# -*- coding: utf-8 -*-
#
# This file is part of SIDEKIT.
#
# SIDEKIT is a python package for speaker verification.
# Home page: http://www-lium.univ-lemans.fr/sidekit/
#
# SIDEKIT is a python package for speaker verification.
# Home page: http://www-lium.univ-lemans.fr/sidekit/
#
# SIDEKIT is free software: you can redistribute it and/or modify
# it under the terms of the GNU LLesser General Public License as
# published by the Free Software Foundation, either version 3 of the License,
# or (at your option) any later version.
#
# SIDEKIT is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with SIDEKIT. If not, see <http://www.gnu.org/licenses/>.
"""
Copyright 2014-2019 Anthony Larcher and Sylvain Meignier
:mod:`features_server` provides methods to test gmm models
"""
import numpy
import warnings
import multiprocessing
import ctypes
import logging
import sidekit.sv_utils
import sidekit.frontend
from sidekit.mixture import Mixture
from sidekit.statserver import StatServer
from sidekit.features_server import FeaturesServer
from sidekit.bosaris import Ndx
from sidekit.bosaris import Scores
__license__ = "LGPL"
__author__ = "Anthony Larcher"
__copyright__ = "Copyright 2014-2019 Anthony Larcher"
__maintainer__ = "Anthony Larcher"
__email__ = "anthony.larcher@univ-lemans.fr"
__status__ = "Production"
__docformat__ = 'reStructuredText'
[docs]def gmm_scoring_singleThread(ubm, enroll, ndx, feature_server, score_mat, seg_idx=None):
"""Compute log-likelihood ratios for sequences of acoustic feature
frames between a Universal Background Model (UBM) and a list of Gaussian
Mixture Models (GMMs) which only mean vectors differ from the UBM.
:param ubm: a Mixture object used to compute the denominator
of the likelihood ratios
:param enroll: a StatServer object which stat1 attribute contains mean
super-vectors of the GMMs to use to compute the numerator of the
likelihood ratios.
:param ndx: an Ndx object which define the list of trials to compute
:param feature_server: sidekit.FeaturesServer used to load the acoustic parameters
:param score_mat: a ndarray of scores to fill
:param seg_idx: the list of unique test segments to process.
Those test segments should belong to the list of test segments
in the ndx object. By setting seg_idx=None, all test segments
from the ndx object will be processed
"""
assert isinstance(ubm, Mixture), 'First parameter should be a Mixture'
assert isinstance(enroll, StatServer), 'Second parameter should be a StatServer'
assert isinstance(ndx, Ndx), 'Third parameter should be a Ndx'
assert isinstance(feature_server, FeaturesServer), 'Fourth parameter should be a FeatureServer'
if seg_idx is None:
seg_idx = range(ndx.segset.shape[0])
for ts in seg_idx:
logging.info('Compute trials involving test segment %d/%d', ts + 1, ndx.segset.shape[0])
# Select the models to test with the current segment
models = ndx.modelset[ndx.trialmask[:, ts]]
ind_dict = dict((k, i) for i, k in enumerate(ndx.modelset))
inter = set(ind_dict.keys()).intersection(models)
idx_ndx = [ind_dict[x] for x in inter]
ind_dict = dict((k, i) for i, k in enumerate(enroll.modelset))
inter = set(ind_dict.keys()).intersection(models)
idx_enroll = [ind_dict[x] for x in inter]
# Load feature file
cep, _ = feature_server.load(ndx.segset[ts])
llr = numpy.zeros(numpy.array(idx_enroll).shape)
for m in range(llr.shape[0]):
# Compute llk for the current model
if ubm.invcov.ndim == 2:
lp = ubm.compute_log_posterior_probabilities(cep, enroll.stat1[idx_enroll[m], :])
elif ubm.invcov.ndim == 3:
lp = ubm.compute_log_posterior_probabilities_full(cep, enroll.stat1[idx_enroll[m], :])
pp_max = numpy.max(lp, axis=1)
log_lk = pp_max + numpy.log(numpy.sum(numpy.exp((lp.transpose() - pp_max).transpose()), axis=1))
llr[m] = log_lk.mean()
# Compute and substract llk for the ubm
if ubm.invcov.ndim == 2:
lp = ubm.compute_log_posterior_probabilities(cep)
elif ubm.invcov.ndim == 3:
lp = ubm.compute_log_posterior_probabilities_full(cep)
ppMax = numpy.max(lp, axis=1)
loglk = ppMax + numpy.log(numpy.sum(numpy.exp((lp.transpose() - ppMax).transpose()), axis=1))
llr = llr - loglk.mean()
# Fill the score matrix
score_mat[idx_ndx, ts] = llr
[docs]def gmm_scoring(ubm, enroll, ndx, feature_server, num_thread=1):
"""Compute log-likelihood ratios for sequences of acoustic feature
frames between a Universal Background Model (UBM) and a list of
Gaussian Mixture Models (GMMs) which only mean vectors differ
from the UBM.
:param ubm: a Mixture object used to compute the denominator of the
likelihood ratios
:param enroll: a StatServer object which stat1 attribute contains
mean super-vectors of the GMMs to use to compute the numerator
of the likelihood ratios.
:param ndx: an Ndx object which define the list of trials to compute
:param feature_server: a FeatureServer object to load the features
:param num_thread: number of thread to launch in parallel
:return: a Score object.
"""
assert isinstance(ubm, Mixture), 'First parameter should be a Mixture'
assert isinstance(enroll, StatServer), 'Second parameter should be a StatServer'
assert isinstance(ndx, Ndx), 'Third parameter should be a Ndx'
assert isinstance(feature_server, FeaturesServer), 'Fourth parameter should be a FeatureServer'
# Remove missing models and test segments
if feature_server.features_extractor is None:
existing_test_seg, test_seg_idx = sidekit.sv_utils.check_file_list(ndx.segset,
feature_server.feature_filename_structure)
clean_ndx = ndx.filter(enroll.modelset, existing_test_seg, True)
elif feature_server.features_extractor.audio_filename_structure is not None:
existing_test_seg, test_seg_idx = \
sidekit.sv_utils.check_file_list(ndx.segset, feature_server.features_extractor.audio_filename_structure)
clean_ndx = ndx.filter(enroll.modelset, existing_test_seg, True)
else:
clean_ndx = ndx
s = numpy.zeros(clean_ndx.trialmask.shape)
dims = s.shape
with warnings.catch_warnings():
warnings.simplefilter('ignore', RuntimeWarning)
tmp_stat1 = multiprocessing.Array(ctypes.c_double, s.size)
s = numpy.ctypeslib.as_array(tmp_stat1.get_obj())
s = s.reshape(dims)
# Split the list of segment to process for multi-threading
los = numpy.array_split(numpy.arange(clean_ndx.segset.shape[0]), num_thread)
jobs = []
for idx in los:
p = multiprocessing.Process(target=gmm_scoring_singleThread, args=(ubm, enroll, ndx, feature_server, s, idx))
jobs.append(p)
p.start()
for p in jobs:
p.join()
score = Scores()
score.scoremat = s
score.modelset = clean_ndx.modelset
score.segset = clean_ndx.segset
score.scoremask = clean_ndx.trialmask
return score