dlib C++ Library - ffmpeg_video_demuxing_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 demuxer API.
 This is a pretty simple example. It loads a video file, and plots
 the image frames on a GUI window.
*/
#include <cstdio>
#include <dlib/media.h>
#include <dlib/gui_widgets.h>
#include <dlib/cmd_line_parser.h>
using namespace std;
using namespace dlib;
using namespace dlib::ffmpeg;
void print_properties(const demuxer& cap)
{
 printf("Video properties:\n\n");
 printf("Estimated duration : %f\n", cap.duration());
 printf("Video contains images : %i\n", cap.video_enabled());
 if (cap.video_enabled())
 {
 printf(" height : %i\n", cap.height());
 printf(" width : %i\n", cap.width());
 printf(" pixel format : %s\n", get_pixel_fmt_str(cap.pixel_fmt()).c_str());
 printf(" fps : %f\n", cap.fps());
 printf(" nframes : %d\n", cap.estimated_nframes());
 printf(" codec : %s\n", cap.get_video_codec_name().c_str());
 }
 printf("Video contains audio : %i\n", cap.audio_enabled());
 if (cap.audio_enabled())
 {
 printf(" sample rate : %i\n", cap.sample_rate());
 printf(" channel layout : %s\n", get_channel_layout_str(cap.channel_layout()).c_str());
 printf(" sample format : %s\n", get_audio_fmt_str(cap.sample_fmt()).c_str());
 printf(" nchannels : %i\n", cap.nchannels());
 printf(" estimated samples : %i\n", cap.estimated_total_samples());
 printf(" codec : %s\n", cap.get_audio_codec_name().c_str());
 }
 printf("\n\n");
 printf("Video metadata:\n");
 
 for (auto&& metadata : cap.get_metadata())
 printf(" key : %-32s ; val : %-32s\n", metadata.first.c_str(), metadata.second.c_str());
}
int main(const int argc, const char** argv)
try
{
 command_line_parser parser;
 parser.add_option("i", "input video", 1);
 parser.add_option("verbose", "enable all internal ffmpeg logging");
 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"};
 parser.check_one_time_options(one_time_opts);
 if (parser.option("h") || parser.option("help"))
 {
 parser.print_options();
 return 0;
 }
 if (parser.option("verbose"))
 {
 // You can set the verbosity of some global loggers:
 // - logger_dlib_wrapper() is the global logger used by dlib's wrappers
 // - logger_ffmpeg() is the global logger used by the internal ffmpeg libraries (Nice that we are able to do that!)
 ffmpeg::logger_dlib_wrapper().set_level(LALL);
 ffmpeg::logger_ffmpeg().set_level(LALL);
 }
 const std::string filepath = parser.option("i").argument();
 // In this example, we only read images.
 // This constructor allows you to concisely enabled images and disable audio frames.
 demuxer cap({filepath, video_enabled, audio_disabled});
 if (!cap.is_open())
 {
 printf("%s is not a valid video file\n", filepath.c_str());
 return EXIT_FAILURE;
 }
 // Print all the demuxer's properties for fun
 print_properties(cap);
 // Read all images and plot
 array2d<rgb_pixel> img;
 image_window win;
 while (cap.read(img))
 win.set_image(img);
 return EXIT_SUCCESS;
}
catch (const std::exception& e)
{
 printf("%s\n", e.what());
 return EXIT_FAILURE;
}