Changeset 57571 in vbox

Timestamp:

Aug 27, 2015 3:37:33 PM (9 years ago)

Author:

vboxsync

Message:

Audio/CoreAudio: Fix cracks and lost samples when the sample rates between guest and the output device don't match. Samples at the end of pvPCMBuf could be lost in case the circular buffer has not enough room at the end. Eliminate the temporary PCM buffer

File:

• trunk/src/VBox/Devices/Audio/DrvHostCoreAudio.cpp (modified) (4 diffs)

trunk/src/VBox/Devices/Audio/DrvHostCoreAudio.cpp

@@ -277 +277 @@
     /* A ring buffer for transferring data to the playback thread. */
     PRTCIRCBUF                  pBuf;
-    /* Temporary buffer for copying over audio data into Core Audio. */
-    void                       *pvPCMBuf;
-    /** Size of the temporary buffer. */
-    size_t                      cbPCMBuf;
     /* Initialization status tracker. Used when some of the device parameters
      * or the device itself is changed during the runtime. */
@@ -1261 +1257 @@
     if (RT_SUCCESS(rc))
     {
-        /* Allocate temporary buffer. */
-        pStreamOut->cbPCMBuf = _4K; /** @todo Make this configurable. */
-        pStreamOut->pvPCMBuf = RTMemAlloc(pStreamOut->cbPCMBuf);
-        if (!pStreamOut->pvPCMBuf)
-            rc = VERR_NO_MEMORY;
-    }
-
-    if (RT_SUCCESS(rc))
-    {
         /*
          * Register callbacks.
@@ -1504 +1491 @@
     int rc = VINF_SUCCESS;
     uint32_t cbReadTotal = 0;
-
-    do
-    {
-        size_t cbMixBuf = AudioMixBufSizeBytes(&pHstStrmOut->MixBuf);
-        size_t cbBuf    = RT_MIN(cbMixBuf, pStreamOut->cbPCMBuf);
-        size_t cbToRead = RT_MIN(cbBuf, RTCircBufFree(pStreamOut->pBuf));
-        LogFlowFunc(("cbToRead=%zu\n", cbToRead));
-
+    uint32_t cAvail = AudioMixBufAvail(&pHstStrmOut->MixBuf);
+    size_t cbAvail  = AUDIOMIXBUF_S2B(&pHstStrmOut->MixBuf, cAvail);
+    size_t cbToRead = RT_MIN(cbAvail, RTCircBufFree(pStreamOut->pBuf));
+    LogFlowFunc(("cbToRead=%zu\n", cbToRead));
+
+    while (cbToRead)
+    {
         uint32_t cRead, cbRead;
         uint8_t *puBuf;
-        size_t   cbToWrite;
-
-        while (cbToRead)
-        {
-            rc = AudioMixBufReadCirc(&pHstStrmOut->MixBuf,
-                                     pStreamOut->pvPCMBuf, cbToRead, &cRead);
-            if (   RT_FAILURE(rc)
-                || !cRead)
-                break;
-
-            cbRead = AUDIOMIXBUF_S2B(&pHstStrmOut->MixBuf, cRead);
-
-            /* Try to acquire the necessary space from the ring buffer. */
-            RTCircBufAcquireWriteBlock(pStreamOut->pBuf, cbRead, (void **)&puBuf, &cbToWrite);
-            if (!cbToWrite)
-            {
-                RTCircBufReleaseWriteBlock(pStreamOut->pBuf, cbToWrite);
-                break;
-            }
-
-            /* Transfer data into stream's own ring buffer. The playback will operate on this
-             * own ring buffer separately. */
-            Assert(cbToWrite <= cbRead);
-            memcpy(puBuf, pStreamOut->pvPCMBuf, cbToWrite);
-
-            /* Release the ring buffer, so the read thread could start reading this data. */
-            RTCircBufReleaseWriteBlock(pStreamOut->pBuf, cbToWrite);
-
-            Assert(cbToRead >= cbRead);
-            cbToRead -= cbRead;
-            cbReadTotal += cbRead;
-        }
-    }
-    while (0);
+        size_t   cbCopy;
+
+        /* Try to acquire the necessary space from the ring buffer. */
+        RTCircBufAcquireWriteBlock(pStreamOut->pBuf, cbToRead, (void **)&puBuf, &cbCopy);
+        if (!cbCopy)
+        {
+            RTCircBufReleaseWriteBlock(pStreamOut->pBuf, cbCopy);
+            break;
+        }        
+
+        Assert(cbCopy <= cbToRead);
+
+        rc = AudioMixBufReadCirc(&pHstStrmOut->MixBuf,
+                                 puBuf, cbCopy, &cRead);
+
+        if (   RT_FAILURE(rc)
+            || !cRead)
+        {
+            RTCircBufReleaseWriteBlock(pStreamOut->pBuf, 0);
+            break;
+        }
+
+        cbRead = AUDIOMIXBUF_S2B(&pHstStrmOut->MixBuf, cRead);
+
+        /* Release the ring buffer, so the read thread could start reading this data. */
+        RTCircBufReleaseWriteBlock(pStreamOut->pBuf, cbRead);
+
+        Assert(cbToRead >= cbRead);
+        cbToRead -= cbRead;
+        cbReadTotal += cbRead;
+    }
 
     if (RT_SUCCESS(rc))
@@ -1860 +1843 @@
                 pStreamOut->audioUnit = NULL;
                 pStreamOut->deviceID  = kAudioDeviceUnknown;
-
-                if (pStreamOut->pvPCMBuf)
-                {
-                    RTMemFree(pStreamOut->pvPCMBuf);
-                    pStreamOut->pvPCMBuf = NULL;
-                    pStreamOut->cbPCMBuf = 0;
-                }
 
                 ASMAtomicXchgU32(&pStreamOut->status, CA_STATUS_UNINIT);