-
Notifications
You must be signed in to change notification settings - Fork 79
/
transform.py
3706 lines (3018 loc) · 134 KB
/
transform.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
#!/usr/bin/env python
# -*- coding: utf-8 -*-
'''
Python wrapper around the SoX library.
This module requires that SoX is installed.
'''
from __future__ import print_function
import os
import random
from pathlib import Path
from typing import List, Optional, Dict, Union, Tuple
import numpy as np
from typing_extensions import Literal
from . import file_info
from .core import ENCODING_VALS, EncodingValue
from .core import SoxError
from .core import VALID_FORMATS
from .core import is_number
from .core import play
from .core import sox
from .log import logger
VERBOSITY_VALS = [0, 1, 2, 3, 4]
ENCODINGS_MAPPING = {
np.int16: 's16',
np.int8: 's8',
np.float32: 'f32',
np.float64: 'f64',
}
GainType = Literal['amplitude', 'power', 'db']
class Transformer:
'''Audio file transformer.
Class which allows multiple effects to be chained to create an output
file, saved to output_filepath.
Methods
-------
set_globals
Overwrite the default global arguments.
build
Execute the current chain of commands to create an output file.
build_file
Alias of build.
build_array
Execute the current chain of commands to create an output array.
'''
def __init__(self):
'''
Attributes
----------
input_format : list of str
Input file format arguments that will be passed to SoX.
output_format : list of str
Output file format arguments that will be bassed to SoX.
effects : list of str
Effects arguments that will be passed to SoX.
effects_log : list of str
Ordered sequence of effects applied.
globals : list of str
Global arguments that will be passed to SoX.
'''
self.input_format = {} # type: Dict
self.output_format = {} # type : Dict
self.effects = [] # type: List[str]
self.effects_log = [] # type: List[str]
self.globals = [] # type: List[str]
self.set_globals()
def set_globals(self, dither: bool = False,
guard: bool = False,
multithread: bool = False,
replay_gain: bool = False,
verbosity: int = 2):
'''Sets SoX's global arguments.
Overwrites any previously set global arguments.
If this function is not explicity called, globals are set to this
function's defaults.
Parameters
----------
dither : bool, default=False
If True, dithering is applied for low files with low bit rates.
guard : bool, default=False
If True, invokes the gain effect to guard against clipping.
multithread : bool, default=False
If True, each channel is processed in parallel.
replay_gain : bool, default=False
If True, applies replay-gain adjustment to input-files.
verbosity : int, default=2
SoX's verbosity level. One of:
* 0 : No messages are shown at all
* 1 : Only error messages are shown. These are generated if SoX
cannot complete the requested commands.
* 2 : Warning messages are also shown. These are generated if
SoX can complete the requested commands, but not exactly
according to the requested command parameters, or if
clipping occurs.
* 3 : Descriptions of SoX’s processing phases are also shown.
Useful for seeing exactly how SoX is processing your audio.
* 4, >4 : Messages to help with debugging SoX are also shown.
'''
if not isinstance(dither, bool):
raise ValueError('dither must be a boolean.')
if not isinstance(guard, bool):
raise ValueError('guard must be a boolean.')
if not isinstance(multithread, bool):
raise ValueError('multithread must be a boolean.')
if not isinstance(replay_gain, bool):
raise ValueError('replay_gain must be a boolean.')
if verbosity not in VERBOSITY_VALS:
raise ValueError(
'Invalid value for VERBOSITY. Must be one {}'.format(
VERBOSITY_VALS)
)
global_args = []
if not dither:
global_args.append('-D')
if guard:
global_args.append('-G')
if multithread:
global_args.append('--multi-threaded')
if replay_gain:
global_args.append('--replay-gain')
global_args.append('track')
global_args.append('-V{}'.format(verbosity))
self.globals = global_args
return self
def _validate_input_format(self, input_format):
'''Private helper function for validating input formats
'''
file_type = input_format.get('file_type')
rate = input_format.get('rate')
bits = input_format.get('bits')
channels = input_format.get('channels')
encoding = input_format.get('encoding')
ignore_length = input_format.get('ignore_length', False)
if file_type not in VALID_FORMATS + [None]:
raise ValueError(
'Invalid file_type. Must be one of {}'.format(VALID_FORMATS)
)
if not is_number(rate) and rate is not None:
raise ValueError('rate must be a float or None')
if rate is not None and rate <= 0:
raise ValueError('rate must be a positive number')
if not isinstance(bits, int) and bits is not None:
raise ValueError('bits must be an int or None')
if bits is not None and bits <= 0:
raise ValueError('bits must be a positive number')
if not isinstance(channels, int) and channels is not None:
raise ValueError('channels must be an int or None')
if channels is not None and channels <= 0:
raise ValueError('channels must be a positive number')
if encoding not in ENCODING_VALS + [None]:
raise ValueError(
'Invalid encoding {}. Must be one of {}'.format(
encoding, ENCODING_VALS)
)
if not isinstance(ignore_length, bool):
raise ValueError('ignore_length must be a boolean')
def _input_format_args(self, input_format):
'''Private helper function for set_input_format
'''
self._validate_input_format(input_format)
file_type = input_format.get('file_type')
rate = input_format.get('rate')
bits = input_format.get('bits')
channels = input_format.get('channels')
encoding = input_format.get('encoding')
ignore_length = input_format.get('ignore_length', False)
input_format_args = []
if file_type is not None:
input_format_args.extend(['-t', '{}'.format(file_type)])
if rate is not None:
input_format_args.extend(['-r', '{:f}'.format(rate)])
if bits is not None:
input_format_args.extend(['-b', '{}'.format(bits)])
if channels is not None:
input_format_args.extend(['-c', '{}'.format(channels)])
if encoding is not None:
input_format_args.extend(['-e', '{}'.format(encoding)])
if ignore_length:
input_format_args.append('--ignore-length')
return input_format_args
def set_input_format(self,
file_type: Optional[str] = None,
rate: Optional[float] = None,
bits: Optional[int] = None,
channels: Optional[int] = None,
encoding: Optional[EncodingValue] = None,
ignore_length: bool = False):
'''Sets input file format arguments. This is primarily useful when
dealing with audio files without a file extension. Overwrites any
previously set input file arguments.
If this function is not explicity called the input format is inferred
from the file extension or the file's header.
Parameters
----------
file_type : str or None, default=None
The file type of the input audio file. Should be the same as what
the file extension would be, for ex. 'mp3' or 'wav'.
rate : float or None, default=None
The sample rate of the input audio file. If None the sample rate
is inferred.
bits : int or None, default=None
The number of bits per sample. If None, the number of bits per
sample is inferred.
channels : int or None, default=None
The number of channels in the audio file. If None the number of
channels is inferred.
encoding : str or None, default=None
The audio encoding type. Sometimes needed with file-types that
support more than one encoding type. One of:
* signed-integer : PCM data stored as signed (‘two’s
complement’) integers. Commonly used with a 16 or 24−bit
encoding size. A value of 0 represents minimum signal
power.
* unsigned-integer : PCM data stored as unsigned integers.
Commonly used with an 8-bit encoding size. A value of 0
represents maximum signal power.
* floating-point : PCM data stored as IEEE 753 single precision
(32-bit) or double precision (64-bit) floating-point
(‘real’) numbers. A value of 0 represents minimum signal
power.
* a-law : International telephony standard for logarithmic
encoding to 8 bits per sample. It has a precision
equivalent to roughly 13-bit PCM and is sometimes encoded
with reversed bit-ordering.
* u-law : North American telephony standard for logarithmic
encoding to 8 bits per sample. A.k.a. μ-law. It has a
precision equivalent to roughly 14-bit PCM and is sometimes
encoded with reversed bit-ordering.
* oki-adpcm : OKI (a.k.a. VOX, Dialogic, or Intel) 4-bit ADPCM;
it has a precision equivalent to roughly 12-bit PCM. ADPCM
is a form of audio compression that has a good compromise
between audio quality and encoding/decoding speed.
* ima-adpcm : IMA (a.k.a. DVI) 4-bit ADPCM; it has a precision
equivalent to roughly 13-bit PCM.
* ms-adpcm : Microsoft 4-bit ADPCM; it has a precision
equivalent to roughly 14-bit PCM.
* gsm-full-rate : GSM is currently used for the vast majority
of the world’s digital wireless telephone calls. It
utilises several audio formats with different bit-rates and
associated speech quality. SoX has support for GSM’s
original 13kbps ‘Full Rate’ audio format. It is usually
CPU-intensive to work with GSM audio.
ignore_length : bool, default=False
If True, overrides an (incorrect) audio length given in an audio
file’s header. If this option is given then SoX will keep reading
audio until it reaches the end of the input file.
'''
input_format = {
'file_type': file_type,
'rate': rate,
'bits': bits,
'channels': channels,
'encoding': encoding,
'ignore_length': ignore_length
}
self._validate_input_format(input_format)
self.input_format = input_format
def _validate_output_format(self, output_format):
'''Private helper function for validating input formats
'''
file_type = output_format.get('file_type')
rate = output_format.get('rate')
bits = output_format.get('bits')
channels = output_format.get('channels')
encoding = output_format.get('encoding')
comments = output_format.get('comments')
append_comments = output_format.get('append_comments', True)
if file_type not in VALID_FORMATS + [None]:
raise ValueError(
'Invalid file_type. Must be one of {}'.format(VALID_FORMATS)
)
if not is_number(rate) and rate is not None:
raise ValueError('rate must be a float or None')
if rate is not None and rate <= 0:
raise ValueError('rate must be a positive number')
if not isinstance(bits, int) and bits is not None:
raise ValueError('bits must be an int or None')
if bits is not None and bits <= 0:
raise ValueError('bits must be a positive number')
if not isinstance(channels, int) and channels is not None:
raise ValueError('channels must be an int or None')
if channels is not None and channels <= 0:
raise ValueError('channels must be a positive number')
if encoding not in ENCODING_VALS + [None]:
raise ValueError(
'Invalid encoding. Must be one of {}'.format(ENCODING_VALS)
)
if comments is not None and not isinstance(comments, str):
raise ValueError('comments must be a string or None')
if not isinstance(append_comments, bool):
raise ValueError('append_comments must be a boolean')
def _output_format_args(self, output_format):
'''Private helper function for set_output_format
'''
self._validate_output_format(output_format)
file_type = output_format.get('file_type')
rate = output_format.get('rate')
bits = output_format.get('bits')
channels = output_format.get('channels')
encoding = output_format.get('encoding')
comments = output_format.get('comments')
append_comments = output_format.get('append_comments', True)
output_format_args = []
if file_type is not None:
output_format_args.extend(['-t', '{}'.format(file_type)])
if rate is not None:
output_format_args.extend(['-r', '{:f}'.format(rate)])
if bits is not None:
output_format_args.extend(['-b', '{}'.format(bits)])
if channels is not None:
output_format_args.extend(['-c', '{}'.format(channels)])
if encoding is not None:
output_format_args.extend(['-e', '{}'.format(encoding)])
if comments is not None:
if append_comments:
output_format_args.extend(['--add-comment', comments])
else:
output_format_args.extend(['--comment', comments])
return output_format_args
def set_output_format(self,
file_type: Optional[str] = None,
rate: Optional[float] = None,
bits: Optional[int] = None,
channels: Optional[int] = None,
encoding: Optional[EncodingValue] = None,
comments: Optional[str] = None,
append_comments: bool = True):
'''Sets output file format arguments. These arguments will overwrite
any format related arguments supplied by other effects (e.g. rate).
If this function is not explicity called the output format is inferred
from the file extension or the file's header.
Parameters
----------
file_type : str or None, default=None
The file type of the output audio file. Should be the same as what
the file extension would be, for ex. 'mp3' or 'wav'.
rate : float or None, default=None
The sample rate of the output audio file. If None the sample rate
is inferred.
bits : int or None, default=None
The number of bits per sample. If None, the number of bits per
sample is inferred.
channels : int or None, default=None
The number of channels in the audio file. If None the number of
channels is inferred.
encoding : str or None, default=None
The audio encoding type. Sometimes needed with file-types that
support more than one encoding type. One of:
* signed-integer : PCM data stored as signed (‘two’s
complement’) integers. Commonly used with a 16 or 24−bit
encoding size. A value of 0 represents minimum signal
power.
* unsigned-integer : PCM data stored as unsigned integers.
Commonly used with an 8-bit encoding size. A value of 0
represents maximum signal power.
* floating-point : PCM data stored as IEEE 753 single precision
(32-bit) or double precision (64-bit) floating-point
(‘real’) numbers. A value of 0 represents minimum signal
power.
* a-law : International telephony standard for logarithmic
encoding to 8 bits per sample. It has a precision
equivalent to roughly 13-bit PCM and is sometimes encoded
with reversed bit-ordering.
* u-law : North American telephony standard for logarithmic
encoding to 8 bits per sample. A.k.a. μ-law. It has a
precision equivalent to roughly 14-bit PCM and is sometimes
encoded with reversed bit-ordering.
* oki-adpcm : OKI (a.k.a. VOX, Dialogic, or Intel) 4-bit ADPCM;
it has a precision equivalent to roughly 12-bit PCM. ADPCM
is a form of audio compression that has a good compromise
between audio quality and encoding/decoding speed.
* ima-adpcm : IMA (a.k.a. DVI) 4-bit ADPCM; it has a precision
equivalent to roughly 13-bit PCM.
* ms-adpcm : Microsoft 4-bit ADPCM; it has a precision
equivalent to roughly 14-bit PCM.
* gsm-full-rate : GSM is currently used for the vast majority
of the world’s digital wireless telephone calls. It
utilises several audio formats with different bit-rates and
associated speech quality. SoX has support for GSM’s
original 13kbps ‘Full Rate’ audio format. It is usually
CPU-intensive to work with GSM audio.
comments : str or None, default=None
If not None, the string is added as a comment in the header of the
output audio file. If None, no comments are added.
append_comments : bool, default=True
If True, comment strings are appended to SoX's default comments. If
False, the supplied comment replaces the existing comment.
'''
output_format = {
'file_type': file_type,
'rate': rate,
'bits': bits,
'channels': channels,
'encoding': encoding,
'comments': comments,
'append_comments': append_comments
}
self._validate_output_format(output_format)
self.output_format = output_format
def clear_effects(self):
'''Remove all effects processes.
'''
self.effects = list()
self.effects_log = list()
return self
def _parse_inputs(self, input_filepath, input_array, sample_rate_in):
'''Private helper function for parsing inputs to build and build_array
Parameters
----------
input_filepath : str or None
Either path to input audio file or None.
input_array : np.ndarray or None
A np.ndarray of an waveform with shape (n_samples, n_channels)
or None
sample_rate_in : int or None
Sample rate of input_array or None
Returns
-------
input_format : dict
Input format dictionary
input_filepath : str
Formatted input filepath.
'''
if input_filepath is not None and input_array is not None:
raise ValueError(
"Only one of input_filepath and input_array may be specified"
)
# set input parameters
if input_filepath is not None:
file_info.validate_input_file(input_filepath)
input_format = self.input_format
if input_format.get('channels') is None:
input_format['channels'] = file_info.channels(input_filepath)
elif input_array is not None:
if not isinstance(input_array, np.ndarray):
raise TypeError("input_array must be a numpy array or None")
if sample_rate_in is None:
raise ValueError(
"sample_rate_in must be specified for array inputs"
)
input_filepath = '-'
input_format = {
'file_type': ENCODINGS_MAPPING[input_array.dtype.type],
'rate': sample_rate_in,
'bits': None,
'channels': (
input_array.shape[-1] if len(input_array.shape) > 1 else 1
),
'encoding': None,
'ignore_length': False
}
else:
raise ValueError(
"One of input_filepath or input_array must be specified"
)
return input_format, input_filepath
def build(self,
input_filepath: Optional[Union[str, Path]] = None,
output_filepath: Optional[Union[str, Path]] = None,
input_array: Optional[str] = None,
sample_rate_in: Optional[float] = None,
extra_args: Optional[List[str]] = None,
return_output: bool = False):
'''Given an input file or array, creates an output_file on disk by
executing the current set of commands. This function returns True on
success. If return_output is True, this function returns a triple of
(status, out, err), giving the success state, along with stdout and
stderr returned by sox.
Parameters
----------
input_filepath : str or None
Either path to input audio file or None for array input.
output_filepath : str
Path to desired output file. If a file already exists at
the given path, the file will be overwritten.
If '-n', no file is created.
input_array : np.ndarray or None
An np.ndarray of an waveform with shape (n_samples, n_channels).
sample_rate_in must also be provided.
If None, input_filepath must be specified.
sample_rate_in : int
Sample rate of input_array.
This argument is ignored if input_array is None.
extra_args : list or None, default=None
If a list is given, these additional arguments are passed to SoX
at the end of the list of effects.
Don't use this argument unless you know exactly what you're doing!
return_output : bool, default=False
If True, returns the status and information sent to stderr and
stdout as a tuple (status, stdout, stderr).
If output_filepath is None, return_output=True by default.
If False, returns True on success.
Returns
-------
status : bool
True on success.
out : str (optional)
This is not returned unless return_output is True.
When returned, captures the stdout produced by sox.
err : str (optional)
This is not returned unless return_output is True.
When returned, captures the stderr produced by sox.
Examples
--------
>>> import numpy as np
>>> import sox
>>> tfm = sox.Transformer()
>>> sample_rate = 44100
>>> y = np.sin(2 * np.pi * 440.0 * np.arange(sample_rate * 1.0) / sample_rate)
file in, file out - basic usage
>>> status = tfm.build('path/to/input.wav', 'path/to/output.mp3')
file in, file out - equivalent usage
>>> status = tfm.build(
input_filepath='path/to/input.wav',
output_filepath='path/to/output.mp3'
)
array in, file out
>>> status = tfm.build(
input_array=y, sample_rate_in=sample_rate,
output_filepath='path/to/output.mp3'
)
'''
input_format, input_filepath = self._parse_inputs(
input_filepath, input_array, sample_rate_in
)
if output_filepath is None:
raise ValueError("output_filepath is not specified!")
# set output parameters
if input_filepath == output_filepath:
raise ValueError(
"input_filepath must be different from output_filepath."
)
file_info.validate_output_file(output_filepath)
args = []
args.extend(self.globals)
args.extend(self._input_format_args(input_format))
args.append(input_filepath)
args.extend(self._output_format_args(self.output_format))
args.append(output_filepath)
args.extend(self.effects)
if extra_args is not None:
if not isinstance(extra_args, list):
raise ValueError("extra_args must be a list.")
args.extend(extra_args)
status, out, err = sox(args, input_array, True)
if status != 0:
raise SoxError(
"Stdout: {}\nStderr: {}".format(out, err)
)
logger.info(
"Created %s with effects: %s",
output_filepath,
" ".join(self.effects_log)
)
if return_output:
return status, out, err
return True
def build_file(self,
input_filepath: Optional[Union[str, Path]] = None,
output_filepath: Optional[Union[str, Path]] = None,
input_array: Optional[np.ndarray] = None,
sample_rate_in: Optional[float] = None,
extra_args: Optional[List[str]] = None,
return_output: bool = False):
'''An alias for build.
Given an input file or array, creates an output_file on disk by
executing the current set of commands. This function returns True on
success. If return_output is True, this function returns a triple of
(status, out, err), giving the success state, along with stdout and
stderr returned by sox.
Parameters
----------
input_filepath : str or None
Either path to input audio file or None for array input.
output_filepath : str
Path to desired output file. If a file already exists at
the given path, the file will be overwritten.
If '-n', no file is created.
input_array : np.ndarray or None
An np.ndarray of an waveform with shape (n_samples, n_channels).
sample_rate_in must also be provided.
If None, input_filepath must be specified.
sample_rate_in : int
Sample rate of input_array.
This argument is ignored if input_array is None.
extra_args : list or None, default=None
If a list is given, these additional arguments are passed to SoX
at the end of the list of effects.
Don't use this argument unless you know exactly what you're doing!
return_output : bool, default=False
If True, returns the status and information sent to stderr and
stdout as a tuple (status, stdout, stderr).
If output_filepath is None, return_output=True by default.
If False, returns True on success.
Returns
-------
status : bool
True on success.
out : str (optional)
This is not returned unless return_output is True.
When returned, captures the stdout produced by sox.
err : str (optional)
This is not returned unless return_output is True.
When returned, captures the stderr produced by sox.
Examples
--------
>>> import numpy as np
>>> import sox
>>> tfm = sox.Transformer()
>>> sample_rate = 44100
>>> y = np.sin(2 * np.pi * 440.0 * np.arange(sample_rate * 1.0) / sample_rate)
file in, file out - basic usage
>>> status = tfm.build('path/to/input.wav', 'path/to/output.mp3')
file in, file out - equivalent usage
>>> status = tfm.build(
input_filepath='path/to/input.wav',
output_filepath='path/to/output.mp3'
)
array in, file out
>>> status = tfm.build(
input_array=y, sample_rate_in=sample_rate,
output_filepath='path/to/output.mp3'
)
'''
return self.build(
input_filepath, output_filepath, input_array, sample_rate_in,
extra_args, return_output
)
def build_array(self,
input_filepath: Optional[Union[str, Path]] = None,
input_array: Optional[np.ndarray] = None,
sample_rate_in: Optional[float] = None,
extra_args: Optional[List[str]] = None):
'''Given an input file or array, returns the ouput as a numpy array
by executing the current set of commands. By default the array will
have the same sample rate as the input file unless otherwise specified
using set_output_format. Functions such as rate, channels and convert
will be ignored!
Parameters
----------
input_filepath : str or None
Either path to input audio file or None.
input_array : np.ndarray or None
A np.ndarray of an waveform with shape (n_samples, n_channels).
If this argument is passed, sample_rate_in must also be provided.
If None, input_filepath must be specified.
sample_rate_in : int
Sample rate of input_array.
This argument is ignored if input_array is None.
extra_args : list or None, default=None
If a list is given, these additional arguments are passed to SoX
at the end of the list of effects.
Don't use this argument unless you know exactly what you're doing!
Returns
-------
output_array : np.ndarray
Output audio as a numpy array
Examples
--------
>>> import numpy as np
>>> import sox
>>> tfm = sox.Transformer()
>>> sample_rate = 44100
>>> y = np.sin(2 * np.pi * 440.0 * np.arange(sample_rate * 1.0) / sample_rate)
file in, array out
>>> output_array = tfm.build(input_filepath='path/to/input.wav')
array in, array out
>>> output_array = tfm.build(input_array=y, sample_rate_in=sample_rate)
specifying the output sample rate
>>> tfm.set_output_format(rate=8000)
>>> output_array = tfm.build(input_array=y, sample_rate_in=sample_rate)
if an effect changes the number of channels, you must explicitly
specify the number of output channels
>>> tfm.remix(remix_dictionary={1: [1], 2: [1], 3: [1]})
>>> tfm.set_output_format(channels=3)
>>> output_array = tfm.build(input_array=y, sample_rate_in=sample_rate)
'''
input_format, input_filepath = self._parse_inputs(
input_filepath, input_array, sample_rate_in
)
# check if any of the below commands are part of the effects chain
ignored_commands = ['rate', 'channels', 'convert']
if set(ignored_commands) & set(self.effects_log):
logger.warning(
"When outputting to an array, rate, channels and convert " +
"effects may be ignored. Use set_output_format() to " +
"specify output formats."
)
output_filepath = '-'
if input_format.get('file_type') is None:
encoding_out = np.int16
else:
encoding_out = [
k for k, v in ENCODINGS_MAPPING.items()
if input_format['file_type'] == v
][0]
n_bits = np.dtype(encoding_out).itemsize * 8
output_format = {
'file_type': 'raw',
'rate': sample_rate_in,
'bits': n_bits,
'channels': input_format['channels'],
'encoding': None,
'comments': None,
'append_comments': True,
}
if self.output_format.get('rate') is not None:
output_format['rate'] = self.output_format['rate']
if self.output_format.get('channels') is not None:
output_format['channels'] = self.output_format['channels']
if self.output_format.get('bits') is not None:
n_bits = self.output_format['bits']
output_format['bits'] = n_bits
if n_bits == 8:
encoding_out = np.int8
elif n_bits == 16:
encoding_out = np.int16
elif n_bits == 32:
encoding_out = np.float32
elif n_bits == 64:
encoding_out = np.float64
else:
raise ValueError("invalid n_bits {}".format(n_bits))
args = []
args.extend(self.globals)
args.extend(self._input_format_args(input_format))
args.append(input_filepath)
args.extend(self._output_format_args(output_format))
args.append(output_filepath)
args.extend(self.effects)
if extra_args is not None:
if not isinstance(extra_args, list):
raise ValueError("extra_args must be a list.")
args.extend(extra_args)
status, out, err = sox(args, input_array, False)
if status != 0:
raise SoxError(
"Stdout: {}\nStderr: {}".format(out, err)
)
out = np.frombuffer(out, dtype=encoding_out)
if output_format['channels'] > 1:
out = out.reshape(
(
output_format['channels'],
int(len(out) / output_format['channels'])
), order='F'
).T
logger.info(
"Created array with effects: %s",
" ".join(self.effects_log)
)
return out
def preview(self, input_filepath: Union[str, Path]):
'''Play a preview of the output with the current set of effects
Parameters
----------
input_filepath : str
Path to input audio file.
'''
args = ["play", "--no-show-progress"]
args.extend(self.globals)
args.extend(self.input_format)
args.append(input_filepath)
args.extend(self.effects)
play(args)
def allpass(self, frequency: float, width_q: float = 2.0):
'''Apply a two-pole all-pass filter. An all-pass filter changes the
audio’s frequency to phase relationship without changing its frequency
to amplitude relationship. The filter is described in detail in at
http://musicdsp.org/files/Audio-EQ-Cookbook.txt
Parameters
----------
frequency : float
The filter's center frequency in Hz.
width_q : float, default=2.0
The filter's width as a Q-factor.
See Also
--------
equalizer, highpass, lowpass, sinc
'''
if not is_number(frequency) or frequency <= 0:
raise ValueError("frequency must be a positive number.")
if not is_number(width_q) or width_q <= 0:
raise ValueError("width_q must be a positive number.")
effect_args = [
'allpass', '{:f}'.format(frequency), '{:f}q'.format(width_q)
]
self.effects.extend(effect_args)
self.effects_log.append('allpass')
return self
def bandpass(self, frequency: float, width_q: float = 2.0,
constant_skirt: bool = False):
'''Apply a two-pole Butterworth band-pass filter with the given central
frequency, and (3dB-point) band-width. The filter rolls off at 6dB per
octave (20dB per decade) and is described in detail in
http://musicdsp.org/files/Audio-EQ-Cookbook.txt
Parameters
----------
frequency : float
The filter's center frequency in Hz.
width_q : float, default=2.0
The filter's width as a Q-factor.
constant_skirt : bool, default=False
If True, selects constant skirt gain (peak gain = width_q).
If False, selects constant 0dB peak gain.
See Also
--------
bandreject, sinc
'''
if not is_number(frequency) or frequency <= 0:
raise ValueError("frequency must be a positive number.")
if not is_number(width_q) or width_q <= 0:
raise ValueError("width_q must be a positive number.")
if not isinstance(constant_skirt, bool):
raise ValueError("constant_skirt must be a boolean.")
effect_args = ['bandpass']
if constant_skirt:
effect_args.append('-c')
effect_args.extend(['{:f}'.format(frequency), '{:f}q'.format(width_q)])
self.effects.extend(effect_args)
self.effects_log.append('bandpass')
return self
def bandreject(self, frequency: float, width_q: float = 2.0,
constant_skirt: bool = False):
'''Apply a two-pole Butterworth band-reject filter with the given
central frequency, and (3dB-point) band-width. The filter rolls off at
6dB per octave (20dB per decade) and is described in detail in
http://musicdsp.org/files/Audio-EQ-Cookbook.txt
Parameters
----------
frequency : float
The filter's center frequency in Hz.
width_q : float, default=2.0
The filter's width as a Q-factor.
constant_skirt : bool, default=False
If True, selects constant skirt gain (peak gain = width_q).
If False, selects constant 0dB peak gain.