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""" | |
DeepSpeech features processing routines. | |
NB: Based on VOCA code. See the corresponding license restrictions. | |
""" | |
__all__ = ['conv_audios_to_deepspeech'] | |
import numpy as np | |
import warnings | |
import resampy | |
from scipy.io import wavfile | |
from python_speech_features import mfcc | |
import tensorflow.compat.v1 as tf | |
tf.disable_v2_behavior() | |
def conv_audios_to_deepspeech(audios, | |
out_files, | |
num_frames_info, | |
deepspeech_pb_path, | |
audio_window_size=1, | |
audio_window_stride=1): | |
""" | |
Convert list of audio files into files with DeepSpeech features. | |
Parameters | |
---------- | |
audios : list of str or list of None | |
Paths to input audio files. | |
out_files : list of str | |
Paths to output files with DeepSpeech features. | |
num_frames_info : list of int | |
List of numbers of frames. | |
deepspeech_pb_path : str | |
Path to DeepSpeech 0.1.0 frozen model. | |
audio_window_size : int, default 16 | |
Audio window size. | |
audio_window_stride : int, default 1 | |
Audio window stride. | |
""" | |
# deepspeech_pb_path="/disk4/keyu/DeepSpeech/deepspeech-0.9.2-models.pbmm" | |
graph, logits_ph, input_node_ph, input_lengths_ph = prepare_deepspeech_net( | |
deepspeech_pb_path) | |
with tf.compat.v1.Session(graph=graph) as sess: | |
for audio_file_path, out_file_path, num_frames in zip(audios, out_files, num_frames_info): | |
print(audio_file_path) | |
print(out_file_path) | |
audio_sample_rate, audio = wavfile.read(audio_file_path) | |
if audio.ndim != 1: | |
warnings.warn( | |
"Audio has multiple channels, the first channel is used") | |
audio = audio[:, 0] | |
ds_features = pure_conv_audio_to_deepspeech( | |
audio=audio, | |
audio_sample_rate=audio_sample_rate, | |
audio_window_size=audio_window_size, | |
audio_window_stride=audio_window_stride, | |
num_frames=num_frames, | |
net_fn=lambda x: sess.run( | |
logits_ph, | |
feed_dict={ | |
input_node_ph: x[np.newaxis, ...], | |
input_lengths_ph: [x.shape[0]]})) | |
net_output = ds_features.reshape(-1, 29) | |
win_size = 16 | |
zero_pad = np.zeros((int(win_size / 2), net_output.shape[1])) | |
net_output = np.concatenate( | |
(zero_pad, net_output, zero_pad), axis=0) | |
windows = [] | |
for window_index in range(0, net_output.shape[0] - win_size, 2): | |
windows.append( | |
net_output[window_index:window_index + win_size]) | |
print(np.array(windows).shape) | |
np.save(out_file_path, np.array(windows)) | |
def prepare_deepspeech_net(deepspeech_pb_path): | |
""" | |
Load and prepare DeepSpeech network. | |
Parameters | |
---------- | |
deepspeech_pb_path : str | |
Path to DeepSpeech 0.1.0 frozen model. | |
Returns | |
------- | |
graph : obj | |
ThensorFlow graph. | |
logits_ph : obj | |
ThensorFlow placeholder for `logits`. | |
input_node_ph : obj | |
ThensorFlow placeholder for `input_node`. | |
input_lengths_ph : obj | |
ThensorFlow placeholder for `input_lengths`. | |
""" | |
# Load graph and place_holders: | |
with tf.io.gfile.GFile(deepspeech_pb_path, "rb") as f: | |
graph_def = tf.compat.v1.GraphDef() | |
graph_def.ParseFromString(f.read()) | |
graph = tf.compat.v1.get_default_graph() | |
tf.import_graph_def(graph_def, name="deepspeech") | |
logits_ph = graph.get_tensor_by_name("deepspeech/logits:0") | |
input_node_ph = graph.get_tensor_by_name("deepspeech/input_node:0") | |
input_lengths_ph = graph.get_tensor_by_name("deepspeech/input_lengths:0") | |
return graph, logits_ph, input_node_ph, input_lengths_ph | |
def pure_conv_audio_to_deepspeech(audio, | |
audio_sample_rate, | |
audio_window_size, | |
audio_window_stride, | |
num_frames, | |
net_fn): | |
""" | |
Core routine for converting audion into DeepSpeech features. | |
Parameters | |
---------- | |
audio : np.array | |
Audio data. | |
audio_sample_rate : int | |
Audio sample rate. | |
audio_window_size : int | |
Audio window size. | |
audio_window_stride : int | |
Audio window stride. | |
num_frames : int or None | |
Numbers of frames. | |
net_fn : func | |
Function for DeepSpeech model call. | |
Returns | |
------- | |
np.array | |
DeepSpeech features. | |
""" | |
target_sample_rate = 16000 | |
if audio_sample_rate != target_sample_rate: | |
resampled_audio = resampy.resample( | |
x=audio.astype(np.float), | |
sr_orig=audio_sample_rate, | |
sr_new=target_sample_rate) | |
else: | |
resampled_audio = audio.astype(np.float32) | |
input_vector = conv_audio_to_deepspeech_input_vector( | |
audio=resampled_audio.astype(np.int16), | |
sample_rate=target_sample_rate, | |
num_cepstrum=26, | |
num_context=9) | |
network_output = net_fn(input_vector) | |
# print(network_output.shape) | |
deepspeech_fps = 50 | |
video_fps = 50 # Change this option if video fps is different | |
audio_len_s = float(audio.shape[0]) / audio_sample_rate | |
if num_frames is None: | |
num_frames = int(round(audio_len_s * video_fps)) | |
else: | |
video_fps = num_frames / audio_len_s | |
network_output = interpolate_features( | |
features=network_output[:, 0], | |
input_rate=deepspeech_fps, | |
output_rate=video_fps, | |
output_len=num_frames) | |
# Make windows: | |
zero_pad = np.zeros((int(audio_window_size / 2), network_output.shape[1])) | |
network_output = np.concatenate( | |
(zero_pad, network_output, zero_pad), axis=0) | |
windows = [] | |
for window_index in range(0, network_output.shape[0] - audio_window_size, audio_window_stride): | |
windows.append( | |
network_output[window_index:window_index + audio_window_size]) | |
return np.array(windows) | |
def conv_audio_to_deepspeech_input_vector(audio, | |
sample_rate, | |
num_cepstrum, | |
num_context): | |
""" | |
Convert audio raw data into DeepSpeech input vector. | |
Parameters | |
---------- | |
audio : np.array | |
Audio data. | |
audio_sample_rate : int | |
Audio sample rate. | |
num_cepstrum : int | |
Number of cepstrum. | |
num_context : int | |
Number of context. | |
Returns | |
------- | |
np.array | |
DeepSpeech input vector. | |
""" | |
# Get mfcc coefficients: | |
features = mfcc( | |
signal=audio, | |
samplerate=sample_rate, | |
numcep=num_cepstrum) | |
# We only keep every second feature (BiRNN stride = 2): | |
features = features[::2] | |
# One stride per time step in the input: | |
num_strides = len(features) | |
# Add empty initial and final contexts: | |
empty_context = np.zeros((num_context, num_cepstrum), dtype=features.dtype) | |
features = np.concatenate((empty_context, features, empty_context)) | |
# Create a view into the array with overlapping strides of size | |
# numcontext (past) + 1 (present) + numcontext (future): | |
window_size = 2 * num_context + 1 | |
train_inputs = np.lib.stride_tricks.as_strided( | |
features, | |
shape=(num_strides, window_size, num_cepstrum), | |
strides=(features.strides[0], | |
features.strides[0], features.strides[1]), | |
writeable=False) | |
# Flatten the second and third dimensions: | |
train_inputs = np.reshape(train_inputs, [num_strides, -1]) | |
train_inputs = np.copy(train_inputs) | |
train_inputs = (train_inputs - np.mean(train_inputs)) / \ | |
np.std(train_inputs) | |
return train_inputs | |
def interpolate_features(features, | |
input_rate, | |
output_rate, | |
output_len): | |
""" | |
Interpolate DeepSpeech features. | |
Parameters | |
---------- | |
features : np.array | |
DeepSpeech features. | |
input_rate : int | |
input rate (FPS). | |
output_rate : int | |
Output rate (FPS). | |
output_len : int | |
Output data length. | |
Returns | |
------- | |
np.array | |
Interpolated data. | |
""" | |
input_len = features.shape[0] | |
num_features = features.shape[1] | |
input_timestamps = np.arange(input_len) / float(input_rate) | |
output_timestamps = np.arange(output_len) / float(output_rate) | |
output_features = np.zeros((output_len, num_features)) | |
for feature_idx in range(num_features): | |
output_features[:, feature_idx] = np.interp( | |
x=output_timestamps, | |
xp=input_timestamps, | |
fp=features[:, feature_idx]) | |
return output_features | |