diff -Nraub mplayer.ori/libao2/ao_pcm.c mplayer/libao2/ao_pcm.c
--- mplayer.ori/libao2/ao_pcm.c	2006-06-05 15:46:03.000000000 -0400
+++ mplayer/libao2/ao_pcm.c	2006-10-10 09:48:30.000000000 -0400
@@ -205,8 +205,20 @@
 	}
 #endif 
 
+    if (ao_data.channels == 6 || ao_data.channels == 5) {
+        int i, samplesize = wavhdr.bits/8;
+        for (i = 0; i < len; i += samplesize*ao_data.channels) {
+            //L R SL SR C LFE -> L R C LFE SL SR
+            //L R SL SR C     -> L R C     SL SR
+            fwrite(data+i, samplesize, 2, fp);
+            fwrite(data+i+4*samplesize, samplesize, (ao_data.channels+1)%2+1, fp);
+            fwrite(data+i+2*samplesize, samplesize, 2, fp);
+        }
+        len -= len % (ao_data.channels*samplesize);
+    } else {
 	//printf("PCM: Writing chunk!\n");
 	fwrite(data,len,1,fp);
+    }
 
 	if(ao_pcm_waveheader)
 		wavhdr.data_length += len;