am e737cda6: audioflinger: refine latency latency calculation.

* commit 'e737cda649acbfa43fc1b74612a83f2fac9aa449':
  audioflinger: refine latency latency calculation.

3 files changed, 23 insertions, 1 deletions

diff --git a/services/audioflinger/AudioFlinger.cpp b/services/audioflinger/AudioFlinger.cpp
index 3c60e5a..68be7a7 100644
--- a/services/audioflinger/AudioFlinger.cpp
+++ b/services/audioflinger/AudioFlinger.cpp
@@ -1804,11 +1804,25 @@ Exit:
     return track;
 }
 
+uint32_t AudioFlinger::MixerThread::correctLatency(uint32_t latency) const
+{
+    if (mFastMixer != NULL) {
+        MonoPipe *pipe = (MonoPipe *)mPipeSink.get();
+        latency += (pipe->getAvgFrames() * 1000) / mSampleRate;
+    }
+    return latency;
+}
+
+uint32_t AudioFlinger::PlaybackThread::correctLatency(uint32_t latency) const
+{
+    return latency;
+}
+
 uint32_t AudioFlinger::PlaybackThread::latency() const
 {
     Mutex::Autolock _l(mLock);
     if (initCheck() == NO_ERROR) {
-        return mOutput->stream->get_latency(mOutput->stream);
+        return correctLatency(mOutput->stream->get_latency(mOutput->stream));
     } else {
         return 0;
     }
@@ -2020,6 +2034,7 @@ void AudioFlinger::PlaybackThread::readOutputParameters()
     }
 }
 
+
 status_t AudioFlinger::PlaybackThread::getRenderPosition(uint32_t *halFrames, uint32_t *dspFrames)
 {
     if (halFrames == NULL || dspFrames == NULL) {
diff --git a/services/audioflinger/AudioFlinger.h b/services/audioflinger/AudioFlinger.h
index 1ae5414..51cbae7 100644
--- a/services/audioflinger/AudioFlinger.h
+++ b/services/audioflinger/AudioFlinger.h
@@ -1048,6 +1048,8 @@ public:
         // Cache various calculated values, at threadLoop() entry and after a parameter change
         virtual     void        cacheParameters_l();
 
+        virtual     uint32_t    correctLatency(uint32_t latency) const;
+
     private:
 
         friend class AudioFlinger;      // for numerous
@@ -1154,6 +1156,7 @@ public:
         virtual     void        threadLoop_mix();
         virtual     void        threadLoop_sleepTime();
         virtual     void        threadLoop_removeTracks(const Vector< sp<Track> >& tracksToRemove);
+        virtual     uint32_t    correctLatency(uint32_t latency) const;
 
                     AudioMixer* mAudioMixer;    // normal mixer
     private:
diff --git a/services/audioflinger/MonoPipe.h b/services/audioflinger/MonoPipe.h
index 1f56e54..545d6ac 100644
--- a/services/audioflinger/MonoPipe.h
+++ b/services/audioflinger/MonoPipe.h
@@ -56,6 +56,10 @@ public:
     virtual ssize_t write(const void *buffer, size_t count);
     //virtual ssize_t writeVia(writeVia_t via, size_t total, void *user, size_t block);
 
+            // average number of frames present in the pipe under normal conditions.
+            // See throttling mechanism in MonoPipe::write()
+            size_t  getAvgFrames() const { return (mMaxFrames * 11) / 16; }
+
 private:
     const size_t    mMaxFrames;     // always a power of 2
     void * const    mBuffer;