Support floating-point audio output for Linux

media/base/audio_bus.cc

Index: media/base/audio_bus.cc
diff --git a/media/base/audio_bus.cc b/media/base/audio_bus.cc
index d261e87f8dc9f26ae29338b874343eebf728f275..bf9a7409d55ff00c6227e7e3612363467f5b1cd3 100644
--- a/media/base/audio_bus.cc
+++ b/media/base/audio_bus.cc
@@ -337,6 +337,23 @@ void AudioBus::Scale(float volume) {
   }
 }
 
+void AudioBus::Clamp() {

[DaleCurtis, 2016/11/01 23:07:53]

No need IIRC, interleave should take care of this.

[Raymond Toy, 2016/11/01 23:18:50]

You're right. I tested with a webaudio manual test that intentionally overflows
to test clipping and the output is clipped as expected.

+  for (int ch = 0; ch < channels(); ++ch) {
+    // Replace NaN with 0 and then clamp the data to [-1, 1].
+    float* channel_data = channel(ch);
+    for (int k = 0; k < frames_; ++k) {
+      float value = channel_data[k];
+      if (value < -1)
+        value = -1;
+      else if (value > 1)
+        value = 1;
+      else if (std::isnan(value))
+        value = 0;
+      channel_data[k] = value;
+    }
+  }
+}
+
 void AudioBus::SwapChannels(int a, int b) {
   DCHECK(a < channels() && a >= 0);
   DCHECK(b < channels() && b >= 0);