1// libjingle
2// Copyright 2004 Google Inc.
3//
4// Redistribution and use in source and binary forms, with or without
5// modification, are permitted provided that the following conditions are met:
6//
7//  1. Redistributions of source code must retain the above copyright notice,
8//     this list of conditions and the following disclaimer.
9//  2. Redistributions in binary form must reproduce the above copyright notice,
10//     this list of conditions and the following disclaimer in the documentation
11//     and/or other materials provided with the distribution.
12//  3. The name of the author may not be used to endorse or promote products
13//     derived from this software without specific prior written permission.
14//
15// THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
16// WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
17// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
18// EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
19// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
21// OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
22// WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
23// OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
24// ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25//
26// This file contains two classes, VideoRecorder and FileVideoCapturer.
27// VideoRecorder records the captured frames into a file. The file stores a
28// sequence of captured frames; each frame has a header defined in struct
29// CapturedFrame, followed by the frame data.
30//
31// FileVideoCapturer, a subclass of VideoCapturer, is a simulated video capturer
32// that periodically reads images from a previously recorded file.
33
34#ifndef TALK_MEDIA_DEVICES_FILEVIDEOCAPTURER_H_
35#define TALK_MEDIA_DEVICES_FILEVIDEOCAPTURER_H_
36
37#include <string>
38#include <vector>
39
40#include "talk/base/stream.h"
41#include "talk/base/stringutils.h"
42#include "talk/media/base/videocapturer.h"
43
44namespace talk_base {
45class FileStream;
46}
47
48namespace cricket {
49
50// Utility class to record the frames captured by a video capturer into a file.
51class VideoRecorder {
52 public:
53  VideoRecorder() {}
54  ~VideoRecorder() { Stop(); }
55
56  // Start the recorder by opening the specified file. Return true if the file
57  // is opened successfully. write_header should normally be true; false means
58  // write raw frame pixel data to file without any headers.
59  bool Start(const std::string& filename, bool write_header);
60  // Stop the recorder by closing the file.
61  void Stop();
62  // Record a video frame to the file. Return true if the frame is written to
63  // the file successfully. This method needs to be called after Start() and
64  // before Stop().
65  bool RecordFrame(const CapturedFrame& frame);
66
67 private:
68  talk_base::FileStream video_file_;
69  bool write_header_;
70
71  DISALLOW_COPY_AND_ASSIGN(VideoRecorder);
72};
73
74// Simulated video capturer that periodically reads frames from a file.
75class FileVideoCapturer : public VideoCapturer {
76 public:
77  FileVideoCapturer();
78  virtual ~FileVideoCapturer();
79
80  // Determines if the given device is actually a video file, to be captured
81  // with a FileVideoCapturer.
82  static bool IsFileVideoCapturerDevice(const Device& device) {
83    return talk_base::starts_with(device.id.c_str(), kVideoFileDevicePrefix);
84  }
85
86  // Creates a fake device for the given filename.
87  static Device CreateFileVideoCapturerDevice(const std::string& filename) {
88    std::stringstream id;
89    id << kVideoFileDevicePrefix << filename;
90    return Device(filename, id.str());
91  }
92
93  // Set how many times to repeat reading the file. Repeat forever if the
94  // parameter is talk_base::kForever(-1); no repeat if the parameter is 0 or
95  // less than -1.
96  void set_repeat(int repeat) { repeat_ = repeat; }
97
98  // If ignore_framerate is true, file is read as quickly as possible. If
99  // false, read rate is controlled by the timestamps in the video file
100  // (thus simulating camera capture). Default value set to false.
101  void set_ignore_framerate(bool ignore_framerate) {
102    ignore_framerate_ = ignore_framerate;
103  }
104
105  // Initializes the capturer with the given file.
106  bool Init(const std::string& filename);
107
108  // Initializes the capturer with the given device. This should only be used
109  // if IsFileVideoCapturerDevice returned true for the given device.
110  bool Init(const Device& device);
111
112  // Override virtual methods of parent class VideoCapturer.
113  virtual CaptureState Start(const VideoFormat& capture_format);
114  virtual void Stop();
115  virtual bool IsRunning();
116  virtual bool IsScreencast() const { return false; }
117
118 protected:
119  // Override virtual methods of parent class VideoCapturer.
120  virtual bool GetPreferredFourccs(std::vector<uint32>* fourccs);
121
122  // Read the frame header from the file stream, video_file_.
123  talk_base::StreamResult ReadFrameHeader(CapturedFrame* frame);
124
125  // Read a frame and determine how long to wait for the next frame. If the
126  // frame is read successfully, Set the output parameter, wait_time_ms and
127  // return true. Otherwise, do not change wait_time_ms and return false.
128  bool ReadFrame(bool first_frame, int* wait_time_ms);
129
130  // Return the CapturedFrame - useful for extracting contents after reading
131  // a frame. Should be used only while still reading a file (i.e. only while
132  // the CapturedFrame object still exists).
133  const CapturedFrame* frame() const {
134    return &captured_frame_;
135  }
136
137 private:
138  class FileReadThread;  // Forward declaration, defined in .cc.
139
140  static const char* kVideoFileDevicePrefix;
141  talk_base::FileStream video_file_;
142  CapturedFrame captured_frame_;
143  // The number of bytes allocated buffer for captured_frame_.data.
144  uint32 frame_buffer_size_;
145  FileReadThread* file_read_thread_;
146  int repeat_;  // How many times to repeat the file.
147  int64 start_time_ns_;  // Time when the file video capturer starts.
148  int64 last_frame_timestamp_ns_;  // Timestamp of last read frame.
149  bool ignore_framerate_;
150
151  DISALLOW_COPY_AND_ASSIGN(FileVideoCapturer);
152};
153
154}  // namespace cricket
155
156#endif  // TALK_MEDIA_DEVICES_FILEVIDEOCAPTURER_H_
157