From 0bb13dd31c40eeda294935285629fced1f6fa3bd Mon Sep 17 00:00:00 2001
From: Ken Thomases <ken@codeweavers.com>
Date: Thu, 21 Dec 2006 03:49:24 -0600
Subject: [PATCH] winecoreaudio: Report when the render callback is just
 providing silence.

---
 dlls/winmm/winecoreaudio/audio.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/dlls/winmm/winecoreaudio/audio.c b/dlls/winmm/winecoreaudio/audio.c
index c967ebb5faa..ae1067a96e2 100644
--- a/dlls/winmm/winecoreaudio/audio.c
+++ b/dlls/winmm/winecoreaudio/audio.c
@@ -63,6 +63,11 @@ WINE_DEFAULT_DEBUG_CHANNEL(wave);
 typedef void *AudioUnit;
 
 /* From AudioUnit/AUComponents.h */
+enum
+{
+    kAudioUnitRenderAction_OutputIsSilence  = (1 << 4),
+        /* provides hint on return from Render(): if set the buffer contains all zeroes */
+};
 typedef UInt32 AudioUnitRenderActionFlags;
 
 /* only allow 10 output devices through this driver, this ought to be adequate */
@@ -1441,6 +1446,8 @@ OSStatus CoreAudio_woAudioUnitIOProc(void *inRefCon,
         }
         else
         {
+            if (!dataProvided)
+                *ioActionFlags |= kAudioUnitRenderAction_OutputIsSilence;
             memset((char*)ioData->mBuffers[0].mData + dataProvided, 0, dataNeeded);
             dataProvided += dataNeeded;
             dataNeeded = 0;