public WaveFormGeneratorData Generate(IOutputStream stream)
{
return(this.Cache.GetOrCreate(
stream,
this.Resolution.Value,
() =>
{
var length = Convert.ToInt32(
Math.Ceiling(
stream.GetDuration(stream.Length).TotalMilliseconds / this.Resolution.Value
)
);
var data = new WaveFormGeneratorData()
{
Resolution = this.Resolution.Value,
Data = new WaveFormDataElement[length, stream.Channels],
Position = 0,
Capacity = length,
Peak = 0,
Channels = stream.Channels,
CancellationToken = new CancellationToken(),
};
this.Dispatch(() => this.Populate(stream, data));
return data;
}
));
}
private static void PopulateFloat(IOutputStream stream, WaveFormGeneratorData data)
{
var duration = TimeSpan.FromMilliseconds(data.Resolution);
var buffer = stream.GetBuffer <float>(duration);
var interval = data.Capacity / 10;
Logger.Write(typeof(WaveFormGenerator), LogLevel.Debug, "Creating 32 bit wave form for file \"{0}\" with resolution of {1}ms", stream.FileName, duration.TotalMilliseconds);
do
{
var length = stream.GetData(buffer) / sizeof(float);
if (length <= 0)
{
break;
}
if (data.Position >= data.Capacity)
{
break;
}
for (var a = 0; a < length; a += data.Channels)
{
for (var b = 0; b < data.Channels; b++)
{
var value = buffer[a + b];
data.Data[data.Position, b].Min = Math.Min(data.Data[data.Position, b].Min, value);
data.Data[data.Position, b].Max = Math.Max(data.Data[data.Position, b].Max, value);
data.Data[data.Position, b].Rms += value * value;
}
}
for (var a = 0; a < data.Channels; a++)
{
data.Data[data.Position, a].Rms = Convert.ToSingle(
Math.Sqrt(data.Data[data.Position, a].Rms / (length / data.Channels))
);
data.Peak = Math.Max(
data.Peak,
Math.Max(
Math.Abs(data.Data[data.Position, a].Min),
Math.Abs(data.Data[data.Position, a].Max)
)
);
}
data.Position++;
if (data.Position % interval == 0)
{
data.Update();
}
} while (!data.CancellationToken.IsCancellationRequested);
}
protected virtual async Task Populate(IOutputStream stream, WaveFormGeneratorData data)
{
using (var duplicated = await this.Output.Duplicate(stream).ConfigureAwait(false))
{
if (duplicated == null)
{
Logger.Write(this, LogLevel.Warn, "Failed to duplicate stream for file \"{0}\", cannot generate.", stream.FileName);
return;
}
switch (duplicated.Format)
{
case OutputStreamFormat.Short:
PopulateShort(duplicated, data);
break;
case OutputStreamFormat.Float:
PopulateFloat(duplicated, data);
break;
default:
throw new NotImplementedException();
}
}
if (data.CancellationToken.IsCancellationRequested)
{
Logger.Write(typeof(WaveFormGenerator), LogLevel.Debug, "Wave form generation for file \"{0}\" was cancelled.", stream.FileName);
this.Cache.Remove(stream, data.Resolution);
return;
}
data.Update();
Logger.Write(typeof(WaveFormGenerator), LogLevel.Debug, "Wave form generated for file \"{0}\" with {1} elements: Peak = {2:0.00}", stream.FileName, data.Capacity, data.Peak);
try
{
this.Cache.Save(stream, data);
}
catch (Exception e)
{
Logger.Write(typeof(WaveFormGenerator), LogLevel.Warn, "Failed to save wave form data for file \"{0}\": {1}", stream.FileName, e.Message);
}
}
