Allow the LFO tool to set options and output FLAC

tests/PlotLFO.cpp

@@ -18,16 +18,23 @@
 #include "sfizz/Synth.h"
 #include "sfizz/LFO.h"
 #include "sfizz/LFODescription.h"
+#include "sfizz/MathHelpers.h"
 #include "cxxopts.hpp"
 #include <absl/types/span.h>
 #include <vector>
 #include <iostream>
 #include <cmath>
+#ifdef _WIN32
+#define ENABLE_SNDFILE_WINDOWS_PROTOTYPES 1
+#endif
+#include <sndfile.hh>
 
 //==============================================================================
 
 static double sampleRate = 1000.0; // sample rate used to compute
 static double duration = 5.0; // length in seconds
+static std::string outputFilename;
+static bool saveFlac = false;
 
 static std::vector<sfz::LFODescription> lfoDescriptionFromSfzFile(const fs::path &sfzPath, bool &success)
 {
@@ -59,6 +66,8 @@ int main(int argc, char* argv[])
     options.add_options()
         ("s,samplerate", "Sample rate", cxxopts::value(sampleRate))
         ("d,duration", "Duration", cxxopts::value(duration))
+        ("o,output", "Output file", cxxopts::value(outputFilename))
+        ("F,flac", "Save output as FLAC", cxxopts::value(saveFlac))
         ("h,help", "Print usage")
     ;
     options.positional_help("sfz-file");
@@ -119,11 +128,72 @@ int main(int argc, char* argv[])
         lfos[l].process(lfoOutputs[l]);
     }
 
-    for (size_t i = 0; i < numFrames; ++i) {
-        std::cout << (i / sampleRate);
-        for (size_t l = 0; l < numLfos; ++l)
-            std::cout << ' ' << lfoOutputs[l][i];
-        std::cout << '\n';
+    if (saveFlac) {
+        if (outputFilename.empty()) {
+            std::cerr << "Please indicate the audio file to save.\n";
+            return 1;
+        }
+
+        fs::path outputPath = fs::u8path(outputFilename);
+        SndfileHandle snd(
+#ifndef _WIN32
+            outputPath.c_str(),
+#else
+            outputPath.wstring().c_str(),
+#endif
+            SFM_WRITE, SF_FORMAT_FLAC|SF_FORMAT_PCM_16, numLfos, sampleRate);
+
+        std::unique_ptr<float[]> frame(new float[numLfos]);
+        size_t numClips = 0;
+
+        for (size_t i = 0; i < numFrames; ++i) {
+            for (size_t l = 0; l < numLfos; ++l) {
+                float orig = lfoOutputs[l][i];
+                float clamped = clamp(orig, -1.0f, 1.0f);
+                numClips += clamped != orig;
+                frame[l] = clamped;
+            }
+            snd.writef(frame.get(), 1);
+        }
+        snd.writeSync();
+
+        if (snd.error()) {
+            std::error_code ec;
+            fs::remove(outputPath, ec);
+            std::cerr << "Could not save audio to the output file.\n";
+            return 1;
+        }
+
+        if (numClips > 0)
+            std::cerr << "Warning: the audio output has been clipped on " << numClips << " frames.\n";
+    }
+    else {
+        std::ostream* os = &std::cout;
+        fs::ofstream of;
+
+        fs::path outputPath;
+        if (!outputFilename.empty()) {
+            outputPath = fs::u8path(outputFilename);
+            of.open(outputPath);
+            os = &of;
+        }
+
+        for (size_t i = 0; i < numFrames; ++i) {
+            *os << (i / sampleRate);
+            for (size_t l = 0; l < numLfos; ++l)
+                *os << ' ' << lfoOutputs[l][i];
+            *os << '\n';
+        }
+
+        if (os == &of) {
+            of.flush();
+            if (!of) {
+                std::error_code ec;
+                fs::remove(outputPath, ec);
+                std::cerr << "Could not save data to the output file.\n";
+                return 1;
+            }
+        }
     }
 
     return 0;