/// <summary>
/// Generates a signal.
/// </summary>
/// <returns>The signal.</returns>
public override float Generate()
{
switch (WindowType)
{
case WindowType.None:
this.windowMethod = null;
break;
case WindowType.Hann:
this.windowMethod = Hann;
break;
case WindowType.Cosine:
this.windowMethod = Cosine;
break;
case WindowType.Rectangular:
this.windowMethod = Rectangular;
break;
case WindowType.Triangular:
this.windowMethod = Triangular;
break;
case WindowType.BlackmanHarris:
this.windowMethod = BlackmanHarris;
break;
case WindowType.BlackmanNutall:
this.windowMethod = BlackmanNutall;
break;
case WindowType.Gauss:
this.windowMethod = Gauss;
break;
default:
this.windowMethod = null;
break;
}
this.CurrentSample = this.windowMethod != null ? (float)this.windowMethod(this.Phase) : 0f;
this.Phase += this.increment;
if (this.Phase >= 1.0)
{
this.Phase -= 1.0;
}
return(this.CurrentSample);
}
public static double GetWindow(int i, int signalLength, double windowLen, WindowMethod windowType)
{
var pos = i / (double)signalLength;
if (pos < 1 - windowLen)
{
return(1.0);
}
if (i >= signalLength)
{
return(0.0);
}
if (windowLen < 0.002) // no effect of tiny window
{
return(1.0);
}
var posInWindow = (pos - (1 - windowLen)) / windowLen;
if (windowType == WindowMethod.Truncate)
{
return(0.0);
}
if (windowType == WindowMethod.Linear)
{
return(1 - posInWindow);
}
if (windowType == WindowMethod.Logarithmic)
{
return(AudioLib.Utils.DB2gain(-posInWindow * 60));
}
if (windowType == WindowMethod.Cosine)
{
return((Math.Cos(posInWindow * Math.PI) + 1) * 0.5);
}
return(1.0);
}
public void Validate()
{
if (this.GetEncoderModeIndex() < 0)
{
throw new Exception("unsupported encoder mode");
}
this.SetDefaultValuesForMode();
if (Padding < 0)
{
throw new Exception("unsupported padding value " + Padding.ToString());
}
if (BlockSize != 0 && (BlockSize < 256 || BlockSize >= FlakeConstants.MAX_BLOCKSIZE))
{
throw new Exception("unsupported block size " + BlockSize.ToString());
}
if (MinLPCOrder > MaxLPCOrder || MaxLPCOrder > lpc.MAX_LPC_ORDER)
{
throw new Exception("invalid MaxLPCOrder " + MaxLPCOrder.ToString());
}
if (MinFixedOrder < 0 || MinFixedOrder > 4)
{
throw new Exception("invalid MinFixedOrder " + MinFixedOrder.ToString());
}
if (MaxFixedOrder < 0 || MaxFixedOrder > 4)
{
throw new Exception("invalid MaxFixedOrder " + MaxFixedOrder.ToString());
}
if (MinPartitionOrder < 0)
{
throw new Exception("invalid MinPartitionOrder " + MinPartitionOrder.ToString());
}
if (MinPartitionOrder > MaxPartitionOrder || MaxPartitionOrder > 8)
{
throw new Exception("invalid MaxPartitionOrder " + MaxPartitionOrder.ToString());
}
if (PredictionType == PredictionType.None)
{
throw new Exception("invalid PredictionType " + PredictionType.ToString());
}
if (PredictionType != PredictionType.Fixed)
{
if (WindowMethod == WindowMethod.Invalid)
{
throw new InvalidOperationException("invalid WindowMethod " + WindowMethod.ToString());
}
if (WindowFunctions == WindowFunction.None)
{
throw new InvalidOperationException("invalid WindowFunctions " + WindowFunctions.ToString());
}
if (EstimationDepth > 32 || EstimationDepth < 1)
{
throw new InvalidOperationException("invalid EstimationDepth " + EstimationDepth.ToString());
}
if (MinPrecisionSearch < 0 || MinPrecisionSearch >= lpc.MAX_LPC_PRECISIONS)
{
throw new Exception("unsupported MinPrecisionSearch value");
}
if (MaxPrecisionSearch < 0 || MaxPrecisionSearch >= lpc.MAX_LPC_PRECISIONS)
{
throw new Exception("unsupported MaxPrecisionSearch value");
}
if (MaxPrecisionSearch < MinPrecisionSearch)
{
throw new Exception("unsupported MaxPrecisionSearch value");
}
}
if (!AllowNonSubset && !IsSubset())
{
throw new Exception("the encoding parameters specified do not conform to the FLAC Subset");
}
}
public int flake_set_defaults(int lvl)
{
compression = lvl;
if ((lvl < 0 || lvl > 12) && (lvl != 99))
{
return -1;
}
// default to level 5 params
window_function = WindowFunction.Flattop | WindowFunction.Tukey;
order_method = OrderMethod.Akaike;
stereo_method = StereoMethod.Evaluate;
window_method = WindowMethod.Evaluate;
block_size = 0;
block_time_ms = 105;
prediction_type = PredictionType.Search;
min_prediction_order = 1;
max_prediction_order = 12;
estimation_depth = 1;
min_fixed_order = 2;
max_fixed_order = 2;
min_partition_order = 0;
max_partition_order = 8;
variable_block_size = 0;
lpc_min_precision_search = 1;
lpc_max_precision_search = 1;
do_seektable = true;
// differences from level 7
switch (lvl)
{
case 0:
block_time_ms = 53;
prediction_type = PredictionType.Fixed;
stereo_method = StereoMethod.Independent;
max_partition_order = 6;
break;
case 1:
prediction_type = PredictionType.Levinson;
stereo_method = StereoMethod.Independent;
window_function = WindowFunction.Bartlett;
max_prediction_order = 8;
max_partition_order = 6;
break;
case 2:
stereo_method = StereoMethod.Independent;
window_function = WindowFunction.Bartlett;
max_partition_order = 6;
break;
case 3:
stereo_method = StereoMethod.Estimate;
window_function = WindowFunction.Bartlett;
max_prediction_order = 8;
break;
case 4:
stereo_method = StereoMethod.Estimate;
window_function = WindowFunction.Bartlett;
break;
case 5:
stereo_method = StereoMethod.Estimate;
window_method = WindowMethod.Estimate;
break;
case 6:
stereo_method = StereoMethod.Estimate;
break;
case 7:
break;
case 8:
estimation_depth = 2;
min_fixed_order = 0;
lpc_min_precision_search = 0;
break;
case 9:
window_function = WindowFunction.Bartlett;
max_prediction_order = 32;
break;
case 10:
min_fixed_order = 0;
max_fixed_order = 4;
max_prediction_order = 32;
//lpc_max_precision_search = 2;
break;
case 11:
min_fixed_order = 0;
max_fixed_order = 4;
max_prediction_order = 32;
estimation_depth = 5;
//lpc_max_precision_search = 2;
variable_block_size = 4;
break;
}
return 0;
}
public int flake_set_defaults(FlakeWriterSettings settings)
{
// default to level 7 params
window_function = WindowFunction.Flattop | WindowFunction.Tukey;
order_method = OrderMethod.Akaike;
stereo_method = StereoMethod.Evaluate;
window_method = WindowMethod.Evaluate;
block_time_ms = 105;
prediction_type = PredictionType.Search;
estimation_depth = 1;
variable_block_size = 0;
lpc_min_precision_search = 1;
lpc_max_precision_search = 1;
do_seektable = true;
development_mode = -1;
// differences from level 7
switch (settings.EncoderModeIndex)
{
case 0:
block_time_ms = 53;
prediction_type = PredictionType.Fixed;
stereo_method = StereoMethod.Independent;
break;
case 1:
prediction_type = PredictionType.Levinson;
stereo_method = StereoMethod.Independent;
window_function = WindowFunction.Bartlett;
break;
case 2:
stereo_method = StereoMethod.Independent;
window_function = WindowFunction.Bartlett;
break;
case 3:
stereo_method = StereoMethod.Estimate;
window_function = WindowFunction.Bartlett;
break;
case 4:
stereo_method = StereoMethod.Estimate;
window_function = WindowFunction.Bartlett;
break;
case 5:
stereo_method = StereoMethod.Estimate;
window_method = WindowMethod.Estimate;
break;
case 6:
stereo_method = StereoMethod.Estimate;
break;
case 7:
break;
case 8:
estimation_depth = 2;
lpc_min_precision_search = 0;
break;
case 9:
window_function = WindowFunction.Bartlett;
break;
case 10:
//lpc_max_precision_search = 2;
break;
case 11:
estimation_depth = 5;
//lpc_max_precision_search = 2;
variable_block_size = 4;
break;
}
return 0;
}
public int set_defaults(int lvl)
{
compression = lvl;
if ((lvl < 0 || lvl > 12) && (lvl != 99))
{
return -1;
}
// default to level 5 params
window_function = WindowFunction.Flattop | WindowFunction.Tukey;
order_method = OrderMethod.Estimate;
stereo_method = StereoMethod.Evaluate;
window_method = WindowMethod.Evaluate;
block_size = 0;
block_time_ms = 105;
min_modifier = 4;
max_modifier = 4;
min_prediction_order = 1;
max_prediction_order = 12;
estimation_depth = 1;
adaptive_passes = 0;
do_seektable = false;
chunk_size = 5;
// differences from level 6
switch (lvl)
{
case 0:
stereo_method = StereoMethod.Independent;
window_function = WindowFunction.Hann;
max_prediction_order = 6;
break;
case 1:
stereo_method = StereoMethod.Independent;
window_function = WindowFunction.Hann;
max_prediction_order = 8;
break;
case 2:
stereo_method = StereoMethod.Estimate;
window_function = WindowFunction.Hann;
max_prediction_order = 6;
break;
case 3:
stereo_method = StereoMethod.Estimate;
window_function = WindowFunction.Hann;
max_prediction_order = 8;
break;
case 4:
stereo_method = StereoMethod.Estimate;
window_method = WindowMethod.Estimate;
max_prediction_order = 8;
break;
case 5:
stereo_method = StereoMethod.Estimate;
window_method = WindowMethod.Estimate;
break;
case 6:
stereo_method = StereoMethod.Estimate;
break;
case 7:
stereo_method = StereoMethod.Estimate;
adaptive_passes = 1;
min_modifier = 2;
break;
case 8:
adaptive_passes = 1;
min_modifier = 2;
break;
case 9:
adaptive_passes = 1;
max_prediction_order = 30;
min_modifier = 2;
break;
case 10:
estimation_depth = 2;
adaptive_passes = 2;
max_prediction_order = 30;
min_modifier = 2;
break;
}
return 0;
}
