Skip to content

Commit e3cc791

Browse files
orgadsorgads
committed
Implement alaw2lin and ulaw2lin
1 parent 996cec4 commit e3cc791

File tree

1 file changed

+94
-2
lines changed

1 file changed

+94
-2
lines changed

‎pydub/pyaudioop.py‎

Lines changed: 94 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -529,20 +529,112 @@ def ratecv(cp, size, nchannels, inrate, outrate, state, weightA=1, weightB=0):
529529
d -= inrate
530530

531531

532+
def _to_lin(table, cp, size):
533+
result = create_string_buffer(len(cp) * size)
534+
535+
for i, sample in enumerate(cp):
536+
_put_sample(result, size, i, table[sample])
537+
538+
return result.raw
539+
540+
# Source: https://github.com/python/cpython/blob/3.12/Modules/audioop.c#L91
541+
_ulaw2lin_table = [
542+
-32124, -31100, -30076, -29052, -28028, -27004, -25980,
543+
-24956, -23932, -22908, -21884, -20860, -19836, -18812,
544+
-17788, -16764, -15996, -15484, -14972, -14460, -13948,
545+
-13436, -12924, -12412, -11900, -11388, -10876, -10364,
546+
-9852, -9340, -8828, -8316, -7932, -7676, -7420,
547+
-7164, -6908, -6652, -6396, -6140, -5884, -5628,
548+
-5372, -5116, -4860, -4604, -4348, -4092, -3900,
549+
-3772, -3644, -3516, -3388, -3260, -3132, -3004,
550+
-2876, -2748, -2620, -2492, -2364, -2236, -2108,
551+
-1980, -1884, -1820, -1756, -1692, -1628, -1564,
552+
-1500, -1436, -1372, -1308, -1244, -1180, -1116,
553+
-1052, -988, -924, -876, -844, -812, -780,
554+
-748, -716, -684, -652, -620, -588, -556,
555+
-524, -492, -460, -428, -396, -372, -356,
556+
-340, -324, -308, -292, -276, -260, -244,
557+
-228, -212, -196, -180, -164, -148, -132,
558+
-120, -112, -104, -96, -88, -80, -72,
559+
-64, -56, -48, -40, -32, -24, -16,
560+
-8, 0, 32124, 31100, 30076, 29052, 28028,
561+
27004, 25980, 24956, 23932, 22908, 21884, 20860,
562+
19836, 18812, 17788, 16764, 15996, 15484, 14972,
563+
14460, 13948, 13436, 12924, 12412, 11900, 11388,
564+
10876, 10364, 9852, 9340, 8828, 8316, 7932,
565+
7676, 7420, 7164, 6908, 6652, 6396, 6140,
566+
5884, 5628, 5372, 5116, 4860, 4604, 4348,
567+
4092, 3900, 3772, 3644, 3516, 3388, 3260,
568+
3132, 3004, 2876, 2748, 2620, 2492, 2364,
569+
2236, 2108, 1980, 1884, 1820, 1756, 1692,
570+
1628, 1564, 1500, 1436, 1372, 1308, 1244,
571+
1180, 1116, 1052, 988, 924, 876, 844,
572+
812, 780, 748, 716, 684, 652, 620,
573+
588, 556, 524, 492, 460, 428, 396,
574+
372, 356, 340, 324, 308, 292, 276,
575+
260, 244, 228, 212, 196, 180, 164,
576+
148, 132, 120, 112, 104, 96, 88,
577+
80, 72, 64, 56, 48, 40, 32,
578+
24, 16, 8, 0
579+
]
580+
581+
532582
def lin2ulaw(cp, size):
533583
raise NotImplementedError()
534584

535585

536586
def ulaw2lin(cp, size):
537-
raise NotImplementedError()
587+
return _to_lin(_ulaw2lin_table, cp, size)
588+
589+
590+
# Source: https://github.com/python/cpython/blob/3.12/Modules/audioop.c#L198
591+
_alaw2lin_table = [
592+
-5504, -5248, -6016, -5760, -4480, -4224, -4992,
593+
-4736, -7552, -7296, -8064, -7808, -6528, -6272,
594+
-7040, -6784, -2752, -2624, -3008, -2880, -2240,
595+
-2112, -2496, -2368, -3776, -3648, -4032, -3904,
596+
-3264, -3136, -3520, -3392, -22016, -20992, -24064,
597+
-23040, -17920, -16896, -19968, -18944, -30208, -29184,
598+
-32256, -31232, -26112, -25088, -28160, -27136, -11008,
599+
-10496, -12032, -11520, -8960, -8448, -9984, -9472,
600+
-15104, -14592, -16128, -15616, -13056, -12544, -14080,
601+
-13568, -344, -328, -376, -360, -280, -264,
602+
-312, -296, -472, -456, -504, -488, -408,
603+
-392, -440, -424, -88, -72, -120, -104,
604+
-24, -8, -56, -40, -216, -200, -248,
605+
-232, -152, -136, -184, -168, -1376, -1312,
606+
-1504, -1440, -1120, -1056, -1248, -1184, -1888,
607+
-1824, -2016, -1952, -1632, -1568, -1760, -1696,
608+
-688, -656, -752, -720, -560, -528, -624,
609+
-592, -944, -912, -1008, -976, -816, -784,
610+
-880, -848, 5504, 5248, 6016, 5760, 4480,
611+
4224, 4992, 4736, 7552, 7296, 8064, 7808,
612+
6528, 6272, 7040, 6784, 2752, 2624, 3008,
613+
2880, 2240, 2112, 2496, 2368, 3776, 3648,
614+
4032, 3904, 3264, 3136, 3520, 3392, 22016,
615+
20992, 24064, 23040, 17920, 16896, 19968, 18944,
616+
30208, 29184, 32256, 31232, 26112, 25088, 28160,
617+
27136, 11008, 10496, 12032, 11520, 8960, 8448,
618+
9984, 9472, 15104, 14592, 16128, 15616, 13056,
619+
12544, 14080, 13568, 344, 328, 376, 360,
620+
280, 264, 312, 296, 472, 456, 504,
621+
488, 408, 392, 440, 424, 88, 72,
622+
120, 104, 24, 8, 56, 40, 216,
623+
200, 248, 232, 152, 136, 184, 168,
624+
1376, 1312, 1504, 1440, 1120, 1056, 1248,
625+
1184, 1888, 1824, 2016, 1952, 1632, 1568,
626+
1760, 1696, 688, 656, 752, 720, 560,
627+
528, 624, 592, 944, 912, 1008, 976,
628+
816, 784, 880, 848
629+
]
538630

539631

540632
def lin2alaw(cp, size):
541633
raise NotImplementedError()
542634

543635

544636
def alaw2lin(cp, size):
545-
raise NotImplementedError()
637+
return _to_lin(_alaw2lin_table, cp, size)
546638

547639

548640
def lin2adpcm(cp, size, state):

0 commit comments

Comments
 (0)