Added commandline parsing

CMakeLists.txt

@@ -6,9 +6,10 @@ project(spectralyze)
 
 add_executable(spectralyze
 	"src/main.cpp"
- "src/FFT.hpp")
+ "src/FFT.hpp" "lib/cxxopts/cxxopts.hpp")
 
 target_include_directories(spectralyze PRIVATE
 	"lib/AudioFile"
 	"lib/json"
+	"lib/cxxopts"
 )

README.md

@@ -24,3 +24,8 @@ Each audio channel in the file is transformed separately. The resulting JSON has
 }
 ```
 Every supplied audio file will result in one JSON file. The magnitude is the absolute value of the real and imaginary part of the Fourier transformation.
+
+## Used libraries
+* [AudioFile](https://github.com/adamstark/AudioFile) for loading audio files
+* [JSON for Modern C++](https://github.com/nlohmann/json) for writing JSON data
+* [cxxopts](https://github.com/jarro2783/cxxopts) for parsing commandline arguments

src/FFT.hpp

@@ -49,8 +49,9 @@ std::vector<std::complex<double>> radix2dit(const std::vector<double>::const_ite
 	return output;
 }
 
-std::vector<std::pair<double, double>> FFT(std::vector<double> signal, size_t sampleRate)
+std::vector<std::pair<double, double>> FFT(const std::vector<double>::const_iterator& begin, const std::vector<double>::const_iterator& end, size_t sampleRate)
 {
+	std::vector<double> signal(begin, end);
 	size_t N = signal.size();
 	while (!POW_OF_TWO(N))
 	{

src/main.cpp

@@ -5,49 +5,135 @@
 
 #include "AudioFile.h"
 #include "json.hpp"
+#include "cxxopts.hpp"
 #include "FFT.hpp"
 
-void PrintUsage();
+#define PRINTER(s, x) if(!s.quiet) { std::cout << x; }
+
+struct Settings {
+	std::vector<std::filesystem::path> files;
+	bool quiet;
+	float splitInterval;
+};
+
+Settings Parse(int argc, char** argv);
 
 int main(int argc, char** argv)
 {
-	if (argc < 2) {
-		PrintUsage();
-		return 1;
-	}
+	Settings setts;
+	setts = Parse(argc, argv);
 
-	int numFiles = argc - 1;
-	for (int i = 1; i < argc; i++) {
+	int numFiles = setts.files.size();
+	for (auto& file : setts.files) {
 		AudioFile<double> audioFile;
-		audioFile.load(argv[i]);
 
-		std::string filename = std::filesystem::path(argv[i]).filename().string();
+		if (!audioFile.load(file.string()))
+		{
+			continue;
+		}
+
+		std::string filename = file.filename().string();
 
 		int sampleRate = audioFile.getSampleRate();
 		int numChannels = audioFile.getNumChannels();
 
 		nlohmann::json output;
 		for (int c = 1; c <= numChannels; c++) {
-			std::cout << "\rAnalyzing " << filename << "... Channel " << c << "/" << numChannels << "            ";
-			std::vector<std::pair<double, double>> spectrum = FFT(audioFile.samples[c-1], sampleRate);
+			PRINTER(setts, "\rAnalyzing " << filename << "... Channel " << c << "/" << numChannels << " 0%                  ");
 
 			std::string chName = "channel_" + std::to_string(c);
 			output[chName] = nlohmann::json::array();
-			for (const std::pair<double, double>& pair : spectrum) {
-				output[chName].push_back({ {"freq", pair.first}, {"mag", pair.second } });
+
+			if (setts.splitInterval == 0.0f)
+			{
+				std::vector<std::pair<double, double>> spectrum = FFT(audioFile.samples[c-1].cbegin(), audioFile.samples[c-1].cend(), sampleRate);
+
+				output[chName] = nlohmann::json::array();
+				for (const std::pair<double, double>& pair : spectrum) {
+					output[chName].push_back({ {"freq", pair.first}, {"mag", pair.second } });
+				}
+			}
+			else
+			{
+				int sampleInterval = sampleRate * setts.splitInterval / 1000;
+				int currentSample;
+				for (currentSample = 0; currentSample < audioFile.samples[c - 1].size(); currentSample += sampleInterval)
+				{
+					std::vector<std::pair<double, double>> spectrum = 
+						FFT(
+							audioFile.samples[c-1].cbegin() + currentSample, 
+							std::min(
+								audioFile.samples[c-1].cbegin() + currentSample + sampleInterval, 
+								audioFile.samples[c-1].cend()), 
+							sampleRate
+						);
+
+					output[chName].push_back({
+						{"begin", currentSample},
+						{"end", currentSample + sampleInterval},
+						{"spectrum", nlohmann::json::array()}
+					});
+
+					for (const std::pair<double, double>& pair : spectrum) {
+						output[chName].back()["spectrum"].push_back({ {"freq", pair.first}, {"mag", pair.second } });
+					}
+
+					PRINTER(setts, "\rAnalyzing " << filename << "... Channel " << c << "/" << numChannels << " " << (int)std::floor((float)currentSample / (float)audioFile.samples[c-1].size() * 100.0f) << "%                  ");
+				}
 			}
 		}
 
-		std::ofstream ofs(std::filesystem::path(argv[i]).replace_extension("json"));
+		std::ofstream ofs(file.replace_extension("json"));
 		ofs << std::setw(4) << output << std::endl;
 		ofs.close();
-		std::cout << "\rAnalyzing " << filename << "... Done!        " << std::endl;
+
+		PRINTER(setts, "\rAnalyzing " << filename << "... 100%                      " << std::endl);
 	}
 
 	return 0;
 }
 
-void PrintUsage()
+Settings Parse(int argc, char** argv)
 {
-	std::cerr << "Usage: spectralyze file1 [file2...]" << std::endl;
+	Settings setts;
+
+	try
+	{
+		cxxopts::Options options("spectralyze", "Fourier transforms audio files");
+		options
+			.set_width(70)
+			.positional_help("file1 [file2...]")
+			.add_options()
+			("q,quiet", "Suppress text output", cxxopts::value<bool>()->default_value("false"))
+			("i,interval", "Splits audio file into intervals of length i milliseconds and transforms them individually (0 to not split file)", cxxopts::value<float>())
+			("files", "Files to fourier transform", cxxopts::value<std::vector<std::filesystem::path>>())
+			("h,help", "Print usage")
+			;
+
+		options.parse_positional("files");
+
+		auto result = options.parse(argc, argv);
+		if (result.count("help"))
+		{
+			std::cout << options.help() << std::endl;
+			exit(0);
+		}
+
+		if (!result.count("files"))
+		{
+			std::cerr << "At least one positional argument is required." << std::endl;
+			exit(1);
+		}
+
+		setts.files = result["files"].as<std::vector<std::filesystem::path>>();
+		setts.quiet = (result.count("quiet") ? result["quiet"].as<bool>() : false);
+		setts.splitInterval = (result.count("interval") ? result["interval"].as<float>() : 0.0f);
+	}
+	catch (const cxxopts::OptionException& e)
+	{
+		std::cout << "Invalid parameters: " << e.what() << std::endl;
+		exit(1);
+	}
+
+	return setts;
 }