From 8088bc8081133a12abc97bc30558beb681d8a1f4 Mon Sep 17 00:00:00 2001
From: Robert O'Callahan <robert@ocallahan.org>
Date: Thu, 25 Oct 2012 23:09:40 +1300
Subject: [PATCH] Bug 805254. Part 9: Get rid of some more #ifdefs in
 nsWaveDecoder. r=kinetik

---
 content/media/wave/nsWaveReader.cpp | 40 ++++++++++++++++++++---------
 1 file changed, 28 insertions(+), 12 deletions(-)

diff --git a/content/media/wave/nsWaveReader.cpp b/content/media/wave/nsWaveReader.cpp
index 4b4ea62485dc..5f2ef1a893ce 100644
--- a/content/media/wave/nsWaveReader.cpp
+++ b/content/media/wave/nsWaveReader.cpp
@@ -146,6 +146,31 @@ nsresult nsWaveReader::ReadMetadata(nsVideoInfo* aInfo,
   return NS_OK;
 }
 
+template <typename T> T UnsignedByteToAudioSample(uint8_t aValue);
+template <typename T> T SignedShortToAudioSample(int16_t aValue);
+
+template <> inline float
+UnsignedByteToAudioSample<float>(uint8_t aValue)
+{
+  return aValue * (2.0f / UINT8_MAX) - 1.0f;
+}
+template <> inline int16_t
+UnsignedByteToAudioSample<int16_t>(uint8_t aValue)
+{
+  return int16_t(aValue * UINT16_MAX / UINT8_MAX + INT16_MIN);
+}
+
+template <> inline float
+SignedShortToAudioSample<float>(int16_t aValue)
+{
+  return AudioSampleToFloat(aValue);
+}
+template <> inline int16_t
+SignedShortToAudioSample<int16_t>(int16_t aValue)
+{
+  return aValue;
+}
+
 bool nsWaveReader::DecodeAudioData()
 {
   NS_ASSERTION(mDecoder->OnDecodeThread(), "Should be on decode thread.");
@@ -178,19 +203,10 @@ bool nsWaveReader::DecodeAudioData()
     for (unsigned int j = 0; j < mChannels; ++j) {
       if (mSampleFormat == FORMAT_U8) {
         uint8_t v =  ReadUint8(&d);
-#if defined(MOZ_SAMPLE_TYPE_S16)
-        *s++ = (v * (1.F/UINT8_MAX)) * UINT16_MAX + INT16_MIN;
-#elif defined(MOZ_SAMPLE_TYPE_FLOAT32)
-        *s++ = (v * (1.F/UINT8_MAX)) * 2.F - 1.F;
-#endif
-      }
-      else if (mSampleFormat == FORMAT_S16) {
+        *s++ = UnsignedByteToAudioSample<AudioDataValue>(v);
+      } else if (mSampleFormat == FORMAT_S16) {
         int16_t v =  ReadInt16LE(&d);
-#if defined(MOZ_SAMPLE_TYPE_S16)
-        *s++ = v;
-#elif defined(MOZ_SAMPLE_TYPE_FLOAT32)
-        *s++ = (int32_t(v) - INT16_MIN) / float(UINT16_MAX) * 2.F - 1.F;
-#endif
+        *s++ = SignedShortToAudioSample<AudioDataValue>(v);
       }
     }
   }