am fb578b6: Merge "audioflinger: fix clicks on 48kHz audio." into ics-mr1

* commit 'fb578b6b88af51812b71a86ad4dd3a7de56e394b':
  audioflinger: fix clicks on 48kHz audio.

Author: Eric Laurent

services/audioflinger/AudioFlinger.cpp

@@ -2111,7 +2111,15 @@ uint32_t AudioFlinger::MixerThread::prepareTracks_l(const SortedVector< wp<Track
             if (t->sampleRate() == (int)mSampleRate) {
                 minFrames = mFrameCount;
             } else {
-                minFrames = (mFrameCount * t->sampleRate()) / mSampleRate + 1;
+                // +1 for rounding and +1 for additional sample needed for interpolation
+                minFrames = (mFrameCount * t->sampleRate()) / mSampleRate + 1 + 1;
+                // add frames already consumed but not yet released by the resampler
+                // because cblk->framesReady() will  include these frames
+                minFrames += mAudioMixer->getUnreleasedFrames(track->name());
+                // the minimum track buffer size is normally twice the number of frames necessary
+                // to fill one buffer and the resampler should not leave more than one buffer worth
+                // of unreleased frames after each pass, but just in case...
+                LOG_ASSERT(minFrames <= cblk->frameCount);
             }
         }
         if ((cblk->framesReady() >= minFrames) && track->isReady() &&

services/audioflinger/AudioMixer.cpp

@@ -331,6 +331,23 @@ void AudioMixer::track_t::adjustVolumeRamp(bool aux)
     }
 }
 
+size_t AudioMixer::track_t::getUnreleasedFrames()
+{
+    if (resampler != NULL) {
+        return resampler->getUnreleasedFrames();
+    }
+    return 0;
+}
+
+size_t AudioMixer::getUnreleasedFrames(int name)
+{
+    name -= TRACK0;
+    if (uint32_t(name) < MAX_NUM_TRACKS) {
+        track_t& track(mState.tracks[name]);
+        return track.getUnreleasedFrames();
+    }
+    return 0;
+}
 
 status_t AudioMixer::setBufferProvider(AudioBufferProvider* buffer)
 {

services/audioflinger/AudioMixer.h

@@ -91,6 +91,8 @@ class AudioMixer
 
     static void ditherAndClamp(int32_t* out, int32_t const *sums, size_t c);
 
+    size_t      getUnreleasedFrames(int name);
+
 private:
 
     enum {
@@ -167,6 +169,7 @@ class AudioMixer
         bool        doesResample() const;
         void        resetResampler();
         void        adjustVolumeRamp(bool aux);
+        size_t      getUnreleasedFrames();
     };
 
     // pad to 32-bytes to fill cache line

services/audioflinger/AudioResampler.h

@@ -54,6 +54,7 @@ class AudioResampler {
             AudioBufferProvider* provider) = 0;
 
     virtual void reset();
+    virtual size_t getUnreleasedFrames() { return mInputIndex; }
 
 protected:
     // number of bits for phase fraction - 30 bits allows nearly 2x downsampling