Index: /trunk/src/VBox/Devices/Audio/AudioMixBuffer.cpp
===================================================================
--- /trunk/src/VBox/Devices/Audio/AudioMixBuffer.cpp	(revision 65015)
+++ /trunk/src/VBox/Devices/Audio/AudioMixBuffer.cpp	(revision 65016)
@@ -256,4 +256,6 @@
         cClearOff = pMixBuf->offRead - cSamplesToClear;
         cClearLen = cSamplesToClear;
+
+        Assert(cClearOff + cClearLen <= pMixBuf->cSamples);
 
         AUDMIXBUF_LOG(("Clearing2: %RU32 - %RU32\n", cClearOff, cClearOff + cClearLen));
@@ -1390,5 +1392,5 @@
 {
     AssertPtrReturn(pMixBuf, VERR_INVALID_POINTER);
-    AssertPtrReturn(pvBuf, VERR_INVALID_POINTER);
+    AssertPtrReturn(pvBuf,   VERR_INVALID_POINTER);
     /* pcbRead is optional. */
 
@@ -1402,6 +1404,6 @@
     uint32_t cToRead = RT_MIN(AUDIOMIXBUF_B2S(pMixBuf, cbBuf), pMixBuf->cUsed);
 
-    AUDMIXBUF_LOG(("%s: pvBuf=%p, cbBuf=%RU32 (%RU32 samples), cToRead=%RU32\n",
-                   pMixBuf->pszName, pvBuf, cbBuf, AUDIOMIXBUF_B2S(pMixBuf, cbBuf), cToRead));
+    AUDMIXBUF_LOG(("%s: cbBuf=%RU32 (%RU32 samples), cToRead=%RU32, fmtSrc=0x%x, fmtDst=0x%x\n",
+                   pMixBuf->pszName, cbBuf, AUDIOMIXBUF_B2S(pMixBuf, cbBuf), cToRead, pMixBuf->AudioFmt, enmFmt));
 
     if (!cToRead)
@@ -1789,6 +1791,6 @@
     PPDMAUDIOMIXBUF pParent = pMixBuf->pParent;
 
-    AUDMIXBUF_LOG(("%s: enmFmt=%d, pvBuf=%p, cbBuf=%RU32 (%RU32 samples)\n",
-                   pMixBuf->pszName, enmFmt, pvBuf, cbBuf, AUDIOMIXBUF_B2S(pMixBuf, cbBuf)));
+    AUDMIXBUF_LOG(("%s: enmFmt=0x%x, cbBuf=%RU32 (%RU32 samples)\n",
+                   pMixBuf->pszName, enmFmt, cbBuf, AUDIOMIXBUF_B2S(pMixBuf, cbBuf)));
 
     if (   pParent
@@ -1917,6 +1919,6 @@
 #endif
 
-    AUDMIXBUF_LOG(("offWrite=%RU32, cLenDst1=%RU32, cLenDst2=%RU32, cTotal=%RU32 (%zu bytes), rc=%Rrc\n",
-                   pMixBuf->offWrite, cLenDst1, cLenDst2, cLenDst1 + cLenDst2,
+    AUDMIXBUF_LOG(("%s: offWrite=%RU32, cLenDst1=%RU32, cLenDst2=%RU32, cTotal=%RU32 (%zu bytes), rc=%Rrc\n",
+                   pMixBuf->pszName, pMixBuf->offWrite, cLenDst1, cLenDst2, cLenDst1 + cLenDst2,
                    AUDIOMIXBUF_S2B(pMixBuf, cLenDst1 + cLenDst2), rc));
     return rc;