| // Copyright 2013 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 MEDIA_CAPTURE_VIDEO_FILE_VIDEO_CAPTURE_DEVICE_H_ |
| #define MEDIA_CAPTURE_VIDEO_FILE_VIDEO_CAPTURE_DEVICE_H_ |
| |
| #include <stdint.h> |
| |
| #include <memory> |
| #include <string> |
| |
| #include "base/files/file.h" |
| #include "base/files/memory_mapped_file.h" |
| #include "base/macros.h" |
| #include "base/threading/thread.h" |
| #include "base/threading/thread_checker.h" |
| #include "media/capture/video/video_capture_device.h" |
| |
| namespace media { |
| |
| class VideoFileParser; |
| |
| // Implementation of a VideoCaptureDevice class that reads from a file. Used for |
| // testing the video capture pipeline when no real hardware is available. The |
| // supported file formats are YUV4MPEG2 (a.k.a. Y4M) and MJPEG/JPEG. YUV4MPEG2 |
| // is a minimal container with a series of uncompressed video only frames, see |
| // the link http://wiki.multimedia.cx/index.php?title=YUV4MPEG2 for more |
| // information on the file format. Several restrictions and notes apply, see the |
| // implementation file. |
| // Example Y4M videos can be found in http://media.xiph.org/video/derf. |
| // Example MJPEG videos can be found in media/data/test/bear.mjpeg. |
| // Restrictions: Y4M videos should have .y4m file extension and MJPEG videos |
| // should have .mjpeg file extension. |
| class CAPTURE_EXPORT FileVideoCaptureDevice : public VideoCaptureDevice { |
| public: |
| // Reads and parses the header of a |file_path|, returning the collected |
| // pixel format in |video_format|. Returns true on file parsed successfully, |
| // or false. |
| // Restrictions: Only trivial Y4M per-frame headers and MJPEG are supported. |
| static bool GetVideoCaptureFormat(const base::FilePath& file_path, |
| VideoCaptureFormat* video_format); |
| |
| // Constructor of the class, with a fully qualified file path as input, which |
| // represents the Y4M or MJPEG file to stream repeatedly. |
| explicit FileVideoCaptureDevice(const base::FilePath& file_path); |
| |
| // VideoCaptureDevice implementation, class methods. |
| ~FileVideoCaptureDevice() override; |
| void AllocateAndStart( |
| const VideoCaptureParams& params, |
| std::unique_ptr<VideoCaptureDevice::Client> client) override; |
| void StopAndDeAllocate() override; |
| void GetPhotoState(GetPhotoStateCallback callback) override; |
| void SetPhotoOptions(mojom::PhotoSettingsPtr settings, |
| SetPhotoOptionsCallback callback) override; |
| void TakePhoto(TakePhotoCallback callback) override; |
| |
| private: |
| // Opens a given file |file_path| for reading, and stores collected format |
| // information in |video_format|. Returns the parsed file to the |
| // caller, who is responsible for closing it. |
| static std::unique_ptr<VideoFileParser> GetVideoFileParser( |
| const base::FilePath& file_path, |
| VideoCaptureFormat* video_format); |
| |
| // Called on the |capture_thread_|. |
| void OnAllocateAndStart(const VideoCaptureParams& params, |
| std::unique_ptr<Client> client); |
| void OnStopAndDeAllocate(); |
| const uint8_t* GetNextFrame(); |
| void OnCaptureTask(); |
| |
| // |thread_checker_| is used to check that destructor, AllocateAndStart() and |
| // StopAndDeAllocate() are called in the correct thread that owns the object. |
| base::ThreadChecker thread_checker_; |
| |
| // |capture_thread_| is used for internal operations via posting tasks to it. |
| // It is active between OnAllocateAndStart() and OnStopAndDeAllocate(). |
| base::Thread capture_thread_; |
| // The following members belong to |capture_thread_|. |
| std::unique_ptr<VideoCaptureDevice::Client> client_; |
| const base::FilePath file_path_; |
| std::unique_ptr<VideoFileParser> file_parser_; |
| VideoCaptureFormat capture_format_; |
| // Target time for the next frame. |
| base::TimeTicks next_frame_time_; |
| // The system time when we receive the first frame. |
| base::TimeTicks first_ref_time_; |
| |
| // Guards the below variables from concurrent access between methods running |
| // on the main thread and |capture_thread_|. |
| base::Lock lock_; |
| base::queue<TakePhotoCallback> take_photo_callbacks_; |
| |
| DISALLOW_COPY_AND_ASSIGN(FileVideoCaptureDevice); |
| }; |
| |
| } // namespace media |
| |
| #endif // MEDIA_CAPTURE_VIDEO_FILE_VIDEO_CAPTURE_DEVICE_H_ |