avfilter/af_afir: do not over allocate fft buffer
[ffmpeg.git] / libavfilter / vf_xbr.c
1 /*
2  * This file is part of FFmpeg.
3  *
4  * Copyright (c) 2011, 2012 Hyllian/Jararaca <sergiogdb@gmail.com>
5  * Copyright (c) 2014 Arwa Arif <arwaarif1994@gmail.com>
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21
22 /**
23  * @file
24  * XBR Filter is used for depixelization of image.
25  * This is based on Hyllian's xBR shader.
26  *
27  * @see https://forums.libretro.com/t/xbr-algorithm-tutorial/123
28  * @see https://github.com/yoyofr/iFBA/blob/master/fba_src/src/intf/video/scalers/xbr.cpp
29  */
30
31 #include "libavutil/opt.h"
32 #include "libavutil/avassert.h"
33 #include "libavutil/pixdesc.h"
34 #include "internal.h"
35
36 #define LB_MASK       0x00FEFEFE
37 #define RED_BLUE_MASK 0x00FF00FF
38 #define GREEN_MASK    0x0000FF00
39
40 #ifdef PI
41 #undef PI
42 #endif
43
44 typedef int (*xbrfunc_t)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
45
46 typedef struct XBRContext {
47     const AVClass *class;
48     int n;
49     xbrfunc_t func;
50     uint32_t rgbtoyuv[1<<24];
51 } XBRContext;
52
53 typedef struct ThreadData {
54     AVFrame *in, *out;
55     const uint32_t *rgbtoyuv;
56 } ThreadData;
57
58 #define OFFSET(x) offsetof(XBRContext, x)
59 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
60 static const AVOption xbr_options[] = {
61     { "n", "set scale factor", OFFSET(n), AV_OPT_TYPE_INT, {.i64 = 3}, 2, 4, .flags = FLAGS },
62     { NULL }
63 };
64
65 AVFILTER_DEFINE_CLASS(xbr);
66
67 static uint32_t pixel_diff(uint32_t x, uint32_t y, const uint32_t *r2y)
68 {
69 #define YMASK 0xff0000
70 #define UMASK 0x00ff00
71 #define VMASK 0x0000ff
72 #define ABSDIFF(a,b) (abs((int)(a)-(int)(b)))
73
74     uint32_t yuv1 = r2y[x & 0xffffff];
75     uint32_t yuv2 = r2y[y & 0xffffff];
76
77     return (ABSDIFF(yuv1 & YMASK, yuv2 & YMASK) >> 16) +
78            (ABSDIFF(yuv1 & UMASK, yuv2 & UMASK) >>  8) +
79             ABSDIFF(yuv1 & VMASK, yuv2 & VMASK);
80 }
81
82 #define ALPHA_BLEND_128_W(a, b) ((((a) & LB_MASK) >> 1) + (((b) & LB_MASK) >> 1))
83 #define ALPHA_BLEND_BASE(a, b, m, s) (  (RED_BLUE_MASK & (((a) & RED_BLUE_MASK) + (((((b) & RED_BLUE_MASK) - ((a) & RED_BLUE_MASK)) * (m)) >> (s)))) \
84                                       | (GREEN_MASK    & (((a) & GREEN_MASK)    + (((((b) & GREEN_MASK)    - ((a) & GREEN_MASK))    * (m)) >> (s)))))
85 #define ALPHA_BLEND_32_W(a, b)  ALPHA_BLEND_BASE(a, b, 1, 3)
86 #define ALPHA_BLEND_64_W(a, b)  ALPHA_BLEND_BASE(a, b, 1, 2)
87 #define ALPHA_BLEND_192_W(a, b) ALPHA_BLEND_BASE(a, b, 3, 2)
88 #define ALPHA_BLEND_224_W(a, b) ALPHA_BLEND_BASE(a, b, 7, 3)
89
90 #define df(A, B) pixel_diff(A, B, r2y)
91 #define eq(A, B) (df(A, B) < 155)
92
93 #define FILT2(PE, PI, PH, PF, PG, PC, PD, PB, PA, G5, C4, G0, D0, C1, B1, F4, I4, H5, I5, A0, A1,   \
94               N0, N1, N2, N3) do {                                                                  \
95     if (PE != PH && PE != PF) {                                                                     \
96         const unsigned e = df(PE,PC) + df(PE,PG) + df(PI,H5) + df(PI,F4) + (df(PH,PF)<<2);          \
97         const unsigned i = df(PH,PD) + df(PH,I5) + df(PF,I4) + df(PF,PB) + (df(PE,PI)<<2);          \
98         if (e <= i) {                                                                               \
99             const unsigned px = df(PE,PF) <= df(PE,PH) ? PF : PH;                                   \
100             if (e < i && (!eq(PF,PB) && !eq(PH,PD) || eq(PE,PI)                                     \
101                           && (!eq(PF,I4) && !eq(PH,I5))                                             \
102                           || eq(PE,PG) || eq(PE,PC))) {                                             \
103                 const unsigned ke = df(PF,PG);                                                      \
104                 const unsigned ki = df(PH,PC);                                                      \
105                 const int left    = ke<<1 <= ki && PE != PG && PD != PG;                            \
106                 const int up      = ke >= ki<<1 && PE != PC && PB != PC;                            \
107                 if (left && up) {                                                                   \
108                     E[N3] = ALPHA_BLEND_224_W(E[N3], px);                                           \
109                     E[N2] = ALPHA_BLEND_64_W( E[N2], px);                                           \
110                     E[N1] = E[N2];                                                                  \
111                 } else if (left) {                                                                  \
112                     E[N3] = ALPHA_BLEND_192_W(E[N3], px);                                           \
113                     E[N2] = ALPHA_BLEND_64_W( E[N2], px);                                           \
114                 } else if (up) {                                                                    \
115                     E[N3] = ALPHA_BLEND_192_W(E[N3], px);                                           \
116                     E[N1] = ALPHA_BLEND_64_W( E[N1], px);                                           \
117                 } else { /* diagonal */                                                             \
118                     E[N3] = ALPHA_BLEND_128_W(E[N3], px);                                           \
119                 }                                                                                   \
120             } else {                                                                                \
121                 E[N3] = ALPHA_BLEND_128_W(E[N3], px);                                               \
122             }                                                                                       \
123         }                                                                                           \
124     }                                                                                               \
125 } while (0)
126
127 #define FILT3(PE, PI, PH, PF, PG, PC, PD, PB, PA, G5, C4, G0, D0, C1, B1, F4, I4, H5, I5, A0, A1,   \
128               N0, N1, N2, N3, N4, N5, N6, N7, N8) do {                                              \
129     if (PE != PH && PE != PF) {                                                                     \
130         const unsigned e = df(PE,PC) + df(PE,PG) + df(PI,H5) + df(PI,F4) + (df(PH,PF)<<2);          \
131         const unsigned i = df(PH,PD) + df(PH,I5) + df(PF,I4) + df(PF,PB) + (df(PE,PI)<<2);          \
132         if (e <= i) {                                                                               \
133             const unsigned px = df(PE,PF) <= df(PE,PH) ? PF : PH;                                   \
134             if (e < i && (!eq(PF,PB) && !eq(PF,PC) || !eq(PH,PD) && !eq(PH,PG) || eq(PE,PI)         \
135                           && (!eq(PF,F4) && !eq(PF,I4) || !eq(PH,H5) && !eq(PH,I5))                 \
136                           || eq(PE,PG) || eq(PE,PC))) {                                             \
137                 const unsigned ke = df(PF,PG);                                                      \
138                 const unsigned ki = df(PH,PC);                                                      \
139                 const int left    = ke<<1 <= ki && PE != PG && PD != PG;                            \
140                 const int up      = ke >= ki<<1 && PE != PC && PB != PC;                            \
141                 if (left && up) {                                                                   \
142                     E[N7] = ALPHA_BLEND_192_W(E[N7], px);                                           \
143                     E[N6] = ALPHA_BLEND_64_W( E[N6], px);                                           \
144                     E[N5] = E[N7];                                                                  \
145                     E[N2] = E[N6];                                                                  \
146                     E[N8] = px;                                                                     \
147                 } else if (left) {                                                                  \
148                     E[N7] = ALPHA_BLEND_192_W(E[N7], px);                                           \
149                     E[N5] = ALPHA_BLEND_64_W( E[N5], px);                                           \
150                     E[N6] = ALPHA_BLEND_64_W( E[N6], px);                                           \
151                     E[N8] = px;                                                                     \
152                 } else if (up) {                                                                    \
153                     E[N5] = ALPHA_BLEND_192_W(E[N5], px);                                           \
154                     E[N7] = ALPHA_BLEND_64_W( E[N7], px);                                           \
155                     E[N2] = ALPHA_BLEND_64_W( E[N2], px);                                           \
156                     E[N8] = px;                                                                     \
157                 } else { /* diagonal */                                                             \
158                     E[N8] = ALPHA_BLEND_224_W(E[N8], px);                                           \
159                     E[N5] = ALPHA_BLEND_32_W( E[N5], px);                                           \
160                     E[N7] = ALPHA_BLEND_32_W( E[N7], px);                                           \
161                 }                                                                                   \
162             } else {                                                                                \
163                 E[N8] = ALPHA_BLEND_128_W(E[N8], px);                                               \
164             }                                                                                       \
165         }                                                                                           \
166     }                                                                                               \
167 } while (0)
168
169 #define FILT4(PE, PI, PH, PF, PG, PC, PD, PB, PA, G5, C4, G0, D0, C1, B1, F4, I4, H5, I5, A0, A1,   \
170               N15, N14, N11, N3, N7, N10, N13, N12, N9, N6, N2, N1, N5, N8, N4, N0) do {            \
171     if (PE != PH && PE != PF) {                                                                     \
172         const unsigned e = df(PE,PC) + df(PE,PG) + df(PI,H5) + df(PI,F4) + (df(PH,PF)<<2);          \
173         const unsigned i = df(PH,PD) + df(PH,I5) + df(PF,I4) + df(PF,PB) + (df(PE,PI)<<2);          \
174         if (e <= i) {                                                                               \
175             const unsigned px = df(PE,PF) <= df(PE,PH) ? PF : PH;                                   \
176             if (e < i && (!eq(PF,PB) && !eq(PH,PD) || eq(PE,PI)                                     \
177                           && (!eq(PF,I4) && !eq(PH,I5))                                             \
178                           || eq(PE,PG) || eq(PE,PC))) {                                             \
179                 const unsigned ke = df(PF,PG);                                                      \
180                 const unsigned ki = df(PH,PC);                                                      \
181                 const int left    = ke<<1 <= ki && PE != PG && PD != PG;                            \
182                 const int up      = ke >= ki<<1 && PE != PC && PB != PC;                            \
183                 if (left && up) {                                                                   \
184                     E[N13] = ALPHA_BLEND_192_W(E[N13], px);                                         \
185                     E[N12] = ALPHA_BLEND_64_W( E[N12], px);                                         \
186                     E[N15] = E[N14] = E[N11] = px;                                                  \
187                     E[N10] = E[N3]  = E[N12];                                                       \
188                     E[N7]  = E[N13];                                                                \
189                 } else if (left) {                                                                  \
190                     E[N11] = ALPHA_BLEND_192_W(E[N11], px);                                         \
191                     E[N13] = ALPHA_BLEND_192_W(E[N13], px);                                         \
192                     E[N10] = ALPHA_BLEND_64_W( E[N10], px);                                         \
193                     E[N12] = ALPHA_BLEND_64_W( E[N12], px);                                         \
194                     E[N14] = px;                                                                    \
195                     E[N15] = px;                                                                    \
196                 } else if (up) {                                                                    \
197                     E[N14] = ALPHA_BLEND_192_W(E[N14], px);                                         \
198                     E[N7 ] = ALPHA_BLEND_192_W(E[N7 ], px);                                         \
199                     E[N10] = ALPHA_BLEND_64_W( E[N10], px);                                         \
200                     E[N3 ] = ALPHA_BLEND_64_W( E[N3 ], px);                                         \
201                     E[N11] = px;                                                                    \
202                     E[N15] = px;                                                                    \
203                 } else { /* diagonal */                                                             \
204                     E[N11] = ALPHA_BLEND_128_W(E[N11], px);                                         \
205                     E[N14] = ALPHA_BLEND_128_W(E[N14], px);                                         \
206                     E[N15] = px;                                                                    \
207                 }                                                                                   \
208             } else {                                                                                \
209                 E[N15] = ALPHA_BLEND_128_W(E[N15], px);                                             \
210             }                                                                                       \
211         }                                                                                           \
212     }                                                                                               \
213 } while (0)
214
215 static av_always_inline void xbr_filter(const ThreadData *td, int jobnr, int nb_jobs, int n)
216 {
217     int x, y;
218     const AVFrame *input = td->in;
219     AVFrame *output = td->out;
220     const uint32_t *r2y = td->rgbtoyuv;
221     const int slice_start = (input->height *  jobnr   ) / nb_jobs;
222     const int slice_end   = (input->height * (jobnr+1)) / nb_jobs;
223     const int nl = output->linesize[0] >> 2;
224     const int nl1 = nl + nl;
225     const int nl2 = nl1 + nl;
226
227     for (y = slice_start; y < slice_end; y++) {
228
229         uint32_t *E = (uint32_t *)(output->data[0] + y * output->linesize[0] * n);
230         const uint32_t *sa2 = (uint32_t *)(input->data[0] + y * input->linesize[0] - 8); /* center */
231         const uint32_t *sa1 = sa2 - (input->linesize[0]>>2); /* up x1 */
232         const uint32_t *sa0 = sa1 - (input->linesize[0]>>2); /* up x2 */
233         const uint32_t *sa3 = sa2 + (input->linesize[0]>>2); /* down x1 */
234         const uint32_t *sa4 = sa3 + (input->linesize[0]>>2); /* down x2 */
235
236         if (y <= 1) {
237             sa0 = sa1;
238             if (y == 0) {
239                 sa0 = sa1 = sa2;
240             }
241         }
242
243         if (y >= input->height - 2) {
244             sa4 = sa3;
245             if (y == input->height - 1) {
246                 sa4 = sa3 = sa2;
247             }
248         }
249
250         for (x = 0; x < input->width; x++) {
251             const uint32_t B1 = sa0[2];
252             const uint32_t PB = sa1[2];
253             const uint32_t PE = sa2[2];
254             const uint32_t PH = sa3[2];
255             const uint32_t H5 = sa4[2];
256
257             const int pprev = 2 - (x > 0);
258             const uint32_t A1 = sa0[pprev];
259             const uint32_t PA = sa1[pprev];
260             const uint32_t PD = sa2[pprev];
261             const uint32_t PG = sa3[pprev];
262             const uint32_t G5 = sa4[pprev];
263
264             const int pprev2 = pprev - (x > 1);
265             const uint32_t A0 = sa1[pprev2];
266             const uint32_t D0 = sa2[pprev2];
267             const uint32_t G0 = sa3[pprev2];
268
269             const int pnext = 3 - (x == input->width - 1);
270             const uint32_t C1 = sa0[pnext];
271             const uint32_t PC = sa1[pnext];
272             const uint32_t PF = sa2[pnext];
273             const uint32_t PI = sa3[pnext];
274             const uint32_t I5 = sa4[pnext];
275
276             const int pnext2 = pnext + 1 - (x >= input->width - 2);
277             const uint32_t C4 = sa1[pnext2];
278             const uint32_t F4 = sa2[pnext2];
279             const uint32_t I4 = sa3[pnext2];
280
281             if (n == 2) {
282                 E[0]  = E[1]      =     // 0, 1
283                 E[nl] = E[nl + 1] = PE; // 2, 3
284
285                 FILT2(PE, PI, PH, PF, PG, PC, PD, PB, PA, G5, C4, G0, D0, C1, B1, F4, I4, H5, I5, A0, A1, 0, 1, nl, nl+1);
286                 FILT2(PE, PC, PF, PB, PI, PA, PH, PD, PG, I4, A1, I5, H5, A0, D0, B1, C1, F4, C4, G5, G0, nl, 0, nl+1, 1);
287                 FILT2(PE, PA, PB, PD, PC, PG, PF, PH, PI, C1, G0, C4, F4, G5, H5, D0, A0, B1, A1, I4, I5, nl+1, nl, 1, 0);
288                 FILT2(PE, PG, PD, PH, PA, PI, PB, PF, PC, A0, I5, A1, B1, I4, F4, H5, G5, D0, G0, C1, C4, 1, nl+1, 0, nl);
289             } else if (n == 3) {
290                 E[0]   = E[1]     = E[2]     =     // 0, 1, 2
291                 E[nl]  = E[nl+1]  = E[nl+2]  =     // 3, 4, 5
292                 E[nl1] = E[nl1+1] = E[nl1+2] = PE; // 6, 7, 8
293
294                 FILT3(PE, PI, PH, PF, PG, PC, PD, PB, PA, G5, C4, G0, D0, C1, B1, F4, I4, H5, I5, A0, A1, 0, 1, 2, nl, nl+1, nl+2, nl1, nl1+1, nl1+2);
295                 FILT3(PE, PC, PF, PB, PI, PA, PH, PD, PG, I4, A1, I5, H5, A0, D0, B1, C1, F4, C4, G5, G0, nl1, nl, 0, nl1+1, nl+1, 1, nl1+2, nl+2, 2);
296                 FILT3(PE, PA, PB, PD, PC, PG, PF, PH, PI, C1, G0, C4, F4, G5, H5, D0, A0, B1, A1, I4, I5, nl1+2, nl1+1, nl1, nl+2, nl+1, nl, 2, 1, 0);
297                 FILT3(PE, PG, PD, PH, PA, PI, PB, PF, PC, A0, I5, A1, B1, I4, F4, H5, G5, D0, G0, C1, C4, 2, nl+2, nl1+2, 1, nl+1, nl1+1, 0, nl, nl1);
298             } else if (n == 4) {
299                 E[0]   = E[1]     = E[2]     = E[3]     =     //  0,  1,  2,  3
300                 E[nl]  = E[nl+1]  = E[nl+2]  = E[nl+3]  =     //  4,  5,  6,  7
301                 E[nl1] = E[nl1+1] = E[nl1+2] = E[nl1+3] =     //  8,  9, 10, 11
302                 E[nl2] = E[nl2+1] = E[nl2+2] = E[nl2+3] = PE; // 12, 13, 14, 15
303
304                 FILT4(PE, PI, PH, PF, PG, PC, PD, PB, PA, G5, C4, G0, D0, C1, B1, F4, I4, H5, I5, A0, A1, nl2+3, nl2+2, nl1+3, 3, nl+3, nl1+2, nl2+1, nl2, nl1+1, nl+2, 2, 1, nl+1, nl1, nl, 0);
305                 FILT4(PE, PC, PF, PB, PI, PA, PH, PD, PG, I4, A1, I5, H5, A0, D0, B1, C1, F4, C4, G5, G0, 3, nl+3, 2, 0, 1, nl+2, nl1+3, nl2+3, nl1+2, nl+1, nl, nl1, nl1+1, nl2+2, nl2+1, nl2);
306                 FILT4(PE, PA, PB, PD, PC, PG, PF, PH, PI, C1, G0, C4, F4, G5, H5, D0, A0, B1, A1, I4, I5, 0, 1, nl, nl2, nl1, nl+1, 2, 3, nl+2, nl1+1, nl2+1, nl2+2, nl1+2, nl+3, nl1+3, nl2+3);
307                 FILT4(PE, PG, PD, PH, PA, PI, PB, PF, PC, A0, I5, A1, B1, I4, F4, H5, G5, D0, G0, C1, C4, nl2, nl1, nl2+1, nl2+3, nl2+2, nl1+1, nl, 0, nl+1, nl1+2, nl1+3, nl+3, nl+2, 1, 2, 3);
308             }
309
310             sa0 += 1;
311             sa1 += 1;
312             sa2 += 1;
313             sa3 += 1;
314             sa4 += 1;
315
316             E += n;
317         }
318     }
319 }
320
321 #define XBR_FUNC(size) \
322 static int xbr##size##x(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs) \
323 { \
324     xbr_filter(arg, jobnr, nb_jobs, size); \
325     return 0; \
326 }
327
328 XBR_FUNC(2)
329 XBR_FUNC(3)
330 XBR_FUNC(4)
331
332
333 static int config_output(AVFilterLink *outlink)
334 {
335     AVFilterContext *ctx = outlink->src;
336     XBRContext *s = ctx->priv;
337     AVFilterLink *inlink = ctx->inputs[0];
338
339     outlink->w = inlink->w * s->n;
340     outlink->h = inlink->h * s->n;
341     return 0;
342 }
343
344 static int query_formats(AVFilterContext *ctx)
345 {
346     static const enum AVPixelFormat pix_fmts[] = {
347         AV_PIX_FMT_0RGB32, AV_PIX_FMT_NONE,
348     };
349
350     AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
351     if (!fmts_list)
352         return AVERROR(ENOMEM);
353     return ff_set_common_formats(ctx, fmts_list);
354 }
355
356 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
357 {
358     AVFilterContext *ctx = inlink->dst;
359     AVFilterLink *outlink = ctx->outputs[0];
360     XBRContext *s = ctx->priv;
361     ThreadData td;
362
363     AVFrame *out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
364     if (!out) {
365         av_frame_free(&in);
366         return AVERROR(ENOMEM);
367     }
368
369     av_frame_copy_props(out, in);
370
371     td.in = in;
372     td.out = out;
373     td.rgbtoyuv = s->rgbtoyuv;
374     ctx->internal->execute(ctx, s->func, &td, NULL, FFMIN(inlink->h, ff_filter_get_nb_threads(ctx)));
375
376     out->width  = outlink->w;
377     out->height = outlink->h;
378
379     av_frame_free(&in);
380     return ff_filter_frame(outlink, out);
381 }
382
383 static int init(AVFilterContext *ctx)
384 {
385     XBRContext *s = ctx->priv;
386     static const xbrfunc_t xbrfuncs[] = {xbr2x, xbr3x, xbr4x};
387
388     uint32_t c;
389     int bg, rg, g;
390
391     for (bg = -255; bg < 256; bg++) {
392         for (rg = -255; rg < 256; rg++) {
393             const uint32_t u = (uint32_t)((-169*rg + 500*bg)/1000) + 128;
394             const uint32_t v = (uint32_t)(( 500*rg -  81*bg)/1000) + 128;
395             int startg = FFMAX3(-bg, -rg, 0);
396             int endg = FFMIN3(255-bg, 255-rg, 255);
397             uint32_t y = (uint32_t)(( 299*rg + 1000*startg + 114*bg)/1000);
398             c = bg + (rg<<16) + 0x010101 * startg;
399             for (g = startg; g <= endg; g++) {
400                 s->rgbtoyuv[c] = ((y++) << 16) + (u << 8) + v;
401                 c+= 0x010101;
402             }
403         }
404     }
405
406     s->func = xbrfuncs[s->n - 2];
407     return 0;
408 }
409
410 static const AVFilterPad xbr_inputs[] = {
411     {
412         .name         = "default",
413         .type         = AVMEDIA_TYPE_VIDEO,
414         .filter_frame = filter_frame,
415     },
416     { NULL }
417 };
418
419 static const AVFilterPad xbr_outputs[] = {
420     {
421         .name         = "default",
422         .type         = AVMEDIA_TYPE_VIDEO,
423         .config_props = config_output,
424     },
425     { NULL }
426 };
427
428 AVFilter ff_vf_xbr = {
429     .name          = "xbr",
430     .description   = NULL_IF_CONFIG_SMALL("Scale the input using xBR algorithm."),
431     .inputs        = xbr_inputs,
432     .outputs       = xbr_outputs,
433     .query_formats = query_formats,
434     .priv_size     = sizeof(XBRContext),
435     .priv_class    = &xbr_class,
436     .init          = init,
437     .flags         = AVFILTER_FLAG_SLICE_THREADS,
438 };