commit 0490e2bf3c65a78c35878de1ae56a5b2d2c8be48
Author: Alban Bedel <address@hidden>
Date:   Wed Mar 21 16:19:28 2012 +0100

    audiomixer: Optimize the mixing of inactive channels
    
    The data comming from a channel would always be read in the input
    buffer, even if it would never be used. Instead the data is now
    dropped without doing any useless copy.

diff --git a/mediastreamer2/src/audiomixer.c b/mediastreamer2/src/audiomixer.c
index 34186f0..51ffd4e 100644
--- a/mediastreamer2/src/audiomixer.c
+++ b/mediastreamer2/src/audiomixer.c
@@ -70,15 +70,16 @@ static void channel_prepare(Channel *chan, int bytes_per_tick){
 
 static int channel_process_in(Channel *chan, MSQueue *q, int32_t *sum, int nsamples){
 	ms_bufferizer_put_from_queue(&chan->bufferizer,q);
-	if (ms_bufferizer_read(&chan->bufferizer,(uint8_t*)chan->input,nsamples*2)!=0){
-		if (chan->active){
+	if (chan->active){
+		if (ms_bufferizer_read(&chan->bufferizer,(uint8_t*)chan->input,nsamples*2)!=0){
 			if (chan->gain!=1.0){
 				apply_gain(chan->input,nsamples,chan->gain);
 			}
 			accumulate(sum,chan->input,nsamples);
-		}
-		return nsamples;
-	}else memset(chan->input,0,nsamples*2);
+			return nsamples;
+		}else memset(chan->input,0,nsamples*2);
+	} else
+		ms_bufferizer_skip_bytes(&chan->bufferizer, nsamples*2);
 	return 0;
 }