diff -r 000000000000 -r 6474c204b198 content/media/webrtc/MediaEngine.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/content/media/webrtc/MediaEngine.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,193 @@
+/* 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 MEDIAENGINE_H_
+#define MEDIAENGINE_H_
+
+#include "mozilla/RefPtr.h"
+#include "nsIDOMFile.h"
+#include "DOMMediaStream.h"
+#include "MediaStreamGraph.h"
+
+namespace mozilla {
+
+class VideoTrackConstraintsN;
+class AudioTrackConstraintsN;
+
+/**
+ * Abstract interface for managing audio and video devices. Each platform
+ * must implement a concrete class that will map these classes and methods
+ * to the appropriate backend. For example, on Desktop platforms, these will
+ * correspond to equivalent webrtc (GIPS) calls, and on B2G they will map to
+ * a Gonk interface.
+ */
+class MediaEngineVideoSource;
+class MediaEngineAudioSource;
+struct MediaEnginePrefs;
+
+enum MediaEngineState {
+  kAllocated,
+  kStarted,
+  kStopped,
+  kReleased
+};
+
+// We only support 1 audio and 1 video track for now.
+enum {
+  kVideoTrack = 1,
+  kAudioTrack = 2
+};
+
+class MediaEngine
+{
+public:
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(MediaEngine)
+
+  static const int DEFAULT_VIDEO_FPS = 30;
+  static const int DEFAULT_VIDEO_MIN_FPS = 10;
+  static const int DEFAULT_43_VIDEO_WIDTH = 640;
+  static const int DEFAULT_43_VIDEO_HEIGHT = 480;
+  static const int DEFAULT_169_VIDEO_WIDTH = 1280;
+  static const int DEFAULT_169_VIDEO_HEIGHT = 720;
+  static const int DEFAULT_AUDIO_TIMER_MS = 10;
+
+  /* Populate an array of video sources in the nsTArray. Also include devices
+   * that are currently unavailable. */
+  virtual void EnumerateVideoDevices(nsTArray<nsRefPtr<MediaEngineVideoSource> >*) = 0;
+
+  /* Populate an array of audio sources in the nsTArray. Also include devices
+   * that are currently unavailable. */
+  virtual void EnumerateAudioDevices(nsTArray<nsRefPtr<MediaEngineAudioSource> >*) = 0;
+
+protected:
+  virtual ~MediaEngine() {}
+};
+
+/**
+ * Common abstract base class for audio and video sources.
+ */
+class MediaEngineSource : public nsISupports
+{
+public:
+  virtual ~MediaEngineSource() {}
+
+  /* Populate the human readable name of this device in the nsAString */
+  virtual void GetName(nsAString&) = 0;
+
+  /* Populate the UUID of this device in the nsAString */
+  virtual void GetUUID(nsAString&) = 0;
+
+  /* Release the device back to the system. */
+  virtual nsresult Deallocate() = 0;
+
+  /* Start the device and add the track to the provided SourceMediaStream, with
+   * the provided TrackID. You may start appending data to the track
+   * immediately after. */
+  virtual nsresult Start(SourceMediaStream*, TrackID) = 0;
+
+  /* Take a snapshot from this source. In the case of video this is a single
+   * image, and for audio, it is a snippet lasting aDuration milliseconds. The
+   * duration argument is ignored for a MediaEngineVideoSource.
+   */
+  virtual nsresult Snapshot(uint32_t aDuration, nsIDOMFile** aFile) = 0;
+
+  /* Called when the stream wants more data */
+  virtual void NotifyPull(MediaStreamGraph* aGraph,
+                          SourceMediaStream *aSource,
+                          TrackID aId,
+                          StreamTime aDesiredTime,
+                          TrackTicks &aLastEndTime) = 0;
+
+  /* Stop the device and release the corresponding MediaStream */
+  virtual nsresult Stop(SourceMediaStream *aSource, TrackID aID) = 0;
+
+  /* Change device configuration.  */
+  virtual nsresult Config(bool aEchoOn, uint32_t aEcho,
+                          bool aAgcOn, uint32_t aAGC,
+                          bool aNoiseOn, uint32_t aNoise,
+                          int32_t aPlayoutDelay) = 0;
+
+  /* Returns true if a source represents a fake capture device and
+   * false otherwise
+   */
+  virtual bool IsFake() = 0;
+
+  /* Return false if device is currently allocated or started */
+  bool IsAvailable() {
+    if (mState == kAllocated || mState == kStarted) {
+      return false;
+    } else {
+      return true;
+    }
+  }
+
+  /* It is an error to call Start() before an Allocate(), and Stop() before
+   * a Start(). Only Allocate() may be called after a Deallocate(). */
+
+protected:
+  MediaEngineState mState;
+};
+
+/**
+ * Video source and friends.
+ */
+class MediaEnginePrefs {
+public:
+  int32_t mWidth;
+  int32_t mHeight;
+  int32_t mFPS;
+  int32_t mMinFPS;
+
+  // mWidth and/or mHeight may be zero (=adaptive default), so use functions.
+
+  int32_t GetWidth(bool aHD = false) const {
+    return mWidth? mWidth : (mHeight?
+                             (mHeight * GetDefWidth(aHD)) / GetDefHeight(aHD) :
+                             GetDefWidth(aHD));
+  }
+
+  int32_t GetHeight(bool aHD = false) const {
+    return mHeight? mHeight : (mWidth?
+                               (mWidth * GetDefHeight(aHD)) / GetDefWidth(aHD) :
+                               GetDefHeight(aHD));
+  }
+private:
+  static int32_t GetDefWidth(bool aHD = false) {
+    return aHD ? MediaEngine::DEFAULT_169_VIDEO_WIDTH :
+                 MediaEngine::DEFAULT_43_VIDEO_WIDTH;
+  }
+
+  static int32_t GetDefHeight(bool aHD = false) {
+    return aHD ? MediaEngine::DEFAULT_169_VIDEO_HEIGHT :
+                 MediaEngine::DEFAULT_43_VIDEO_HEIGHT;
+  }
+};
+
+class MediaEngineVideoSource : public MediaEngineSource
+{
+public:
+  virtual ~MediaEngineVideoSource() {}
+
+  /* This call reserves but does not start the device. */
+  virtual nsresult Allocate(const VideoTrackConstraintsN &aConstraints,
+                            const MediaEnginePrefs &aPrefs) = 0;
+};
+
+/**
+ * Audio source and friends.
+ */
+class MediaEngineAudioSource : public MediaEngineSource
+{
+public:
+  virtual ~MediaEngineAudioSource() {}
+
+  /* This call reserves but does not start the device. */
+  virtual nsresult Allocate(const AudioTrackConstraintsN &aConstraints,
+                            const MediaEnginePrefs &aPrefs) = 0;
+
+};
+
+}
+
+#endif /* MEDIAENGINE_H_ */