diff -NubBr -x'*.a' -x'*.exe' -x'*.o' -xconfigure.log -xconfig.mak -x.cvsignore -x'*.ini' -xconfig.h -xcodecs.conf.h -xversion.h main/libao2/ao_win32.c sherpya/libao2/ao_win32.c
--- main/libao2/ao_win32.c	2004-04-08 00:27:33.000000000 +0200
+++ sherpya/libao2/ao_win32.c	2004-06-17 17:59:28.937980800 +0200
@@ -33,7 +33,7 @@
 #define SAMPLESIZE   1024
 #define BUFFER_SIZE  4096
 #define BUFFER_COUNT 16
-
+#define WAVE_FORMAT_DOLBY_AC3_SPDIF 0x0092
 
 static WAVEHDR*     waveBlocks;         //pointer to our ringbuffer memory
 static HWAVEOUT     hWaveOut;           //handle to the waveout device
@@ -121,13 +121,24 @@
 	//fill waveformatex
     ZeroMemory( &wformat, sizeof(WAVEFORMATEX));
     wformat.cbSize          = 0; /* size of _extra_ info */
+    wformat.nSamplesPerSec  = rate;            
+    wformat.nAvgBytesPerSec = wformat.nSamplesPerSec * wformat.nBlockAlign;
+    
+    /* Ac3 pass-through */
+    if (format == AFMT_AC3)
+    {
+        wformat.wFormatTag = WAVE_FORMAT_DOLBY_AC3_SPDIF;  
+        wformat.nChannels = 2;
+        wformat.wBitsPerSample =  16;
+        wformat.nBlockAlign = 4;
+    }
+    else
+    {
 	wformat.wFormatTag      = WAVE_FORMAT_PCM;  
     wformat.nChannels       = channels;                
-    wformat.nSamplesPerSec  = rate;            
     wformat.wBitsPerSample  = audio_out_format_bits(format); 
     wformat.nBlockAlign     = wformat.nChannels * (wformat.wBitsPerSample >> 3);
-    wformat.nAvgBytesPerSec = wformat.nSamplesPerSec * wformat.nBlockAlign;
- 	
+    } 	
     //open sound device
     //WAVE_MAPPER always points to the default wave device on the system
     result = waveOutOpen(&hWaveOut,WAVE_MAPPER,&wformat,(DWORD_PTR)waveOutProc,0,CALLBACK_FUNCTION);