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/**
* @file
* @brief Header file for WriterBase class
* @author Jonathan Thomas <jonathan@openshot.org>
*
* @ref License
*/
/* LICENSE
*
* Copyright (c) 2008-2019 OpenShot Studios, LLC
* <http://www.openshotstudios.com/>. This file is part of
* OpenShot Library (libopenshot), an open-source project dedicated to
* delivering high quality video editing and animation solutions to the
* world. For more information visit <http://www.openshot.org/>.
*
* OpenShot Library (libopenshot) is free software: you can redistribute it
* and/or modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* OpenShot Library (libopenshot) is distributed in the hope that it will be
* useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with OpenShot Library. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef OPENSHOT_WRITER_BASE_H
#define OPENSHOT_WRITER_BASE_H
#include <iostream>
#include <iomanip>
#include "ChannelLayouts.h"
#include "Fraction.h"
#include "Frame.h"
#include "ReaderBase.h"
#include "ZmqLogger.h"
namespace openshot
{
/**
* @brief This struct contains info about encoding a media file, such as height, width, frames per second, etc...
*
* Each derived class of WriterBase is responsible for updating this struct to reflect accurate information
* about the streams.
*/
struct WriterInfo
{
bool has_video; ///< Determines if this file has a video stream
bool has_audio; ///< Determines if this file has an audio stream
bool has_single_image; ///< Determines if this file only contains a single image
float duration; ///< Length of time (in seconds)
int64_t file_size; ///< Size of file (in bytes)
int height; ///< The height of the video (in pixels)
int width; ///< The width of the video (in pixels)
int pixel_format; ///< The pixel format (i.e. YUV420P, RGB24, etc...)
openshot::Fraction fps; ///< Frames per second, as a fraction (i.e. 24/1 = 24 fps)
int video_bit_rate; ///< The bit rate of the video stream (in bytes)
openshot::Fraction pixel_ratio; ///< The pixel ratio of the video stream as a fraction (i.e. some pixels are not square)
openshot::Fraction display_ratio; ///< The ratio of width to height of the video stream (i.e. 640x480 has a ratio of 4/3)
std::string vcodec; ///< The name of the video codec used to encode / decode the video stream
int64_t video_length; ///< The number of frames in the video stream
int video_stream_index; ///< The index of the video stream
openshot::Fraction video_timebase; ///< The video timebase determines how long each frame stays on the screen
bool interlaced_frame; ///< Are the contents of this frame interlaced
bool top_field_first; ///< Which interlaced field should be displayed first
std::string acodec; ///< The name of the audio codec used to encode / decode the video stream
int audio_bit_rate; ///< The bit rate of the audio stream (in bytes)
int sample_rate; ///< The number of audio samples per second (44100 is a common sample rate)
int channels; ///< The number of audio channels used in the audio stream
openshot::ChannelLayout channel_layout; ///< The channel layout (mono, stereo, 5 point surround, etc...)
int audio_stream_index; ///< The index of the audio stream
openshot::Fraction audio_timebase; ///< The audio timebase determines how long each audio packet should be played
std::map<std::string, std::string> metadata; ///< An optional map/dictionary of video & audio metadata
};
/**
* @brief This abstract class is the base class, used by writers. Writers are types of classes that encode
* video, audio, and image files.
*
* The only requirements for a 'writer', are to derive from this base class, and implement the
* WriteFrame method.
*/
class WriterBase
{
public:
/// Constructor for WriterBase class, many things are initialized here
WriterBase();
/// Information about the current media file
WriterInfo info;
/// @brief This method copy's the info struct of a reader, and sets the writer with the same info
/// @param reader The source reader to copy
void CopyReaderInfo(openshot::ReaderBase* reader);
/// Determine if writer is open or closed
virtual bool IsOpen() = 0;
/// This method is required for all derived classes of WriterBase. Write a Frame to the video file.
virtual void WriteFrame(std::shared_ptr<openshot::Frame> frame) = 0;
/// This method is required for all derived classes of WriterBase. Write a block of frames from a reader.
virtual void WriteFrame(openshot::ReaderBase* reader, int64_t start, int64_t length) = 0;
/// Get and Set JSON methods
std::string Json() const; ///< Generate JSON string of this object
Json::Value JsonValue() const; ///< Generate Json::Value for this object
void SetJson(const std::string value); ///< Load JSON string into this object
void SetJsonValue(const Json::Value root); ///< Load Json::Value into this object
/// Display file information in the standard output stream (stdout)
void DisplayInfo();
/// Open the writer (and start initializing streams)
virtual void Open() = 0;
virtual ~WriterBase() = default;
};
}
#endif
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