Removed recording duration limitation:

- Limit WAV size to 2GB for maximum compatibility,
- Continue recording on another file when size gets too big (XXX_001.wav, then XXX_002.wav and so on)
- The sequence assure up to 2000GB worth of recording which should be enough
- Changed file pattern to international Year.Month.Day so its recognizable whether you are English of French or whatever :)

src/audio/AudioFile.cpp

@@ -3,6 +3,8 @@
 
 #include "AudioFile.h"
 #include "CubicSDR.h"
+#include <iomanip>
+#include <sstream>
 
 AudioFile::AudioFile() {
 
@@ -16,7 +18,8 @@ void AudioFile::setOutputFileName(std::string filename) {
     filenameBase = filename;
 }
 
-std::string AudioFile::getOutputFileName() {
+std::string AudioFile::getOutputFileName(int sequenceNumber) {
+
     std::string recPath = wxGetApp().getConfig()->getRecordingPath();
 
     // Strip any invalid characters from the name
@@ -30,16 +33,23 @@ std::string AudioFile::getOutputFileName() {
     }
     
     // Create output file name
-    std::string outputFileName = recPath + filePathSeparator + filenameBaseSafe + "." + getExtension();
+	std::stringstream outputFileName;
+	outputFileName << recPath << filePathSeparator << filenameBaseSafe;
+
+	if (sequenceNumber > 0) {
+		outputFileName << "_" << std::setfill('0') << std::setw(3) << sequenceNumber;
+	}
 
     int idx = 0;
 
     // If the file exists; then find the next non-existing file in sequence.
-    while (FILE *file = fopen(outputFileName.c_str(), "r")) {
+	std::string fileNameCandidate = outputFileName.str();
+
+    while (FILE *file = fopen((fileNameCandidate + "." + getExtension()).c_str(), "r")) {
         fclose(file);
-        outputFileName = recPath + filePathSeparator + filenameBaseSafe + "-" + std::to_string(++idx) + "." + getExtension();
+		fileNameCandidate = outputFileName.str() +  "-" + std::to_string(++idx);
     }
 
-    return outputFileName;
+    return fileNameCandidate + "." + getExtension();
 }
 

src/audio/AudioFile.h

@@ -14,7 +14,7 @@ public:
 
     virtual void setOutputFileName(std::string filename);
     virtual std::string getExtension() = 0;
-    virtual std::string getOutputFileName();
+    virtual std::string getOutputFileName(int sequenceNumber = 0);
 
     virtual bool writeToFile(AudioThreadInputPtr input) = 0;
     virtual bool closeFile() = 0;

src/audio/AudioFileWAV.cpp

@@ -3,6 +3,8 @@
 
 #include "AudioFileWAV.h"
 
+//limit file size to 2GB (- margin) for maximum compatibility.
+#define MAX_WAV_FILE_SIZE (0x7FFFFFFF - 1024)
 
 // Simple endian io read/write handling from 
 // http://www.cplusplus.com/forum/beginner/31584/#msg171056
@@ -61,44 +63,34 @@ std::string AudioFileWAV::getExtension()
 bool AudioFileWAV::writeToFile(AudioThreadInputPtr input)
 {
     if (!outputFileStream.is_open()) {
-        std::string ofName = getOutputFileName();
+        std::string ofName = getOutputFileName(currentSequenceNumber);
                 
         outputFileStream.open(ofName.c_str(), std::ios::binary);
 
-        // Based on simple wav file output code from
-        // http://www.cplusplus.com/forum/beginner/166954/
-
-        // Write the wav file headers
-        outputFileStream << "RIFF----WAVEfmt "; // (chunk size to be filled in later)
-        write_word(outputFileStream, 16, 4); // no extension data
-        write_word(outputFileStream, 1, 2); // PCM - integer samples
-        write_word(outputFileStream, input->channels, 2); // channels
-        write_word(outputFileStream, input->sampleRate, 4); // samples per second (Hz)
-        write_word(outputFileStream, (input->sampleRate * 16 * input->channels) / 8, 4); // (Sample Rate * BitsPerSample * Channels) / 8
-        write_word(outputFileStream, input->channels * 2, 2); // data block size (size of integer samples, one for each channel, in bytes)
-        write_word(outputFileStream, 16, 2); // number of bits per sample (use a multiple of 8)
-
-        // Write the data chunk header
-        dataChunkPos = outputFileStream.tellp();
-        outputFileStream << "data----";  // (chunk size to be filled in later)
+		writeHeaderToFileStream(input);
     }
 
-    // Prevent clipping
-    float intScale = (input->peak < 1.0) ? 32767.0f : (32767.0f / input->peak);
+	size_t maxRoomInCurrentFileInSamples = getMaxWritableNumberOfSamples(input);
 
-    if (input->channels == 1) {
-        for (size_t i = 0, iMax = input->data.size(); i < iMax; i++) {
-            write_word(outputFileStream, int(input->data[i] * intScale), 2);
-        }
-    }
-    else if (input->channels == 2) {
-        for (size_t i = 0, iMax = input->data.size() / 2; i < iMax; i++) {
-            write_word(outputFileStream, int(input->data[i * 2] * intScale), 2);
-            write_word(outputFileStream, int(input->data[i * 2 + 1] * intScale), 2);
-        }
+	if (maxRoomInCurrentFileInSamples >= input->data.size()) {
+		writePayloadToFileStream(input, 0, input->data.size());
 	}
+	else {
+		//we complete the current file and open another:
+		writePayloadToFileStream(input, 0, maxRoomInCurrentFileInSamples);
 
-    // TODO: Periodically update the RIFF/data chunk size in case of crash?
+		closeFile();
+
+		// Open a new file with the next sequence number, and dump the rest of samples in it.
+		currentSequenceNumber++;
+		currentFileSize = 0;
+
+		std::string ofName = getOutputFileName(currentSequenceNumber);
+		outputFileStream.open(ofName.c_str(), std::ios::binary);
+		
+		writeHeaderToFileStream(input);
+		writePayloadToFileStream(input, maxRoomInCurrentFileInSamples, input->data.size());
+	}
 
     return true;
 }
@@ -121,3 +113,56 @@ bool AudioFileWAV::closeFile()
 
     return true;
 }
+
+void AudioFileWAV::writeHeaderToFileStream(AudioThreadInputPtr input) {
+
+	// Based on simple wav file output code from
+	// http://www.cplusplus.com/forum/beginner/166954/
+
+	// Write the wav file headers
+	outputFileStream << "RIFF----WAVEfmt "; // (chunk size to be filled in later)
+	write_word(outputFileStream, 16, 4); // no extension data
+	write_word(outputFileStream, 1, 2); // PCM - integer samples
+	write_word(outputFileStream, input->channels, 2); // channels
+	write_word(outputFileStream, input->sampleRate, 4); // samples per second (Hz)
+	write_word(outputFileStream, (input->sampleRate * 16 * input->channels) / 8, 4); // (Sample Rate * BitsPerSample * Channels) / 8
+	write_word(outputFileStream, input->channels * 2, 2); // data block size (size of integer samples, one for each channel, in bytes)
+	write_word(outputFileStream, 16, 2); // number of bits per sample (use a multiple of 8)
+
+										 // Write the data chunk header
+	dataChunkPos = outputFileStream.tellp();
+	currentFileSize = dataChunkPos;
+	outputFileStream << "data----";  // (chunk size to be filled in later)
+}
+
+void AudioFileWAV::writePayloadToFileStream(AudioThreadInputPtr input, size_t startInputPosition, size_t endInputPosition) {
+
+	// Prevent clipping
+	float intScale = (input->peak < 1.0) ? 32767.0f : (32767.0f / input->peak);
+
+	if (input->channels == 1) {
+		for (size_t i = startInputPosition, iMax = endInputPosition; i < iMax; i++) {
+
+			write_word(outputFileStream, int(input->data[i] * intScale), 2);
+			
+			currentFileSize += 2;
+		}
+	}
+	else if (input->channels == 2) {
+		for (size_t i = startInputPosition, iMax = endInputPosition / 2; i < iMax; i++) {
+
+			write_word(outputFileStream, int(input->data[i * 2] * intScale), 2);
+			write_word(outputFileStream, int(input->data[i * 2 + 1] * intScale), 2);
+
+			currentFileSize += 4;
+		}
+	}
+}
+
+size_t AudioFileWAV::getMaxWritableNumberOfSamples(AudioThreadInputPtr input) {
+
+	long long remainingBytesInFile = (long long)(MAX_WAV_FILE_SIZE) - currentFileSize;
+
+    return (size_t)(remainingBytesInFile / (input->channels * 2));
+	
+}

src/audio/AudioFileWAV.h

@@ -21,4 +21,15 @@ public:
 protected:
     std::ofstream outputFileStream;
     size_t dataChunkPos;
+	long long currentFileSize = 0;
+	int currentSequenceNumber = 0;
+
+private:
+
+	size_t getMaxWritableNumberOfSamples(AudioThreadInputPtr input);
+
+	void writeHeaderToFileStream(AudioThreadInputPtr input);
+
+	//write [startInputPosition; endInputPosition[ samples from input into the file.
+	void writePayloadToFileStream(AudioThreadInputPtr input, size_t startInputPosition, size_t endInputPosition);
 };

src/demod/DemodulatorInstance.cpp

@@ -648,7 +648,8 @@ void DemodulatorInstance::startRecording() {
     //    fileName << "_" << std::put_time(&ltm, "%d-%m-%Y_%H-%M-%S");
     
     char timeStr[512];
-    strftime(timeStr, sizeof(timeStr), "%d-%m-%Y_%H-%M-%S", &ltm);
+	//International format: Year.Month.Day, also lexicographically sortable
+    strftime(timeStr, sizeof(timeStr), "%Y-%m-%d_%H-%M-%S", &ltm);
     fileName << "_" << timeStr;