avcodec/cavsdsp: use av_clip_uint8() for idct
[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 http://www.libretro.com/forums/viewtopic.php?f=6&t=134
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 typedef int (*xbrfunc_t)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
41
42 typedef struct {
43     const AVClass *class;
44     int n;
45     xbrfunc_t func;
46     uint32_t rgbtoyuv[1<<24];
47 } XBRContext;
48
49 typedef struct ThreadData {
50     AVFrame *in, *out;
51     const uint32_t *rgbtoyuv;
52 } ThreadData;
53
54 #define OFFSET(x) offsetof(XBRContext, x)
55 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
56 static const AVOption xbr_options[] = {
57     { "n", "set scale factor", OFFSET(n), AV_OPT_TYPE_INT, {.i64 = 3}, 2, 4, .flags = FLAGS },
58     { NULL }
59 };
60
61 AVFILTER_DEFINE_CLASS(xbr);
62
63 static uint32_t pixel_diff(uint32_t x, uint32_t y, const uint32_t *r2y)
64 {
65 #define YMASK 0xff0000
66 #define UMASK 0x00ff00
67 #define VMASK 0x0000ff
68 #define ABSDIFF(a,b) (abs((int)(a)-(int)(b)))
69
70     uint32_t yuv1 = r2y[x & 0xffffff];
71     uint32_t yuv2 = r2y[y & 0xffffff];
72
73     return (ABSDIFF(yuv1 & YMASK, yuv2 & YMASK) >> 16) +
74            (ABSDIFF(yuv1 & UMASK, yuv2 & UMASK) >>  8) +
75             ABSDIFF(yuv1 & VMASK, yuv2 & VMASK);
76 }
77
78 #define ALPHA_BLEND_128_W(a, b) ((((a) & LB_MASK) >> 1) + (((b) & LB_MASK) >> 1))
79 #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)))) \
80                                       | (GREEN_MASK    & (((a) & GREEN_MASK)    + (((((b) & GREEN_MASK)    - ((a) & GREEN_MASK))    * (m)) >> (s)))))
81 #define ALPHA_BLEND_32_W(a, b)  ALPHA_BLEND_BASE(a, b, 1, 3)
82 #define ALPHA_BLEND_64_W(a, b)  ALPHA_BLEND_BASE(a, b, 1, 2)
83 #define ALPHA_BLEND_192_W(a, b) ALPHA_BLEND_BASE(a, b, 3, 2)
84 #define ALPHA_BLEND_224_W(a, b) ALPHA_BLEND_BASE(a, b, 7, 3)
85
86 #define df(A, B) pixel_diff(A, B, r2y)
87 #define eq(A, B) (df(A, B) < 155)
88
89 #define FILT2(PE, PI, PH, PF, PG, PC, PD, PB, PA, G5, C4, G0, D0, C1, B1, F4, I4, H5, I5, A0, A1,   \
90               N0, N1, N2, N3) do {                                                                  \
91     if (PE != PH && PE != PF) {                                                                     \
92         const unsigned e = df(PE,PC) + df(PE,PG) + df(PI,H5) + df(PI,F4) + (df(PH,PF)<<2);          \
93         const unsigned i = df(PH,PD) + df(PH,I5) + df(PF,I4) + df(PF,PB) + (df(PE,PI)<<2);          \
94         if (e <= i) {                                                                               \
95             const unsigned px = df(PE,PF) <= df(PE,PH) ? PF : PH;                                   \
96             if (e < i && (!eq(PF,PB) && !eq(PH,PD) || eq(PE,PI)                                     \
97                           && (!eq(PF,I4) && !eq(PH,I5))                                             \
98                           || eq(PE,PG) || eq(PE,PC))) {                                             \
99                 const unsigned ke = df(PF,PG);                                                      \
100                 const unsigned ki = df(PH,PC);                                                      \
101                 const int left    = ke<<1 <= ki && PE != PG && PD != PG;                            \
102                 const int up      = ke >= ki<<1 && PE != PC && PB != PC;                            \
103                 if (left && up) {                                                                   \
104                     E[N3] = ALPHA_BLEND_224_W(E[N3], px);                                           \
105                     E[N2] = ALPHA_BLEND_64_W( E[N2], px);                                           \
106                     E[N1] = E[N2];                                                                  \
107                 } else if (left) {                                                                  \
108                     E[N3] = ALPHA_BLEND_192_W(E[N3], px);                                           \
109                     E[N2] = ALPHA_BLEND_64_W( E[N2], px);                                           \
110                 } else if (up) {                                                                    \
111                     E[N3] = ALPHA_BLEND_192_W(E[N3], px);                                           \
112                     E[N1] = ALPHA_BLEND_64_W( E[N1], px);                                           \
113                 } else { /* diagonal */                                                             \
114                     E[N3] = ALPHA_BLEND_128_W(E[N3], px);                                           \
115                 }                                                                                   \
116             } else {                                                                                \
117                 E[N3] = ALPHA_BLEND_128_W(E[N3], px);                                               \
118             }                                                                                       \
119         }                                                                                           \
120     }                                                                                               \
121 } while (0)
122
123 #define FILT3(PE, PI, PH, PF, PG, PC, PD, PB, PA, G5, C4, G0, D0, C1, B1, F4, I4, H5, I5, A0, A1,   \
124               N0, N1, N2, N3, N4, N5, N6, N7, N8) do {                                              \
125     if (PE != PH && PE != PF) {                                                                     \
126         const unsigned e = df(PE,PC) + df(PE,PG) + df(PI,H5) + df(PI,F4) + (df(PH,PF)<<2);          \
127         const unsigned i = df(PH,PD) + df(PH,I5) + df(PF,I4) + df(PF,PB) + (df(PE,PI)<<2);          \
128         if (e <= i) {                                                                               \
129             const unsigned px = df(PE,PF) <= df(PE,PH) ? PF : PH;                                   \
130             if (e < i && (!eq(PF,PB) && !eq(PF,PC) || !eq(PH,PD) && !eq(PH,PG) || eq(PE,PI)         \
131                           && (!eq(PF,F4) && !eq(PF,I4) || !eq(PH,H5) && !eq(PH,I5))                 \
132                           || eq(PE,PG) || eq(PE,PC))) {                                             \
133                 const unsigned ke = df(PF,PG);                                                      \
134                 const unsigned ki = df(PH,PC);                                                      \
135                 const int left    = ke<<1 <= ki && PE != PG && PD != PG;                            \
136                 const int up      = ke >= ki<<1 && PE != PC && PB != PC;                            \
137                 if (left && up) {                                                                   \
138                     E[N7] = ALPHA_BLEND_192_W(E[N7], px);                                           \
139                     E[N6] = ALPHA_BLEND_64_W( E[N6], px);                                           \
140                     E[N5] = E[N7];                                                                  \
141                     E[N2] = E[N6];                                                                  \
142                     E[N8] = px;                                                                     \
143                 } else if (left) {                                                                  \
144                     E[N7] = ALPHA_BLEND_192_W(E[N7], px);                                           \
145                     E[N5] = ALPHA_BLEND_64_W( E[N5], px);                                           \
146                     E[N6] = ALPHA_BLEND_64_W( E[N6], px);                                           \
147                     E[N8] = px;                                                                     \
148                 } else if (up) {                                                                    \
149                     E[N5] = ALPHA_BLEND_192_W(E[N5], px);                                           \
150                     E[N7] = ALPHA_BLEND_64_W( E[N7], px);                                           \
151                     E[N2] = ALPHA_BLEND_64_W( E[N2], px);                                           \
152                     E[N8] = px;                                                                     \
153                 } else { /* diagonal */                                                             \
154                     E[N8] = ALPHA_BLEND_224_W(E[N8], px);                                           \
155                     E[N5] = ALPHA_BLEND_32_W( E[N5], px);                                           \
156                     E[N7] = ALPHA_BLEND_32_W( E[N7], px);                                           \
157                 }                                                                                   \
158             } else {                                                                                \
159                 E[N8] = ALPHA_BLEND_128_W(E[N8], px);                                               \
160             }                                                                                       \
161         }                                                                                           \
162     }                                                                                               \
163 } while (0)
164
165 #define FILT4(PE, PI, PH, PF, PG, PC, PD, PB, PA, G5, C4, G0, D0, C1, B1, F4, I4, H5, I5, A0, A1,   \
166               N15, N14, N11, N3, N7, N10, N13, N12, N9, N6, N2, N1, N5, N8, N4, N0) do {            \
167     if (PE != PH && PE != PF) {                                                                     \
168         const unsigned e = df(PE,PC) + df(PE,PG) + df(PI,H5) + df(PI,F4) + (df(PH,PF)<<2);          \
169         const unsigned i = df(PH,PD) + df(PH,I5) + df(PF,I4) + df(PF,PB) + (df(PE,PI)<<2);          \
170         if (e <= i) {                                                                               \
171             const unsigned px = df(PE,PF) <= df(PE,PH) ? PF : PH;                                   \
172             if (e < i && (!eq(PF,PB) && !eq(PH,PD) || eq(PE,PI)                                     \
173                           && (!eq(PF,I4) && !eq(PH,I5))                                             \
174                           || eq(PE,PG) || eq(PE,PC))) {                                             \
175                 const unsigned ke = df(PF,PG);                                                      \
176                 const unsigned ki = df(PH,PC);                                                      \
177                 const int left    = ke<<1 <= ki && PE != PG && PD != PG;                            \
178                 const int up      = ke >= ki<<1 && PE != PC && PB != PC;                            \
179                 if (left && up) {                                                                   \
180                     E[N13] = ALPHA_BLEND_192_W(E[N13], px);                                         \
181                     E[N12] = ALPHA_BLEND_64_W( E[N12], px);                                         \
182                     E[N15] = E[N14] = E[N11] = px;                                                  \
183                     E[N10] = E[N3]  = E[N12];                                                       \
184                     E[N7]  = E[N13];                                                                \
185                 } else if (left) {                                                                  \
186                     E[N11] = ALPHA_BLEND_192_W(E[N11], px);                                         \
187                     E[N13] = ALPHA_BLEND_192_W(E[N13], px);                                         \
188                     E[N10] = ALPHA_BLEND_64_W( E[N10], px);                                         \
189                     E[N12] = ALPHA_BLEND_64_W( E[N12], px);                                         \
190                     E[N14] = px;                                                                    \
191                     E[N15] = px;                                                                    \
192                 } else if (up) {                                                                    \
193                     E[N14] = ALPHA_BLEND_192_W(E[N14], px);                                         \
194                     E[N7 ] = ALPHA_BLEND_192_W(E[N7 ], px);                                         \
195                     E[N10] = ALPHA_BLEND_64_W( E[N10], px);                                         \
196                     E[N3 ] = ALPHA_BLEND_64_W( E[N3 ], px);                                         \
197                     E[N11] = px;                                                                    \
198                     E[N15] = px;                                                                    \
199                 } else { /* diagonal */                                                             \
200                     E[N11] = ALPHA_BLEND_128_W(E[N11], px);                                         \
201                     E[N14] = ALPHA_BLEND_128_W(E[N14], px);                                         \
202                     E[N15] = px;                                                                    \
203                 }                                                                                   \
204             } else {                                                                                \
205                 E[N15] = ALPHA_BLEND_128_W(E[N15], px);                                             \
206             }                                                                                       \
207         }                                                                                           \
208     }                                                                                               \
209 } while (0)
210
211 static av_always_inline void xbr_filter(const ThreadData *td, int jobnr, int nb_jobs, int n)
212 {
213     int x, y;
214     const AVFrame *input = td->in;
215     AVFrame *output = td->out;
216     const uint32_t *r2y = td->rgbtoyuv;
217     const int slice_start = (input->height *  jobnr   ) / nb_jobs;
218     const int slice_end   = (input->height * (jobnr+1)) / nb_jobs;
219     const int nl = output->linesize[0] >> 2;
220     const int nl1 = nl + nl;
221     const int nl2 = nl1 + nl;
222
223     for (y = slice_start; y < slice_end; y++) {
224
225         uint32_t *E = (uint32_t *)(output->data[0] + y * output->linesize[0] * n);
226         const uint32_t *sa2 = (uint32_t *)(input->data[0] + y * input->linesize[0] - 8); /* center */
227         const uint32_t *sa1 = sa2 - (input->linesize[0]>>2); /* up x1 */
228         const uint32_t *sa0 = sa1 - (input->linesize[0]>>2); /* up x2 */
229         const uint32_t *sa3 = sa2 + (input->linesize[0]>>2); /* down x1 */
230         const uint32_t *sa4 = sa3 + (input->linesize[0]>>2); /* down x2 */
231
232         if (y <= 1) {
233             sa0 = sa1;
234             if (y == 0) {
235                 sa0 = sa1 = sa2;
236             }
237         }
238
239         if (y >= input->height - 2) {
240             sa4 = sa3;
241             if (y == input->height - 1) {
242                 sa4 = sa3 = sa2;
243             }
244         }
245
246         for (x = 0; x < input->width; x++) {
247             const uint32_t B1 = sa0[2];
248             const uint32_t PB = sa1[2];
249             const uint32_t PE = sa2[2];
250             const uint32_t PH = sa3[2];
251             const uint32_t H5 = sa4[2];
252
253             const int pprev = 2 - (x > 0);
254             const uint32_t A1 = sa0[pprev];
255             const uint32_t PA = sa1[pprev];
256             const uint32_t PD = sa2[pprev];
257             const uint32_t PG = sa3[pprev];
258             const uint32_t G5 = sa4[pprev];
259
260             const int pprev2 = pprev - (x > 1);
261             const uint32_t A0 = sa1[pprev2];
262             const uint32_t D0 = sa2[pprev2];
263             const uint32_t G0 = sa3[pprev2];
264
265             const int pnext = 3 - (x == input->width - 1);
266             const uint32_t C1 = sa0[pnext];
267             const uint32_t PC = sa1[pnext];
268             const uint32_t PF = sa2[pnext];
269             const uint32_t PI = sa3[pnext];
270             const uint32_t I5 = sa4[pnext];
271
272             const int pnext2 = pnext + 1 - (x >= input->width - 2);
273             const uint32_t C4 = sa1[pnext2];
274             const uint32_t F4 = sa2[pnext2];
275             const uint32_t I4 = sa3[pnext2];
276
277             if (n == 2) {
278                 E[0]  = E[1]      =     // 0, 1
279                 E[nl] = E[nl + 1] = PE; // 2, 3
280
281                 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);
282                 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);
283                 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);
284                 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);
285             } else if (n == 3) {
286                 E[0]   = E[1]     = E[2]     =     // 0, 1, 2
287                 E[nl]  = E[nl+1]  = E[nl+2]  =     // 3, 4, 5
288                 E[nl1] = E[nl1+1] = E[nl1+2] = PE; // 6, 7, 8
289
290                 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);
291                 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);
292                 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);
293                 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);
294             } else if (n == 4) {
295                 E[0]   = E[1]     = E[2]     = E[3]     =     //  0,  1,  2,  3
296                 E[nl]  = E[nl+1]  = E[nl+2]  = E[nl+3]  =     //  4,  5,  6,  7
297                 E[nl1] = E[nl1+1] = E[nl1+2] = E[nl1+3] =     //  8,  9, 10, 11
298                 E[nl2] = E[nl2+1] = E[nl2+2] = E[nl2+3] = PE; // 12, 13, 14, 15
299
300                 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);
301                 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);
302                 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);
303                 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);
304             }
305
306             sa0 += 1;
307             sa1 += 1;
308             sa2 += 1;
309             sa3 += 1;
310             sa4 += 1;
311
312             E += n;
313         }
314     }
315 }
316
317 #define XBR_FUNC(size) \
318 static int xbr##size##x(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs) \
319 { \
320     xbr_filter(arg, jobnr, nb_jobs, size); \
321     return 0; \
322 }
323
324 XBR_FUNC(2)
325 XBR_FUNC(3)
326 XBR_FUNC(4)
327
328
329 static int config_output(AVFilterLink *outlink)
330 {
331     AVFilterContext *ctx = outlink->src;
332     XBRContext *s = ctx->priv;
333     AVFilterLink *inlink = ctx->inputs[0];
334
335     outlink->w = inlink->w * s->n;
336     outlink->h = inlink->h * s->n;
337     return 0;
338 }
339
340 static int query_formats(AVFilterContext *ctx)
341 {
342     static const enum AVPixelFormat pix_fmts[] = {
343         AV_PIX_FMT_0RGB32, AV_PIX_FMT_NONE,
344     };
345
346     AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
347     if (!fmts_list)
348         return AVERROR(ENOMEM);
349     return ff_set_common_formats(ctx, fmts_list);
350 }
351
352 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
353 {
354     AVFilterContext *ctx = inlink->dst;
355     AVFilterLink *outlink = ctx->outputs[0];
356     XBRContext *s = ctx->priv;
357     ThreadData td;
358
359     AVFrame *out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
360     if (!out) {
361         av_frame_free(&in);
362         return AVERROR(ENOMEM);
363     }
364
365     av_frame_copy_props(out, in);
366
367     td.in = in;
368     td.out = out;
369     td.rgbtoyuv = s->rgbtoyuv;
370     ctx->internal->execute(ctx, s->func, &td, NULL, FFMIN(inlink->h, ff_filter_get_nb_threads(ctx)));
371
372     out->width  = outlink->w;
373     out->height = outlink->h;
374
375     av_frame_free(&in);
376     return ff_filter_frame(outlink, out);
377 }
378
379 static int init(AVFilterContext *ctx)
380 {
381     XBRContext *s = ctx->priv;
382     static const xbrfunc_t xbrfuncs[] = {xbr2x, xbr3x, xbr4x};
383
384     uint32_t c;
385     int bg, rg, g;
386
387     for (bg = -255; bg < 256; bg++) {
388         for (rg = -255; rg < 256; rg++) {
389             const uint32_t u = (uint32_t)((-169*rg + 500*bg)/1000) + 128;
390             const uint32_t v = (uint32_t)(( 500*rg -  81*bg)/1000) + 128;
391             int startg = FFMAX3(-bg, -rg, 0);
392             int endg = FFMIN3(255-bg, 255-rg, 255);
393             uint32_t y = (uint32_t)(( 299*rg + 1000*startg + 114*bg)/1000);
394             c = bg + (rg<<16) + 0x010101 * startg;
395             for (g = startg; g <= endg; g++) {
396                 s->rgbtoyuv[c] = ((y++) << 16) + (u << 8) + v;
397                 c+= 0x010101;
398             }
399         }
400     }
401
402     s->func = xbrfuncs[s->n - 2];
403     return 0;
404 }
405
406 static const AVFilterPad xbr_inputs[] = {
407     {
408         .name         = "default",
409         .type         = AVMEDIA_TYPE_VIDEO,
410         .filter_frame = filter_frame,
411     },
412     { NULL }
413 };
414
415 static const AVFilterPad xbr_outputs[] = {
416     {
417         .name         = "default",
418         .type         = AVMEDIA_TYPE_VIDEO,
419         .config_props = config_output,
420     },
421     { NULL }
422 };
423
424 AVFilter ff_vf_xbr = {
425     .name          = "xbr",
426     .description   = NULL_IF_CONFIG_SMALL("Scale the input using xBR algorithm."),
427     .inputs        = xbr_inputs,
428     .outputs       = xbr_outputs,
429     .query_formats = query_formats,
430     .priv_size     = sizeof(XBRContext),
431     .priv_class    = &xbr_class,
432     .init          = init,
433     .flags         = AVFILTER_FLAG_SLICE_THREADS,
434 };