/// <summary>
/// Perform channel swapping while exporting to a file.
/// </summary>
void ExportProcess(string path)
{
int channels = reader.ChannelCount;
int[] targetIndexes = new int[channels];
for (int i = 0; i < channels; ++i)
{
targetIndexes[i] = -1;
for (int j = 0; j < channels; ++j)
{
if ((ReferenceChannel)sourceChannels.Items[i] == (ReferenceChannel)targetChannels.Items[j])
{
targetIndexes[i] = j;
}
}
}
using RIFFWaveWriter writer = new(path, channels, reader.Length, reader.SampleRate, reader.Bits);
reader.Reset();
writer.WriteHeader();
long position = 0,
end = channels * reader.Length;
float[] source = new float[channels * reader.SampleRate],
target = new float[source.Length];
while (position < end)
{
long stepSize = Math.Min(source.Length, end - position);
reader.ReadBlock(source, 0, stepSize);
Array.Clear(target, 0, (int)stepSize);
for (int ch = 0; ch < channels; ++ch)
{
int targetIndex = targetIndexes[ch];
if (targetIndex == -1)
{
continue;
}
for (int sample = ch, pair = targetIndex; sample < source.Length; sample += channels, pair += channels)
{
target[pair] = source[sample];
}
}
writer.WriteBlock(target, 0, stepSize);
position += stepSize;
double progress = position / (double)end;
process.UpdateStatusLazy($"Exporting... ({progress:0.00%})");
process.UpdateProgressBar(progress);
}
process.UpdateStatus("Finished!");
process.UpdateProgressBar(1);
}
float[] Read(RIFFWaveReader reader, string instrument, double progressGap)
{
const long sampleBlock = 8192;
double progressSrc = task.Progress;
float[] read = new float[reader.Length * reader.ChannelCount];
for (long sample = 0; sample < read.LongLength;)
{
double progress = sample / (double)read.LongLength;
reader.ReadBlock(read, sample, Math.Min(sample += sampleBlock, read.LongLength));
task.UpdateProgressBar(progressSrc + progressGap * progress);
task.UpdateStatusLazy(string.Format("Reading {0} ({1})...", instrument, progress.ToString("0.00%")));
}
task.UpdateProgressBar(progressSrc + progressGap);
task.UpdateStatus(string.Format("Reading {0} (100%)...", instrument));
reader.Dispose();
return(read);
}