livetrax/gtk2_ardour/transcode_ffmpeg.h

/*
 * Copyright (C) 2013-2018 Robin Gareus <robin@gareus.org>
 *
 * This program 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 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
#pragma once

#include <string>

#include "ardour/system_exec.h"
#include "ardour/types.h"

/** @class TranscodeFfmpeg
 *  @brief wrapper around ffmpeg and ffprobe command-line utils
 *
 *  This class includes parsers for stdi/o communication with
 *  'ffmpeg' and 'ffprobe' and provide an abstraction to
 *  transcode video-files and extract aufio tracks and query
 *  file information.
 */
class TranscodeFfmpeg : public sigc::trackable, public PBD::ScopedConnectionList
{
public:
	struct FFAudioStream {
		std::string name;
		std::string stream_id;
		uint32_t    channels;
	};

	typedef std::vector<FFAudioStream>         FFAudioStreams;
	typedef std::map<std::string, std::string> FFSettings;

	/** instantiate a new transcoder. If a file-name is given, the file's
	 * attributes (fps, duration, geometry etc) are read.
	 *
	 * @param f path to the video-file to probe or use as input for \ref extract_audio and \ref transcode .
	 */
	TranscodeFfmpeg (std::string f);

	/** transcode to (import a video-file)
	 *
	 * @param outfile full-path (incl. file-extension) of the file to create
	 * @param width video-width, if \c <0 no scaling
	 * @param height video-height, with \c <0 preserve aspect (\p width \c / \c aspect-ratio)
	 * @param kbitps video bitrate, with \c 0 calculate to use 0.7 bits per pixel on average
	 * @return \c true if the transcoder process was successfully started.
	 */
	bool transcode (std::string outfile, const int width = 0, const int height = 0, const int kbitps = 0);

	/** Extract an audio track from the given input file to a new 32bit float little-endian PCM WAV file.
	 * @param outfile full-path (incl. file-extension) to .wav file to write
	 * @param samplerate target samplerate
	 * @param stream Stream-ID of the audio-track to extract
	 * specified as element-number in \ref get_audio().
	 * @return \c true if the transcoder process was successfully started.
	 */
	bool extract_audio (std::string outfile, ARDOUR::samplecnt_t samplerate, unsigned int stream = 0);

	/** transcode video and mux audio files into a new video-file.
	 * @param outfile full-path of output file to create (existing files are overwritten)
	 * @param inf_a filename of input audio-file
	 * @param inf_v filename of input video-file
	 * @param ffs additional command-line parameters for 'ffmpeg'. key/value pairs
	 * eg ffs["-vcodec"] = "mpeg4"
	 * @param meta additional meta-data results in -metadata "<key>"="<value>" command-line
	 * arguments
	 * @param map if set to \c true stream mapping from input streams to output streams is set to use
	 * only the first available stream from the audio & video file (-map 0.0 -map 1.0).
	 * @return \c true if the encoder process was successfully started.
	 */
	bool encode (std::string outfile, std::string inf_a, std::string inf_v, FFSettings ffs, FFSettings meta, bool map = true);

	/** abort any running transcoding process */
	void cancel ();

	/** @return array with default encoder settings */
	FFSettings default_encoder_settings ();

	/** @return array with default meta data */
	FFSettings default_meta_data ();

	/** @return \c true if the input file was parsed correctly on class creation. */
	bool probe_ok ()
	{
		return probeok;
	}

	/** @return \c true if the ffmpeg/ffparse executables are avail on this system */
	bool ffexec_ok ()
	{
		return ffexecok;
	}

	double get_fps ()
	{
		return m_fps;
	}

	double get_aspect ()
	{
		return m_aspect;
	}

	int get_width ()
	{
		return m_width;
	}

	int get_height ()
	{
		return m_height;
	}

	ARDOUR::samplecnt_t get_duration ()
	{
		return m_duration;
	}

	std::string get_codec ()
	{
		return m_codec;
	}

	FFAudioStreams get_audio ()
	{
		return m_audio;
	}

	/** override file duration used with the \ref Progress signal.
	 * @param d duration in video-frames = length_in_seconds * get_fps()
	 */
	void set_duration (ARDOUR::samplecnt_t d)
	{
		m_duration = d;
	}

	/* offset, lead-in/out are in seconds */
	void set_avoffset (double av_offset)
	{
		m_avoffset = av_offset;
	}

	void set_leadinout (double lead_in, double lead_out)
	{
		m_lead_in  = lead_in;
		m_lead_out = lead_out;
	}

	void set_debug (bool onoff)
	{
		debug_enable = onoff;
	}

	/** signal emitted when ffmpeg reports progress updates
	 * during \ref encode \ref transcode and \ref extract_audio
	 * The parameters are current and last video-frame.
	 */
	PBD::Signal<void(ARDOUR::samplecnt_t, ARDOUR::samplecnt_t)> Progress;

	/** signal emitted when the transcoder process terminates. */
	PBD::Signal<void(int)> Finished;

protected:
	bool probe ();
	void ffmpegparse_v (std::string d, size_t s);
	void ffmpegparse_a (std::string d, size_t s);
	void ffprobeparse (std::string d, size_t s);
	void ffexit ();

	std::string         infile;
	ARDOUR::SystemExec* ffcmd;
	double              m_fps;
	std::string         m_fps_str;
	double              m_aspect;
	std::string         m_sar;
	ARDOUR::samplecnt_t m_duration;
	int                 m_width;
	int                 m_height;
	std::string         m_codec;
	int                 m_videoidx;
	double              m_avoffset;
	double              m_lead_in;
	double              m_lead_out;
	bool                ffexecok;
	bool                probeok;
	FFAudioStreams      m_audio;
	std::string         ffoutput;
	std::string         ffmpeg_exe;
	std::string         ffprobe_exe;
	bool                debug_enable;
};