Changeset 87996 in vbox for trunk/src/VBox

Timestamp:

Mar 7, 2021 7:55:35 PM (4 years ago)

Author:

vboxsync

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

143119

Message:

Audio: Converted DrvAudioHlpFramesToNano and DrvAudioHlpFramesToMilli to use integer arithmetics rather than floating point. bugref:9890

Location:

trunk/src/VBox/Devices/Audio

Files:

• DrvAudioCommon.cpp (modified) (4 diffs)
• testcase/tstAudioMixBuffer.cpp (modified) (1 diff)

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

@@ -1342 +1342 @@
  * @param   pProps      The PCM properties to use.
  * @param   cFrames     Number of audio frames to convert.
+ * @note    No rounding here, result is floored.
  */
 uint64_t DrvAudioHlpFramesToMilli(PCPDMAUDIOPCMPROPS pProps, uint32_t cFrames)
@@ -1347 +1348 @@
     AssertPtrReturn(pProps, 0);
 
-    if (!cFrames)
-        return 0;
-
-    if (!pProps->uHz) /* Prevent division by zero. */
-        return 0;
-
-    /** @todo r=bird: How to do this w/o any floating point:
-    * @code
-    *  ASMMultU32ByU32DivByU32(cFrames, RT_MS_1SEC, pProps->uHz);
-    * // or
-    *  (uint64_t)cFrames * RT_MS_1SEC / pProps->uHz
-    * @endcode
-    */
-    return cFrames / ((double)pProps->uHz / (double)RT_MS_1SEC);
+    /* Check input to prevent division by chainsaw: */
+    uint32_t const uHz = pProps->uHz;
+    if (uHz)
+        return ASMMultU32ByU32DivByU32(cFrames, RT_MS_1SEC, uHz);
+    return 0;
 }
 
@@ -1369 +1361 @@
  * @param   pProps      The PCM properties to use.
  * @param   cFrames     Number of audio frames to convert.
+ * @note    No rounding here, result is floored.
  */
 uint64_t DrvAudioHlpFramesToNano(PCPDMAUDIOPCMPROPS pProps, uint32_t cFrames)
@@ -1374 +1367 @@
     AssertPtrReturn(pProps, 0);
 
-    if (!cFrames)
-        return 0;
-
-    if (!pProps->uHz) /* Prevent division by zero. */
-        return 0;
-
-    return cFrames / ((double)pProps->uHz / (double)RT_NS_1SEC);
+    /* Check input to prevent division by chainsaw: */
+    uint32_t const uHz = pProps->uHz;
+    if (uHz)
+        return ASMMultU32ByU32DivByU32(cFrames, RT_NS_1SEC, uHz);
+    return 0;
 }
 

trunk/src/VBox/Devices/Audio/testcase/tstAudioMixBuffer.cpp

@@ -64 +64 @@
 
 
-    RTTESTI_CHECK_MSG((u64 = DrvAudioHlpFramesToNano(&s_Cfg441StereoS16, 44100)) == RT_NS_1SEC,
-                      ("ns=%RU64\n", u64));
+    RTTESTI_CHECK_MSG((u64 = DrvAudioHlpFramesToNano(&s_Cfg441StereoS16, 44100)) == RT_NS_1SEC, ("ns=%RU64\n", u64));
+    RTTESTI_CHECK_MSG((u64 = DrvAudioHlpFramesToNano(&s_Cfg441StereoS16,     1)) == 22675,      ("ns=%RU64\n", u64));
+    RTTESTI_CHECK_MSG((u64 = DrvAudioHlpFramesToNano(&s_Cfg441StereoS16,    31)) == 702947,     ("ns=%RU64\n", u64));
+    RTTESTI_CHECK_MSG((u64 = DrvAudioHlpFramesToNano(&s_Cfg441StereoS16,   255)) == 5782312,    ("ns=%RU64\n", u64));
     //RTTESTI_CHECK_MSG((u64 = DrvAudioHlpFramesToMicro(&s_Cfg441StereoS16, 44100)) == RT_US_1SEC,
     //                  ("us=%RU64\n", u64));
-    RTTESTI_CHECK_MSG((u64 = DrvAudioHlpFramesToMilli(&s_Cfg441StereoS16, 44100)) == RT_MS_1SEC,
-                      ("ms=%RU64\n", u64));
+    RTTESTI_CHECK_MSG((u64 = DrvAudioHlpFramesToMilli(&s_Cfg441StereoS16, 44100)) == RT_MS_1SEC, ("ms=%RU64\n", u64));
+    RTTESTI_CHECK_MSG((u64 = DrvAudioHlpFramesToMilli(&s_Cfg441StereoS16,   255)) == 5,          ("ms=%RU64\n", u64));
 
 }