OpenShot Library | libopenshot  0.2.5
WriterBase.h
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1 /**
2  * @file
3  * @brief Header file for WriterBase class
4  * @author Jonathan Thomas <jonathan@openshot.org>
5  *
6  * @ref License
7  */
8 
9 /* LICENSE
10  *
11  * Copyright (c) 2008-2019 OpenShot Studios, LLC
12  * <http://www.openshotstudios.com/>. This file is part of
13  * OpenShot Library (libopenshot), an open-source project dedicated to
14  * delivering high quality video editing and animation solutions to the
15  * world. For more information visit <http://www.openshot.org/>.
16  *
17  * OpenShot Library (libopenshot) is free software: you can redistribute it
18  * and/or modify it under the terms of the GNU Lesser General Public License
19  * as published by the Free Software Foundation, either version 3 of the
20  * License, or (at your option) any later version.
21  *
22  * OpenShot Library (libopenshot) is distributed in the hope that it will be
23  * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
25  * GNU Lesser General Public License for more details.
26  *
27  * You should have received a copy of the GNU Lesser General Public License
28  * along with OpenShot Library. If not, see <http://www.gnu.org/licenses/>.
29  */
30 
31 #ifndef OPENSHOT_WRITER_BASE_H
32 #define OPENSHOT_WRITER_BASE_H
33 
34 #include <iostream>
35 #include <iomanip>
36 #include "ChannelLayouts.h"
37 #include "Fraction.h"
38 #include "Frame.h"
39 #include "ReaderBase.h"
40 #include "ZmqLogger.h"
41 
42 namespace openshot
43 {
44  /**
45  * @brief This struct contains info about encoding a media file, such as height, width, frames per second, etc...
46  *
47  * Each derived class of WriterBase is responsible for updating this struct to reflect accurate information
48  * about the streams.
49  */
50  struct WriterInfo
51  {
52  bool has_video; ///< Determines if this file has a video stream
53  bool has_audio; ///< Determines if this file has an audio stream
54  bool has_single_image; ///< Determines if this file only contains a single image
55  float duration; ///< Length of time (in seconds)
56  int64_t file_size; ///< Size of file (in bytes)
57  int height; ///< The height of the video (in pixels)
58  int width; ///< The width of the video (in pixels)
59  int pixel_format; ///< The pixel format (i.e. YUV420P, RGB24, etc...)
60  openshot::Fraction fps; ///< Frames per second, as a fraction (i.e. 24/1 = 24 fps)
61  int video_bit_rate; ///< The bit rate of the video stream (in bytes)
62  openshot::Fraction pixel_ratio; ///< The pixel ratio of the video stream as a fraction (i.e. some pixels are not square)
63  openshot::Fraction display_ratio; ///< The ratio of width to height of the video stream (i.e. 640x480 has a ratio of 4/3)
64  std::string vcodec; ///< The name of the video codec used to encode / decode the video stream
65  int64_t video_length; ///< The number of frames in the video stream
66  int video_stream_index; ///< The index of the video stream
67  openshot::Fraction video_timebase; ///< The video timebase determines how long each frame stays on the screen
68  bool interlaced_frame; ///< Are the contents of this frame interlaced
69  bool top_field_first; ///< Which interlaced field should be displayed first
70  std::string acodec; ///< The name of the audio codec used to encode / decode the video stream
71  int audio_bit_rate; ///< The bit rate of the audio stream (in bytes)
72  int sample_rate; ///< The number of audio samples per second (44100 is a common sample rate)
73  int channels; ///< The number of audio channels used in the audio stream
74  openshot::ChannelLayout channel_layout; ///< The channel layout (mono, stereo, 5 point surround, etc...)
75  int audio_stream_index; ///< The index of the audio stream
76  openshot::Fraction audio_timebase; ///< The audio timebase determines how long each audio packet should be played
77  std::map<std::string, std::string> metadata; ///< An optional map/dictionary of video & audio metadata
78  };
79 
80  /**
81  * @brief This abstract class is the base class, used by writers. Writers are types of classes that encode
82  * video, audio, and image files.
83  *
84  * The only requirements for a 'writer', are to derive from this base class, and implement the
85  * WriteFrame method.
86  */
87  class WriterBase
88  {
89  public:
90  /// Constructor for WriterBase class, many things are initialized here
91  WriterBase();
92 
93  /// Information about the current media file
95 
96  /// @brief This method copy's the info struct of a reader, and sets the writer with the same info
97  /// @param reader The source reader to copy
99 
100  /// Determine if writer is open or closed
101  virtual bool IsOpen() = 0;
102 
103  /// This method is required for all derived classes of WriterBase. Write a Frame to the video file.
104  virtual void WriteFrame(std::shared_ptr<openshot::Frame> frame) = 0;
105 
106  /// This method is required for all derived classes of WriterBase. Write a block of frames from a reader.
107  virtual void WriteFrame(openshot::ReaderBase* reader, int64_t start, int64_t length) = 0;
108 
109  /// Get and Set JSON methods
110  std::string Json() const; ///< Generate JSON string of this object
111  Json::Value JsonValue() const; ///< Generate Json::Value for this object
112  void SetJson(const std::string value); ///< Load JSON string into this object
113  void SetJsonValue(const Json::Value root); ///< Load Json::Value into this object
114 
115  /// Display file information in the standard output stream (stdout)
116  void DisplayInfo();
117 
118  /// Open the writer (and start initializing streams)
119  virtual void Open() = 0;
120 
121  virtual ~WriterBase() = default;
122  };
123 
124 }
125 
126 #endif
openshot::WriterInfo::has_single_image
bool has_single_image
Determines if this file only contains a single image.
Definition: WriterBase.h:54
ChannelLayouts.h
Header file for ChannelLayout class.
openshot::WriterInfo::video_length
int64_t video_length
The number of frames in the video stream.
Definition: WriterBase.h:65
openshot::WriterInfo::video_bit_rate
int video_bit_rate
The bit rate of the video stream (in bytes)
Definition: WriterBase.h:61
openshot::WriterInfo::display_ratio
openshot::Fraction display_ratio
The ratio of width to height of the video stream (i.e. 640x480 has a ratio of 4/3)
Definition: WriterBase.h:63
Fraction.h
Header file for Fraction class.
openshot::WriterBase::JsonValue
Json::Value JsonValue() const
Generate Json::Value for this object.
Definition: WriterBase.cpp:149
openshot::WriterInfo::fps
openshot::Fraction fps
Frames per second, as a fraction (i.e. 24/1 = 24 fps)
Definition: WriterBase.h:60
openshot
This namespace is the default namespace for all code in the openshot library.
Definition: AudioBufferSource.h:38
openshot::WriterBase::Open
virtual void Open()=0
Open the writer (and start initializing streams)
openshot::WriterInfo::audio_bit_rate
int audio_bit_rate
The bit rate of the audio stream (in bytes)
Definition: WriterBase.h:71
openshot::WriterInfo::channels
int channels
The number of audio channels used in the audio stream.
Definition: WriterBase.h:73
openshot::Fraction
This class represents a fraction.
Definition: Fraction.h:45
openshot::WriterInfo
This struct contains info about encoding a media file, such as height, width, frames per second,...
Definition: WriterBase.h:50
openshot::WriterInfo::video_stream_index
int video_stream_index
The index of the video stream.
Definition: WriterBase.h:66
openshot::WriterBase::Json
std::string Json() const
Get and Set JSON methods.
Definition: WriterBase.cpp:142
openshot::WriterInfo::width
int width
The width of the video (in pixels)
Definition: WriterBase.h:58
openshot::WriterInfo::acodec
std::string acodec
The name of the audio codec used to encode / decode the video stream.
Definition: WriterBase.h:70
openshot::WriterBase::~WriterBase
virtual ~WriterBase()=default
openshot::WriterInfo::video_timebase
openshot::Fraction video_timebase
The video timebase determines how long each frame stays on the screen.
Definition: WriterBase.h:67
openshot::WriterBase::DisplayInfo
void DisplayInfo()
Display file information in the standard output stream (stdout)
Definition: WriterBase.cpp:102
openshot::WriterBase::WriteFrame
virtual void WriteFrame(std::shared_ptr< openshot::Frame > frame)=0
This method is required for all derived classes of WriterBase. Write a Frame to the video file.
openshot::WriterInfo::pixel_ratio
openshot::Fraction pixel_ratio
The pixel ratio of the video stream as a fraction (i.e. some pixels are not square)
Definition: WriterBase.h:62
openshot::WriterInfo::top_field_first
bool top_field_first
Which interlaced field should be displayed first.
Definition: WriterBase.h:69
openshot::WriterInfo::file_size
int64_t file_size
Size of file (in bytes)
Definition: WriterBase.h:56
ZmqLogger.h
Header file for ZeroMQ-based Logger class.
openshot::WriterInfo::duration
float duration
Length of time (in seconds)
Definition: WriterBase.h:55
openshot::WriterInfo::channel_layout
openshot::ChannelLayout channel_layout
The channel layout (mono, stereo, 5 point surround, etc...)
Definition: WriterBase.h:74
openshot::WriterInfo::metadata
std::map< std::string, std::string > metadata
An optional map/dictionary of video & audio metadata.
Definition: WriterBase.h:77
openshot::WriterInfo::audio_timebase
openshot::Fraction audio_timebase
The audio timebase determines how long each audio packet should be played.
Definition: WriterBase.h:76
openshot::WriterInfo::pixel_format
int pixel_format
The pixel format (i.e. YUV420P, RGB24, etc...)
Definition: WriterBase.h:59
Frame.h
Header file for Frame class.
openshot::WriterBase::IsOpen
virtual bool IsOpen()=0
Determine if writer is open or closed.
openshot::WriterInfo::has_video
bool has_video
Determines if this file has a video stream.
Definition: WriterBase.h:52
openshot::WriterInfo::has_audio
bool has_audio
Determines if this file has an audio stream.
Definition: WriterBase.h:53
ReaderBase.h
Header file for ReaderBase class.
openshot::WriterInfo::height
int height
The height of the video (in pixels)
Definition: WriterBase.h:57
openshot::WriterBase::CopyReaderInfo
void CopyReaderInfo(openshot::ReaderBase *reader)
This method copy's the info struct of a reader, and sets the writer with the same info.
Definition: WriterBase.cpp:67
openshot::WriterBase::SetJsonValue
void SetJsonValue(const Json::Value root)
Load Json::Value into this object.
Definition: WriterBase.cpp:215
openshot::ReaderBase
This abstract class is the base class, used by all readers in libopenshot.
Definition: ReaderBase.h:97
openshot::WriterInfo::interlaced_frame
bool interlaced_frame
Are the contents of this frame interlaced.
Definition: WriterBase.h:68
openshot::WriterInfo::vcodec
std::string vcodec
The name of the video codec used to encode / decode the video stream.
Definition: WriterBase.h:64
openshot::WriterInfo::sample_rate
int sample_rate
The number of audio samples per second (44100 is a common sample rate)
Definition: WriterBase.h:72
openshot::ChannelLayout
ChannelLayout
This enumeration determines the audio channel layout (such as stereo, mono, 5 point surround,...
Definition: ChannelLayouts.h:46
openshot::WriterInfo::audio_stream_index
int audio_stream_index
The index of the audio stream.
Definition: WriterBase.h:75
openshot::WriterBase::info
WriterInfo info
Information about the current media file.
Definition: WriterBase.h:94
openshot::WriterBase::SetJson
void SetJson(const std::string value)
Load JSON string into this object.
Definition: WriterBase.cpp:198
openshot::WriterBase::WriterBase
WriterBase()
Constructor for WriterBase class, many things are initialized here.
Definition: WriterBase.cpp:36
openshot::WriterBase
This abstract class is the base class, used by writers. Writers are types of classes that encode vide...
Definition: WriterBase.h:87