libopenshot/include/FFmpegWriter.h

/**
 * @file
 * @brief Header file for FFmpegWriter class
 * @author Jonathan Thomas <jonathan@openshot.org>, Fabrice Bellard
 *
 * @section LICENSE
 *
 * Copyright (c) 2008-2013 OpenShot Studios, LLC, Fabrice Bellard
 * (http://www.openshotstudios.com). This file is part of
 * OpenShot Library (http://www.openshot.org), an open-source project
 * dedicated to delivering high quality video editing and animation solutions
 * to the world.
 *
 * This file is originally based on the Libavformat API example, and then modified
 * by the libopenshot project.
 *
 * OpenShot Library is free software: you can redistribute it and/or modify
 * it under the terms of the GNU 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 free software: you can redistribute it
 * and/or modify it under the terms of the GNU Affero 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with OpenShot Library. If not, see <http://www.gnu.org/licenses/>.
 *
 * Also, if your software can interact with users remotely through a computer
 * network, you should also make sure that it provides a way for users to
 * get its source. For example, if your program is a web application, its
 * interface could display a "Source" link that leads users to an archive
 * of the code. There are many ways you could offer source, and different
 * solutions will be better for different programs; see section 13 for the
 * specific requirements.
 *
 * You should also get your employer (if you work as a programmer) or school,
 * if any, to sign a "copyright disclaimer" for the program, if necessary.
 * For more information on this, and how to apply and follow the GNU AGPL, see
 * <http://www.gnu.org/licenses/>.
 */


#ifndef OPENSHOT_FFMPEG_WRITER_H
#define OPENSHOT_FFMPEG_WRITER_H

#include "ReaderBase.h"
#include "WriterBase.h"

// Include FFmpeg headers and macros
#include "FFmpegUtilities.h"

#include <cmath>
#include <ctime>
#include <iostream>
#include <stdio.h>
#include <unistd.h>
#include "Magick++.h"
#include "Cache.h"
#include "Exceptions.h"
#include "OpenMPUtilities.h"
#include "Sleep.h"


using namespace std;

namespace openshot
{

	/// This enumeration designates the type of stream when encoding (video or audio)
	enum StreamType
	{
		VIDEO_STREAM,	///< A video stream (used to determine which type of stream)
		AUDIO_STREAM	///< An audio stream (used to determine which type of stream)
	};

	/**
	 * @brief This class uses the FFmpeg libraries, to write and encode video files and audio files.
	 *
	 * All FFmpeg options can be set using the SetOption() method, and any Reader may be used
	 * to generate openshot::Frame objects needed for writing. Be sure to use valid bit rates, frame
	 * rates, and sample rates (each format / codec has a limited # of valid options).
	 *
	 * @code
	 * // Create a reader for a video
	 * FFmpegReader r("MyAwesomeVideo.webm");
	 * r.Open(); // Open the reader
	 *
	 * // Create a writer (which will create a WebM video)
	 * FFmpegWriter w("/home/jonathan/NewVideo.webm");
	 *
	 * // Set options
	 * w.SetAudioOptions(true, "libvorbis", 44100, 2, 128000); // Sample Rate: 44100, Channels: 2, Bitrate: 128000
	 * w.SetVideoOptions(true, "libvpx", openshot::Fraction(24,1), 720, 480, openshot::Fraction(1,1), false, false, 300000); // FPS: 24, Size: 720x480, Pixel Ratio: 1/1, Bitrate: 300000
	 *
	 * // Prepare Streams
	 * w.PrepareStreams();
	 *
	 * // Write header
	 * w.WriteHeader();
	 *
	 * // Write all frames from the reader
	 * w.WriteFrame(&r, 1, r.info.video_length);
	 *
	 * // Write Footer
	 * w.WriteTrailer();
	 *
	 * // Close the reader & writer
	 * w.Close();
	 * r.Close();
	 * @endcode
	 */
	class FFmpegWriter : public WriterBase
	{
	private:
		string path;
		int cache_size;
		bool is_writing;
		int64 write_video_count;
		int64 write_audio_count;

	    AVOutputFormat *fmt;
	    AVFormatContext *oc;
	    AVStream *audio_st, *video_st;
	    AVCodecContext *video_codec;
	    AVCodecContext *audio_codec;
	    SwsContext *img_convert_ctx;
	    double audio_pts, video_pts;
	    int16_t *samples;
	    uint8_t *audio_outbuf;

	    int num_of_rescalers;
		int rescaler_position;
		vector<SwsContext*> image_rescalers;

	    int audio_outbuf_size;
	    int audio_input_frame_size;
	    int initial_audio_input_frame_size;
	    int audio_input_position;
	    AudioResampler *resampler;

	    /* Resample options */
	    int original_sample_rate;
	    int original_channels;

	    tr1::shared_ptr<Frame> last_frame;
	    deque<tr1::shared_ptr<Frame> > spooled_audio_frames;
	    deque<tr1::shared_ptr<Frame> > spooled_video_frames;

	    deque<tr1::shared_ptr<Frame> > queued_audio_frames;
	    deque<tr1::shared_ptr<Frame> > queued_video_frames;

	    deque<tr1::shared_ptr<Frame> > processed_frames;
	    deque<tr1::shared_ptr<Frame> > deallocate_frames;

	    map<tr1::shared_ptr<Frame>, AVFrame*> av_frames;

	    /// Add an AVFrame to the cache
	    void add_avframe(tr1::shared_ptr<Frame> frame, AVFrame* av_frame);

		/// Add an audio output stream
		AVStream* add_audio_stream();

		/// Add a video output stream
		AVStream* add_video_stream();

		/// Allocate an AVFrame object
		AVFrame* allocate_avframe(PixelFormat pix_fmt, int width, int height, int *buffer_size);

		/// Auto detect format (from path)
		void auto_detect_format();

		/// Close the audio codec
		void close_audio(AVFormatContext *oc, AVStream *st);

		/// Close the video codec
		void close_video(AVFormatContext *oc, AVStream *st);

		/// Flush encoders
		void flush_encoders();

		/// initialize streams
		void initialize_streams();

		/// open audio codec
		void open_audio(AVFormatContext *oc, AVStream *st);

		/// open video codec
		void open_video(AVFormatContext *oc, AVStream *st);

		/// process video frame
		void process_video_packet(tr1::shared_ptr<Frame> frame);

		/// write all queued frames' audio to the video file
		void write_audio_packets(bool final);

		/// write video frame
		void write_video_packet(tr1::shared_ptr<Frame> frame, AVFrame* frame_final);

		/// write all queued frames
		void write_queued_frames();

	public:

		/// Constructor for FFmpegWriter. Throws one of the following exceptions.
		FFmpegWriter(string path) throw(InvalidFile, InvalidFormat, InvalidCodec, InvalidOptions, OutOfMemory);

		/// Close the writer
		void Close();

		/// Get the cache size (number of frames to queue before writing)
		int GetCacheSize() { return cache_size; };

		/// Init a collection of software rescalers (thread safe)
		void InitScalers(int source_width, int source_height);

		/// Output the ffmpeg info about this format, streams, and codecs (i.e. dump format)
		void OutputStreamInfo();

		/// Prepare & initialize streams and open codecs
		void PrepareStreams();

		/// Remove & deallocate all software scalers
		void RemoveScalers();

		/// Set audio resample options
		void ResampleAudio(int sample_rate, int channels);

		/// Set audio export options
		void SetAudioOptions(bool has_audio, string codec, int sample_rate, int channels, int bit_rate);

		/// Set the cache size (number of frames to queue before writing)
		void SetCacheSize(int new_size) { cache_size = new_size; };

		/// Set video export options
		void SetVideoOptions(bool has_video, string codec, Fraction fps, int width, int height,
				Fraction pixel_ratio, bool interlaced, bool top_field_first, int bit_rate);

		/// Set custom options (some codecs accept additional params)
		void SetOption(StreamType stream, string name, string value);

		/// Write the file header (after the options are set)
		void WriteHeader();

		/// Add a frame to the stack waiting to be encoded.
		void WriteFrame(tr1::shared_ptr<Frame> frame);

		/// Write a block of frames from a reader
		void WriteFrame(ReaderBase* reader, int start, int length);

		/// Write the file trailer (after all frames are written)
		void WriteTrailer();

	};

}

#endif