// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CONTENT_BROWSER_MEDIA_CAPTURE_WEB_CONTENTS_VIDEO_CAPTURE_DEVICE_H_
#define CONTENT_BROWSER_MEDIA_CAPTURE_WEB_CONTENTS_VIDEO_CAPTURE_DEVICE_H_
#include <string>
#include "base/memory/scoped_ptr.h"
#include "content/common/content_export.h"
#include "media/video/capture/video_capture_device.h"
namespace content {
class ContentVideoCaptureDeviceCore;
// A virtualized VideoCaptureDevice that mirrors the displayed contents of a
// tab (accessed via its associated WebContents instance), producing a stream of
// video frames.
//
// An instance is created by providing a device_id. The device_id contains the
// routing ID for a RenderViewHost, and from the RenderViewHost instance, a
// reference to its associated WebContents instance is acquired. From then on,
// WebContentsVideoCaptureDevice will capture from whatever render view is
// currently associated with that WebContents instance. This allows the
// underlying render view to be swapped out (e.g., due to navigation or
// crashes/reloads), without any interruption in capturing.
class CONTENT_EXPORT WebContentsVideoCaptureDevice
: public media::VideoCaptureDevice {
public:
// Construct from a |device_id| string of the form:
// "virtual-media-stream://render_process_id:render_view_id", where
// |render_process_id| and |render_view_id| are decimal integers.
// |destroy_cb| is invoked on an outside thread once all outstanding objects
// are completely destroyed -- this will be some time after the
// WebContentsVideoCaptureDevice is itself deleted.
// TODO(miu): Passing a destroy callback suggests needing to revisit the
// design philosophy of an asynchronous DeAllocate(). http://crbug.com/158641
static media::VideoCaptureDevice* Create(const std::string& device_id);
virtual ~WebContentsVideoCaptureDevice();
// VideoCaptureDevice implementation.
virtual void AllocateAndStart(const media::VideoCaptureParams& params,
scoped_ptr<Client> client) OVERRIDE;
virtual void StopAndDeAllocate() OVERRIDE;
private:
WebContentsVideoCaptureDevice(int render_process_id, int render_view_id);
const scoped_ptr<ContentVideoCaptureDeviceCore> core_;
DISALLOW_COPY_AND_ASSIGN(WebContentsVideoCaptureDevice);
};
} // namespace content
#endif // CONTENT_BROWSER_MEDIA_CAPTURE_WEB_CONTENTS_VIDEO_CAPTURE_DEVICE_H_