Add vector_math::FMUL. Replace audio_util::AdjustVolume.

Removes the integer based volume adjustment code from the
melting pot that is audio_util in favor of an
AudioBus::AdjustVolume() method which works on float.

The driver behind the method is a new vector_math::FMUL
method which is SSE optimized.  Benchmarks put it in line
with the vector_math::FMAC() method.

Benchmarking 200000 iterations:
FMUL_C took 1962.52ms.
FMUL_SSE (unaligned size) took 493.03ms; which is 3.98x faster than FMUL_C.
FMUL_SSE (aligned size) took 491.79ms; which is 3.99x faster than FMUL_C and 1.00x faster than FMUL_SSE (unaligned size).

BUG=120319, 171540, 226447
TEST=new media_unittests.

Review URL: https://chromiumcodereview.appspot.com/13726011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@192905 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 2 insertions, 11 deletions

diff --git a/media/audio/mac/audio_auhal_mac.cc b/media/audio/mac/audio_auhal_mac.cc
index 20df6f5..b2a8828 100644
--- a/media/audio/mac/audio_auhal_mac.cc
+++ b/media/audio/mac/audio_auhal_mac.cc
@@ -178,8 +178,6 @@ void AUHALStream::Stop() {
 
 void AUHALStream::SetVolume(double volume) {
   volume_ = static_cast<float>(volume);
-
-  // TODO(crogers): set volume property
 }
 
 void AUHALStream::GetVolume(double* volume) {
@@ -251,6 +249,7 @@ OSStatus AUHALStream::Render(
         input_bus_.get(),
         output_bus_.get(),
         AudioBuffersState(0, hardware_pending_bytes));
+    output_bus_->Scale(volume_);
   }
 
   return noErr;
diff --git a/media/audio/mac/audio_low_latency_output_mac.cc b/media/audio/mac/audio_low_latency_output_mac.cc
index 4b82bef..592a6a1 100644
--- a/media/audio/mac/audio_low_latency_output_mac.cc
+++ b/media/audio/mac/audio_low_latency_output_mac.cc
@@ -10,7 +10,6 @@
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/mac/mac_logging.h"
-#include "media/audio/audio_util.h"
 #include "media/audio/mac/audio_manager_mac.h"
 #include "media/base/media_switches.h"
 
@@ -284,16 +283,9 @@ OSStatus AUAudioOutputStream::Render(UInt32 number_of_frames,
 
   // Note: If this ever changes to output raw float the data must be clipped and
   // sanitized since it may come from an untrusted source such as NaCl.
+  audio_bus_->Scale(volume_);
   audio_bus_->ToInterleaved(
       frames_filled, format_.mBitsPerChannel / 8, audio_data);
-  uint32 filled = frames_filled * format_.mBytesPerFrame;
-
-  // Perform in-place, software-volume adjustments.
-  media::AdjustVolume(audio_data,
-                      filled,
-                      audio_bus_->channels(),
-                      format_.mBitsPerChannel / 8,
-                      volume_);
 
   return noErr;
 }