firefox-main/dom/media/systemservices/VideoEngine.h (file symbol)

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/* 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 mozilla_VideoEngine_h
#define mozilla_VideoEngine_h
#include <memory>
#include "MediaEventSource.h"
#include "mozilla/DefineEnum.h"
#include "video_engine/video_capture_factory.h"
namespace webrtc {
class DesktopCaptureImpl;
}
namespace mozilla::camera {
MOZ_DEFINE_ENUM_CLASS_WITH_TOSTRING(CaptureDeviceType,
(Camera, Screen, Window, Browser));
// Historically the video engine was part of libwebrtc.
// It was removed, and reimplemented in Talk.
//
// Now we are removing more and more of it. Currently it is a fairly thin proxy
// between CamerasParent and libwebrtc, mainly handling things like forwarding
// device-change events and cache invalidation of enumerated devices.
class VideoEngine : public webrtc::VideoInputFeedBack {
private:
virtual ~VideoEngine();
// Base cache expiration period
// Note because cameras use HW plug event detection, this
// only applies to screen based modes.
static const int64_t kCacheExpiryPeriodMs = 2000;
public:
NS_INLINE_DECL_REFCOUNTING(VideoEngine)
static already_AddRefed<VideoEngine> Create(
const CaptureDeviceType& aCaptureDeviceType,
RefPtr<VideoCaptureFactory> aVideoCaptureFactory);
#if defined(ANDROID)
static int SetAndroidObjects();
#endif
int32_t GenerateId();
// Thin layer on top of mVideoCaptureFactory.
VideoCaptureFactory::CreateVideoCaptureResult CreateVideoCapture(
int32_t aCaptureId, const char* aDeviceUniqueIdUTF8);
/** Returns an existing or creates a new DeviceInfo.
* Camera info is cached to prevent repeated lengthy polling for "realness"
* of the hardware devices. Other types of capture, e.g. screen share info,
* are cached for 1 second. This could be handled in a more elegant way in
* the future.
* @return on failure the shared_ptr will be null, otherwise it will contain
* a DeviceInfo.
*/
std::shared_ptr<webrtc::VideoCaptureModule::DeviceInfo>
GetOrCreateVideoCaptureDeviceInfo();
/**
* Destroys existing DeviceInfo.
* The DeviceInfo will be recreated the next time it is needed.
*/
void ClearVideoCaptureDeviceInfo();
void OnDeviceChange() override;
MediaEventSource<void>& DeviceChangeEvent() { return mDeviceChangeEvent; }
private:
VideoEngine(const CaptureDeviceType& aCaptureDeviceType,
RefPtr<VideoCaptureFactory> aVideoCaptureFactory);
const CaptureDeviceType mCaptureDevType;
const RefPtr<VideoCaptureFactory> mVideoCaptureFactory;
std::shared_ptr<webrtc::VideoCaptureModule::DeviceInfo> mDeviceInfo;
MediaEventProducer<void> mDeviceChangeEvent;
// The validity period for non-camera capture device infos`
webrtc::Timestamp mExpiryTime = webrtc::Timestamp::Micros(0);
};
} // namespace mozilla::camera
#endif