From 7ed982a07333cdfcb3721a9845e789c227b4d80b Mon Sep 17 00:00:00 2001
From: Stephen Birarda <commit@birarda.com>
Date: Tue, 18 Mar 2014 11:12:36 -0700
Subject: [PATCH] cleanup writing of silent frame to ring buffer

---
 libraries/audio/src/AudioRingBuffer.cpp | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/libraries/audio/src/AudioRingBuffer.cpp b/libraries/audio/src/AudioRingBuffer.cpp
index ba21c6c9b9..9cef64e216 100644
--- a/libraries/audio/src/AudioRingBuffer.cpp
+++ b/libraries/audio/src/AudioRingBuffer.cpp
@@ -157,16 +157,18 @@ unsigned int AudioRingBuffer::samplesAvailable() const {
 }
 
 void AudioRingBuffer::addSilentFrame(int numSilentSamples) {
-    // setup the silent frame
-    int numSilentBytes = numSilentSamples * sizeof(int16_t);
-    char* silentFrame = new char[numSilentBytes];
-    memset(silentFrame, 0, numSilentBytes);
-    
-    // write it
-    writeData(silentFrame, numSilentBytes);
-    
-    // delete the temporary silent frame
-    delete[] silentFrame;
+    // memset zeroes into the buffer, accomodate a wrap around the end
+    // push the _endOfLastWrite to the correct spot
+    if (_endOfLastWrite + numSilentSamples <= _buffer + _sampleCapacity) {
+        memset(_endOfLastWrite, 0, numSilentSamples * sizeof(int16_t));
+        _endOfLastWrite += numSilentSamples;
+    } else {
+        int numSamplesToEnd = (_buffer + _sampleCapacity) - _endOfLastWrite;
+        memset(_endOfLastWrite, 0, numSilentSamples * sizeof(int16_t));
+        memset(_buffer, 0, (numSilentSamples - numSamplesToEnd) * sizeof(int16_t));
+        
+        _endOfLastWrite = _buffer + (numSilentSamples - numSamplesToEnd);
+    }
 }
 
 bool AudioRingBuffer::isNotStarvedOrHasMinimumSamples(unsigned int numRequiredSamples) const {