always disable wmme clip and dither if an spdif passthrough wave format is requested

include/pa_win_wmme.h

@@ -53,6 +53,10 @@ extern "C"
 #endif /* __cplusplus */
 
 
+/* The following are flags which can be set in 
+  PaWinMmeStreamInfo's flags field.
+*/
+
 #define paWinMmeUseLowLevelLatencyParameters            (0x01)
 #define paWinMmeUseMultipleDevices                      (0x02)  /* use mme specific multiple device feature */
 #define paWinMmeUseChannelMask                          (0x04)
@@ -64,7 +68,8 @@ extern "C"
 */
 #define paWinMmeDontThrottleOverloadedProcessingThread  (0x08)
 
-/* flags for non-PCM spdif passthrough */
+/*  Flags for non-PCM spdif passthrough.
+*/
 #define paWinMmeWaveFormatDolbyAc3Spdif                 (0x10)
 #define paWinMmeWaveFormatWmaSpdif                      (0x20)
 

src/hostapi/wmme/pa_win_wmme.c

@@ -2389,6 +2389,14 @@ static PaError OpenStream( struct PaUtilHostApiRepresentation *hostApi,
         return paInvalidFlag; /* unexpected platform specific flag */
 
 
+    /* always disable clipping and dithering if we are outputting a raw spdif stream */
+    if( (winMmeSpecificOutputFlags & paWinMmeWaveFormatDolbyAc3Spdif)
+            || (winMmeSpecificOutputFlags & paWinMmeWaveFormatWmaSpdif) ){
+
+        streamFlags = streamFlags | paClipOff | paDitherOff;
+    }
+
+
     result = CalculateBufferSettings( &framesPerHostInputBuffer, &hostInputBufferCount,
                 &framesPerHostOutputBuffer, &hostOutputBufferCount,
                 inputChannelCount, hostInputSampleFormat, suggestedInputLatency, inputStreamInfo,

test/patest_wmme_ac3.c

@@ -182,7 +182,7 @@ int main(int argc, char* argv[])
               &outputParameters,
               SAMPLE_RATE,
               FRAMES_PER_BUFFER,
-              paClipOff | paDitherOff,  /* IMPORTANT must disable clipping and dithering for WMME AC3 */
+              0,
               patestCallback,
               &data );
     if( err != paNoError ) goto error;