libvmaf-sys 0.4.4

Library bindings for Netflix's VMAF
Documentation
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
/**
 *
 *  Copyright 2016-2020 Netflix, Inc.
 *
 *     Licensed under the BSD+Patent License (the "License");
 *     you may not use this file except in compliance with the License.
 *     You may obtain a copy of the License at
 *
 *         https://opensource.org/licenses/BSDplusPatent
 *
 *     Unless required by applicable law or agreed to in writing, software
 *     distributed under the License is distributed on an "AS IS" BASIS,
 *     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *     See the License for the specific language governing permissions and
 *     limitations under the License.
 *
 */

#include <float.h>
#include <math.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>

#include "config.h"
#include "cpu.h"
#include "mem.h"
#include "common/convolution.h"
#include "vif_options.h"
#include "vif_tools.h"

#define MIN(x, y) (((x) < (y)) ? (x) : (y))
#define MAX(x, y) (((x) > (y)) ? (x) : (y))

#ifdef VIF_OPT_FAST_LOG2 // option to replace log2 calculation with faster speed

static const float log2_poly_s[9] = { -0.012671635276421, 0.064841182402670, -0.157048836463065, 0.257167726303123, -0.353800560300520, 0.480131410397451, -0.721314327952201, 1.442694803896991, 0 };

static float horner_s(const float *poly, float x, int n)
{
    float var = 0;
    int i;

    for (i = 0; i < n; ++i) {
        var = var * x + poly[i];
    }
    return var;
}

static float log2f_approx(float x)
{
    const uint32_t exp_zero_const = 0x3F800000UL;

    const uint32_t exp_expo_mask = 0x7F800000UL;
    const uint32_t exp_mant_mask = 0x007FFFFFUL;

    float remain;
    float log_base, log_remain;
    uint32_t u32, u32remain;
    uint32_t exponent, mant;

    if (x == 0)
        return -INFINITY;
    if (x < 0)
        return NAN;

    memcpy(&u32, &x, sizeof(float));

    exponent  = (u32 & exp_expo_mask) >> 23;
    mant      = (u32 & exp_mant_mask) >> 0;
    u32remain = mant | exp_zero_const;

    memcpy(&remain, &u32remain, sizeof(float));

    log_base = (int32_t)exponent - 127;
    log_remain = horner_s(log2_poly_s, (remain - 1.0f), sizeof(log2_poly_s) / sizeof(float));

    return log_base + log_remain;
}

#define log2f log2f_approx

#endif /* VIF_FAST_LOG2 */

#if 1 //defined(_MSC_VER)
const float vif_filter1d_table_s[11][4][65] = {
        { // kernelscale = 1.0
                {0.00745626912, 0.0142655009, 0.0250313189, 0.0402820669, 0.0594526194, 0.0804751068, 0.0999041125, 0.113746084, 0.118773937, 0.113746084, 0.0999041125, 0.0804751068, 0.0594526194, 0.0402820669, 0.0250313189, 0.0142655009, 0.00745626912},
                {0.0189780835, 0.0558981746, 0.120920904, 0.192116052, 0.224173605, 0.192116052, 0.120920904, 0.0558981746, 0.0189780835},
                {0.054488685, 0.244201347, 0.402619958, 0.244201347, 0.054488685},
                {0.166378498, 0.667243004, 0.166378498}
        },
        { // kernelscale = 0.5
                {0.01483945381483146, 0.04981728920101665, 0.11832250618647212, 0.19882899654808195, 0.2363835084991954, 0.19882899654808195, 0.11832250618647212, 0.04981728920101665, 0.01483945381483146},
                {0.03765705331865383, 0.23993597758503457, 0.4448139381926232, 0.23993597758503457, 0.03765705331865383},
                {0.10650697891920077, 0.7869860421615985, 0.10650697891920077},
                {0.00383625879916893, 0.9923274824016621, 0.00383625879916893}
        },
        { // kernelscale = 1.5
                {0.003061411879755733, 0.004950361473107714, 0.007702910451476288, 0.011533883865671363, 0.01661877803810386, 0.02304227676257057, 0.030743582802885815, 0.039471747635457924, 0.04876643642871142, 0.057977365173867444, 0.06632827707341536, 0.07301998612791924, 0.0773548527900372, 0.07885625899404015, 0.0773548527900372, 0.07301998612791924, 0.06632827707341536, 0.057977365173867444, 0.04876643642871142, 0.039471747635457924, 0.030743582802885815, 0.02304227676257057, 0.01661877803810386, 0.011533883865671363, 0.007702910451476288, 0.004950361473107714, 0.003061411879755733},
                {0.005155279152239917, 0.012574282300781493, 0.026738695950137843, 0.049570492793231676, 0.08011839616706516, 0.11289306247174812, 0.13868460659463525, 0.14853036914032117, 0.13868460659463525, 0.11289306247174812, 0.08011839616706516, 0.049570492793231676, 0.026738695950137843, 0.012574282300781493, 0.005155279152239917},
                {0.007614419169296345, 0.03607496968918391, 0.10958608179781394, 0.2134445419434044, 0.26655997480060273, 0.2134445419434044, 0.10958608179781394, 0.03607496968918391, 0.007614419169296345},
                {0.03765705331865383, 0.23993597758503457, 0.4448139381926232, 0.23993597758503457, 0.03765705331865383}
        },
        { // kernelscale = 2.0
                {0.0026037269587503567, 0.0037202012799425984, 0.005201699435890725, 0.007117572324831842, 0.009530733850673961, 0.012489027248675568, 0.016015433656466918, 0.02009817440675194, 0.024682113028122028, 0.02966305528852977, 0.03488648739727233, 0.04015192995666896, 0.045223422276224175, 0.04984576229541491, 0.05376515201297315, 0.05675202106130506, 0.058623211304833, 0.059260552433345506, 0.058623211304833, 0.05675202106130506, 0.05376515201297315, 0.04984576229541491, 0.045223422276224175, 0.04015192995666896, 0.03488648739727233, 0.02966305528852977, 0.024682113028122028, 0.02009817440675194, 0.016015433656466918, 0.012489027248675568, 0.009530733850673961, 0.007117572324831842, 0.005201699435890725, 0.0037202012799425984, 0.0026037269587503567},
                {0.004908790159284653, 0.009458290945313327, 0.01687098713840658, 0.027858513730912443, 0.04258582005051434, 0.06026452109898014, 0.07894925354042928, 0.09574673424578385, 0.10749531455964786, 0.11172354906145505, 0.10749531455964786, 0.09574673424578385, 0.07894925354042928, 0.06026452109898014, 0.04258582005051434, 0.027858513730912443, 0.01687098713840658, 0.009458290945313327, 0.004908790159284653},
                {0.008812229292562283, 0.027143577143479366, 0.06511405659938266, 0.12164907301380957, 0.17699835683135567, 0.2005654142388208, 0.17699835683135567, 0.12164907301380957, 0.06511405659938266, 0.027143577143479366, 0.008812229292562283},
                {0.014646255580395366, 0.08312087071417153, 0.23555925344404363, 0.3333472405227789, 0.23555925344404363, 0.08312087071417153, 0.014646255580395366}
        },
        { // kernelscale = 2.0/3
                {0.005316919191158936, 0.015508616400966175, 0.03723543338250509, 0.07358853152438767, 0.11971104580936091, 0.16029821187968224, 0.17668248362387792, 0.16029821187968224, 0.11971104580936091, 0.07358853152438767, 0.03723543338250509, 0.015508616400966175, 0.005316919191158936},
                {0.014646255580395366, 0.08312087071417153, 0.23555925344404363, 0.3333472405227789, 0.23555925344404363, 0.08312087071417153, 0.014646255580395366},
                {0.006646032999923536, 0.1942255544092176, 0.5982568251817177, 0.1942255544092176, 0.006646032999923536},
                {0.04038789325328935, 0.9192242134934214, 0.04038789325328935}
        },
        { // kernelscale = 2.4
                {0.0024545290205999935, 0.003289682353098358, 0.004343275824783345, 0.005648830035496486, 0.007237311348814264, 0.009134266042662214, 0.01135658376291313, 0.0139091122480005, 0.01678142232148741, 0.019945079588083118, 0.023351803735371327, 0.026932876628807743, 0.030600089953844747, 0.0342484022907008, 0.03776031258766088, 0.04101176848166929, 0.04387923676578804, 0.046247395983335465, 0.048016793525188006, 0.04911076259025178, 0.04948092982288614, 0.04911076259025178, 0.048016793525188006, 0.046247395983335465, 0.04387923676578804, 0.04101176848166929, 0.03776031258766088, 0.0342484022907008, 0.030600089953844747, 0.026932876628807743, 0.023351803735371327, 0.019945079588083118, 0.01678142232148741, 0.0139091122480005, 0.01135658376291313, 0.009134266042662214, 0.007237311348814264, 0.005648830035496486, 0.004343275824783345, 0.003289682353098358, 0.0024545290205999935},
                {0.003637908247873508, 0.0063855489460743495, 0.010623647203380349, 0.016752435202957758, 0.02503866437045789, 0.03547098721241576, 0.047628214164962705, 0.0606155744031302, 0.07311947377207272, 0.08360086952227502, 0.09059775517499266, 0.09305784355881423, 0.09059775517499266, 0.08360086952227502, 0.07311947377207272, 0.0606155744031302, 0.047628214164962705, 0.03547098721241576, 0.02503866437045789, 0.016752435202957758, 0.010623647203380349, 0.0063855489460743495, 0.003637908247873508},
                {0.007350293016136075, 0.019098337505782634, 0.04171460426536077, 0.07659181203740582, 0.11821653158869994, 0.15338247260964522, 0.1672918979539392, 0.15338247260964522, 0.11821653158869994, 0.07659181203740582, 0.04171460426536077, 0.019098337505782634, 0.007350293016136075},
                {0.00585668412070982, 0.03167315245079435, 0.10575256915549137, 0.21799709606017553, 0.27744099642565795, 0.21799709606017553, 0.10575256915549137, 0.03167315245079435, 0.00585668412070982}
        },
        { // kernelscale = 360.0 / 97.0 (1080p -> 291p)
                {0.0012816791204082075, 0.0015620523909898277, 0.0018918399027484485, 0.0022769089575337843, 0.0027231994378439997, 0.003236575413413638, 0.0038226497837505957, 0.004486583874601567, 0.005232865467640872, 0.006065070407937307, 0.006985614620544574, 0.00799550497717726, 0.009094098875819743, 0.010278883514029925, 0.011545286536358305, 0.012886529914069893, 0.01429353848739285, 0.01575491351167377, 0.017256979780457923, 0.018783912474459312, 0.02031794687526095, 0.021839670601917226, 0.023328394235385276, 0.024762592283158524, 0.026120402622622926, 0.02738016907584346, 0.028521008836012274, 0.02952338429169555, 0.03036965754835163, 0.03104460574645926, 0.03153587618024757, 0.03183436222109175, 0.03193448406620358, 0.03183436222109175, 0.03153587618024757, 0.03104460574645926, 0.03036965754835163, 0.02952338429169555, 0.028521008836012274, 0.02738016907584346, 0.026120402622622926, 0.024762592283158524, 0.023328394235385276, 0.021839670601917226, 0.02031794687526095, 0.018783912474459312, 0.017256979780457923, 0.01575491351167377, 0.01429353848739285, 0.012886529914069893, 0.011545286536358305, 0.010278883514029925, 0.009094098875819743, 0.00799550497717726, 0.006985614620544574, 0.006065070407937307, 0.005232865467640872, 0.004486583874601567, 0.0038226497837505957, 0.003236575413413638, 0.0027231994378439997, 0.0022769089575337843, 0.0018918399027484485, 0.0015620523909898277, 0.0012816791204082075},
                {0.0023644174536255184, 0.0034221036550523224, 0.0048431811011422285, 0.006702499696259348, 0.009070086779378358, 0.012002027755765152, 0.015529817658257908, 0.01964927955626293, 0.02431058735737885, 0.029411204931348196, 0.03479354885462776, 0.04024882291916349, 0.0455277497133199, 0.05035791396527277, 0.0544662936498729, 0.05760450646430479, 0.05957357217624005, 0.060244772625455, 0.05957357217624005, 0.05760450646430479, 0.0544662936498729, 0.05035791396527277, 0.0455277497133199, 0.04024882291916349, 0.03479354885462776, 0.029411204931348196, 0.02431058735737885, 0.01964927955626293, 0.015529817658257908, 0.012002027755765152, 0.009070086779378358, 0.006702499696259348, 0.0048431811011422285, 0.0034221036550523224, 0.0023644174536255184},
                {0.005739705984167229, 0.010638831007972463, 0.018338687970180532, 0.029397655644830867, 0.04382553457697562, 0.06075917001712261, 0.07833692675250763, 0.09392718641207363, 0.10473363656553764, 0.10860533013726342, 0.10473363656553764, 0.09392718641207363, 0.07833692675250763, 0.06075917001712261, 0.04382553457697562, 0.029397655644830867, 0.018338687970180532, 0.010638831007972463, 0.005739705984167229},
                {0.004765886490117418, 0.014449429659230515, 0.03580755131873149, 0.07252962766809999, 0.1200806914901692, 0.16249792490873866, 0.17973777692982543, 0.16249792490873866, 0.1200806914901692, 0.07252962766809999, 0.03580755131873149, 0.014449429659230515, 0.004765886490117418}
        },
        { // kernelscale = 4.0 / 3.0
                {0.00468593450369258, 0.007810637942127317, 0.012400648305837857, 0.018752961660127826, 0.027012385060515166, 0.0370615509191398, 0.048434167336838044, 0.06029033231050093, 0.07148437238577607, 0.0807313343364795, 0.08684418500467246, 0.08898298046858494, 0.08684418500467246, 0.0807313343364795, 0.07148437238577607, 0.06029033231050093, 0.048434167336838044, 0.0370615509191398, 0.027012385060515166, 0.018752961660127826, 0.012400648305837857, 0.007810637942127317, 0.00468593450369258},
                {0.007350293016136075, 0.019098337505782634, 0.04171460426536077, 0.07659181203740582, 0.11821653158869994, 0.15338247260964522, 0.1672918979539392, 0.15338247260964522, 0.11821653158869994, 0.07659181203740582, 0.04171460426536077, 0.019098337505782634, 0.007350293016136075},
                {0.023977406661157635, 0.09784278911234541, 0.22749130044200694, 0.30137700756898, 0.22749130044200694, 0.09784278911234541, 0.023977406661157635},
                {0.021929644862389363, 0.22851214688447105, 0.49911641650627925, 0.22851214688447105, 0.021929644862389363}
        },
        { // kernelscale = 3.5 / 3.0
                {0.004225481445163885, 0.0077284175478382604, 0.013264883597653383, 0.021365585324475772, 0.03229420764197194, 0.04580711688347506, 0.060973309616983565, 0.07616317964123727, 0.08927890406929252, 0.09820896199705818, 0.10137990446970037, 0.09820896199705818, 0.08927890406929252, 0.07616317964123727, 0.060973309616983565, 0.04580711688347506, 0.03229420764197194, 0.021365585324475772, 0.013264883597653383, 0.0077284175478382604, 0.004225481445163885},
                {0.011253064073270563, 0.03121967849226136, 0.06904092264126249, 0.12170411773975143, 0.17101117222357906, 0.19154208965975011, 0.17101117222357906, 0.12170411773975143, 0.06904092264126249, 0.03121967849226136, 0.011253064073270563},
                {0.012560200468474614, 0.07882796468173003, 0.23729607711717063, 0.34263151546524945, 0.23729607711717063, 0.07882796468173003, 0.012560200468474614},
                {0.009620056834605945, 0.20542369732245147, 0.5699124916858852, 0.20542369732245147, 0.009620056834605945}
        },
        { // kernelscale = 3.75 / 3.0
                {0.003317211135862137, 0.0059324619144260895, 0.01003813004663814, 0.01607040018215851, 0.024342018059788077, 0.03488530174522498, 0.04730253352513053, 0.06068513681455791, 0.07366077493233217, 0.08459530222840861, 0.09192046741565756, 0.09450052399963076, 0.09192046741565756, 0.08459530222840861, 0.07366077493233217, 0.06068513681455791, 0.04730253352513053, 0.03488530174522498, 0.024342018059788077, 0.01607040018215851, 0.01003813004663814, 0.0059324619144260895, 0.003317211135862137},
                {0.0050830940167887065, 0.01506448350708729, 0.03664323313832898, 0.0731554625933815, 0.11987073595060249, 0.16121038612766267, 0.17794520933229682, 0.16121038612766267, 0.11987073595060249, 0.0731554625933815, 0.03664323313832898, 0.01506448350708729, 0.0050830940167887065},
                {0.017988208587689274, 0.08909618039160763, 0.2326921801242316, 0.3204468617929429, 0.2326921801242316, 0.08909618039160763, 0.017988208587689274},
                {0.015199625365883403, 0.21875173294350592, 0.5320972833812214, 0.21875173294350592, 0.015199625365883403}
        },
        { // kernelscale = 4.25 / 3.0
                {0.0037535214972137234, 0.006161856952968067, 0.009688687555946651, 0.014591465886006169, 0.021048130695628536, 0.02908096232945107, 0.03848439382348116, 0.04877992869222271, 0.059221350419380495, 0.06886460899713377, 0.07669984741736877, 0.08182265140547183, 0.08360518865545416, 0.08182265140547183, 0.07669984741736877, 0.06886460899713377, 0.059221350419380495, 0.04877992869222271, 0.03848439382348116, 0.02908096232945107, 0.021048130695628536, 0.014591465886006169, 0.009688687555946651, 0.006161856952968067, 0.0037535214972137234},
                {0.009923596815614544, 0.023121061729092417, 0.0461910237358901, 0.07912588025538068, 0.11622262324531331, 0.14637737178419374, 0.15807688486903043, 0.14637737178419374, 0.11622262324531331, 0.07912588025538068, 0.0461910237358901, 0.023121061729092417, 0.009923596815614544},
                {0.005235891862728509, 0.029948577627467506, 0.10407966050653025, 0.21976557644809397, 0.2819405871103595, 0.21976557644809397, 0.10407966050653025, 0.029948577627467506, 0.005235891862728509},
                {0.029519066107809168, 0.23537051469301665, 0.47022083839834844, 0.23537051469301665, 0.029519066107809168}
        }
};
#else
const float vif_filter1d_table_s[11][4][65] = {
        { // kernelscale = 1.0
                { 0x1.e8a77p-8,  0x1.d373b2p-7, 0x1.9a1cf6p-6, 0x1.49fd9ep-5, 0x1.e7092ep-5, 0x1.49a044p-4, 0x1.99350ep-4, 0x1.d1e76ap-4, 0x1.e67f8p-4, 0x1.d1e76ap-4, 0x1.99350ep-4, 0x1.49a044p-4, 0x1.e7092ep-5, 0x1.49fd9ep-5, 0x1.9a1cf6p-6, 0x1.d373b2p-7, 0x1.e8a77p-8 },
                { 0x1.36efdap-6, 0x1.c9eaf8p-5, 0x1.ef4ac2p-4, 0x1.897424p-3, 0x1.cb1b88p-3, 0x1.897424p-3, 0x1.ef4ac2p-4, 0x1.c9eaf8p-5, 0x1.36efdap-6 },
                { 0x1.be5f0ep-5, 0x1.f41fd6p-3, 0x1.9c4868p-2, 0x1.f41fd6p-3, 0x1.be5f0ep-5 },
                { 0x1.54be4p-3,  0x1.55a0ep-1,  0x1.54be4p-3 }
        },
        { // kernelscale = 0.5
                { 1.483945e-02, 4.981729e-02, 1.183225e-01, 1.988290e-01, 2.363835e-01, 1.988290e-01, 1.183225e-01, 4.981729e-02, 1.483945e-02 },
                { 3.765705e-02, 2.399360e-01, 4.448139e-01, 2.399360e-01, 3.765705e-02 },
                { 1.065070e-01, 7.869860e-01, 1.065070e-01 },
                { 3.836259e-03, 9.923275e-01, 3.836259e-03 }
        },
        { // kernelscale = 1.5
                { 3.061412e-03, 4.950361e-03, 7.702910e-03, 1.153388e-02, 1.661878e-02, 2.304228e-02, 3.074358e-02, 3.947175e-02, 4.876644e-02, 5.797737e-02, 6.632828e-02, 7.301999e-02, 7.735485e-02, 7.885626e-02, 7.735485e-02, 7.301999e-02, 6.632828e-02, 5.797737e-02, 4.876644e-02, 3.947175e-02, 3.074358e-02, 2.304228e-02, 1.661878e-02, 1.153388e-02, 7.702910e-03, 4.950361e-03, 3.061412e-03 },
                { 5.155279e-03, 1.257428e-02, 2.673870e-02, 4.957049e-02, 8.011840e-02, 1.128931e-01, 1.386846e-01, 1.485304e-01, 1.386846e-01, 1.128931e-01, 8.011840e-02, 4.957049e-02, 2.673870e-02, 1.257428e-02, 5.155279e-03 },
                { 7.614419e-03, 3.607497e-02, 1.095861e-01, 2.134445e-01, 2.665600e-01, 2.134445e-01, 1.095861e-01, 3.607497e-02, 7.614419e-03 },
                { 3.765705e-02, 2.399360e-01, 4.448139e-01, 2.399360e-01, 3.765705e-02 }
        },
        { // kernelscale = 2.0
                { 2.603727e-03, 3.720201e-03, 5.201699e-03, 7.117572e-03, 9.530734e-03, 1.248903e-02, 1.601543e-02, 2.009817e-02, 2.468211e-02, 2.966306e-02, 3.488649e-02, 4.015193e-02, 4.522342e-02, 4.984576e-02, 5.376515e-02, 5.675202e-02, 5.862321e-02, 5.926055e-02, 5.862321e-02, 5.675202e-02, 5.376515e-02, 4.984576e-02, 4.522342e-02, 4.015193e-02, 3.488649e-02, 2.966306e-02, 2.468211e-02, 2.009817e-02, 1.601543e-02, 1.248903e-02, 9.530734e-03, 7.117572e-03, 5.201699e-03, 3.720201e-03, 2.603727e-03 },
                { 4.908790e-03, 9.458291e-03, 1.687099e-02, 2.785851e-02, 4.258582e-02, 6.026452e-02, 7.894925e-02, 9.574673e-02, 1.074953e-01, 1.117235e-01, 1.074953e-01, 9.574673e-02, 7.894925e-02, 6.026452e-02, 4.258582e-02, 2.785851e-02, 1.687099e-02, 9.458291e-03, 4.908790e-03 },
                { 8.812229e-03, 2.714358e-02, 6.511406e-02, 1.216491e-01, 1.769984e-01, 2.005654e-01, 1.769984e-01, 1.216491e-01, 6.511406e-02, 2.714358e-02, 8.812229e-03 },
                { 1.464626e-02, 8.312087e-02, 2.355593e-01, 3.333472e-01, 2.355593e-01, 8.312087e-02, 1.464626e-02 }
        },
        { // kernelscale = 2.0/3
                { 5.316919e-03, 1.550862e-02, 3.723543e-02, 7.358853e-02, 1.197110e-01, 1.602982e-01, 1.766825e-01, 1.602982e-01, 1.197110e-01, 7.358853e-02, 3.723543e-02, 1.550862e-02, 5.316919e-03 },
                { 1.464626e-02, 8.312087e-02, 2.355593e-01, 3.333472e-01, 2.355593e-01, 8.312087e-02, 1.464626e-02 },
                { 6.646033e-03, 1.942256e-01, 5.982568e-01, 1.942256e-01, 6.646033e-03 },
                { 4.038789e-02, 9.192242e-01, 4.038789e-02 }
        },
        { // kernelscale = 2.4
                { 2.454529e-03, 3.289682e-03, 4.343276e-03, 5.648830e-03, 7.237311e-03, 9.134266e-03, 1.135658e-02, 1.390911e-02, 1.678142e-02, 1.994508e-02, 2.335180e-02, 2.693288e-02, 3.060009e-02, 3.424840e-02, 3.776031e-02, 4.101177e-02, 4.387924e-02, 4.624740e-02, 4.801679e-02, 4.911076e-02, 4.948093e-02, 4.911076e-02, 4.801679e-02, 4.624740e-02, 4.387924e-02, 4.101177e-02, 3.776031e-02, 3.424840e-02, 3.060009e-02, 2.693288e-02, 2.335180e-02, 1.994508e-02, 1.678142e-02, 1.390911e-02, 1.135658e-02, 9.134266e-03, 7.237311e-03, 5.648830e-03, 4.343276e-03, 3.289682e-03, 2.454529e-03 },
                { 3.637908e-03, 6.385549e-03, 1.062365e-02, 1.675244e-02, 2.503866e-02, 3.547099e-02, 4.762821e-02, 6.061557e-02, 7.311947e-02, 8.360087e-02, 9.059776e-02, 9.305784e-02, 9.059776e-02, 8.360087e-02, 7.311947e-02, 6.061557e-02, 4.762821e-02, 3.547099e-02, 2.503866e-02, 1.675244e-02, 1.062365e-02, 6.385549e-03, 3.637908e-03 },
                { 7.350293e-03, 1.909834e-02, 4.171460e-02, 7.659181e-02, 1.182165e-01, 1.533825e-01, 1.672919e-01, 1.533825e-01, 1.182165e-01, 7.659181e-02, 4.171460e-02, 1.909834e-02, 7.350293e-03 },
                { 5.856684e-03, 3.167315e-02, 1.057526e-01, 2.179971e-01, 2.774410e-01, 2.179971e-01, 1.057526e-01, 3.167315e-02, 5.856684e-03 }
        },
        { // kernelscale = 360.0 / 97.0 (1080p -> 291p)
                { 1.281679e-03, 1.562052e-03, 1.891840e-03, 2.276909e-03, 2.723199e-03, 3.236575e-03, 3.822650e-03, 4.486584e-03, 5.232865e-03, 6.065070e-03, 6.985615e-03, 7.995505e-03, 9.094099e-03, 1.027888e-02, 1.154529e-02, 1.288653e-02, 1.429354e-02, 1.575491e-02, 1.725698e-02, 1.878391e-02, 2.031795e-02, 2.183967e-02, 2.332839e-02, 2.476259e-02, 2.612040e-02, 2.738017e-02, 2.852101e-02, 2.952338e-02, 3.036966e-02, 3.104461e-02, 3.153588e-02, 3.183436e-02, 3.193448e-02, 3.183436e-02, 3.153588e-02, 3.104461e-02, 3.036966e-02, 2.952338e-02, 2.852101e-02, 2.738017e-02, 2.612040e-02, 2.476259e-02, 2.332839e-02, 2.183967e-02, 2.031795e-02, 1.878391e-02, 1.725698e-02, 1.575491e-02, 1.429354e-02, 1.288653e-02, 1.154529e-02, 1.027888e-02, 9.094099e-03, 7.995505e-03, 6.985615e-03, 6.065070e-03, 5.232865e-03, 4.486584e-03, 3.822650e-03, 3.236575e-03, 2.723199e-03, 2.276909e-03, 1.891840e-03, 1.562052e-03, 1.281679e-03 },
                { 2.364417e-03, 3.422104e-03, 4.843181e-03, 6.702500e-03, 9.070087e-03, 1.200203e-02, 1.552982e-02, 1.964928e-02, 2.431059e-02, 2.941120e-02, 3.479355e-02, 4.024882e-02, 4.552775e-02, 5.035791e-02, 5.446629e-02, 5.760451e-02, 5.957357e-02, 6.024477e-02, 5.957357e-02, 5.760451e-02, 5.446629e-02, 5.035791e-02, 4.552775e-02, 4.024882e-02, 3.479355e-02, 2.941120e-02, 2.431059e-02, 1.964928e-02, 1.552982e-02, 1.200203e-02, 9.070087e-03, 6.702500e-03, 4.843181e-03, 3.422104e-03, 2.364417e-03 },
                { 5.739706e-03, 1.063883e-02, 1.833869e-02, 2.939766e-02, 4.382553e-02, 6.075917e-02, 7.833693e-02, 9.392719e-02, 1.047336e-01, 1.086053e-01, 1.047336e-01, 9.392719e-02, 7.833693e-02, 6.075917e-02, 4.382553e-02, 2.939766e-02, 1.833869e-02, 1.063883e-02, 5.739706e-03 },
                { 4.765886e-03, 1.444943e-02, 3.580755e-02, 7.252963e-02, 1.200807e-01, 1.624979e-01, 1.797378e-01, 1.624979e-01, 1.200807e-01, 7.252963e-02, 3.580755e-02, 1.444943e-02, 4.765886e-03 }
        },
        { // kernelscale = 4.0 / 3.0
                { 4.685935e-03, 7.810638e-03, 1.240065e-02, 1.875296e-02, 2.701239e-02, 3.706155e-02, 4.843417e-02, 6.029033e-02, 7.148437e-02, 8.073133e-02, 8.684419e-02, 8.898298e-02, 8.684419e-02, 8.073133e-02, 7.148437e-02, 6.029033e-02, 4.843417e-02, 3.706155e-02, 2.701239e-02, 1.875296e-02, 1.240065e-02, 7.810638e-03, 4.685935e-03 },
                { 7.350293e-03, 1.909834e-02, 4.171460e-02, 7.659181e-02, 1.182165e-01, 1.533825e-01, 1.672919e-01, 1.533825e-01, 1.182165e-01, 7.659181e-02, 4.171460e-02, 1.909834e-02, 7.350293e-03 },
                { 2.397741e-02, 9.784279e-02, 2.274913e-01, 3.013770e-01, 2.274913e-01, 9.784279e-02, 2.397741e-02 },
                { 2.192964e-02, 2.285121e-01, 4.991164e-01, 2.285121e-01, 2.192964e-02 }
        },
        { // kernelscale = 3.5 / 3.0
                { 4.225481e-03, 7.728418e-03, 1.326488e-02, 2.136559e-02, 3.229421e-02, 4.580712e-02, 6.097331e-02, 7.616318e-02, 8.927890e-02, 9.820896e-02, 1.013799e-01, 9.820896e-02, 8.927890e-02, 7.616318e-02, 6.097331e-02, 4.580712e-02, 3.229421e-02, 2.136559e-02, 1.326488e-02, 7.728418e-03, 4.225481e-03 },
                { 1.125306e-02, 3.121968e-02, 6.904092e-02, 1.217041e-01, 1.710112e-01, 1.915421e-01, 1.710112e-01, 1.217041e-01, 6.904092e-02, 3.121968e-02, 1.125306e-02 },
                { 1.256020e-02, 7.882796e-02, 2.372961e-01, 3.426315e-01, 2.372961e-01, 7.882796e-02, 1.256020e-02 },
                { 9.620057e-03, 2.054237e-01, 5.699125e-01, 2.054237e-01, 9.620057e-03 }
        },
        { // kernelscale = 3.75 / 3.0
                { 3.317211e-03, 5.932462e-03, 1.003813e-02, 1.607040e-02, 2.434202e-02, 3.488530e-02, 4.730253e-02, 6.068514e-02, 7.366077e-02, 8.459530e-02, 9.192047e-02, 9.450052e-02, 9.192047e-02, 8.459530e-02, 7.366077e-02, 6.068514e-02, 4.730253e-02, 3.488530e-02, 2.434202e-02, 1.607040e-02, 1.003813e-02, 5.932462e-03, 3.317211e-03 },
                { 5.083094e-03, 1.506448e-02, 3.664323e-02, 7.315546e-02, 1.198707e-01, 1.612104e-01, 1.779452e-01, 1.612104e-01, 1.198707e-01, 7.315546e-02, 3.664323e-02, 1.506448e-02, 5.083094e-03 },
                { 1.798821e-02, 8.909618e-02, 2.326922e-01, 3.204469e-01, 2.326922e-01, 8.909618e-02, 1.798821e-02 },
                { 1.519963e-02, 2.187517e-01, 5.320973e-01, 2.187517e-01, 1.519963e-02 }
        },
        { // kernelscale = 4.25 / 3.0
                { 3.753521e-03, 6.161857e-03, 9.688688e-03, 1.459147e-02, 2.104813e-02, 2.908096e-02, 3.848439e-02, 4.877993e-02, 5.922135e-02, 6.886461e-02, 7.669985e-02, 8.182265e-02, 8.360519e-02, 8.182265e-02, 7.669985e-02, 6.886461e-02, 5.922135e-02, 4.877993e-02, 3.848439e-02, 2.908096e-02, 2.104813e-02, 1.459147e-02, 9.688688e-03, 6.161857e-03, 3.753521e-03 },
                { 9.923597e-03, 2.312106e-02, 4.619102e-02, 7.912588e-02, 1.162226e-01, 1.463774e-01, 1.580769e-01, 1.463774e-01, 1.162226e-01, 7.912588e-02, 4.619102e-02, 2.312106e-02, 9.923597e-03 },
                { 5.235892e-03, 2.994858e-02, 1.040797e-01, 2.197656e-01, 2.819406e-01, 2.197656e-01, 1.040797e-01, 2.994858e-02, 5.235892e-03 },
                { 2.951907e-02, 2.353705e-01, 4.702208e-01, 2.353705e-01, 2.951907e-02 }
        }
};
#endif

const int vif_filter1d_width[11][4] = {
        { 17, 9, 5, 3 }, // kernelscale = 1.0
        { 9, 5, 3, 3 }, // kernelscale = 0.5
        { 27, 15, 9, 5 },  // kernelscale = 1.5
        { 35, 19, 11, 7 },  // kernelscale = 2.0
        { 13, 7, 5, 3 },  // kernelscale = 2.0/3
        { 41, 23, 13, 9 }, // kernelscale = 2.4/1.0
        { 65, 35, 19, 13 },  // kernelscale = 360.0/97.0
        { 23, 13, 7, 5 },  // kernelscale = 4.0/3.0
        { 21, 11, 7, 5 },  // kernelscale = 3.5/3.0
        { 23, 13, 7, 5 },  // kernelscale = 3.75/3.0
        { 25, 13, 9, 5 }  // kernelscale = 4.25/3.0
};

void vif_dec2_s(const float *src, float *dst, int src_w, int src_h, int src_stride, int dst_stride)
{
    int src_px_stride = src_stride / sizeof(float); // src_stride is in bytes
    int dst_px_stride = dst_stride / sizeof(float);

    int i, j;

    // decimation by 2 in each direction (after gaussian blur? check)
    for (i = 0; i < src_h / 2; ++i) {
        for (j = 0; j < src_w / 2; ++j) {
            dst[i * dst_px_stride + j] = src[(i * 2) * src_px_stride + (j * 2)];
        }
    }
}

float vif_sum_s(const float *x, int w, int h, int stride)
{
    int px_stride = stride / sizeof(float);
    int i, j;

    float accum = 0;

    for (i = 0; i < h; ++i) {
        float accum_inner = 0;

        for (j = 0; j < w; ++j) {
            accum_inner += x[i * px_stride + j];
        } // having an inner accumulator help reduce numerical error (no accumulation of near-0 terms)

        accum += accum_inner;
    }

    return accum;
}

void vif_statistic_s(const float *mu1, const float *mu2, const float *xx_filt, const float *yy_filt, const float *xy_filt, float *num, float *den,
	int w, int h, int mu1_stride, int mu2_stride, int xx_filt_stride, int yy_filt_stride, int xy_filt_stride,
	double vif_enhn_gain_limit)
{
	static const float sigma_nsq = 2;
	static const float sigma_max_inv = 4.0 / (255.0*255.0);

	int mu1_px_stride = mu1_stride / sizeof(float);
	int mu2_px_stride = mu2_stride / sizeof(float);
	int xx_filt_px_stride = xx_filt_stride / sizeof(float);
	int yy_filt_px_stride = yy_filt_stride / sizeof(float);
	int xy_filt_px_stride = xy_filt_stride / sizeof(float);

	float mu1_sq_val, mu2_sq_val, mu1_mu2_val, xx_filt_val, yy_filt_val, xy_filt_val;
	float sigma1_sq, sigma2_sq, sigma12;
	float num_val, den_val;
	int i, j;

    /* ==== vif_stat_mode = 'matching_c' ==== */
    // float num_log_den, num_log_num;
    /* ==== vif_stat_mode = 'matching_matlab' ==== */
	float g, sv_sq, eps = 1.0e-10f;
	float vif_enhn_gain_limit_f = (float) vif_enhn_gain_limit;
    /* == end of vif_stat_mode = 'matching_matlab' == */

	float accum_num = 0.0f;
	float accum_den = 0.0f;

	for (i = 0; i < h; ++i) {
		float accum_inner_num = 0;
		float accum_inner_den = 0;
		for (j = 0; j < w; ++j) {
			float mu1_val = mu1[i * mu1_px_stride + j];
			float mu2_val = mu2[i * mu2_px_stride + j];
			mu1_sq_val = mu1_val * mu1_val; // same name as the Matlab code vifp_mscale.m
			mu2_sq_val = mu2_val * mu2_val;
			mu1_mu2_val = mu1_val * mu2_val; //mu1_mu2[i * mu1_mu2_px_stride + j];
			xx_filt_val = xx_filt[i * xx_filt_px_stride + j];
			yy_filt_val = yy_filt[i * yy_filt_px_stride + j];
			xy_filt_val = xy_filt[i * xy_filt_px_stride + j];

			sigma1_sq = xx_filt_val - mu1_sq_val;
			sigma2_sq = yy_filt_val - mu2_sq_val;
			sigma12 = xy_filt_val - mu1_mu2_val;

			/* ==== vif_stat_mode = 'matching_c' ==== */

            /* if (sigma1_sq < sigma_nsq) {
                num_val = 1.0 - sigma2_sq * sigma_max_inv;
                den_val = 1.0;
            }
            else {
                num_log_num = (sigma2_sq + sigma_nsq) * sigma1_sq;
                if (sigma12 < 0)
                {
                    num_val = 0.0;
                }
                else
                {
                    num_log_den = num_log_num - sigma12 * sigma12;
                    num_val = log2f(num_log_num / num_log_den);
                }
                den_val = log2f(1.0f + sigma1_sq / sigma_nsq);
            } */

            /* ==== vif_stat_mode = 'matching_matlab' ==== */

            sigma1_sq = MAX(sigma1_sq, 0.0f);
            sigma2_sq = MAX(sigma2_sq, 0.0f);

			g = sigma12 / (sigma1_sq + eps);
			sv_sq = sigma2_sq - g * sigma12;

			if (sigma1_sq < eps) {
			    g = 0.0f;
                sv_sq = sigma2_sq;
                sigma1_sq = 0.0f;
			}

			if (sigma2_sq < eps) {
			    g = 0.0f;
			    sv_sq = 0.0f;
			}

			if (g < 0.0f) {
			    sv_sq = sigma2_sq;
			    g = 0.0f;
			}
			sv_sq = MAX(sv_sq, eps);

            g = MIN(g, vif_enhn_gain_limit_f);

            num_val = log2f(1.0f + (g * g * sigma1_sq) / (sv_sq + sigma_nsq));
            den_val = log2f(1.0f + (sigma1_sq) / (sigma_nsq));

            if (sigma12 < 0.0f) {
                num_val = 0.0f;
            }

            if (sigma1_sq < sigma_nsq) {
                num_val = 1.0f - sigma2_sq * sigma_max_inv;
                den_val = 1.0f;
            }

            /* == end of vif_stat_mode = 'matching_matlab' == */

            accum_inner_num += num_val;
			accum_inner_den += den_val;
		}

		accum_num += accum_inner_num;
		accum_den += accum_inner_den;
	}
	num[0] = accum_num;
	den[0] = accum_den;
}

void vif_filter1d_s(const float *f, const float *src, float *dst, float *tmpbuf, int w, int h, int src_stride, int dst_stride, int fwidth)
{

    int src_px_stride = src_stride / sizeof(float);
    int dst_px_stride = dst_stride / sizeof(float);

    /* if support avx */

#if ARCH_X86
    const unsigned flags = vmaf_get_cpu_flags();
    if ((flags & VMAF_X86_CPU_FLAG_AVX2) && (fwidth == 17 || fwidth == 9 || fwidth == 5 || fwidth == 3)) {
        convolution_f32_avx_s(f, fwidth, src, dst, tmpbuf, w, h,
                              src_px_stride, dst_px_stride);
        return;
    }
#endif

    /* fall back */

    float *tmp = aligned_malloc(ALIGN_CEIL(w * sizeof(float)), MAX_ALIGN);
    float fcoeff, imgcoeff;

    int i, j, fi, fj, ii, jj;

    for (i = 0; i < h; ++i) {
        /* Vertical pass. */
        for (j = 0; j < w; ++j) {
            float accum = 0;

            for (fi = 0; fi < fwidth; ++fi) {
                fcoeff = f[fi];

                ii = i - fwidth / 2 + fi;
                ii = ii < 0 ? -ii : (ii >= h ? 2 * h - ii - 1 : ii);

                imgcoeff = src[ii * src_px_stride + j];

                accum += fcoeff * imgcoeff;
            }

            tmp[j] = accum;
        }

        /* Horizontal pass. */
        for (j = 0; j < w; ++j) {
            float accum = 0;

            for (fj = 0; fj < fwidth; ++fj) {
                fcoeff = f[fj];

                jj = j - fwidth / 2 + fj;
                jj = jj < 0 ? -jj : (jj >= w ? 2 * w - jj - 1 : jj);

                imgcoeff = tmp[jj];

                accum += fcoeff * imgcoeff;
            }

            dst[i * dst_px_stride + j] = accum;
        }
    }

    aligned_free(tmp);
}

// Code optimized by adding intrinsic code for the functions,
// vif_filter1d_sq and vif_filter1d_sq

void vif_filter1d_sq_s(const float *f, const float *src, float *dst, float *tmpbuf, int w, int h, int src_stride, int dst_stride, int fwidth)
{

	int src_px_stride = src_stride / sizeof(float);
	int dst_px_stride = dst_stride / sizeof(float);

	/* if support avx */
	
#if ARCH_X86
    const unsigned flags = vmaf_get_cpu_flags();
    if ((flags & VMAF_X86_CPU_FLAG_AVX2) && (fwidth == 17 || fwidth == 9 || fwidth == 5 || fwidth == 3)) {
        convolution_f32_avx_sq_s(f, fwidth, src, dst, tmpbuf, w, h,
                                 src_px_stride, dst_px_stride);
        return;
    }
#endif

	/* fall back */

	float *tmp = aligned_malloc(ALIGN_CEIL(w * sizeof(float)), MAX_ALIGN);
	float fcoeff, imgcoeff;

	int i, j, fi, fj, ii, jj;

	for (i = 0; i < h; ++i) {
		/* Vertical pass. */
		for (j = 0; j < w; ++j) {
			float accum = 0;

			for (fi = 0; fi < fwidth; ++fi) {
				fcoeff = f[fi];

				ii = i - fwidth / 2 + fi;
				ii = ii < 0 ? -ii : (ii >= h ? 2 * h - ii - 1 : ii);

				imgcoeff = src[ii * src_px_stride + j];

				accum += fcoeff * (imgcoeff * imgcoeff);
			}

			tmp[j] = accum;
		}

		/* Horizontal pass. */
		for (j = 0; j < w; ++j) {
			float accum = 0;

			for (fj = 0; fj < fwidth; ++fj) {
				fcoeff = f[fj];

				jj = j - fwidth / 2 + fj;
				jj = jj < 0 ? -jj : (jj >= w ? 2 * w - jj - 1 : jj);

				imgcoeff = tmp[jj];

				accum += fcoeff * imgcoeff;
			}

			dst[i * dst_px_stride + j] = accum;
		}
	}

	aligned_free(tmp);
}

void vif_filter1d_xy_s(const float *f, const float *src1, const float *src2, float *dst, float *tmpbuf, int w, int h, int src1_stride, int src2_stride, int dst_stride, int fwidth)
{

	int src1_px_stride = src1_stride / sizeof(float);
	int src2_px_stride = src2_stride / sizeof(float);
	int dst_px_stride = dst_stride / sizeof(float);

	/* if support avx */

#if ARCH_X86
    const unsigned flags = vmaf_get_cpu_flags();
    if ((flags & VMAF_X86_CPU_FLAG_AVX2) && (fwidth == 17 || fwidth == 9 || fwidth == 5 || fwidth == 3)) {
        convolution_f32_avx_xy_s(f, fwidth, src1, src2, dst, tmpbuf, w, h,
                                 src1_px_stride, src2_px_stride, dst_px_stride);
        return;
    }
#endif

	/* fall back */

	float *tmp = aligned_malloc(ALIGN_CEIL(w * sizeof(float)), MAX_ALIGN);
	float fcoeff, imgcoeff, imgcoeff1, imgcoeff2;

	int i, j, fi, fj, ii, jj;

	for (i = 0; i < h; ++i) {
		/* Vertical pass. */
		for (j = 0; j < w; ++j) {
			float accum = 0;

			for (fi = 0; fi < fwidth; ++fi) {
				fcoeff = f[fi];

				ii = i - fwidth / 2 + fi;
				ii = ii < 0 ? -ii : (ii >= h ? 2 * h - ii - 1 : ii);

				imgcoeff1 = src1[ii * src1_px_stride + j];
				imgcoeff2 = src2[ii * src2_px_stride + j];

				accum += fcoeff * (imgcoeff1 * imgcoeff2);
			}

			tmp[j] = accum;
		}

		/* Horizontal pass. */
		for (j = 0; j < w; ++j) {
			float accum = 0;

			for (fj = 0; fj < fwidth; ++fj) {
				fcoeff = f[fj];

				jj = j - fwidth / 2 + fj;
				jj = jj < 0 ? -jj : (jj >= w ? 2 * w - jj - 1 : jj);

				imgcoeff = tmp[jj];

				accum += fcoeff * imgcoeff;
			}

			dst[i * dst_px_stride + j] = accum;
		}
	}

	aligned_free(tmp);
}