Bug 853721 - Part 1: Refactor the code to convert GainNode's AudioParamTimeline to ticks into WebAudioUtils; r=roc

content/media/webaudio/AudioParam.h

@@ -7,7 +7,7 @@
 #ifndef AudioParam_h_
 #define AudioParam_h_
 
-#include "AudioEventTimeline.h"
+#include "AudioParamTimeline.h"
 #include "nsWrapperCache.h"
 #include "nsCycleCollectionParticipant.h"
 #include "nsCOMPtr.h"
@@ -16,7 +16,6 @@
 #include "AudioNode.h"
 #include "mozilla/dom/TypedArray.h"
 #include "mozilla/Util.h"
-#include "mozilla/ErrorResult.h"
 #include "WebAudioUtils.h"
 
 struct JSContext;
@@ -26,8 +25,6 @@ namespace mozilla {
 
 namespace dom {
 
-typedef AudioEventTimeline<ErrorResult> AudioParamTimeline;
-
 class AudioParam MOZ_FINAL : public nsWrapperCache,
                              public EnableWebAudioCheck,
                              public AudioParamTimeline

content/media/webaudio/AudioParamTimeline.h

@@ -0,0 +1,26 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef AudioParamTimeline_h_
+#define AudioParamTimeline_h_
+
+// This header is intended to make it possible to use AudioParamTimeline
+// from multiple places without dealing with #include hell!
+
+#include "AudioEventTimeline.h"
+#include "mozilla/ErrorResult.h"
+
+namespace mozilla {
+
+namespace dom {
+
+typedef AudioEventTimeline<ErrorResult> AudioParamTimeline;
+
+}
+}
+
+#endif
+

content/media/webaudio/GainNode.cpp

@@ -9,6 +9,7 @@
 #include "AudioNodeEngine.h"
 #include "AudioNodeStream.h"
 #include "AudioDestinationNode.h"
+#include "WebAudioUtils.h"
 
 namespace mozilla {
 namespace dom {
@@ -22,24 +23,6 @@ NS_INTERFACE_MAP_END_INHERITING(AudioNode)
 NS_IMPL_ADDREF_INHERITED(GainNode, AudioNode)
 NS_IMPL_RELEASE_INHERITED(GainNode, AudioNode)
 
-struct ConvertTimeToTickHelper
-{
-  AudioNodeStream* mSourceStream;
-  AudioNodeStream* mDestinationStream;
-
-  static int64_t Convert(double aTime, void* aClosure)
-  {
-    TrackRate sampleRate = IdealAudioRate();
-
-    ConvertTimeToTickHelper* This = static_cast<ConvertTimeToTickHelper*> (aClosure);
-    TrackTicks tick = This->mSourceStream->GetCurrentPosition();
-    StreamTime streamTime = TicksToTimeRoundDown(sampleRate, tick);
-    GraphTime graphTime = This->mSourceStream->StreamTimeToGraphTime(streamTime);
-    StreamTime destinationStreamTime = This->mDestinationStream->GraphTimeToStreamTime(graphTime);
-    return TimeToTicksRoundDown(sampleRate, destinationStreamTime + SecondsToMediaTime(aTime));
-  }
-};
-
 class GainNodeEngine : public AudioNodeEngine
 {
 public:
@@ -65,10 +48,7 @@ public:
     case GAIN:
       MOZ_ASSERT(mSource && mDestination);
       mGain = aValue;
-      ConvertTimeToTickHelper ctth;
-      ctth.mSourceStream = mSource;
-      ctth.mDestinationStream = mDestination;
-      mGain.ConvertEventTimesToTicks(ConvertTimeToTickHelper::Convert, &ctth);
+      WebAudioUtils::ConvertAudioParamToTicks(mGain, mSource, mDestination);
       break;
     default:
       NS_ERROR("Bad GainNodeEngine TimelineParameter");

content/media/webaudio/Makefile.in

@@ -32,6 +32,7 @@ CPPSRCS := \
   MediaBufferDecoder.cpp \
   PannerNode.cpp \
   ThreeDPoint.cpp \
+  WebAudioUtils.cpp \
   $(NULL)
 
 EXPORTS_NAMESPACES := mozilla/dom
@@ -53,6 +54,7 @@ EXPORTS_mozilla/dom := \
   $(NULL)
 
 EXPORTS := \
+  AudioParamTimeline.h \
   MediaBufferDecoder.h \
   ThreeDPoint.h \
   WebAudioUtils.h \

content/media/webaudio/WebAudioUtils.cpp

@@ -0,0 +1,44 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "WebAudioUtils.h"
+#include "AudioNodeStream.h"
+
+namespace mozilla {
+
+namespace dom {
+
+struct ConvertTimeToTickHelper
+{
+  AudioNodeStream* mSourceStream;
+  AudioNodeStream* mDestinationStream;
+
+  static int64_t Convert(double aTime, void* aClosure)
+  {
+    TrackRate sampleRate = IdealAudioRate();
+
+    ConvertTimeToTickHelper* This = static_cast<ConvertTimeToTickHelper*> (aClosure);
+    TrackTicks tick = This->mSourceStream->GetCurrentPosition();
+    StreamTime streamTime = TicksToTimeRoundDown(sampleRate, tick);
+    GraphTime graphTime = This->mSourceStream->StreamTimeToGraphTime(streamTime);
+    StreamTime destinationStreamTime = This->mDestinationStream->GraphTimeToStreamTime(graphTime);
+    return TimeToTicksRoundDown(sampleRate, destinationStreamTime + SecondsToMediaTime(aTime));
+  }
+};
+
+void
+WebAudioUtils::ConvertAudioParamToTicks(AudioParamTimeline& aParam,
+                                        AudioNodeStream* aSource,
+                                        AudioNodeStream* aDest)
+{
+  ConvertTimeToTickHelper ctth;
+  ctth.mSourceStream = aSource;
+  ctth.mDestinationStream = aDest;
+  aParam.ConvertEventTimesToTicks(ConvertTimeToTickHelper::Convert, &ctth);
+}
+
+}
+}

content/media/webaudio/WebAudioUtils.h

@@ -8,9 +8,12 @@
 #define WebAudioUtils_h_
 
 #include <cmath>
+#include "AudioParamTimeline.h"
 
 namespace mozilla {
 
+class AudioNodeStream;
+
 namespace dom {
 
 struct WebAudioUtils {
@@ -24,6 +27,19 @@ struct WebAudioUtils {
     using namespace std;
     return fabs(v1 - v2) < 1e-7;
   }
+
+  /**
+   * Converts AudioParamTimeline floating point time values to tick values
+   * with respect to a source and a destination AudioNodeStream.
+   *
+   * This needs to be called for each AudioParamTimeline that gets sent to an
+   * AudioNodeEngine on the engine side where the AudioParamTimeline is
+   * received.  This means that such engines need to be aware of their source
+   * and destination streams as well.
+   */
+  static void ConvertAudioParamToTicks(AudioParamTimeline& aParam,
+                                       AudioNodeStream* aSource,
+                                       AudioNodeStream* aDest);
 };
 
 }