private void ResetStream(bool hardReset)
{
if (position > byteMappings.Omega.To)
{
throw new Exception("position beyond length");
}
length = byteMappings.Omega.To;
byteMappings.SetWarpedPosition(position);
ByteTimeWarp mL = byteMappings.Lower;
ByteTimeWarp mH = byteMappings.Upper;
if (cropStream == null || cropStream.Begin != mL.From || cropStream.End != mH.From || resamplingStream.Length != byteMappings.Omega.To)
{
// mapping has changed, stream subsection must be renewed
if (hardReset)
{
// Each internal stream for each warped/resampled section works on the same underlying source stream, so
// we add the SourceClosePreventionStream to avoid the source being closed when an internally used stream
// of a section is disposed or closed (as in the call below). The source stream continues to get closed
// when this stream is closed.
cropStream = new CropStream(new SourceClosePreventionStream(sourceStream), mL.From, mH.From);
// Get rid of stream for previous section
if (resamplingStream != null)
{
resamplingStream.Close();
}
// Create stream for current section
resamplingStream = new ResamplingStream(cropStream, ResamplingQuality.VariableRate, ByteTimeWarp.CalculateSampleRateRatio(mL, mH));
resamplingStream.Position = position - mL.To;
}
else
{
// Reset the streams to the new conditions without creating new instances as the hard reset does
// NOTE always hard resetting works too, but this mode has been added to keep the sample resampler throughout playback
// Reset crop stream to source bounds, else the successive setting of begin and end can fail if
// the new begin position is after the old end position and the validation in the crop stream fails
cropStream.Begin = 0;
cropStream.End = sourceStream.Length;
// Reset the crop stream to the new bounds
cropStream.Begin = mL.From;
cropStream.End = mH.From;
cropStream.Position = 0;
// Reset the resampling stream
resamplingStream.SampleRateRatio = ByteTimeWarp.CalculateSampleRateRatio(mL, mH);
resamplingStream.Position = position - mL.To;
}
}
}
private void ResetStream(bool hardReset)
{
if (position > byteMappings.Omega.To)
{
throw new Exception("position beyond length");
}
length = byteMappings.Omega.To;
byteMappings.SetWarpedPosition(position);
ByteTimeWarp mL = byteMappings.Lower;
ByteTimeWarp mH = byteMappings.Upper;
if (cropStream == null || cropStream.Begin != mL.From || cropStream.End != mH.From || resamplingStream.Length != byteMappings.Omega.To)
{
// mapping has changed, stream subsection must be renewed
if (hardReset)
{
cropStream = new CropStream(sourceStream, mL.From, mH.From);
if (resamplingStream != null)
{
resamplingStream.Close();
}
resamplingStream = new ResamplingStream(cropStream, ResamplingQuality.VariableRate, ByteTimeWarp.CalculateSampleRateRatio(mL, mH));
resamplingStream.Position = position - mL.To;
}
else
{
// Reset the streams to the new conditions without creating new instances as the hard reset does
// NOTE always hard resetting works too, but this mode has been added to keep the sample resampler throughout playback
// Reset crop stream to source bounds, else the successive setting of begin and end can fail if
// the new begin position is after the old end position and the validation in the crop stream fails
cropStream.Begin = 0;
cropStream.End = sourceStream.Length;
// Reset the crop stream to the new bounds
cropStream.Begin = mL.From;
cropStream.End = mH.From;
cropStream.Position = 0;
// Reset the resampling stream
resamplingStream.SampleRateRatio = ByteTimeWarp.CalculateSampleRateRatio(mL, mH);
resamplingStream.Position = position - mL.To;
}
}
}
private void mappings_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
{
var alpha = new ByteTimeWarp {
From = 0, To = 0
};
var omega = new ByteTimeWarp {
From = sourceStream.Length, To = sourceStream.Length
};
if (mappings.Count > 0)
{
// Convert time mappings to byte mappings
// This is the place where the TimeWarps and ByteTimeWarps are kept in sync!!
byteMappings = new ByteTimeWarpCollection(mappings.Count);
foreach (TimeWarp mapping in mappings)
{
byteMappings.Add(ByteTimeWarp.Convert(mapping, Properties));
}
var first = byteMappings.Alpha;
if (first.From > alpha.From)
{
// The first mapping is not at the start of the stream, insert start of stream alpha
byteMappings.Insert(0, alpha);
}
var last = byteMappings.Omega;
if (last.From < omega.From)
{
// The last mapping is not at the end of the stream, insert EOS omega
omega.To += last.Offset;
byteMappings.Insert(byteMappings.Count, omega);
}
}
else
{
byteMappings.Add(alpha);
byteMappings.Add(omega);
}
if (position > byteMappings.Omega.To)
{
Position = byteMappings.Omega.To;
}
ResetStream();
}
public static double CalculateSampleRateRatio(ByteTimeWarp mL, ByteTimeWarp mH)
{
return((mH.To - mL.To) / (double)(mH.From - mL.From));
}
