def process_spectrogram(filename, block_size, hop_size):
x, times, fs = open_file(filename, block_size, hop_size)
w = create_window(block_size)
X, X_cross_time, X_cross_freq, X_inst_freqs, X_group_delays = compute_spectra(x, w)
X_reassigned_f = requantize_f_spectrogram(X_cross_time, X_inst_freqs)
# N = X_cross.shape[1]
# magnitude_spectrum = abs(X_cross_time) / N
# weights = db_scale(magnitude_spectrum)
X_magnitudes = abs(X_cross_time) / X.shape[1]
weights = X_magnitudes
X_reassigned_tf = requantize_tf_spectrogram(X_group_delays, X_inst_freqs, times, block_size, fs, weights)[0]
X_reassigned_tf = db_scale(X_reassigned_tf ** 2)
image_filename = os.path.basename(filename).replace('.wav', '.png')
scipy.misc.imsave('reassigned_f_' + image_filename, real_half(X_reassigned_f).T[::-1])
scipy.misc.imsave('reassigned_tf_' + image_filename, real_half(X_reassigned_tf).T[::-1])
scipy.misc.imsave('normal_' + image_filename, real_half(X_magnitudes).T[::-1])
def chromagram(x, w, fs, bin_range=(-48, 67), bin_division=1, to_log=True):
"complete reassigned spectrogram with requantization to pitch bins"
# TODO: better give frequency range
X, X_cross_time, X_cross_freq, X_inst_freqs, X_group_delays = compute_spectra(x, w)
n_blocks, n_freqs = X_cross_time.shape
X_mag = abs(X_cross_time) / n_freqs
weights = real_half(X_mag).flatten()
eps = np.finfo(np.float32).eps
pitch_bins = quantize_freqs_to_pitch_bins(np.maximum(fs * real_half(X_inst_freqs), eps), bin_division=bin_division).flatten()
nonzero_ix = abs(weights) > eps
X_chromagram = np.histogram2d(
np.repeat(np.arange(n_blocks), n_freqs / 2),
pitch_bins,
bins=(np.arange(n_blocks + 1),
np.arange(bin_range[0], bin_range[1] + 1, 1 / bin_division)),
weights=weights
)[0]
X_chromagram = X_chromagram ** 2
if to_log:
X_chromagram = db_scale(X_chromagram)
return X_chromagram
def reassigned_spectrogram(x, w, to_log=True):
X, X_cross_time, X_cross_freq, X_inst_freqs, X_group_delays = compute_spectra(x, w)
X_reassigned_f = requantize_f_spectrogram(X_cross_time, X_inst_freqs, to_log)
return real_half(X_reassigned_f)