def waveform_to_examples(data, sample_rate):
"""Converts audio waveform into an array of examples for VGGish.
Args:
data: np.array of either one dimension (mono) or two dimensions
(multi-channel, with the outer dimension representing channels).
Each sample is generally expected to lie in the range [-1.0, +1.0],
although this is not required.
sample_rate: Sample rate of data.
Returns:
3-D np.array of shape [num_examples, num_frames, num_bands] which represents
a sequence of examples, each of which contains a patch of log mel
spectrogram, covering num_frames frames of audio and num_bands mel frequency
bands, where the frame length is vggish_params.STFT_HOP_LENGTH_SECONDS.
"""
# Convert to mono.
if len(data.shape) > 1:
data = np.mean(data, axis=1)
# Resample to the rate assumed by VGGish.
if sample_rate != vggish_params.SAMPLE_RATE:
data = resampy.resample(data, sample_rate, vggish_params.SAMPLE_RATE)
# Compute log mel spectrogram features.
log_mel = mel_features.log_mel_spectrogram(
data,
audio_sample_rate=vggish_params.SAMPLE_RATE,
log_offset=vggish_params.LOG_OFFSET,
window_length_secs=vggish_params.STFT_WINDOW_LENGTH_SECONDS,
hop_length_secs=vggish_params.STFT_HOP_LENGTH_SECONDS,
num_mel_bins=vggish_params.NUM_MEL_BINS,
lower_edge_hertz=vggish_params.MEL_MIN_HZ,
upper_edge_hertz=vggish_params.MEL_MAX_HZ)
# Frame features into examples.
features_sample_rate = 1.0 / vggish_params.STFT_HOP_LENGTH_SECONDS
example_window_length = int(round(
vggish_params.EXAMPLE_WINDOW_SECONDS * features_sample_rate))
example_hop_length = int(round(
vggish_params.EXAMPLE_HOP_SECONDS * features_sample_rate))
log_mel_examples = mel_features.frame(
log_mel,
window_length=example_window_length,
hop_length=example_hop_length)
return log_mel_examples
def wavfile_to_examples(wav_file):
"""Converting the waveform in to mel psectrum
"""
sr, wav_data = wavfile.read(wav_file)
print(("SR, {}".format(sr)))
print(("wav_data, {}, and shape is {}".format(wav_data, wav_data.shape)))
print("max element in wav_data is {}".format(np.amax(wav_data)))
assert wav_data.dtype == np.int16, 'Bad sample type: %r' % wav_data.dtype
samples = wav_data / 32768.0 # Convert to [-1.0, +1.0]
data = wav_data
sample_rate = sr
if len(data.shape) > 1:
data = np.mean(data, axis=1)
# Resample to the rate assumed by VGGish.
if sample_rate != vggish_params.SAMPLE_RATE:
data = resampy.resample(data, sample_rate, vggish_params.SAMPLE_RATE)
# Compute log mel spectrogram features.
log_mel = mel_features.log_mel_spectrogram(
data,
audio_sample_rate=vggish_params.SAMPLE_RATE,
log_offset=vggish_params.LOG_OFFSET,
window_length_secs=vggish_params.STFT_WINDOW_LENGTH_SECONDS,
hop_length_secs=vggish_params.STFT_HOP_LENGTH_SECONDS,
num_mel_bins=vggish_params.NUM_MEL_BINS,
lower_edge_hertz=vggish_params.MEL_MIN_HZ,
upper_edge_hertz=vggish_params.MEL_MAX_HZ)
# Frame features into examples.
features_sample_rate = 1.0 / vggish_params.STFT_HOP_LENGTH_SECONDS
example_window_length = int(
round(vggish_params.EXAMPLE_WINDOW_SECONDS * features_sample_rate))
example_hop_length = int(
round(vggish_params.EXAMPLE_HOP_SECONDS * features_sample_rate))
log_mel_examples = mel_features.frame(log_mel,
window_length=example_window_length,
hop_length=example_hop_length)
return log_mel_examples
def vggish_melspec(y, sr=22050, do_resample=False, frames=None):
"""
Extract melspec for vggish model
"""
if sr != vggish_params.SAMPLE_RATE and do_resample:
if frames is not None:
raise Exception("Resampled not supported with frames argument.")
y = resample(y, sr, vggish_params.SAMPLE_RATE)
sr = vggish_params.SAMPLE_RATE
log_mel = mel_features.log_mel_spectrogram(
y,
frames=frames,
audio_sample_rate=sr,
log_offset=vggish_params.LOG_OFFSET,
window_length_secs=vggish_params.STFT_WINDOW_LENGTH_SECONDS,
hop_length_secs=vggish_params.STFT_HOP_LENGTH_SECONDS,
num_mel_bins=vggish_params.NUM_MEL_BINS,
lower_edge_hertz=vggish_params.MEL_MIN_HZ,
upper_edge_hertz=vggish_params.MEL_MAX_HZ)
return log_mel