commit 680b795435a5a501a56610258dce5eda40a1725d
author Andy Hung <hunga@google.com> Wed Nov 12 13:18:52 2014 -0800
committer Andy Hung <hunga@google.com> Mon Nov 24 17:25:18 2014 -0800
tree db2d003b9b147e5f51e4cf6bf05d497d8ce4acb7
parent bc0f452b9a76dd8c8244e775bc9c5aa85cae3ddf

Fix AudioTrack loop mode to play audio from buffer start

Bug: 18217633
Change-Id: Ica77acf0a32832d9b04eb657ef2f4f5329f8fbda

media/libmedia/AudioTrack.cpp

diff --git a/media/libmedia/AudioTrack.cpp b/media/libmedia/AudioTrack.cpp
index c11050e..bbab2c1 100644
--- a/media/libmedia/AudioTrack.cpp
+++ b/media/libmedia/AudioTrack.cpp
@@ -742,8 +742,7 @@
 
 void AudioTrack::setLoop_l(uint32_t loopStart, uint32_t loopEnd, int loopCount)
 {
-    // FIXME If setting a loop also sets position to start of loop, then
-    //       this is correct.  Otherwise it should be removed.
+    // Setting the loop will reset next notification update period (like setPosition).
     mNewPosition = updateAndGetPosition_l() + mUpdatePeriod;
     mLoopPeriod = loopCount != 0 ? loopEnd - loopStart : 0;
     mStaticProxy->setLoop(loopStart, loopEnd, loopCount);

media/libmedia/AudioTrackShared.cpp

diff --git a/media/libmedia/AudioTrackShared.cpp b/media/libmedia/AudioTrackShared.cpp
index 62362da..4a783b3 100644
--- a/media/libmedia/AudioTrackShared.cpp
+++ b/media/libmedia/AudioTrackShared.cpp
@@ -503,7 +503,11 @@
     newState.mLoopStart = (uint32_t) loopStart;
     newState.mLoopEnd = (uint32_t) loopEnd;
     newState.mLoopCount = loopCount;
-    mBufferPosition = loopStart;
+    size_t bufferPosition;
+    if (loopCount == 0 || (bufferPosition = getBufferPosition()) >= loopEnd) {
+        bufferPosition = loopStart;
+    }
+    mBufferPosition = bufferPosition; // snapshot buffer position until loop is acknowledged.
     (void) mMutator.push(newState);
 }
 
@@ -776,7 +780,9 @@
         } else if (state.mLoopCount >= -1) {
             if (loopStart < loopEnd && loopEnd <= mFrameCount &&
                     loopEnd - loopStart >= MIN_LOOP) {
-                if (!(loopStart <= position && position < loopEnd)) {
+                // If the current position is greater than the end of the loop
+                // we "wrap" to the loop start. This might cause an audible pop.
+                if (position >= loopEnd) {
                     mPosition = position = loopStart;
                 }
                 if (state.mLoopCount == -1) {