dlib C++ Library - ffmpeg_video_muxing_ex.cpp

// The contents of this file are in the public domain. See LICENSE_FOR_EXAMPLE_PROGRAMS.txt
/*
 This is an example illustrating the use of the ffmpeg wrappers, in this case the muxing API.
 This is a pretty simple example. It loads a video file, extracts images and audio frames (if present) and
 re-encodes them into a video file.
 
 Please see the following examples on how to decode, demux, and get information on your installation of ffmpeg:
 - ffmpeg_info_ex.cpp
 - ffmpeg_video_decoding_ex.cpp
 - ffmpeg_video_decoding2_ex.cpp
 - ffmpeg_video_demuxing_ex.cpp
 - ffmpeg_video_demuxing2_ex.cpp
*/
#include <cstdio>
#include <dlib/media.h>
#include <dlib/cmd_line_parser.h>
using namespace std;
using namespace dlib;
using namespace dlib::ffmpeg;
int main(const int argc, const char** argv)
try
{
 command_line_parser parser;
 parser.add_option("i", "input video", 1);
 parser.add_option("o", "output file", 1);
 parser.add_option("codec_video", "video codec name. e.g. `h264`", 1);
 parser.add_option("codec_audio", "audio codec name. e.g. `aac`", 1);
 parser.add_option("height", "height of encoded stream. Defaults to whatever is in the video file", 1);
 parser.add_option("width", "width of encoded stream. Defaults to whatever is in the video file", 1);
 parser.add_option("sample_rate", "sample rate of encoded stream. Defaults to whatever is in the video file", 1);
 parser.set_group_name("Help Options");
 parser.add_option("h", "alias of --help");
 parser.add_option("help", "display this message and exit");
 parser.parse(argc, argv);
 const char* one_time_opts[] = {"i", "o", "codec_video", "codec_audio", "height", "width", "sample_rate"};
 parser.check_one_time_options(one_time_opts);
 if (parser.option("h") || parser.option("help"))
 {
 parser.print_options();
 return 0;
 }
 const std::string input_filepath = parser.option("i").argument();
 const std::string output_filepath = parser.option("o").argument();
 demuxer cap(input_filepath);
 if (!cap.is_open())
 {
 cout << "Failed to open " << input_filepath << endl;
 return EXIT_FAILURE;
 }
 muxer writer([&] {
 muxer::args args;
 args.filepath = output_filepath;
 args.enable_image = cap.video_enabled();
 args.enable_audio = cap.audio_enabled();
 if (args.enable_image)
 {
 args.args_image.codec_name = get_option(parser, "codec_video", "");;
 args.args_image.h = get_option(parser, "height", cap.height());
 args.args_image.w = get_option(parser, "width", cap.width());
 args.args_image.fmt = cap.pixel_fmt();
 args.args_image.framerate = cap.fps();
 }
 if (args.enable_audio)
 {
 args.args_audio.codec_name = get_option(parser, "codec_audio", "");;
 args.args_audio.sample_rate = get_option(parser, "sample_rate", cap.sample_rate());
 args.args_audio.channel_layout = cap.channel_layout();
 args.args_audio.fmt = cap.sample_fmt();
 }
 return args;
 }());
 if (!writer.is_open())
 {
 cout << "Failed to open " << output_filepath << endl;
 return EXIT_FAILURE;
 }
 frame f;
 while (cap.read(f))
 writer.push(std::move(f));
 // writer.flush(); 
 // You don't have to call flush() here because it's called in the destructor of muxer
 // If you call it more than once, it becomes a no-op basically.
 return EXIT_SUCCESS;
}
catch (const std::exception& e)
{
 cout << e.what() << '\n';
 return EXIT_FAILURE;
}