab0bd25f9bc1bd9e4092318b
---
 services/audioflinger/AudioMixer.cpp        |  3 ++-
 services/audioflinger/AudioResamplerQTI.cpp | 21 +++++++++++++--------
 services/audioflinger/AudioResamplerQTI.h   |  2 +-
 3 files changed, 16 insertions(+), 10 deletions(-)

(limited to 'services/audioflinger')

diff --git a/services/audioflinger/AudioMixer.cpp b/services/audioflinger/AudioMixer.cpp
index 806eaf1..bb9d4e5 100644
--- a/services/audioflinger/AudioMixer.cpp
+++ b/services/audioflinger/AudioMixer.cpp
@@ -781,7 +781,8 @@ bool AudioMixer::track_t::setResampler(uint32_t trackSampleRate, uint32_t devSam
 #ifdef QTI_RESAMPLER
                 if ((trackSampleRate <= QTI_RESAMPLER_MAX_SAMPLERATE) &&
                        (trackSampleRate > devSampleRate * 2) &&
-                       ((devSampleRate == 48000)||(devSampleRate == 44100))) {
+                       ((devSampleRate == 48000)||(devSampleRate == 44100)) &&
+                       (resamplerChannelCount <= 2)) {
                     quality = AudioResampler::QTI_QUALITY;
                 }
 #endif
diff --git a/services/audioflinger/AudioResamplerQTI.cpp b/services/audioflinger/AudioResamplerQTI.cpp
index 44b741e..0d57e09 100644
--- a/services/audioflinger/AudioResamplerQTI.cpp
+++ b/services/audioflinger/AudioResamplerQTI.cpp
@@ -51,8 +51,9 @@ size_t AudioResamplerQTI::resample(int32_t* out, size_t outFrameCount,
 {
     int16_t vl = mVolume[0];
     int16_t vr = mVolume[1];
-    int16_t *pBuf;
+    int32_t *pBuf;
 
+    int64_t tempL, tempR;
     size_t inFrameRequest;
     size_t inFrameCount = getNumInSample(outFrameCount);
     size_t index = 0;
@@ -74,7 +75,7 @@ size_t AudioResamplerQTI::resample(int32_t* out, size_t outFrameCount,
         if(mResamplerOutBuf) {
             delete [] mResamplerOutBuf;
         }
-        mTmpBuf = new int16_t[inFrameRequest + 16];
+        mTmpBuf = new int32_t[inFrameRequest + 16];
         mResamplerOutBuf = new int32_t[out_count];
     }
 
@@ -95,7 +96,7 @@ size_t AudioResamplerQTI::resample(int32_t* out, size_t outFrameCount,
                 goto resample_exit;
             }
 
-            mTmpBuf[index++] = clamp16_from_float(*((float *)mBuffer.raw + frameIndex++));
+            mTmpBuf[index++] = clampq4_27_from_float(*((float *)mBuffer.raw + frameIndex++));
 
             if (frameIndex >= mBuffer.frameCount) {
                 provider->releaseBuffer(&mBuffer);
@@ -121,8 +122,8 @@ size_t AudioResamplerQTI::resample(int32_t* out, size_t outFrameCount,
                 goto resample_exit;
             }
 
-            mTmpBuf[index] = clamp16_from_float(*((float *)mBuffer.raw + frameIndex++));
-            pBuf[index++] = clamp16_from_float(*((float *)mBuffer.raw + frameIndex++));
+            mTmpBuf[index] = clampq4_27_from_float(*((float *)mBuffer.raw + frameIndex++));
+            pBuf[index++] = clampq4_27_from_float(*((float *)mBuffer.raw + frameIndex++));
             if (frameIndex >= mBuffer.frameCount * 2) {
                 provider->releaseBuffer(&mBuffer);
             }
@@ -133,8 +134,12 @@ size_t AudioResamplerQTI::resample(int32_t* out, size_t outFrameCount,
 
 resample_exit:
     for (int i = 0; i < out_count; i += 2) {
-        fout[i] += float_from_q4_27(mResamplerOutBuf[i] * vl);
-        fout[i+1] += float_from_q4_27(mResamplerOutBuf[i+1] * vr);
+        // Multiplying q4.27 data with u4.12 gain could result in 39 fractional bit data(27+12)
+        // To get back the 27 fractional bit format output data, do right shift by 12
+        tempL = (int64_t)mResamplerOutBuf[i] * vl;
+        tempR = (int64_t)mResamplerOutBuf[i+1] * vr;
+        fout[i] += float_from_q4_27((int32_t)(tempL>>12));
+        fout[i+1] += float_from_q4_27((int32_t)(tempR>>12));
     }
 
     mFrameIndex = frameIndex;
@@ -151,7 +156,7 @@ void AudioResamplerQTI::setSampleRate(int32_t inSampleRate)
 
 void AudioResamplerQTI::init()
 {
-    QCT_Resampler::Init(mState, mChannelCount, mInSampleRate, mSampleRate);
+    QCT_Resampler::Init(mState, mChannelCount, mInSampleRate, mSampleRate, 1/*32bit in*/);
 }
 
 size_t AudioResamplerQTI::getNumInSample(size_t outFrameCount)
diff --git a/services/audioflinger/AudioResamplerQTI.h b/services/audioflinger/AudioResamplerQTI.h
index 0b30a9f..1cf93fc 100644
--- a/services/audioflinger/AudioResamplerQTI.h
+++ b/services/audioflinger/AudioResamplerQTI.h
@@ -35,7 +35,7 @@ public:
     size_t getNumInSample(size_t outFrameCount);
 
     int16_t *mState;
-    int16_t *mTmpBuf;
+    int32_t *mTmpBuf;
     int32_t *mResamplerOutBuf;
     size_t mFrameIndex;
     size_t stateSize;
-- 
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