Changeset 71113 in vbox

Timestamp:

Feb 23, 2018 9:51:14 AM (7 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

120980

Message:

Audio/DrvAudioCommon.cpp: Implemented DrvAudioHlpBytesToMs().

Location:

trunk/src/VBox/Devices/Audio

Files:

• DrvAudio.h (modified) (1 diff)
• DrvAudioCommon.cpp (modified) (1 diff)

trunk/src/VBox/Devices/Audio/DrvAudio.h

@@ -154 +154 @@
 uint32_t DrvAudioHlpCalcBitrate(uint8_t cBits, uint32_t uHz, uint8_t cChannels);
 uint32_t DrvAudioHlpCalcBitrate(const PPDMAUDIOPCMPROPS pProps);
+uint64_t DrvAudioHlpBytesToMs(const PPDMAUDIOPCMPROPS pProps, size_t cbBytes);
 uint32_t DrvAudioHlpMsToBytes(const PPDMAUDIOPCMPROPS pProps, uint32_t uMs);
 bool DrvAudioHlpPCMPropsAreEqual(const PPDMAUDIOPCMPROPS pPCMProps1, const PPDMAUDIOPCMPROPS pPCMProps2);

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

@@ -1050 +1050 @@
 {
     return DrvAudioHlpCalcBitrate(pProps->cBits, pProps->uHz, pProps->cChannels);
+}
+
+/**
+ * Returns the time (in ms) for given byte amount and PCM properties.
+ *
+ * @return  uint64_t            Calculated time (in ms).
+ * @param   pProps              PCM properties to calculate amount of bytes for.
+ * @param   cbBytes             Amount of bytes to calculate time for.
+ */
+uint64_t DrvAudioHlpBytesToMs(const PPDMAUDIOPCMPROPS pProps, size_t cbBytes)
+{
+    AssertPtrReturn(pProps, 0);
+
+    if (!cbBytes)
+        return 0;
+
+    const float dbBytesPerMs = ((pProps->cBits / 8) * pProps->cChannels * pProps->uHz) / 1000;
+    Assert(dbBytesPerMs >= 0.0f);
+    if (!dbBytesPerMs) /* Prevent division by zero. */
+        return 0;
+
+    return cbBytes / dbBytesPerMs;
 }