pyACA.PitchTimeZeroCrossings Namespace Reference

Functions
	PitchTimeZeroCrossings (x, iBlockLength, iHopLength, f_s)
	computes f0 via zero crossing distances

Function Documentation

PitchTimeZeroCrossings()

PitchTimeZeroCrossings	(		x,
			iBlockLength,
			iHopLength,
			f_s )

computes f0 via zero crossing distances

Parameters

x	array with floating point audio data (dimension samples x channels)
iBlockLength	internal block length
iHopLength	internal hop length
f_s	sample rate of audio data

Returns

f_0: fundamental frequency (in Hz)

t: time stamp

Definition at line 17 of file PitchTimeZeroCrossings.py.

def PitchTimeZeroCrossings(x, iBlockLength, iHopLength, f_s):
 
    # block audio data
    x_b, t = ToolBlockAudio(x, iBlockLength, iHopLength, f_s)
    iNumOfBlocks = x_b.shape[0]
 
    # initialize
    f_0 = np.zeros(iNumOfBlocks)
 
    for n, block in enumerate(x_b):
 
        # get current block
        if not block.sum():
             continue
        else:
            x_tmp = block
 
        # compute zero crossing indices
        x_tmp = x_tmp[np.arange(0, iBlockLength - 1)] * x_tmp[np.arange(1, iBlockLength)]
        i_tmp = np.diff(np.argwhere(x_tmp < 0), axis=0)
 
        # average distance of zero crossings indicates half period
        if i_tmp.size:
            f_0[n] = f_s / np.mean(2 * i_tmp)
 
    return f_0, t