Fix bug in WAVExtractor for 24-bit per sample wav

support stereo/multichannel 24-bit format
kMaxFrameSize is fixed to 32768. When converting 24-bit to 16-bit,
number of samlpes is maxBytesToRead /3.
In this case, if the maxBytesToRead is not multiple of 3,
pcm data is messed when converting.

Bug:7630939
Change-Id: I0ea1b53eb1272a8d83b63815fc0a05b73cef75f1

diff --git a/media/libstagefright/WAVExtractor.cpp b/media/libstagefright/WAVExtractor.cpp
index a38400b..2a7f628 100644 (file)
--- a/media/libstagefright/WAVExtractor.cpp
+++ b/media/libstagefright/WAVExtractor.cpp
@@ -401,8 +401,10 @@ status_t WAVSource::read(
         return err;
     }
 
+    // make sure that maxBytesToRead is multiple of 3, in 24-bit case
     size_t maxBytesToRead =
-        mBitsPerSample == 8 ? kMaxFrameSize / 2 : kMaxFrameSize;
+        mBitsPerSample == 8 ? kMaxFrameSize / 2 : 
+        (mBitsPerSample == 24 ? 3*(kMaxFrameSize/3): kMaxFrameSize);
 
     size_t maxBytesAvailable =
         (mCurrentPos - mOffset >= (off64_t)mSize)
@@ -425,7 +427,7 @@ status_t WAVSource::read(
 
     buffer->set_range(0, n);
 
-    if (mWaveFormat == WAVE_FORMAT_PCM) {
+    if (mWaveFormat == WAVE_FORMAT_PCM || mWaveFormat == WAVE_FORMAT_EXTENSIBLE) {
         if (mBitsPerSample == 8) {
             // Convert 8-bit unsigned samples to 16-bit signed.