Merge PR #44: Fix a bug with buffer size calculation in the AudioUnit inputCallback

3 files changed, 24 insertions, 3 deletions

diff --git a/src/MKMacAudioDevice.m b/src/MKMacAudioDevice.m
index 24e7e22..2be75d1 100644
--- a/src/MKMacAudioDevice.m
+++ b/src/MKMacAudioDevice.m
@@ -45,7 +45,7 @@ static OSStatus inputCallback(void *udata, AudioUnitRenderActionFlags *flags, co
         b->mData = calloc(1, b->mDataByteSize);
     }
     
-    if (dev->_recordBufList.mBuffers->mDataByteSize < (nframes/dev->_recordSampleSize)) {
+    if (dev->_recordBufList.mBuffers->mDataByteSize < (dev->_recordSampleSize * nframes)) {
         NSLog(@"MKMacAudioDevice: Buffer too small. Allocating more space.");
         AudioBuffer *b = dev->_recordBufList.mBuffers;
         free(b->mData);
@@ -53,11 +53,18 @@ static OSStatus inputCallback(void *udata, AudioUnitRenderActionFlags *flags, co
         b->mData = calloc(1, b->mDataByteSize);
     }
     
+    /*
+     AudioUnitRender modifies the mDataByteSize members with the
+     actual read bytes count. We need to write it back otherwise
+     we'll reallocate the buffer even if not needed.
+     */
+    UInt32 dataByteSize = dev->_buflist.mBuffers->mDataByteSize;
     err = AudioUnitRender(dev->_recordAudioUnit, flags, ts, busnum, nframes, &dev->_recordBufList);
     if (err != noErr) {
         NSLog(@"MKMacAudioDevice: AudioUnitRender failed. err = %ld", (unsigned long)err);
         return err;
     }
+    dev->_buflist.mBuffers->mDataByteSize = dataByteSize;
     
     NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
     short *buf = (short *) dev->_recordBufList.mBuffers->mData;
diff --git a/src/MKVoiceProcessingDevice.m b/src/MKVoiceProcessingDevice.m
index 069fcaf..9105dab 100644
--- a/src/MKVoiceProcessingDevice.m
+++ b/src/MKVoiceProcessingDevice.m
@@ -53,7 +53,7 @@ static OSStatus inputCallback(void *udata, AudioUnitRenderActionFlags *flags, co
         b->mData = calloc(1, b->mDataByteSize);
     }
     
-    if (dev->_buflist.mBuffers->mDataByteSize < (nframes/dev->_micSampleSize)) {
+    if (dev->_buflist.mBuffers->mDataByteSize < (dev->_micSampleSize * nframes)) {
         NSLog(@"MKVoiceProcessingDevice: Buffer too small. Allocating more space.");
         AudioBuffer *b = dev->_buflist.mBuffers;
         free(b->mData);
@@ -61,11 +61,18 @@ static OSStatus inputCallback(void *udata, AudioUnitRenderActionFlags *flags, co
         b->mData = calloc(1, b->mDataByteSize);
     }
         
+    /*
+     AudioUnitRender modifies the mDataByteSize members with the
+     actual read bytes count. We need to write it back otherwise
+     we'll reallocate the buffer even if not needed.
+     */
+    UInt32 dataByteSize = dev->_buflist.mBuffers->mDataByteSize;
     err = AudioUnitRender(dev->_audioUnit, flags, ts, busnum, nframes, &dev->_buflist);
     if (err != noErr) {
         NSLog(@"MKVoiceProcessingDevice: AudioUnitRender failed. err = %li", (long int)err);
         return err;
     }
+    dev->_buflist.mBuffers->mDataByteSize = dataByteSize;
     
     NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
     short *buf = (short *) dev->_buflist.mBuffers->mData;
diff --git a/src/MKiOSAudioDevice.m b/src/MKiOSAudioDevice.m
index 1d5aca8..1124ce4 100644
--- a/src/MKiOSAudioDevice.m
+++ b/src/MKiOSAudioDevice.m
@@ -38,7 +38,7 @@ static OSStatus inputCallback(void *udata, AudioUnitRenderActionFlags *flags, co
         b->mData = calloc(1, b->mDataByteSize);
     }
     
-    if (dev->_buflist.mBuffers->mDataByteSize < (nframes/dev->_micSampleSize)) {
+    if (dev->_buflist.mBuffers->mDataByteSize < (dev->_micSampleSize * nframes)) {
         NSLog(@"MKiOSAudioDevice: Buffer too small. Allocating more space.");
         AudioBuffer *b = dev->_buflist.mBuffers;
         free(b->mData);
@@ -46,6 +46,12 @@ static OSStatus inputCallback(void *udata, AudioUnitRenderActionFlags *flags, co
         b->mData = calloc(1, b->mDataByteSize);
     }
     
+    /*
+     AudioUnitRender modifies the mDataByteSize members with the
+     actual read bytes count. We need to write it back otherwise
+     we'll reallocate the buffer even if not needed.
+     */
+    UInt32 dataByteSize = dev->_buflist.mBuffers->mDataByteSize;
     err = AudioUnitRender(dev->_audioUnit, flags, ts, busnum, nframes, &dev->_buflist);
     if (err != noErr) {
 #ifndef TARGET_IPHONE_SIMULATOR
@@ -53,6 +59,7 @@ static OSStatus inputCallback(void *udata, AudioUnitRenderActionFlags *flags, co
 #endif
         return err;
     }
+    dev->_buflist.mBuffers->mDataByteSize = dataByteSize;
     
     NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
     short *buf = (short *) dev->_buflist.mBuffers->mData;