TriangularBands¶

streaming mode | Spectral category

Inputs¶

spectrum (vector_real) - the input spectrum (must be greater than size one)

Outputs¶

bands (vector_real) - the energy in each band

Parameters¶

frequencyBands (vector_real, default = [21.533203125, 43.06640625, 64.599609375, 86.1328125, 107.666015625, 129.19921875, 150.732421875, 172.265625, 193.798828125, 215.33203125, 236.865234375, 258.3984375, 279.931640625, 301.46484375, 322.998046875, 344.53125, 366.064453125, 387.59765625, 409.130859375, 430.6640625, 452.197265625, 473.73046875, 495.263671875, 516.796875, 538.330078125, 559.86328125, 581.396484375, 602.9296875, 624.462890625, 645.99609375, 667.529296875, 689.0625, 710.595703125, 732.12890625, 753.662109375, 775.1953125, 796.728515625, 839.794921875, 861.328125, 882.861328125, 904.39453125, 925.927734375, 968.994140625, 990.52734375, 1012.06054688, 1055.12695312, 1076.66015625, 1098.19335938, 1141.25976562, 1184.32617188, 1205.859375, 1248.92578125, 1270.45898438, 1313.52539062, 1356.59179688, 1399.65820312, 1442.72460938, 1485.79101562, 1528.85742188, 1571.92382812, 1614.99023438, 1658.05664062, 1701.12304688, 1765.72265625, 1808.7890625, 1873.38867188, 1916.45507812, 1981.0546875, 2024.12109375, 2088.72070312, 2153.3203125, 2217.91992188, 2282.51953125, 2347.11914062, 2411.71875, 2497.8515625, 2562.45117188, 2627.05078125, 2713.18359375, 2799.31640625, 2885.44921875, 2950.04882812, 3036.18164062, 3143.84765625, 3229.98046875, 3316.11328125, 3423.77929688, 3509.91210938, 3617.578125, 3725.24414062, 3832.91015625, 3940.57617188, 4069.77539062, 4177.44140625, 4306.640625, 4435.83984375, 4565.0390625, 4694.23828125, 4844.97070312, 4974.16992188, 5124.90234375, 5275.63476562, 5426.3671875, 5577.09960938, 5749.36523438, 5921.63085938, 6093.89648438, 6266.16210938, 6459.9609375, 6653.75976562, 6847.55859375, 7041.35742188, 7256.68945312, 7450.48828125, 7687.35351562, 7902.68554688, 8139.55078125, 8376.41601562, 8613.28125, 8871.6796875, 9130.078125, 9388.4765625, 9668.40820312, 9948.33984375, 10249.8046875, 10551.2695312, 10852.734375, 11175.7324219, 11498.7304688, 11843.2617188, 12187.7929688, 12553.8574219, 12919.921875, 13285.9863281, 13673.5839844, 14082.7148438, 14491.8457031, 14922.5097656, 15353.1738281, 15805.3710938, 16257.5683594]) :
list of frequency ranges into which the spectrum is divided (these must be in ascending order and connot contain duplicates),each triangle is build as x(i-1)=0, x(i)=1, x(i+1)=0 over i, the resulting number of bands is size of input array - 2

inputSize (integer ∈ (1, ∞), default = 1025) :
the size of the spectrum

log (bool ∈ {true, false}, default = true) :
compute log-energies (log2 (1 + energy))

normalize (string ∈ {unit_sum, unit_tri, unit_max}, default = unit_sum) :
spectrum bin weights to use for each triangular band: ‘unit_max’ to make each triangle vertex equal to 1, ‘unit_sum’ to make each triangle area equal to 1 summing the actual weights of spectrum bins, ‘unit_area’ to make each triangle area equal to 1 normalizing the weights of each triangle by its bandwidth

sampleRate (real ∈ (0, ∞), default = 44100) :
the sampling rate of the audio signal [Hz]

type (string ∈ {magnitude, power}, default = power) :
use magnitude or power spectrum

weighting (string ∈ {linear, slaneyMel, htkMel}, default = linear) :
type of weighting function for determining triangle area

Description¶

This algorithm computes energy in triangular frequency bands of a spectrum. The arbitrary number of overlapping bands can be specified. For each band the power-spectrum (mag-squared) is summed.

Parameter “frequencyBands” must contain at least two frequencies, they all must be positive and must be ordered ascentdantly, otherwise an exception will be thrown. TriangularBands is only defined for spectrum, which size is greater than 1.

Source code¶

C++ source code

C++ header file