content/browser/media/capture/web_contents_video_capture_device.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CONTENT_BROWSER_MEDIA_CAPTURE_WEB_CONTENTS_VIDEO_CAPTURE_DEVICE_H_
   6 #define CONTENT_BROWSER_MEDIA_CAPTURE_WEB_CONTENTS_VIDEO_CAPTURE_DEVICE_H_
   7
   8 #include <string>
   9
  10 #include "base/memory/scoped_ptr.h"
  11 #include "content/common/content_export.h"
  12 #include "media/video/capture/video_capture_device.h"
  13
  14 namespace content {
  15
  16 class ContentVideoCaptureDeviceCore;
  17
  18 // A virtualized VideoCaptureDevice that mirrors the displayed contents of a
  19 // tab (accessed via its associated WebContents instance), producing a stream of
  20 // video frames.
  21 //
  22 // An instance is created by providing a device_id.  The device_id contains
  23 // information necessary for finding a WebContents instance.  From then on,
  24 // WebContentsVideoCaptureDevice will capture from whatever render view is
  25 // currently associated with that WebContents instance.  This allows the
  26 // underlying render view to be swapped out (e.g., due to navigation or
  27 // crashes/reloads), without any interruption in capturing.
  28 //
  29 // TODO(miu): In a soon upcoming change, the cross-site isolation migration of
  30 // this code will be completed such that the main RenderFrameHost is tracked
  31 // instead of the RenderViewHost.
  32 class CONTENT_EXPORT WebContentsVideoCaptureDevice
  33     : public media::VideoCaptureDevice {
  34  public:
  35   // Create a WebContentsVideoCaptureDevice instance from the given
  36   // |device_id|.  Returns NULL if |device_id| is invalid.
  37   static media::VideoCaptureDevice* Create(const std::string& device_id);
  38
  39   virtual ~WebContentsVideoCaptureDevice();
  40
  41   // VideoCaptureDevice implementation.
  42   virtual void AllocateAndStart(const media::VideoCaptureParams& params,
  43                                 scoped_ptr<Client> client) OVERRIDE;
  44   virtual void StopAndDeAllocate() OVERRIDE;
  45
  46  private:
  47   WebContentsVideoCaptureDevice(
  48       int render_process_id, int main_render_frame_id);
  49
  50   const scoped_ptr<ContentVideoCaptureDeviceCore> core_;
  51
  52   DISALLOW_COPY_AND_ASSIGN(WebContentsVideoCaptureDevice);
  53 };
  54
  55
  56 }  // namespace content
  57
  58 #endif  // CONTENT_BROWSER_MEDIA_CAPTURE_WEB_CONTENTS_VIDEO_CAPTURE_DEVICE_H_