avfilter/xbr: fix style in FILT4() calls
[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 RGB_MASK      0x00FFFFFF
37 #define LB_MASK       0x00FEFEFE
38 #define RED_BLUE_MASK 0x00FF00FF
39 #define GREEN_MASK    0x0000FF00
40
41 typedef int (*xbrfunc_t)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
42
43 typedef struct {
44     const AVClass *class;
45     int n;
46     xbrfunc_t func;
47     uint32_t rgbtoyuv[1<<24];
48 } XBRContext;
49
50 typedef struct ThreadData {
51     AVFrame *in, *out;
52     const uint32_t *rgbtoyuv;
53 } ThreadData;
54
55 #define OFFSET(x) offsetof(XBRContext, x)
56 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
57 static const AVOption xbr_options[] = {
58     { "n", "set scale factor", OFFSET(n), AV_OPT_TYPE_INT, {.i64 = 3}, 2, 4, .flags = FLAGS },
59     { NULL }
60 };
61
62 AVFILTER_DEFINE_CLASS(xbr);
63
64 static uint32_t pixel_diff(uint32_t x, uint32_t y, const uint32_t *r2y)
65 {
66 #define YMASK 0xff0000
67 #define UMASK 0x00ff00
68 #define VMASK 0x0000ff
69
70     uint32_t yuv1 = r2y[x & 0xffffff];
71     uint32_t yuv2 = r2y[y & 0xffffff];
72
73     return (abs((yuv1 & YMASK) - (yuv2 & YMASK)) >> 16) +
74            (abs((yuv1 & UMASK) - (yuv2 & UMASK)) >>  8) +
75            abs((yuv1 & VMASK) - (yuv2 & VMASK));
76 }
77
78 #define ALPHA_BLEND_128_W(dst, src) dst = ((src & LB_MASK) >> 1) + ((dst & LB_MASK) >> 1)
79
80 #define ALPHA_BLEND_32_W(dst, src) \
81     dst = ((RED_BLUE_MASK & ((dst & RED_BLUE_MASK) + ((((src & RED_BLUE_MASK) - \
82           (dst & RED_BLUE_MASK))) >> 3))) | (GREEN_MASK & ((dst & GREEN_MASK) + \
83           ((((src & GREEN_MASK) - (dst & GREEN_MASK))) >> 3))))
84
85 #define ALPHA_BLEND_64_W(dst, src) \
86     dst = ((RED_BLUE_MASK & ((dst & RED_BLUE_MASK) + ((((src & RED_BLUE_MASK) - \
87           (dst & RED_BLUE_MASK))) >> 2))) | (GREEN_MASK & ((dst & GREEN_MASK) + \
88           ((((src & GREEN_MASK) - (dst & GREEN_MASK))) >> 2))))
89
90 #define ALPHA_BLEND_192_W(dst, src) \
91     dst = ((RED_BLUE_MASK & ((dst & RED_BLUE_MASK) + ((((src & RED_BLUE_MASK) - \
92           (dst & RED_BLUE_MASK)) * 3) >> 2))) | (GREEN_MASK & ((dst & GREEN_MASK) + \
93           ((((src & GREEN_MASK) - (dst & GREEN_MASK)) * 3) >> 2))))
94
95 #define ALPHA_BLEND_224_W(dst, src) \
96     dst = ((RED_BLUE_MASK & ((dst & RED_BLUE_MASK) + ((((src & RED_BLUE_MASK) - \
97           (dst & RED_BLUE_MASK)) * 7) >> 3))) | (GREEN_MASK & ((dst & GREEN_MASK) + \
98           ((((src & GREEN_MASK) - (dst & GREEN_MASK)) * 7) >> 3))))
99
100 #define df(A, B) pixel_diff(A, B, r2y)
101 #define eq(A, B) (df(A, B) < 155)
102
103 #define FILT2(PE, PI, PH, PF, PG, PC, PD, PB, PA, G5, C4, G0, D0, C1, B1, F4, I4, H5, I5, A0, A1,   \
104               N0, N1, N2, N3) do {                                                                  \
105     if (PE != PH && PE != PF) {                                                                     \
106         const unsigned e = df(PE,PC) + df(PE,PG) + df(PI,H5) + df(PI,F4) + (df(PH,PF)<<2);          \
107         const unsigned i = df(PH,PD) + df(PH,I5) + df(PF,I4) + df(PF,PB) + (df(PE,PI)<<2);          \
108         if (e < i && (!eq(PF,PB) && !eq(PH,PD) || eq(PE,PI)                                         \
109                       && (!eq(PF,I4) && !eq(PH,I5))                                                 \
110                       || eq(PE,PG) || eq(PE,PC))) {                                                 \
111             const unsigned ke = df(PF,PG);                                                          \
112             const unsigned ki = df(PH,PC);                                                          \
113             const int left    = ke<<1 <= ki && PE != PG && PD != PG;                                \
114             const int up      = ke >= ki<<1 && PE != PC && PB != PC;                                \
115             const unsigned px = df(PE,PF) <= df(PE,PH) ? PF : PH;                                   \
116             if (left && up) {                                                                       \
117                 ALPHA_BLEND_224_W(E[N3], px);                                                       \
118                 ALPHA_BLEND_64_W( E[N2], px);                                                       \
119                 E[N1] = E[N2];                                                                      \
120             } else if (left) {                                                                      \
121                 ALPHA_BLEND_192_W(E[N3], px);                                                       \
122                 ALPHA_BLEND_64_W( E[N2], px);                                                       \
123             } else if (up) {                                                                        \
124                 ALPHA_BLEND_192_W(E[N3], px);                                                       \
125                 ALPHA_BLEND_64_W( E[N1], px);                                                       \
126             } else { /* diagonal */                                                                 \
127                 ALPHA_BLEND_128_W(E[N3], px);                                                       \
128             }                                                                                       \
129         } else if (e <= i) {                                                                        \
130             ALPHA_BLEND_128_W( E[N3], ((df(PE,PF) <= df(PE,PH)) ? PF : PH));                        \
131         }                                                                                           \
132     }                                                                                               \
133 } while (0)
134
135 #define FILT3(PE, PI, PH, PF, PG, PC, PD, PB, PA, G5, C4, G0, D0, C1, B1, F4, I4, H5, I5, A0, A1,   \
136               N0, N1, N2, N3, N4, N5, N6, N7, N8) do {                                              \
137     if (PE != PH && PE != PF) {                                                                     \
138         const unsigned e = df(PE,PC) + df(PE,PG) + df(PI,H5) + df(PI,F4) + (df(PH,PF)<<2);          \
139         const unsigned i = df(PH,PD) + df(PH,I5) + df(PF,I4) + df(PF,PB) + (df(PE,PI)<<2);          \
140         if (e < i && (!eq(PF,PB) && !eq(PF,PC) || !eq(PH,PD) && !eq(PH,PG) || eq(PE,PI)             \
141                       && (!eq(PF,F4) && !eq(PF,I4) || !eq(PH,H5) && !eq(PH,I5))                     \
142                       || eq(PE,PG) || eq(PE,PC))) {                                                 \
143             const unsigned ke = df(PF,PG);                                                          \
144             const unsigned ki = df(PH,PC);                                                          \
145             const int left    = ke<<1 <= ki && PE != PG && PD != PG;                                \
146             const int up      = ke >= ki<<1 && PE != PC && PB != PC;                                \
147             const unsigned px = df(PE,PF) <= df(PE,PH) ? PF : PH;                                   \
148             if (left && up) {                                                                       \
149                 ALPHA_BLEND_192_W(E[N7], px);                                                       \
150                 ALPHA_BLEND_64_W( E[N6], px);                                                       \
151                 E[N5] = E[N7];                                                                      \
152                 E[N2] = E[N6];                                                                      \
153                 E[N8] = px;                                                                         \
154             } else if (left) {                                                                      \
155                 ALPHA_BLEND_192_W(E[N7], px);                                                       \
156                 ALPHA_BLEND_64_W( E[N5], px);                                                       \
157                 ALPHA_BLEND_64_W( E[N6], px);                                                       \
158                 E[N8] = px;                                                                         \
159             } else if (up) {                                                                        \
160                 ALPHA_BLEND_192_W(E[N5], px);                                                       \
161                 ALPHA_BLEND_64_W( E[N7], px);                                                       \
162                 ALPHA_BLEND_64_W( E[N2], px);                                                       \
163                 E[N8] = px;                                                                         \
164             } else { /* diagonal */                                                                 \
165                 ALPHA_BLEND_224_W(E[N8], px);                                                       \
166                 ALPHA_BLEND_32_W( E[N5], px);                                                       \
167                 ALPHA_BLEND_32_W( E[N7], px);                                                       \
168             }                                                                                       \
169         } else if (e <= i) {                                                                        \
170             ALPHA_BLEND_128_W(E[N8], ((df(PE,PF) <= df(PE,PH)) ? PF : PH));                         \
171         }                                                                                           \
172     }                                                                                               \
173 } while (0)
174
175 #define FILT4(PE, PI, PH, PF, PG, PC, PD, PB, PA, G5, C4, G0, D0, C1, B1, F4, I4, H5, I5, A0, A1,   \
176               N15, N14, N11, N3, N7, N10, N13, N12, N9, N6, N2, N1, N5, N8, N4, N0) do {            \
177     if (PE != PH && PE != PF) {                                                                     \
178         const unsigned e = df(PE,PC) + df(PE,PG) + df(PI,H5) + df(PI,F4) + (df(PH,PF)<<2);          \
179         const unsigned i = df(PH,PD) + df(PH,I5) + df(PF,I4) + df(PF,PB) + (df(PE,PI)<<2);          \
180         if (e < i && (!eq(PF,PB) && !eq(PH,PD) || eq(PE,PI)                                         \
181                       && (!eq(PF,I4) && !eq(PH,I5))                                                 \
182                       || eq(PE,PG) || eq(PE,PC))) {                                                 \
183             const unsigned ke = df(PF,PG);                                                          \
184             const unsigned ki = df(PH,PC);                                                          \
185             const int left    = ke<<1 <= ki && PE != PG && PD != PG;                                \
186             const int up      = ke >= ki<<1 && PE != PC && PB != PC;                                \
187             const unsigned px = df(PE,PF) <= df(PE,PH) ? PF : PH;                                   \
188             if (left && up) {                                                                       \
189                 ALPHA_BLEND_192_W(E[N13], px);                                                      \
190                 ALPHA_BLEND_64_W( E[N12], px);                                                      \
191                 E[N15] = E[N14] = E[N11] = px;                                                      \
192                 E[N10] = E[N3]  = E[N12];                                                           \
193                 E[N7]  = E[N13];                                                                    \
194             } else if (left) {                                                                      \
195                 ALPHA_BLEND_192_W(E[N11], px);                                                      \
196                 ALPHA_BLEND_192_W(E[N13], px);                                                      \
197                 ALPHA_BLEND_64_W( E[N10], px);                                                      \
198                 ALPHA_BLEND_64_W( E[N12], px);                                                      \
199                 E[N14] = px;                                                                        \
200                 E[N15] = px;                                                                        \
201             } else if (up) {                                                                        \
202                 ALPHA_BLEND_192_W(E[N14], px);                                                      \
203                 ALPHA_BLEND_192_W(E[N7 ], px);                                                      \
204                 ALPHA_BLEND_64_W( E[N10], px);                                                      \
205                 ALPHA_BLEND_64_W( E[N3 ], px);                                                      \
206                 E[N11] = px;                                                                        \
207                 E[N15] = px;                                                                        \
208             } else { /* diagonal */                                                                 \
209                 ALPHA_BLEND_128_W(E[N11], px);                                                      \
210                 ALPHA_BLEND_128_W(E[N14], px);                                                      \
211                 E[N15] = px;                                                                        \
212             }                                                                                       \
213         } else if (e <= i) {                                                                        \
214             ALPHA_BLEND_128_W( E[N15], ((df(PE,PF) <= df(PE,PH)) ? PF : PH));                       \
215         }                                                                                           \
216     }                                                                                               \
217 } while (0)
218
219 static av_always_inline void xbr_filter(const ThreadData *td, int jobnr, int nb_jobs, int n)
220 {
221     int x, y;
222     const AVFrame *input = td->in;
223     AVFrame *output = td->out;
224     const uint32_t *r2y = td->rgbtoyuv;
225     const int slice_start = (input->height *  jobnr   ) / nb_jobs;
226     const int slice_end   = (input->height * (jobnr+1)) / nb_jobs;
227     const int nl = output->linesize[0] >> 2;
228     const int nl1 = nl + nl;
229     const int nl2 = nl1 + nl;
230
231     for (y = slice_start; y < slice_end; y++) {
232
233         uint32_t *E = (uint32_t *)(output->data[0] + y * output->linesize[0] * n);
234         const uint32_t *sa2 = (uint32_t *)(input->data[0] + y * input->linesize[0] - 8); /* center */
235         const uint32_t *sa1 = sa2 - (input->linesize[0]>>2); /* up x1 */
236         const uint32_t *sa0 = sa1 - (input->linesize[0]>>2); /* up x2 */
237         const uint32_t *sa3 = sa2 + (input->linesize[0]>>2); /* down x1 */
238         const uint32_t *sa4 = sa3 + (input->linesize[0]>>2); /* down x2 */
239
240         if (y <= 1) {
241             sa0 = sa1;
242             if (y == 0) {
243                 sa0 = sa1 = sa2;
244             }
245         }
246
247         if (y >= input->height - 2) {
248             sa4 = sa3;
249             if (y == input->height - 1) {
250                 sa4 = sa3 = sa2;
251             }
252         }
253
254         for (x = 0; x < input->width; x++) {
255             const uint32_t B1 = sa0[2];
256             const uint32_t PB = sa1[2];
257             const uint32_t PE = sa2[2];
258             const uint32_t PH = sa3[2];
259             const uint32_t H5 = sa4[2];
260
261             const int pprev = 2 - (x > 0);
262             const uint32_t A1 = sa0[pprev];
263             const uint32_t PA = sa1[pprev];
264             const uint32_t PD = sa2[pprev];
265             const uint32_t PG = sa3[pprev];
266             const uint32_t G5 = sa4[pprev];
267
268             const int pprev2 = pprev - (x > 1);
269             const uint32_t A0 = sa1[pprev2];
270             const uint32_t D0 = sa2[pprev2];
271             const uint32_t G0 = sa3[pprev2];
272
273             const int pnext = 3 - (x == input->width - 1);
274             const uint32_t C1 = sa0[pnext];
275             const uint32_t PC = sa1[pnext];
276             const uint32_t PF = sa2[pnext];
277             const uint32_t PI = sa3[pnext];
278             const uint32_t I5 = sa4[pnext];
279
280             const int pnext2 = pnext + 1 - (x >= input->width - 2);
281             const uint32_t C4 = sa1[pnext2];
282             const uint32_t F4 = sa2[pnext2];
283             const uint32_t I4 = sa3[pnext2];
284
285             if (n == 2) {
286                 E[0]  = E[1]      =     // 0, 1
287                 E[nl] = E[nl + 1] = PE; // 2, 3
288
289                 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);
290                 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);
291                 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);
292                 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);
293             } else if (n == 3) {
294                 E[0]   = E[1]     = E[2]     =     // 0, 1, 2
295                 E[nl]  = E[nl+1]  = E[nl+2]  =     // 3, 4, 5
296                 E[nl1] = E[nl1+1] = E[nl1+2] = PE; // 6, 7, 8
297
298                 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);
299                 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);
300                 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);
301                 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);
302             } else if (n == 4) {
303                 E[0]   = E[1]     = E[2]     = E[3]     =     //  0,  1,  2,  3
304                 E[nl]  = E[nl+1]  = E[nl+2]  = E[nl+3]  =     //  4,  5,  6,  7
305                 E[nl1] = E[nl1+1] = E[nl1+2] = E[nl1+3] =     //  8,  9, 10, 11
306                 E[nl2] = E[nl2+1] = E[nl2+2] = E[nl2+3] = PE; // 12, 13, 14, 15
307
308                 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);
309                 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);
310                 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);
311                 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);
312             }
313
314             sa0 += 1;
315             sa1 += 1;
316             sa2 += 1;
317             sa3 += 1;
318             sa4 += 1;
319
320             E += n;
321         }
322     }
323 }
324
325 #define XBR_FUNC(size) \
326 static int xbr##size##x(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs) \
327 { \
328     xbr_filter(arg, jobnr, nb_jobs, size); \
329     return 0; \
330 }
331
332 XBR_FUNC(2)
333 XBR_FUNC(3)
334 XBR_FUNC(4)
335
336
337 static int config_output(AVFilterLink *outlink)
338 {
339     AVFilterContext *ctx = outlink->src;
340     XBRContext *xbr = ctx->priv;
341     AVFilterLink *inlink = ctx->inputs[0];
342
343     outlink->w = inlink->w * xbr->n;
344     outlink->h = inlink->h * xbr->n;
345     return 0;
346 }
347
348 static int query_formats(AVFilterContext *ctx)
349 {
350     static const enum AVPixelFormat pix_fmts[] = {
351         AV_PIX_FMT_0RGB32, AV_PIX_FMT_NONE,
352     };
353
354     ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
355     return 0;
356 }
357
358 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
359 {
360     AVFilterContext *ctx = inlink->dst;
361     AVFilterLink *outlink = ctx->outputs[0];
362     XBRContext *xbr = ctx->priv;
363     ThreadData td;
364
365     AVFrame *out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
366     if (!out) {
367         av_frame_free(&in);
368         return AVERROR(ENOMEM);
369     }
370
371     av_frame_copy_props(out, in);
372
373     td.in = in;
374     td.out = out;
375     td.rgbtoyuv = xbr->rgbtoyuv;
376     ctx->internal->execute(ctx, xbr->func, &td, NULL, FFMIN(inlink->h, ctx->graph->nb_threads));
377
378     out->width  = outlink->w;
379     out->height = outlink->h;
380
381     av_frame_free(&in);
382     return ff_filter_frame(outlink, out);
383 }
384
385 static int init(AVFilterContext *ctx)
386 {
387     XBRContext *xbr = ctx->priv;
388     static const xbrfunc_t xbrfuncs[] = {xbr2x, xbr3x, xbr4x};
389
390     uint32_t c;
391     int bg, rg, g;
392
393     for (bg = -255; bg < 256; bg++) {
394         for (rg = -255; rg < 256; rg++) {
395             const uint32_t u = (uint32_t)((-169*rg + 500*bg)/1000) + 128;
396             const uint32_t v = (uint32_t)(( 500*rg -  81*bg)/1000) + 128;
397             int startg = FFMAX3(-bg, -rg, 0);
398             int endg = FFMIN3(255-bg, 255-rg, 255);
399             uint32_t y = (uint32_t)(( 299*rg + 1000*startg + 114*bg)/1000);
400             c = bg + (rg<<16) + 0x010101 * startg;
401             for (g = startg; g <= endg; g++) {
402                 xbr->rgbtoyuv[c] = ((y++) << 16) + (u << 8) + v;
403                 c+= 0x010101;
404             }
405         }
406     }
407
408     xbr->func = xbrfuncs[xbr->n - 2];
409     return 0;
410 }
411
412 static const AVFilterPad xbr_inputs[] = {
413     {
414         .name         = "default",
415         .type         = AVMEDIA_TYPE_VIDEO,
416         .filter_frame = filter_frame,
417     },
418     { NULL }
419 };
420
421 static const AVFilterPad xbr_outputs[] = {
422     {
423         .name         = "default",
424         .type         = AVMEDIA_TYPE_VIDEO,
425         .config_props = config_output,
426     },
427     { NULL }
428 };
429
430 AVFilter ff_vf_xbr = {
431     .name          = "xbr",
432     .description   = NULL_IF_CONFIG_SMALL("Scale the input using xBR algorithm."),
433     .inputs        = xbr_inputs,
434     .outputs       = xbr_outputs,
435     .query_formats = query_formats,
436     .priv_size     = sizeof(XBRContext),
437     .priv_class    = &xbr_class,
438     .init          = init,
439     .flags         = AVFILTER_FLAG_SLICE_THREADS,
440 };