dlib C++ Library - ffmpeg_microphone_to_file_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.
 It attempts to read audio from a microphone if available, and saves the audio to wav.
*/
#include <iostream>
#include <chrono>
#include <dlib/media.h>
#include <dlib/cmd_line_parser.h>
using namespace std;
using namespace std::chrono;
using namespace std::chrono_literals;
using namespace dlib;
using namespace dlib::ffmpeg;
int main(const int argc, const char** argv)
try
{
 command_line_parser parser;
 parser.add_option("t", "capture time in seconds", 1);
 parser.add_option("i", "input microphone device. E.g. hw:0,0", 1);
 parser.add_option("o", "output audio file. E.g. recording.m4a, recording.wav. Default: recording.m4a", 1);
 parser.add_option("codec", "audio codec. E.g. `aac`, `pcm_s16le`. Recommend `pcm_s16le` for WAV files and `aac` for `M4A` files. Default: `aac`", 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[] = {"t", "i", "o", "codec"};
 parser.check_one_time_options(one_time_opts);
 if (parser.option("h") || parser.option("help"))
 {
 parser.print_options();
 return 0;
 }
 const seconds time{get_option(parser, "t", 1)};
 const std::string device = get_option(parser, "i", "hw:0,0");
 const std::string filename = get_option(parser, "o", "recording.m4a");
 const std::string codec = get_option(parser, "codec", "aac");
 // Open microphone
 demuxer cap([&] {
 demuxer::args args;
 args.filepath = device;
 args.input_format = "alsa";
 return args;
 }());
 if (!cap.is_open())
 {
 cout << "Failed to open device: " << device << '\n';
 return EXIT_FAILURE;
 }
 // Create WAV file
 muxer writer([&] {
 muxer::args args;
 args.filepath = filename;
 args.enable_image = false;
 args.args_audio.codec_name = codec;
 args.args_audio.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 wav file" << endl;
 return EXIT_FAILURE;
 }
 // Pull and push
 const auto start = high_resolution_clock::now();
 frame f;
 while (cap.read(f) && (high_resolution_clock::now() - start) < time)
 writer.push(std::move(f));
 return EXIT_SUCCESS;
}
catch (const std::exception& e)
{
 printf("%s\n", e.what());
 return EXIT_FAILURE;
}