def select_features(cls, features_id, file_struct, annot_beats, framesync):
"""Selects the features from the given parameters.
Parameters
----------
features_id: str
The identifier of the features (it must be a key inside the
`features_registry`)
file_struct: msaf.io.FileStruct
The file struct containing the files to extract the features from
annot_beats: boolean
Whether to use annotated (`True`) or estimated (`False`) beats
framesync: boolean
Whether to use framesync (`True`) or beatsync (`False`) features
Returns
-------
features: obj
The actual features object that inherits from `msaf.Features`
"""
if framesync:
feat_type = FeatureTypes.est_beatsync
elif annot_beats and not framesync:
feat_type = FeatureTypes.ann_beatsync
elif not annot_beats and not framesync:
feat_type = FeatureTypes.est_beatsync
else:
raise FeatureTypeNotFound("Type of features not valid.")
# Select features with default parameters
return features_registry[features_id](file_struct, feat_type)
def features(self):
"""This getter will compute the actual features if they haven't
been computed yet.
Returns
-------
features: np.array
The actual features. Each row corresponds to a feature vector.
"""
# Compute features if needed
if self._features is None:
try:
self.read_features()
except (NoFeaturesFileError, FeaturesNotFound,
WrongFeaturesFormatError, FeatureParamsError) as e:
try:
self._compute_all_features()
self.write_features()
except IOError:
if isinstance(e, FeaturesNotFound) or \
isinstance(e, FeatureParamsError):
msg = "Computation of the features is needed for " \
"current parameters but no audio file was found." \
"Please, change your parameters or add the audio" \
" file in %s"
else:
msg = "Couldn't find audio file in %s"
raise NoAudioFileError(msg % self.file_struct.audio_file)
# Choose features based on type
if self.feat_type is FeatureTypes.framesync:
self._features = self._framesync_features
elif self.feat_type is FeatureTypes.est_beatsync:
self._features = self._est_beatsync_features
elif self.feat_type is FeatureTypes.ann_beatsync:
if self._ann_beatsync_features is None:
raise FeatureTypeNotFound(
"Feature type %s is not valid because no annotated beats "
"were found" % self.feat_type)
self._features = self._ann_beatsync_features
else:
raise FeatureTypeNotFound("Feature type %s is not valid." %
self.feat_type)
return self._features
def frame_times(self):
"""This getter returns the frame times, for the corresponding type of
features."""
frame_times = None
# Make sure we have already computed the features
features = self.features
if self.feat_type is FeatureTypes.framesync:
frame_times = np.array([
i * self.hop_length / float(self.sr)
for i in np.arange(features.shape[0])
])
elif self.feat_type is FeatureTypes.est_beatsync:
frame_times = self._est_beats_times
elif self.feat_type is FeatureTypes.ann_beatsync:
if self._ann_beatsync_features is None:
raise FeatureTypeNotFound(
"Feature type %s is not valid because no annotated beats "
"were found" % self.feat_type)
frame_times = self._ann_beats_times
else:
raise FeatureTypeNotFound("Feature type %s is not valid" %
self.feat_type)
return frame_times