From 14e3160d502a2afa60728da730f5a8ef1d38d43c Mon Sep 17 00:00:00 2001
From: Stephen Birarda <commit@birarda.com>
Date: Mon, 11 Mar 2013 17:46:57 -0700
Subject: [PATCH] only keep the threshold number of frames on mixer as well

---
 mixer/src/main.cpp | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/mixer/src/main.cpp b/mixer/src/main.cpp
index 155f63f9e0..5735b6e03d 100644
--- a/mixer/src/main.cpp
+++ b/mixer/src/main.cpp
@@ -81,6 +81,22 @@ void *sendBuffer(void *args)
                     printf("Buffer %d starved.\n", i);
                     agentBuffer->setStarted(false);
                 } else {
+                    
+                    // check if we have more than we need to play out
+                    int thresholdFrames = ceilf((BUFFER_LENGTH_SAMPLES_PER_CHANNEL + JITTER_BUFFER_SAMPLES) / (float)BUFFER_LENGTH_SAMPLES_PER_CHANNEL);
+                    int thresholdSamples = thresholdFrames * BUFFER_LENGTH_SAMPLES_PER_CHANNEL;
+                    
+                    if (agentBuffer->diffLastWriteNextOutput() > thresholdSamples) {
+                        // we need to push the next output forwards
+                        int samplesToPush = agentBuffer->diffLastWriteNextOutput() - thresholdSamples;
+                        
+                        if (agentBuffer->getNextOutput() + samplesToPush > agentBuffer->getBuffer()) {
+                            agentBuffer->setNextOutput(agentBuffer->getBuffer() + (samplesToPush - (agentBuffer->getBuffer() + RING_BUFFER_SAMPLES - agentBuffer->getNextOutput())));
+                        } else {
+                            agentBuffer->setNextOutput(agentBuffer->getNextOutput() + samplesToPush);
+                        }
+                    }
+                    
                     // good buffer, add this to the mix
                     agentBuffer->setStarted(true);
                     agentBuffer->setAddedToMix(true);