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// Copyright 2014 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_RENDERER_MEDIA_MEDIA_STREAM_VIDEO_SOURCE_H_
#define CONTENT_RENDERER_MEDIA_MEDIA_STREAM_VIDEO_SOURCE_H_
#include <string>
#include <vector>
#include "base/compiler_specific.h"
#include "base/macros.h"
#include "base/memory/weak_ptr.h"
#include "base/message_loop/message_loop.h"
#include "base/threading/non_thread_safe.h"
#include "content/common/content_export.h"
#include "content/common/media/video_capture.h"
#include "content/public/renderer/media_stream_video_sink.h"
#include "content/renderer/media/media_stream_source.h"
#include "media/base/video_capture_types.h"
#include "media/base/video_frame.h"
#include "third_party/WebKit/public/platform/WebMediaConstraints.h"
#include "third_party/WebKit/public/platform/WebMediaStreamSource.h"
#include "third_party/WebKit/public/platform/WebMediaStreamTrack.h"
namespace content {
class MediaStreamVideoTrack;
class VideoTrackAdapter;
// MediaStreamVideoSource is an interface used for sending video frames to a
// MediaStreamVideoTrack.
// http://dev.w3.org/2011/webrtc/editor/getusermedia.html
// The purpose of this base class is to be able to implement different
// MediaStreaVideoSources such as local video capture, video sources received
// on a PeerConnection or a source created in NaCl.
// All methods calls will be done from the main render thread.
//
// When the first track is added to the source by calling AddTrack, the
// MediaStreamVideoSource implementation calls GetCurrentSupportedFormats.
// The source implementation must call OnSupportedFormats.
// MediaStreamVideoSource then match the constraints provided in AddTrack with
// the formats and call StartSourceImpl. The source implementation must call
// OnStartDone when the underlying source has been started or failed to start.
class CONTENT_EXPORT MediaStreamVideoSource
: public MediaStreamSource,
NON_EXPORTED_BASE(public base::NonThreadSafe) {
public:
// Constraint keys used by a video source.
// Specified by draft-alvestrand-constraints-resolution-00b
static const char kMinAspectRatio[]; // minAspectRatio
static const char kMaxAspectRatio[]; // maxAspectRatio
static const char kMaxWidth[]; // maxWidth
static const char kMinWidth[]; // minWidth
static const char kMaxHeight[]; // maxHeight
static const char kMinHeight[]; // minHeight
static const char kMaxFrameRate[]; // maxFrameRate
static const char kMinFrameRate[]; // minFrameRate
enum {
// Default resolution. If no constraints are specified and the delegate
// support it, this is the resolution that will be used.
kDefaultWidth = 640,
kDefaultHeight = 480,
kDefaultFrameRate = 30,
kUnknownFrameRate = 0,
};
MediaStreamVideoSource();
~MediaStreamVideoSource() override;
// Returns the MediaStreamVideoSource object owned by |source|.
static MediaStreamVideoSource* GetVideoSource(
const blink::WebMediaStreamSource& source);
// Puts |track| in the registered tracks list.
void AddTrack(MediaStreamVideoTrack* track,
const VideoCaptureDeliverFrameCB& frame_callback,
const blink::WebMediaConstraints& constraints,
const ConstraintsCallback& callback);
void RemoveTrack(MediaStreamVideoTrack* track);
// Return true if |name| is a constraint supported by MediaStreamVideoSource.
static bool IsConstraintSupported(const std::string& name);
// Returns the task runner where video frames will be delivered on.
base::SingleThreadTaskRunner* io_task_runner() const;
const media::VideoCaptureFormat* GetCurrentFormat() const;
protected:
void DoStopSource() override;
// Sets ready state and notifies the ready state to all registered tracks.
virtual void SetReadyState(blink::WebMediaStreamSource::ReadyState state);
// Sets muted state and notifies it to all registered tracks.
virtual void SetMutedState(bool state);
// An implementation must fetch the formats that can currently be used by
// the source and call OnSupportedFormats when done.
// |max_requested_height| and |max_requested_width| is the max height and
// width set as a mandatory constraint if set when calling
// MediaStreamVideoSource::AddTrack. If max height and max width is not set
// |max_requested_height| and |max_requested_width| are 0.
virtual void GetCurrentSupportedFormats(
int max_requested_width,
int max_requested_height,
double max_requested_frame_rate,
const VideoCaptureDeviceFormatsCB& callback) = 0;
// An implementation must start capturing frames using the requested
// |format|. The fulfilled |constraints| are provided as additional context,
// and may be used to modify the behavior of the source. When the source has
// started or the source failed to start OnStartDone must be called. An
// implementation must call |frame_callback| on the IO thread with the
// captured frames.
virtual void StartSourceImpl(
const media::VideoCaptureFormat& format,
const blink::WebMediaConstraints& constraints,
const VideoCaptureDeliverFrameCB& frame_callback) = 0;
void OnStartDone(MediaStreamRequestResult result);
// An implementation must immediately stop capture video frames and must not
// call OnSupportedFormats after this method has been called. After this
// method has been called, MediaStreamVideoSource may be deleted.
virtual void StopSourceImpl() = 0;
enum State {
NEW,
RETRIEVING_CAPABILITIES,
STARTING,
STARTED,
ENDED
};
State state() const { return state_; }
private:
void OnSupportedFormats(const media::VideoCaptureFormats& formats);
// Finds the first WebMediaConstraints in |track_descriptors_| that allows
// the use of one of the |formats|. |best_format| and |fulfilled_constraints|
// are set to the results of this search-and-match operation. Returns false
// if no WebMediaConstraints allow the use any of the |formats|.
bool FindBestFormatWithConstraints(
const media::VideoCaptureFormats& formats,
media::VideoCaptureFormat* best_format,
blink::WebMediaConstraints* fulfilled_constraints);
// Trigger all cached callbacks from AddTrack. AddTrack is successful
// if the capture delegate has started and the constraints provided in
// AddTrack match the format that was used to start the device.
// Note that it must be ok to delete the MediaStreamVideoSource object
// in the context of the callback. If gUM fail, the implementation will
// simply drop the references to the blink source and track which will lead
// to that this object is deleted.
void FinalizeAddTrack();
State state_;
media::VideoCaptureFormat current_format_;
struct TrackDescriptor {
TrackDescriptor(MediaStreamVideoTrack* track,
const VideoCaptureDeliverFrameCB& frame_callback,
const blink::WebMediaConstraints& constraints,
const ConstraintsCallback& callback);
TrackDescriptor(const TrackDescriptor& other);
~TrackDescriptor();
MediaStreamVideoTrack* track;
VideoCaptureDeliverFrameCB frame_callback;
blink::WebMediaConstraints constraints;
ConstraintsCallback callback;
};
std::vector<TrackDescriptor> track_descriptors_;
media::VideoCaptureFormats supported_formats_;
// |track_adapter_| delivers video frames to the tracks on the IO-thread.
const scoped_refptr<VideoTrackAdapter> track_adapter_;
// Tracks that currently are connected to this source.
std::vector<MediaStreamVideoTrack*> tracks_;
// NOTE: Weak pointers must be invalidated before all other member variables.
base::WeakPtrFactory<MediaStreamVideoSource> weak_factory_;
DISALLOW_COPY_AND_ASSIGN(MediaStreamVideoSource);
};
} // namespace content
#endif // CONTENT_RENDERER_MEDIA_MEDIA_STREAM_VIDEO_SOURCE_H_
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