dom/camera/DOMCameraPreview.h

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   3  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #ifndef DOM_CAMERA_DOMCAMERAPREVIEW_H
   6 #define DOM_CAMERA_DOMCAMERAPREVIEW_H
   7
   8 #include "nsCycleCollectionParticipant.h"
   9 #include "MediaStreamGraph.h"
  10 #include "StreamBuffer.h"
  11 #include "ICameraControl.h"
  12 #include "nsDOMMediaStream.h"
  13 #include "CameraCommon.h"
  14
  15 using namespace mozilla;
  16 using namespace mozilla::layers;
  17
  18 namespace mozilla {
  19
  20 typedef void (*FrameBuilder)(Image* aImage, void* aBuffer, uint32_t aWidth, uint32_t aHeight);
  21
  22 /**
  23  * DOMCameraPreview is only exposed to the DOM as an nsDOMMediaStream,
  24  * which is a cycle-collection participant already.
  25  */
  26 class DOMCameraPreview : public nsDOMMediaStream
  27 {
  28 protected:
  29   enum { TRACK_VIDEO = 1 };
  30
  31 public:
  32   DOMCameraPreview(ICameraControl* aCameraControl, uint32_t aWidth, uint32_t aHeight, uint32_t aFramesPerSecond = 30);
  33   bool ReceiveFrame(void* aBuffer, ImageFormat aFormat, FrameBuilder aBuilder);
  34   bool HaveEnoughBuffered();
  35
  36   NS_IMETHODIMP
  37   GetCurrentTime(double* aCurrentTime) {
  38     return nsDOMMediaStream::GetCurrentTime(aCurrentTime);
  39   }
  40
  41   void Start();   // called by the MediaStreamListener to start preview
  42   void Started(); // called by the CameraControl when preview is started
  43   void Stop();    // called by the MediaStreamListener to stop preview
  44   void Stopped(bool aForced = false);
  45                   // called by the CameraControl when preview is stopped
  46   void Error();   // something went wrong, NS_RELEASE needed
  47
  48   void SetStateStarted();
  49   void SetStateStopped();
  50
  51 protected:
  52   virtual ~DOMCameraPreview();
  53
  54   enum {
  55     STOPPED,
  56     STARTING,
  57     STARTED,
  58     STOPPING
  59   };
  60   uint32_t mState;
  61
  62   uint32_t mWidth;
  63   uint32_t mHeight;
  64   uint32_t mFramesPerSecond;
  65   SourceMediaStream* mInput;
  66   nsRefPtr<ImageContainer> mImageContainer;
  67   VideoSegment mVideoSegment;
  68   uint32_t mFrameCount;
  69   nsRefPtr<ICameraControl> mCameraControl;
  70
  71   // Raw pointer; AddListener() keeps the reference for us
  72   MediaStreamListener* mListener;
  73
  74 private:
  75   DOMCameraPreview(const DOMCameraPreview&) MOZ_DELETE;
  76   DOMCameraPreview& operator=(const DOMCameraPreview&) MOZ_DELETE;
  77 };
  78
  79 } // namespace mozilla
  80
  81 #endif // DOM_CAMERA_DOMCAMERAPREVIEW_H