@ -33,55 +33,14 @@ from deepspeech.decoders.swig_wrapper import Scorer
from deepspeech . decoders . swig_wrapper import ctc_greedy_decoder
from deepspeech . decoders . swig_wrapper import ctc_beam_search_decoder_batch
from deepspeech . modules . loss import CTCLoss
logger = logging . getLogger ( __name__ )
__all__ = [ ' DeepSpeech2Model ' ]
class DeepSpeech2Model ( nn . Layer ) :
""" The DeepSpeech2 network structure.
: param audio_data : Audio spectrogram data layer .
: type audio_data : Variable
: param text_data : Transcription text data layer .
: type text_data : Variable
: param audio_len : Valid sequence length data layer .
: type audio_len : Variable
: param masks : Masks data layer to reset padding .
: type masks : Variable
: param dict_size : Dictionary size for tokenized transcription .
: type dict_size : int
: param num_conv_layers : Number of stacking convolution layers .
: type num_conv_layers : int
: param num_rnn_layers : Number of stacking RNN layers .
: type num_rnn_layers : int
: param rnn_size : RNN layer size ( dimension of RNN cells ) .
: type rnn_size : int
: param use_gru : Use gru if set True . Use simple rnn if set False .
: type use_gru : bool
: param share_rnn_weights : Whether to share input - hidden weights between
forward and backward direction RNNs .
It is only available when use_gru = False .
: type share_weights : bool
: return : A tuple of an output unnormalized log probability layer (
before softmax ) and a ctc cost layer .
: rtype : tuple of LayerOutput
"""
@classmethod
def params ( cls , config : Optional [ CfgNode ] = None ) - > CfgNode :
default = CfgNode (
dict (
num_conv_layers = 2 , #Number of stacking convolution layers.
num_rnn_layers = 3 , #Number of stacking RNN layers.
rnn_layer_size = 1024 , #RNN layer size (number of RNN cells).
use_gru = True , #Use gru if set True. Use simple rnn if set False.
share_rnn_weights = True #Whether to share input-hidden weights between forward and backward directional RNNs.Notice that for GRU, weight sharing is not supported.
) )
if config is not None :
config . merge_from_other_cfg ( default )
return default
class CRNNEncoder ( nn . Layer ) :
def __init__ ( self ,
feat_size ,
dict_size ,
@ -91,6 +50,7 @@ class DeepSpeech2Model(nn.Layer):
use_gru = False ,
share_rnn_weights = True ) :
super ( ) . __init__ ( )
self . rnn_size = rnn_size
self . feat_size = feat_size # 161 for linear
self . dict_size = dict_size
@ -103,49 +63,89 @@ class DeepSpeech2Model(nn.Layer):
num_stacks = num_rnn_layers ,
use_gru = use_gru ,
share_rnn_weights = share_rnn_weights )
self . fc = nn . Linear ( rnn_size * 2 , dict_size + 1 )
self . logger = logging . getLogger ( __name__ )
self . _ext_scorer = None
@property
def output_size ( self ) :
return self . rnn_size * 2
def infer ( self , audio , audio_len ) :
def forward ( self , audio , audio_len ) :
"""
audio : shape [ B , D , T ]
text : shape [ B , T ]
audio_len : shape [ B ]
text_len : shape [ B ]
"""
""" Compute Encoder outputs
Args :
audio ( Tensor ) : [ B , D , T ]
text ( Tensor ) : [ B , T ]
audio_len ( Tensor ) : [ B ]
text_len ( Tensor ) : [ B ]
Returns :
x ( Tensor ) : encoder outputs , [ B , T , D ]
x_lens ( Tensor ) : encoder length , [ B ]
"""
# [B, D, T] -> [B, C=1, D, T]
audio = audio . unsqueeze ( 1 )
x = audio . unsqueeze ( 1 )
x_lens = audio_len
# convolution group
x , audio_len = self . conv ( audio , audio_len )
#print('conv out', x.shape)
x , x_lens = self . conv ( x , x_lens )
# convert data from convolution feature map to sequence of vectors
B , C , D , T = paddle . shape ( x )
#B, C, D, T = paddle.shape(x) # not work under jit
x = x . transpose ( [ 0 , 3 , 1 , 2 ] ) #[B, T, C, D]
x = x . reshape ( [ B , T , C * D ] ) #[B, T, C*D]
#print('rnn input', x.shape)
#x = x.reshape([B, T, C * D]) #[B, T, C*D] # not work under jit
x = x . reshape ( [ 0 , 0 , - 1 ] ) #[B, T, C*D]
# remove padding part
x , audio_len = self . rnn ( x , audio_len ) #[B, T, D]
#print('rnn output', x.shape)
x , x_lens = self . rnn ( x , x_lens ) #[B, T, D]
return x , x_lens
logits = self . fc ( x ) #[B, T, V + 1]
#ctcdecoder need probs, not log_probs
probs = F . softmax ( logits )
class CTCDecoder ( nn . Layer ) :
def __init__ ( self , enc_n_units , vocab_size ) :
super ( ) . __init__ ( )
self . blank_id = vocab_size
self . output = nn . Linear ( enc_n_units ,
vocab_size + 1 ) # blank id is last id
self . criterion = CTCLoss ( self . blank_id )
self . _ext_scorer = None
return logits , probs , audio_len
def forward ( self , eout , eout_lens , texts , texts_len ) :
""" Compute CTC Loss
def forward ( self , audio , text , audio_len , text_len ) :
Args :
eout ( Tensor ) :
eout_lens ( Tensor ) :
texts ( Tenosr ) :
texts_len ( Tensor ) :
Returns :
loss ( Tenosr ) : [ 1 ]
"""
audio : shape [ B , D , T ]
text : shape [ B , T ]
audio_len : shape [ B ]
text_len : shape [ B ]
logits = self . output ( eout )
loss = self . criterion ( logits , texts , eout_lens , texts_len )
return loss
def probs ( self , eouts , temperature = 1. ) :
""" Get CTC probabilities.
Args :
eouts ( FloatTensor ) : ` [ B , T , enc_units ] `
Returns :
probs ( FloatTensor ) : ` [ B , T , vocab ] `
"""
return self . infer ( audio , audio_len )
@paddle.no_grad ( )
def predict ( self , audio , audio_len ) :
""" Model infer """
return self . infer ( audio , audio_len )
return F . softmax ( self . output ( eouts ) / temperature , axis = - 1 )
def scores ( self , eouts , temperature = 1. ) :
""" Get log-scale CTC probabilities.
Args :
eouts ( FloatTensor ) : ` [ B , T , enc_units ] `
Returns :
log_probs ( FloatTensor ) : ` [ B , T , vocab ] `
"""
return F . log_softmax ( self . output ( eouts ) / temperature , axis = - 1 )
def _decode_batch_greedy ( self , probs_split , vocab_list ) :
""" Decode by best path for a batch of probs matrix input.
@ -184,21 +184,21 @@ class DeepSpeech2Model(nn.Layer):
return
if language_model_path != ' ' :
self . logger . info ( " begin to initialize the external scorer "
logger . info ( " begin to initialize the external scorer "
" for decoding " )
self . _ext_scorer = Scorer ( beam_alpha , beam_beta ,
language_model_path , vocab_list )
lm_char_based = self . _ext_scorer . is_character_based ( )
lm_max_order = self . _ext_scorer . get_max_order ( )
lm_dict_size = self . _ext_scorer . get_dict_size ( )
self . logger . info ( " language model: "
logger . info ( " language model: "
" is_character_based = %d , " % lm_char_based +
" max_order = %d , " % lm_max_order +
" dict_size = %d " % lm_dict_size )
self . logger . info ( " end initializing scorer " )
" max_order = %d , " % lm_max_order + " dict_size = %d " %
lm_dict_size )
logger . info ( " end initializing scorer " )
else :
self . _ext_scorer = None
self . logger . info ( " no language model provided, "
logger . info ( " no language model provided, "
" decoding by pure beam search without scorer. " )
def _decode_batch_beam_search ( self , probs_split , beam_alpha , beam_beta ,
@ -275,14 +275,107 @@ class DeepSpeech2Model(nn.Layer):
raise ValueError ( f " Not support: { decoding_method } " )
return result_transcripts
class DeepSpeech2Model ( nn . Layer ) :
""" The DeepSpeech2 network structure.
: param audio_data : Audio spectrogram data layer .
: type audio_data : Variable
: param text_data : Transcription text data layer .
: type text_data : Variable
: param audio_len : Valid sequence length data layer .
: type audio_len : Variable
: param masks : Masks data layer to reset padding .
: type masks : Variable
: param dict_size : Dictionary size for tokenized transcription .
: type dict_size : int
: param num_conv_layers : Number of stacking convolution layers .
: type num_conv_layers : int
: param num_rnn_layers : Number of stacking RNN layers .
: type num_rnn_layers : int
: param rnn_size : RNN layer size ( dimension of RNN cells ) .
: type rnn_size : int
: param use_gru : Use gru if set True . Use simple rnn if set False .
: type use_gru : bool
: param share_rnn_weights : Whether to share input - hidden weights between
forward and backward direction RNNs .
It is only available when use_gru = False .
: type share_weights : bool
: return : A tuple of an output unnormalized log probability layer (
before softmax ) and a ctc cost layer .
: rtype : tuple of LayerOutput
"""
@classmethod
def params ( cls , config : Optional [ CfgNode ] = None ) - > CfgNode :
default = CfgNode (
dict (
num_conv_layers = 2 , #Number of stacking convolution layers.
num_rnn_layers = 3 , #Number of stacking RNN layers.
rnn_layer_size = 1024 , #RNN layer size (number of RNN cells).
use_gru = True , #Use gru if set True. Use simple rnn if set False.
share_rnn_weights = True #Whether to share input-hidden weights between forward and backward directional RNNs.Notice that for GRU, weight sharing is not supported.
) )
if config is not None :
config . merge_from_other_cfg ( default )
return default
def __init__ ( self ,
feat_size ,
dict_size ,
num_conv_layers = 2 ,
num_rnn_layers = 3 ,
rnn_size = 1024 ,
use_gru = False ,
share_rnn_weights = True ) :
super ( ) . __init__ ( )
self . encoder = CRNNEncoder (
feat_size = feat_size ,
dict_size = dict_size ,
num_conv_layers = num_conv_layers ,
num_rnn_layers = num_rnn_layers ,
rnn_size = rnn_size ,
use_gru = use_gru ,
share_rnn_weights = share_rnn_weights )
assert ( self . encoder . output_size == rnn_size * 2 )
self . decoder = CTCDecoder (
enc_n_units = self . encoder . output_size , vocab_size = dict_size )
def forward ( self , audio , text , audio_len , text_len ) :
""" Compute Model loss
Args :
audio ( Tenosr ) : [ B , D , T ]
text ( Tensor ) : [ B , T ]
audio_len ( Tensor ) : [ B ]
text_len ( Tensor ) : [ B ]
Returns :
loss ( Tenosr ) : [ 1 ]
"""
eouts , eouts_len = self . encoder ( audio , audio_len )
loss = self . decoder ( eouts , eouts_len , text , text_len )
return loss
@paddle.no_grad ( )
def decode ( self , audio , audio_len , vocab_list , decoding_method ,
lang_model_path , beam_alpha , beam_beta , beam_size , cutoff_prob ,
cutoff_top_n , num_processes ) :
_ , probs , logits_lens = self . predict ( audio , audio_len )
return self . decode_probs ( probs . numpy ( ) , logits_lens , vocab_list ,
decoding_method , lang_model_path , beam_alpha ,
beam_beta , beam_size , cutoff_prob ,
# init once
# decoders only accept string encoded in utf-8
self . decoder . init_decode (
beam_alpha = beam_alpha ,
beam_beta = beam_beta ,
lang_model_path = lang_model_path ,
vocab_list = vocab_list ,
decoding_method = decoding_method )
eouts , eouts_len = self . encoder ( audio , audio_len )
probs = self . decoder . probs ( eouts )
return self . decoder . decode_probs (
probs . numpy ( ) , eouts_len , vocab_list , decoding_method ,
lang_model_path , beam_alpha , beam_beta , beam_size , cutoff_prob ,
cutoff_top_n , num_processes )
def from_pretrained ( self , checkpoint_path ) :
@ -302,3 +395,36 @@ class DeepSpeech2Model(nn.Layer):
"""
checkpoint . load_parameters ( self , checkpoint_path = checkpoint_path )
return
class DeepSpeech2InferModel ( DeepSpeech2Model ) :
def __init__ ( self ,
feat_size ,
dict_size ,
num_conv_layers = 2 ,
num_rnn_layers = 3 ,
rnn_size = 1024 ,
use_gru = False ,
share_rnn_weights = True ) :
super ( ) . __init__ (
feat_size = feat_size ,
dict_size = dict_size ,
num_conv_layers = num_conv_layers ,
num_rnn_layers = num_rnn_layers ,
rnn_size = rnn_size ,
use_gru = use_gru ,
share_rnn_weights = share_rnn_weights )
def forward ( self , audio , audio_len ) :
""" export model function
Args :
audio ( Tensor ) : [ B , D , T ]
audio_len ( Tensor ) : [ B ]
Returns :
probs : probs after softmax
"""
eouts , eouts_len = self . encoder ( audio , audio_len )
probs = self . decoder . probs ( eouts )
return probs
Hui Zhang
5 years ago