static void OutputPSGSamples(SN76489 psg, WaveFileWriter writer, int sampleCount)
{
for (int i = 0; i < sampleCount; i++)
{
_psgUpdateClock += _psgClocksPerSample;
uint updateCycles = (uint)_psgUpdateClock; // truncate to get integer clock value, keeping the decimal part to accumulate
psg.Update(updateCycles);
if (!_options.MultiChannelOutput)
{
var(left, right) = psg.Output;
writer.WriteSample(left);
writer.WriteSample(right);
}
else
{
writer.WriteSample(psg.Channel0Output);
writer.WriteSample(psg.Channel1Output);
writer.WriteSample(psg.Channel2Output);
writer.WriteSample(psg.Channel3Output);
}
_psgUpdateClock -= updateCycles;
}
}
static void Main(string[] args)
{
_options = Options.ParseCommandLine(args);
string vgmPath = _options.Filename;
if (!File.Exists(vgmPath))
{
Console.WriteLine($"File {vgmPath} not found.");
return;
}
string vgmFileName = Path.GetFileNameWithoutExtension(vgmPath);
VgmFile vgmFile;
using (var fileStream = File.Open(vgmPath, FileMode.Open, FileAccess.Read))
{
vgmFile = VgmFile.Load(fileStream);
}
if (_options.PrintVgmInfo)
{
Console.WriteLine($"Filename: {Path.GetFileName(vgmPath)}");
Console.WriteLine();
Console.WriteLine($"Track: {vgmFile.Gd3.English.TrackName}");
Console.WriteLine($"Game: {vgmFile.Gd3.English.GameName}");
Console.WriteLine($"System: {vgmFile.Gd3.English.SystemName}");
Console.WriteLine($"Composer: {vgmFile.Gd3.English.TrackAuthor}");
Console.WriteLine($"Release: {vgmFile.Gd3.ReleaseDate}");
Console.WriteLine($"VGM By: {vgmFile.Gd3.VgmAuthor}");
Console.WriteLine();
Console.WriteLine("Notes:");
Console.WriteLine(vgmFile.Gd3.Notes);
Console.WriteLine();
}
// generate the audio samples into a memory stream
using (var writer = new WaveFileWriter(File.Open($"{vgmFileName}.wav", FileMode.Create),
new WaveFormat(_sampleRate, 16, (ushort)(_options.MultiChannelOutput ? 4 : 2))))
{
var psg = new SN76489(vgmFile.Header.SN76489ShiftRegisterWidth, vgmFile.Header.SN76489Feedback);
_psgClocksPerSample = vgmFile.Header.SN76489Clock / (double)_sampleRate;
bool playing = true;
int loopLimit = 0;
int loopCount = 0;
uint playCursor = 0;
while (playing)
{
byte command = vgmFile.VgmData[playCursor++];
switch (command)
{
// 0x50 dd: PSG(SN76489 / SN76496) write value dd
case VgmCommand.PSGWriteDD:
psg.WriteData(vgmFile.VgmData[playCursor++]);
break;
//0x61 nn nn : Wait n samples, n can range from 0 to 65535 (approx 1.49
// seconds). Longer pauses than this are represented by multiple
// wait commands.
case VgmCommand.WaitNSamples:
int sampleCount = vgmFile.VgmData[playCursor++];
sampleCount |= vgmFile.VgmData[playCursor++] << 8;
OutputPSGSamples(psg, writer, sampleCount);
break;
// 0x62: wait 735 samples(60th of a second), a shortcut for 0x61 0xdf 0x02
case VgmCommand.Wait735Samples:
OutputPSGSamples(psg, writer, 735);
break;
// 0x63: wait 882 samples(50th of a second), a shortcut for 0x61 0x72 0x03
case VgmCommand.Wait882Samples:
OutputPSGSamples(psg, writer, 882);
break;
// 0x66: end of sound data
case VgmCommand.EndOfSoundData:
if (vgmFile.LoopOffset != 0 && loopCount < loopLimit)
{
playCursor = vgmFile.LoopOffset;
loopCount++;
}
else
{
playing = false;
}
break;
// 0x7n: wait n+1 samples, n can range from 0 to 15.
case VgmCommand.Wait01Samples:
case VgmCommand.Wait02Samples:
case VgmCommand.Wait03Samples:
case VgmCommand.Wait04Samples:
case VgmCommand.Wait05Samples:
case VgmCommand.Wait06Samples:
case VgmCommand.Wait07Samples:
case VgmCommand.Wait08Samples:
case VgmCommand.Wait09Samples:
case VgmCommand.Wait10Samples:
case VgmCommand.Wait11Samples:
case VgmCommand.Wait12Samples:
case VgmCommand.Wait13Samples:
case VgmCommand.Wait14Samples:
case VgmCommand.Wait15Samples:
case VgmCommand.Wait16Samples:
OutputPSGSamples(psg, writer, (command & 0x0F) + 1);
break;
// game gear stereo shift, ignore for now
case 0x4F:
int stereoByte = vgmFile.VgmData[playCursor++];
Console.WriteLine($"GG Stereo Write: 0x{stereoByte:X2}");
break;
default:
Console.Error.WriteLine("Unknown command: 0x{0:X2} at 0x{1:X4}", command, playCursor - 1);
playing = false;
break;
}
}
}
if (Debugger.IsAttached)
{
Console.Write("Press any key to continue...");
Console.ReadKey(true);
}
}