private void InitializeHeader()
{
try
{
lock (_randomAccessLock)
{
_randomAccessWriter = new RandomAccessFile(_filePath, "rw");
_randomAccessWriter.SetLength(0);
// Set file length to 0, to prevent unexpected behavior in case the file already existed
_randomAccessWriter.WriteBytes("RIFF");
_randomAccessWriter.WriteInt(0); // Final file size not known yet, write 0
_randomAccessWriter.WriteBytes("WAVE");
_randomAccessWriter.WriteBytes("fmt ");
_randomAccessWriter.WriteInt(Integer.ReverseBytes(16)); // Sub-chunk size, 16 for PCM
_randomAccessWriter.WriteShort(Short.ReverseBytes(1)); // AudioFormat, 1 for PCM
_randomAccessWriter.WriteShort(Short.ReverseBytes(Channels)); // Number of channels, 1 for mono, 2 for stereo
_randomAccessWriter.WriteInt(Integer.ReverseBytes(_sampleRate)); // Sample rate
_randomAccessWriter.WriteInt(Integer.ReverseBytes(_sampleRate * FmtAvgBps * Channels / 8));
// Byte rate, SampleRate*NumberOfChannels*BitsPerSample/8
_randomAccessWriter.WriteShort(Short.ReverseBytes(Channels * FmtAvgBps / 8));
// Block align, NumberOfChannels*BitsPerSample/8
_randomAccessWriter.WriteShort(Short.ReverseBytes(FmtAvgBps)); // Bits per sample
_randomAccessWriter.WriteBytes("data");
_randomAccessWriter.WriteInt(0); // Data chunk size not known yet, write 0
}
}
catch (NullReferenceException e)
{
Log.Debug(Tag, e.Message + e.StackTrace);
State = WavRecorderState.Error;
}
}
