1#!/usr/bin/env python3
2#
3# Copyright 2022 Google LLC
4#
5# Licensed under the Apache License, Version 2.0 (the "License");
6# you may not use this file except in compliance with the License.
7# You may obtain a copy of the License at
8#
9#     http://www.apache.org/licenses/LICENSE-2.0
10#
11# Unless required by applicable law or agreed to in writing, software
12# distributed under the License is distributed on an "AS IS" BASIS,
13# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14# See the License for the specific language governing permissions and
15# limitations under the License.
16#
17
18import numpy as np
19
20LTPF_H12K8 = np.array([
21    -2.04305583e-05, -4.46345894e-05, -7.16366399e-05, -1.00101113e-04,
22    -1.28372848e-04, -1.54543830e-04, -1.76544567e-04, -1.92256960e-04,
23    -1.99643819e-04, -1.96888686e-04, -1.82538332e-04, -1.55639427e-04,
24    -1.15860365e-04, -6.35893034e-05,  2.81006480e-19,  7.29218021e-05,
25     1.52397076e-04,  2.34920777e-04,  3.16378650e-04,  3.92211738e-04,
26     4.57623849e-04,  5.07824294e-04,  5.38295523e-04,  5.45072918e-04,
27     5.25022155e-04,  4.76098424e-04,  3.97571380e-04,  2.90200217e-04,
28     1.56344667e-04, -5.81880142e-19, -1.73252713e-04, -3.56385965e-04,
29    -5.41155231e-04, -7.18414023e-04, -8.78505232e-04, -1.01171451e-03,
30    -1.10876706e-03, -1.16134522e-03, -1.16260169e-03, -1.10764097e-03,
31    -9.93941563e-04, -8.21692190e-04, -5.94017766e-04, -3.17074654e-04,
32     9.74695082e-19,  3.45293760e-04,  7.04480871e-04,  1.06133447e-03,
33     1.39837473e-03,  1.69763080e-03,  1.94148675e-03,  2.11357591e-03,
34     2.19968245e-03,  2.18860625e-03,  2.07294546e-03,  1.84975249e-03,
35     1.52102188e-03,  1.09397426e-03,  5.81108062e-04, -1.42248266e-18,
36    -6.27153730e-04, -1.27425140e-03, -1.91223839e-03, -2.51026925e-03,
37    -3.03703830e-03, -3.46222687e-03, -3.75800672e-03, -3.90053247e-03,
38    -3.87135231e-03, -3.65866558e-03, -3.25835851e-03, -2.67475555e-03,
39    -1.92103305e-03, -1.01925433e-03,  1.86962369e-18,  1.09841545e-03,
40     2.23113197e-03,  3.34830927e-03,  4.39702277e-03,  5.32342672e-03,
41     6.07510531e-03,  6.60352025e-03,  6.86645399e-03,  6.83034270e-03,
42     6.47239234e-03,  5.78237521e-03,  4.76401273e-03,  3.43586351e-03,
43     1.83165284e-03, -2.25189837e-18, -1.99647619e-03, -4.08266886e-03,
44    -6.17308037e-03, -8.17444895e-03, -9.98882386e-03, -1.15169871e-02,
45    -1.26621006e-02, -1.33334458e-02, -1.34501120e-02, -1.29444881e-02,
46    -1.17654154e-02, -9.88086732e-03, -7.28003640e-03, -3.97473021e-03,
47     2.50961778e-18,  4.58604422e-03,  9.70324900e-03,  1.52512477e-02,
48     2.11120585e-02,  2.71533724e-02,  3.32324245e-02,  3.92003203e-02,
49     4.49066644e-02,  5.02043309e-02,  5.49542017e-02,  5.90297032e-02,
50     6.23209727e-02,  6.47385023e-02,  6.62161245e-02,  6.67132287e-02,
51     6.62161245e-02,  6.47385023e-02,  6.23209727e-02,  5.90297032e-02,
52     5.49542017e-02,  5.02043309e-02,  4.49066644e-02,  3.92003203e-02,
53     3.32324245e-02,  2.71533724e-02,  2.11120585e-02,  1.52512477e-02,
54     9.70324900e-03,  4.58604422e-03,  2.50961778e-18, -3.97473021e-03,
55    -7.28003640e-03, -9.88086732e-03, -1.17654154e-02, -1.29444881e-02,
56    -1.34501120e-02, -1.33334458e-02, -1.26621006e-02, -1.15169871e-02,
57    -9.98882386e-03, -8.17444895e-03, -6.17308037e-03, -4.08266886e-03,
58    -1.99647619e-03, -2.25189837e-18,  1.83165284e-03,  3.43586351e-03,
59     4.76401273e-03,  5.78237521e-03,  6.47239234e-03,  6.83034270e-03,
60     6.86645399e-03,  6.60352025e-03,  6.07510531e-03,  5.32342672e-03,
61     4.39702277e-03,  3.34830927e-03,  2.23113197e-03,  1.09841545e-03,
62     1.86962369e-18, -1.01925433e-03, -1.92103305e-03, -2.67475555e-03,
63    -3.25835851e-03, -3.65866558e-03, -3.87135231e-03, -3.90053247e-03,
64    -3.75800672e-03, -3.46222687e-03, -3.03703830e-03, -2.51026925e-03,
65    -1.91223839e-03, -1.27425140e-03, -6.27153730e-04, -1.42248266e-18,
66     5.81108062e-04,  1.09397426e-03,  1.52102188e-03,  1.84975249e-03,
67     2.07294546e-03,  2.18860625e-03,  2.19968245e-03,  2.11357591e-03,
68     1.94148675e-03,  1.69763080e-03,  1.39837473e-03,  1.06133447e-03,
69     7.04480871e-04,  3.45293760e-04,  9.74695082e-19, -3.17074654e-04,
70    -5.94017766e-04, -8.21692190e-04, -9.93941563e-04, -1.10764097e-03,
71    -1.16260169e-03, -1.16134522e-03, -1.10876706e-03, -1.01171451e-03,
72    -8.78505232e-04, -7.18414023e-04, -5.41155231e-04, -3.56385965e-04,
73    -1.73252713e-04, -5.81880142e-19,  1.56344667e-04,  2.90200217e-04,
74     3.97571380e-04,  4.76098424e-04,  5.25022155e-04,  5.45072918e-04,
75     5.38295523e-04,  5.07824294e-04,  4.57623849e-04,  3.92211738e-04,
76     3.16378650e-04,  2.34920777e-04,  1.52397076e-04,  7.29218021e-05,
77     2.81006480e-19, -6.35893034e-05, -1.15860365e-04, -1.55639427e-04,
78    -1.82538332e-04, -1.96888686e-04, -1.99643819e-04, -1.92256960e-04,
79    -1.76544567e-04, -1.54543830e-04, -1.28372848e-04, -1.00101113e-04,
80    -7.16366399e-05, -4.46345894e-05, -2.04305583e-05
81])
82
83LTPF_HI = np.array([
84     6.69885837e-03,  3.96711478e-02,  1.06999186e-01,  2.09880463e-01,
85     3.35690625e-01,  4.59220930e-01,  5.50075002e-01,  5.83527575e-01,
86     5.50075002e-01,  4.59220930e-01,  3.35690625e-01,  2.09880463e-01,
87     1.06999186e-01,  3.96711478e-02,  6.69885837e-03
88])
89
90def print_table(t, m=4):
91
92    for (i, v) in enumerate(t):
93        print('{:14.8e},'.format(v), end = '\n' if i%m == m-1 else ' ')
94
95    if len(t) % 4:
96        print('')
97
98
99def mdct_fft_twiddles():
100
101    for n in (10, 20, 30, 40, 60, 80, 90, 120, 160, 180, 240):
102
103        print('\n--- fft bf2 twiddles {:3d} ---'.format(n))
104
105        kv = -2 * np.pi * np.arange(n // 2) / n
106        for (i, k) in enumerate(kv):
107            print('{{ {:14.7e}, {:14.7e} }},'.format(np.cos(k), np.sin(k)),
108                  end = '\n' if i%2 == 1 else ' ')
109
110    for n in (15, 45):
111
112        print('\n--- fft bf3 twiddles {:3d} ---'.format(n))
113
114        kv = -2 * np.pi * np.arange(n) / n
115        for k in kv:
116            print(('{{ {{ {:14.7e}, {:14.7e} }},' +
117                     ' {{ {:14.7e}, {:14.7e} }} }},').format(
118                np.cos(k), np.sin(k), np.cos(2*k), np.sin(2*k)))
119
120
121def mdct_rot_twiddles():
122
123    for n in (120, 160, 240, 320, 360, 480, 640, 720, 960):
124
125        print('\n--- mdct rot twiddles {:3d} ---'.format(n))
126
127        kv = 2 * np.pi * (np.arange(n // 4) + 1/8) / n
128        scale = np.sqrt( np.sqrt( 4 / n ) )
129        for (i, k) in enumerate(kv):
130            print('{{ {:14.7e}, {:14.7e} }},'.format(
131                np.cos(k) * scale, np.sin(k) * scale),
132                  end = '\n' if i%2 == 1 else ' ')
133
134
135def mdct_scaling():
136
137    print('\n--- mdct scaling ---')
138    ns = np.array([ [ 60, 120, 180, 240, 360], [ 80, 160, 240, 320, 480] ])
139    print_table(np.sqrt(2 / ns[0]))
140    print_table(np.sqrt(2 / ns[1]))
141
142
143def tns_lag_window():
144
145    print('\n--- tns lag window ---')
146    print_table(np.exp(-0.5 * (0.02 * np.pi * np.arange(9)) ** 2))
147
148
149def tns_quantization_table():
150
151    print('\n--- tns quantization table ---')
152    print_table(np.sin((np.arange(8) + 0.5) * (np.pi / 17)))
153    print_table(np.sin((np.arange(8)) * (np.pi / 17)))
154
155
156def quant_iq_table():
157
158    print('\n--- quantization iq table ---')
159    print_table(10 ** (np.arange(65) / 28))
160
161
162def sns_ge_table():
163
164    g_tilt_table = [ 14, 18, 22, 26, 30 ]
165
166    for (sr, g_tilt) in enumerate(g_tilt_table):
167        print('\n--- sns ge table, sr:{} ---'.format(sr))
168        print_table(10 ** ((np.arange(64) * g_tilt) / 630))
169
170
171def inv_table():
172
173    print('\n--- inv table ---')
174    print_table(np.append(np.zeros(1), 1 / np.arange(1, 28)))
175
176def ltpf_resampler_table():
177
178    for sr in [ 8, 16, 32, 24, 48 ]:
179
180        r = 192 // sr
181        k = 64 if r & (r-1) else 192
182
183        p = (192 // k) * (k // sr)
184        q = p * (0.5 if sr == 8 else 1)
185
186        print('\n--- LTPF resampler {:d} KHz to 12.8 KHz ---'.format(sr))
187
188        h = np.rint(np.append(LTPF_H12K8, 0.) * q * 2**15).astype(int)
189        h = h.reshape((len(h) // p, p)).T
190        h = np.flip(h, axis=0)
191        print('... Gain:', np.max(np.sum(np.abs(h), axis=1)) / 32768.)
192
193        for i in range(0, len(h), 192 // k):
194            for j in range(0, len(h[i]), 10):
195                print('{:5d}, {:5d}, {:5d}, {:5d}, {:5d}, '
196                      '{:5d}, {:5d}, {:5d}, {:5d}, {:5d},'.format(
197                    h[i][j+0], h[i][j+1], h[i][j+2], h[i][j+3], h[i][j+4],
198                    h[i][j+5], h[i][j+6], h[i][j+7], h[i][j+8], h[i][j+9]))
199
200
201def ltpf_interpolate_table():
202
203    print('\n--- LTPF interpolation ---')
204
205    h = np.rint(np.append(LTPF_HI, 0.) * 2**15).astype(int)
206
207    h = h.reshape(len(h) // 4, 4).T
208    h = np.flip(h, axis=0)
209    print('... Gain:', np.max(np.sum(np.abs(h), axis=1)) / 32768.)
210
211    for i in range(len(h)):
212        print('{:5d}, {:5d}, {:5d}, {:5d}'.format(
213            h[i][0], h[i][1], h[i][2], h[i][3]))
214
215
216if __name__ == '__main__':
217
218    mdct_fft_twiddles()
219    mdct_rot_twiddles()
220    mdct_scaling()
221
222    inv_table()
223    sns_ge_table()
224    tns_lag_window()
225    tns_quantization_table()
226    quant_iq_table()
227
228    ltpf_resampler_table()
229    ltpf_interpolate_table()
230
231    print('')
232