public void MixToFile(string filename, bool applyReplayGain)
{
Console.WriteLine("Mixing per-channel data...");
Console.WriteLine("Computing ReplayGain...");
// Mix the audio. We should probably not be re-reading it here... we could do this in the same pass as loading.
foreach (var reader in _data.Select(channel => channel.WavReader))
{
reader.Position = 0;
}
if (applyReplayGain)
{
// We read it in a second at a time, to calculate Replay Gains
var mixer = new MixingSampleProvider(_data.Select(channel => channel.WavReader.ToSampleProvider().ToStereo()));
var buffer = new float[mixer.WaveFormat.SampleRate * 2];
var replayGain = new TrackGain(SampleRate);
for (;;)
{
int numRead = mixer.Read(buffer, 0, buffer.Length);
if (numRead == 0)
{
break;
}
// And analyze
replayGain.AnalyzeSamples(buffer, numRead);
}
// The +3 is to make it at "YouTube loudness", which is a lot louder than ReplayGain defaults to.
var gain = replayGain.GetGain() + 3;
Console.WriteLine($"Applying ReplayGain ({gain:N} dB) and saving to {filename}");
// Reset the readers again
foreach (var reader in _data.Select(channel => channel.WavReader))
{
reader.Position = 0;
}
mixer = new MixingSampleProvider(_data.Select(channel => channel.WavReader.ToSampleProvider().ToStereo()));
var amplifier = new VolumeSampleProvider(mixer)
{
Volume = (float)Math.Pow(10, gain / 20)
};
WaveFileWriter.CreateWaveFile(filename, amplifier.ToWaveProvider());
}
else
{
var mixer = new MixingSampleProvider(_data.Select(channel => channel.WavReader.ToSampleProvider().ToStereo()));
WaveFileWriter.CreateWaveFile(filename, mixer.ToWaveProvider());
}
}
public static void MixToFile(IList <Channel> channels, string filename, bool applyReplayGain)
{
Console.WriteLine("Mixing per-channel data...");
// We make new readers...
var readers = new List <WaveFileReader>();
try
{
readers.AddRange(channels.Select(c => new WaveFileReader(c.Filename)));
if (applyReplayGain)
{
Console.WriteLine("Computing ReplayGain...");
// We read it in a second at a time, to calculate Replay Gains
var mixer = new MixingSampleProvider(readers.Select(x => x.ToSampleProvider().ToStereo()));
const int sampleRate = 44100;
var resampler = new WdlResamplingSampleProvider(mixer, sampleRate);
// We use a 1s buffer...
var buffer = new float[sampleRate * 2]; // *2 for stereo
var replayGain = new TrackGain(sampleRate);
for (;;)
{
int numRead = resampler.Read(buffer, 0, buffer.Length);
if (numRead == 0)
{
break;
}
// And analyze
replayGain.AnalyzeSamples(buffer, numRead);
}
// The +3 is to make it at "YouTube loudness", which is a lot louder than ReplayGain defaults to.
// TODO make this configurable?
var gain = replayGain.GetGain() + 3;
Console.WriteLine($"Applying ReplayGain ({gain:N} dB) and saving to {filename}");
// Reset the readers
foreach (var reader in readers)
{
reader.Position = 0;
}
// We make a new mixer just in case resetting the previous one is problematic...
mixer = new MixingSampleProvider(readers.Select(x => x.ToSampleProvider().ToStereo()));
var amplifier = new VolumeSampleProvider(mixer)
{
Volume = (float)Math.Pow(10, gain / 20)
};
WaveFileWriter.CreateWaveFile(filename, amplifier.ToWaveProvider());
}
else
{
var mixer = new MixingSampleProvider(readers.Select(x => x.ToSampleProvider().ToStereo()));
WaveFileWriter.CreateWaveFile(filename, mixer.ToWaveProvider());
}
}
finally
{
foreach (var reader in readers)
{
reader.Dispose();
}
}
}