Revert to a pipelined approach for test epochs to avoid CPU OOM with large alphabets

This commit is contained in:
Reuben Morais 2019-05-11 08:15:28 -03:00
parent a4b35d2f24
commit 699e4ebcd7
4 changed files with 49 additions and 69 deletions

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@ -19,7 +19,6 @@ from util.evaluate_tools import calculate_report
from util.feeding import create_dataset
from util.flags import create_flags, FLAGS
from util.logging import log_error, log_progress, create_progressbar
from util.text import levenshtein
def sparse_tensor_value_to_texts(value, alphabet):
@ -88,14 +87,13 @@ def evaluate(test_csvs, create_model, try_loading):
exit(1)
def run_test(init_op, dataset):
logitses = []
losses = []
seq_lengths = []
predictions = []
ground_truths = []
bar = create_progressbar(prefix='Computing acoustic model predictions | ',
bar = create_progressbar(prefix='Test epoch | ',
widgets=['Steps: ', progressbar.Counter(), ' | ', progressbar.Timer()]).start()
log_progress('Computing acoustic model predictions...')
log_progress('Test epoch...')
step_count = 0
@ -105,35 +103,23 @@ def evaluate(test_csvs, create_model, try_loading):
# First pass, compute losses and transposed logits for decoding
while True:
try:
logits, loss_, lengths, transcripts = session.run([transposed, loss, batch_x_len, batch_y])
batch_logits, batch_loss, batch_lengths, batch_transcripts = \
session.run([transposed, loss, batch_x_len, batch_y])
except tf.errors.OutOfRangeError:
break
decoded = ctc_beam_search_decoder_batch(batch_logits, batch_lengths, Config.alphabet, FLAGS.beam_width,
num_processes=num_processes, scorer=scorer)
predictions.extend(d[0][1] for d in decoded)
ground_truths.extend(sparse_tensor_value_to_texts(batch_transcripts, Config.alphabet))
losses.extend(batch_loss)
step_count += 1
bar.update(step_count)
logitses.append(logits)
losses.extend(loss_)
seq_lengths.append(lengths)
ground_truths.extend(sparse_tensor_value_to_texts(transcripts, Config.alphabet))
bar.finish()
predictions = []
bar = create_progressbar(max_value=step_count,
prefix='Decoding predictions | ').start()
log_progress('Decoding predictions...')
# Second pass, decode logits and compute WER and edit distance metrics
for logits, seq_length in bar(zip(logitses, seq_lengths)):
decoded = ctc_beam_search_decoder_batch(logits, seq_length, Config.alphabet, FLAGS.beam_width,
num_processes=num_processes, scorer=scorer)
predictions.extend(d[0][1] for d in decoded)
distances = [levenshtein(a, b) for a, b in zip(ground_truths, predictions)]
wer, cer, samples = calculate_report(ground_truths, predictions, distances, losses)
wer, cer, samples = calculate_report(ground_truths, predictions, losses)
mean_loss = np.mean(losses)
# Take only the first report_count items
@ -144,7 +130,7 @@ def evaluate(test_csvs, create_model, try_loading):
print('-' * 80)
for sample in report_samples:
print('WER: %f, CER: %f, loss: %f' %
(sample.wer, sample.distance, sample.loss))
(sample.wer, sample.cer, sample.loss))
print(' - src: "%s"' % sample.src)
print(' - res: "%s"' % sample.res)
print('-' * 80)

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@ -13,7 +13,6 @@ from six.moves import zip, range
from multiprocessing import JoinableQueue, Pool, Process, Queue, cpu_count
from deepspeech import Model
from util.text import levenshtein
from util.evaluate_tools import process_decode_result, calculate_report
r'''
@ -96,9 +95,7 @@ def main():
ground_truths.append(msg['ground_truth'])
predictions.append(msg['prediction'])
distances = [levenshtein(a, b) for a, b in zip(ground_truths, predictions)]
wer, cer, samples = calculate_report(ground_truths, predictions, distances, losses)
wer, cer, samples = calculate_report(ground_truths, predictions, losses)
mean_loss = np.mean(losses)
print('Test - WER: %f, CER: %f, loss: %f' %

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@ -6,7 +6,8 @@ from multiprocessing.dummy import Pool
from attrdict import AttrDict
from util.text import wer_cer_batch, levenshtein
from util.text import levenshtein
def pmap(fun, iterable):
pool = Pool()
@ -14,29 +15,53 @@ def pmap(fun, iterable):
pool.close()
return results
def wer_cer_batch(samples):
r"""
The WER is defined as the edit/Levenshtein distance on word level divided by
the amount of words in the original text.
In case of the original having more words (N) than the result and both
being totally different (all N words resulting in 1 edit operation each),
the WER will always be 1 (N / N = 1).
"""
wer = sum(s.word_distance for s in samples) / sum(s.word_length for s in samples)
cer = sum(s.char_distance for s in samples) / sum(s.char_length for s in samples)
wer = min(wer, 1.0)
cer = min(cer, 1.0)
return wer, cer
def process_decode_result(item):
label, decoding, distance, loss = item
word_distance = levenshtein(label.split(), decoding.split())
word_length = float(len(label.split()))
ground_truth, prediction, loss = item
char_distance = levenshtein(ground_truth, prediction)
char_length = len(ground_truth)
word_distance = levenshtein(ground_truth.split(), prediction.split())
word_length = len(ground_truth.split())
return AttrDict({
'src': label,
'res': decoding,
'src': ground_truth,
'res': prediction,
'loss': loss,
'distance': distance,
'char_distance': char_distance,
'char_length': char_length,
'word_distance': word_distance,
'word_length': word_length,
'cer': char_distance / char_length,
'wer': word_distance / word_length,
})
def calculate_report(labels, decodings, distances, losses):
def calculate_report(labels, decodings, losses):
r'''
This routine will calculate a WER report.
It'll compute the `mean` WER and create ``Sample`` objects of the ``report_count`` top lowest
loss items from the provided WER results tuple (only items with WER!=0 and ordered by their WER).
'''
samples = pmap(process_decode_result, zip(labels, decodings, distances, losses))
samples = pmap(process_decode_result, zip(labels, decodings, losses))
# Getting the WER and CER from the accumulated edit distances and lengths
samples_wer, samples_cer = wer_cer_batch(labels, decodings)
samples_wer, samples_cer = wer_cer_batch(samples)
# Order the remaining items by their loss (lowest loss on top)
samples.sort(key=lambda s: s.loss)

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@ -55,34 +55,6 @@ def text_to_char_array(original, alphabet):
return np.asarray([alphabet.label_from_string(c) for c in original])
def wer_cer_batch(originals, results):
r"""
The WER is defined as the editing/Levenshtein distance on word level
divided by the amount of words in the original text.
In case of the original having more words (N) than the result and both
being totally different (all N words resulting in 1 edit operation each),
the WER will always be 1 (N / N = 1).
"""
# The WER is calculated on word (and NOT on character) level.
# Therefore we split the strings into words first
assert len(originals) == len(results)
total_cer = 0.0
total_char_length = 0.0
total_wer = 0.0
total_word_length = 0.0
for original, result in zip(originals, results):
total_cer += levenshtein(original, result)
total_char_length += len(original)
total_wer += levenshtein(original.split(), result.split())
total_word_length += len(original.split())
return total_wer / total_word_length, total_cer / total_char_length
# The following code is from: http://hetland.org/coding/python/levenshtein.py
# This is a straightforward implementation of a well-known algorithm, and thus