1 /*
2 * Copyright (c) 2003-2013 Loren Merritt
3 * Copyright (c) 2015 Paul B Mahol
4 *
5 * This file is part of FFmpeg.
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 /* Computes the Structural Similarity Metric between two video streams.
23 * original algorithm:
24 * Z. Wang, A. C. Bovik, H. R. Sheikh and E. P. Simoncelli,
25 * "Image quality assessment: From error visibility to structural similarity,"
26 * IEEE Transactions on Image Processing, vol. 13, no. 4, pp. 600-612, Apr. 2004.
27 *
28 * To improve speed, this implementation uses the standard approximation of
29 * overlapped 8x8 block sums, rather than the original gaussian weights.
30 */
31
32 /*
33 * @file
34 * Calculate the SSIM between two input videos.
35 */
36
37 #include "libavutil/avstring.h"
38 #include "libavutil/opt.h"
39 #include "libavutil/pixdesc.h"
40 #include "avfilter.h"
41 #include "drawutils.h"
42 #include "formats.h"
43 #include "framesync.h"
44 #include "internal.h"
45 #include "ssim.h"
46 #include "video.h"
47
48 typedef struct SSIMContext {
49 const AVClass *class;
50 FFFrameSync fs;
51 FILE *stats_file;
52 char *stats_file_str;
53 int nb_components;
54 int nb_threads;
55 int max;
56 uint64_t nb_frames;
57 double ssim[4], ssim_total;
58 char comps[4];
59 double coefs[4];
60 uint8_t rgba_map[4];
61 int planewidth[4];
62 int planeheight[4];
63 int **temp;
64 int is_rgb;
65 double **score;
66 int (*ssim_plane)(AVFilterContext *ctx, void *arg,
67 int jobnr, int nb_jobs);
68 SSIMDSPContext dsp;
69 } SSIMContext;
70
71 #define OFFSET(x) offsetof(SSIMContext, x)
72 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
73
74 static const AVOption ssim_options[] = {
75 {"stats_file", "Set file where to store per-frame difference information", OFFSET(stats_file_str), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, FLAGS },
76 {"f", "Set file where to store per-frame difference information", OFFSET(stats_file_str), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, FLAGS },
77 { NULL }
78 };
79
80 FRAMESYNC_DEFINE_CLASS(ssim, SSIMContext, fs);
81
set_meta(AVDictionary ** metadata,const char * key,char comp,float d)82 static void set_meta(AVDictionary **metadata, const char *key, char comp, float d)
83 {
84 char value[128];
85 snprintf(value, sizeof(value), "%f", d);
86 if (comp) {
87 char key2[128];
88 snprintf(key2, sizeof(key2), "%s%c", key, comp);
89 av_dict_set(metadata, key2, value, 0);
90 } else {
91 av_dict_set(metadata, key, value, 0);
92 }
93 }
94
ssim_4x4xn_16bit(const uint8_t * main8,ptrdiff_t main_stride,const uint8_t * ref8,ptrdiff_t ref_stride,int64_t (* sums)[4],int width)95 static void ssim_4x4xn_16bit(const uint8_t *main8, ptrdiff_t main_stride,
96 const uint8_t *ref8, ptrdiff_t ref_stride,
97 int64_t (*sums)[4], int width)
98 {
99 const uint16_t *main16 = (const uint16_t *)main8;
100 const uint16_t *ref16 = (const uint16_t *)ref8;
101 int x, y, z;
102
103 main_stride >>= 1;
104 ref_stride >>= 1;
105
106 for (z = 0; z < width; z++) {
107 uint64_t s1 = 0, s2 = 0, ss = 0, s12 = 0;
108
109 for (y = 0; y < 4; y++) {
110 for (x = 0; x < 4; x++) {
111 unsigned a = main16[x + y * main_stride];
112 unsigned b = ref16[x + y * ref_stride];
113
114 s1 += a;
115 s2 += b;
116 ss += a*a;
117 ss += b*b;
118 s12 += a*b;
119 }
120 }
121
122 sums[z][0] = s1;
123 sums[z][1] = s2;
124 sums[z][2] = ss;
125 sums[z][3] = s12;
126 main16 += 4;
127 ref16 += 4;
128 }
129 }
130
ssim_4x4xn_8bit(const uint8_t * main,ptrdiff_t main_stride,const uint8_t * ref,ptrdiff_t ref_stride,int (* sums)[4],int width)131 static void ssim_4x4xn_8bit(const uint8_t *main, ptrdiff_t main_stride,
132 const uint8_t *ref, ptrdiff_t ref_stride,
133 int (*sums)[4], int width)
134 {
135 int x, y, z;
136
137 for (z = 0; z < width; z++) {
138 uint32_t s1 = 0, s2 = 0, ss = 0, s12 = 0;
139
140 for (y = 0; y < 4; y++) {
141 for (x = 0; x < 4; x++) {
142 int a = main[x + y * main_stride];
143 int b = ref[x + y * ref_stride];
144
145 s1 += a;
146 s2 += b;
147 ss += a*a;
148 ss += b*b;
149 s12 += a*b;
150 }
151 }
152
153 sums[z][0] = s1;
154 sums[z][1] = s2;
155 sums[z][2] = ss;
156 sums[z][3] = s12;
157 main += 4;
158 ref += 4;
159 }
160 }
161
ssim_end1x(int64_t s1,int64_t s2,int64_t ss,int64_t s12,int max)162 static float ssim_end1x(int64_t s1, int64_t s2, int64_t ss, int64_t s12, int max)
163 {
164 int64_t ssim_c1 = (int64_t)(.01*.01*max*max*64 + .5);
165 int64_t ssim_c2 = (int64_t)(.03*.03*max*max*64*63 + .5);
166
167 int64_t fs1 = s1;
168 int64_t fs2 = s2;
169 int64_t fss = ss;
170 int64_t fs12 = s12;
171 int64_t vars = fss * 64 - fs1 * fs1 - fs2 * fs2;
172 int64_t covar = fs12 * 64 - fs1 * fs2;
173
174 return (float)(2 * fs1 * fs2 + ssim_c1) * (float)(2 * covar + ssim_c2)
175 / ((float)(fs1 * fs1 + fs2 * fs2 + ssim_c1) * (float)(vars + ssim_c2));
176 }
177
ssim_end1(int s1,int s2,int ss,int s12)178 static float ssim_end1(int s1, int s2, int ss, int s12)
179 {
180 static const int ssim_c1 = (int)(.01*.01*255*255*64 + .5);
181 static const int ssim_c2 = (int)(.03*.03*255*255*64*63 + .5);
182
183 int fs1 = s1;
184 int fs2 = s2;
185 int fss = ss;
186 int fs12 = s12;
187 int vars = fss * 64 - fs1 * fs1 - fs2 * fs2;
188 int covar = fs12 * 64 - fs1 * fs2;
189
190 return (float)(2 * fs1 * fs2 + ssim_c1) * (float)(2 * covar + ssim_c2)
191 / ((float)(fs1 * fs1 + fs2 * fs2 + ssim_c1) * (float)(vars + ssim_c2));
192 }
193
ssim_endn_16bit(const int64_t (* sum0)[4],const int64_t (* sum1)[4],int width,int max)194 static float ssim_endn_16bit(const int64_t (*sum0)[4], const int64_t (*sum1)[4], int width, int max)
195 {
196 float ssim = 0.0;
197 int i;
198
199 for (i = 0; i < width; i++)
200 ssim += ssim_end1x(sum0[i][0] + sum0[i + 1][0] + sum1[i][0] + sum1[i + 1][0],
201 sum0[i][1] + sum0[i + 1][1] + sum1[i][1] + sum1[i + 1][1],
202 sum0[i][2] + sum0[i + 1][2] + sum1[i][2] + sum1[i + 1][2],
203 sum0[i][3] + sum0[i + 1][3] + sum1[i][3] + sum1[i + 1][3],
204 max);
205 return ssim;
206 }
207
ssim_endn_8bit(const int (* sum0)[4],const int (* sum1)[4],int width)208 static double ssim_endn_8bit(const int (*sum0)[4], const int (*sum1)[4], int width)
209 {
210 double ssim = 0.0;
211 int i;
212
213 for (i = 0; i < width; i++)
214 ssim += ssim_end1(sum0[i][0] + sum0[i + 1][0] + sum1[i][0] + sum1[i + 1][0],
215 sum0[i][1] + sum0[i + 1][1] + sum1[i][1] + sum1[i + 1][1],
216 sum0[i][2] + sum0[i + 1][2] + sum1[i][2] + sum1[i + 1][2],
217 sum0[i][3] + sum0[i + 1][3] + sum1[i][3] + sum1[i + 1][3]);
218 return ssim;
219 }
220
221 #define SUM_LEN(w) (((w) >> 2) + 3)
222
223 typedef struct ThreadData {
224 const uint8_t *main_data[4];
225 const uint8_t *ref_data[4];
226 int main_linesize[4];
227 int ref_linesize[4];
228 int planewidth[4];
229 int planeheight[4];
230 double **score;
231 int **temp;
232 int nb_components;
233 int max;
234 SSIMDSPContext *dsp;
235 } ThreadData;
236
ssim_plane_16bit(AVFilterContext * ctx,void * arg,int jobnr,int nb_jobs)237 static int ssim_plane_16bit(AVFilterContext *ctx, void *arg,
238 int jobnr, int nb_jobs)
239 {
240 ThreadData *td = arg;
241 double *score = td->score[jobnr];
242 void *temp = td->temp[jobnr];
243 const int max = td->max;
244
245 for (int c = 0; c < td->nb_components; c++) {
246 const uint8_t *main_data = td->main_data[c];
247 const uint8_t *ref_data = td->ref_data[c];
248 const int main_stride = td->main_linesize[c];
249 const int ref_stride = td->ref_linesize[c];
250 int width = td->planewidth[c];
251 int height = td->planeheight[c];
252 const int slice_start = ((height >> 2) * jobnr) / nb_jobs;
253 const int slice_end = ((height >> 2) * (jobnr+1)) / nb_jobs;
254 const int ystart = FFMAX(1, slice_start);
255 int z = ystart - 1;
256 double ssim = 0.0;
257 int64_t (*sum0)[4] = temp;
258 int64_t (*sum1)[4] = sum0 + SUM_LEN(width);
259
260 width >>= 2;
261 height >>= 2;
262
263 for (int y = ystart; y < slice_end; y++) {
264 for (; z <= y; z++) {
265 FFSWAP(void*, sum0, sum1);
266 ssim_4x4xn_16bit(&main_data[4 * z * main_stride], main_stride,
267 &ref_data[4 * z * ref_stride], ref_stride,
268 sum0, width);
269 }
270
271 ssim += ssim_endn_16bit((const int64_t (*)[4])sum0, (const int64_t (*)[4])sum1, width - 1, max);
272 }
273
274 score[c] = ssim;
275 }
276
277 return 0;
278 }
279
ssim_plane(AVFilterContext * ctx,void * arg,int jobnr,int nb_jobs)280 static int ssim_plane(AVFilterContext *ctx, void *arg,
281 int jobnr, int nb_jobs)
282 {
283 ThreadData *td = arg;
284 double *score = td->score[jobnr];
285 void *temp = td->temp[jobnr];
286 SSIMDSPContext *dsp = td->dsp;
287
288 for (int c = 0; c < td->nb_components; c++) {
289 const uint8_t *main_data = td->main_data[c];
290 const uint8_t *ref_data = td->ref_data[c];
291 const int main_stride = td->main_linesize[c];
292 const int ref_stride = td->ref_linesize[c];
293 int width = td->planewidth[c];
294 int height = td->planeheight[c];
295 const int slice_start = ((height >> 2) * jobnr) / nb_jobs;
296 const int slice_end = ((height >> 2) * (jobnr+1)) / nb_jobs;
297 const int ystart = FFMAX(1, slice_start);
298 int z = ystart - 1;
299 double ssim = 0.0;
300 int (*sum0)[4] = temp;
301 int (*sum1)[4] = sum0 + SUM_LEN(width);
302
303 width >>= 2;
304 height >>= 2;
305
306 for (int y = ystart; y < slice_end; y++) {
307 for (; z <= y; z++) {
308 FFSWAP(void*, sum0, sum1);
309 dsp->ssim_4x4_line(&main_data[4 * z * main_stride], main_stride,
310 &ref_data[4 * z * ref_stride], ref_stride,
311 sum0, width);
312 }
313
314 ssim += dsp->ssim_end_line((const int (*)[4])sum0, (const int (*)[4])sum1, width - 1);
315 }
316
317 score[c] = ssim;
318 }
319
320 return 0;
321 }
322
ssim_db(double ssim,double weight)323 static double ssim_db(double ssim, double weight)
324 {
325 return (fabs(weight - ssim) > 1e-9) ? 10.0 * log10(weight / (weight - ssim)) : INFINITY;
326 }
327
do_ssim(FFFrameSync * fs)328 static int do_ssim(FFFrameSync *fs)
329 {
330 AVFilterContext *ctx = fs->parent;
331 SSIMContext *s = ctx->priv;
332 AVFrame *master, *ref;
333 AVDictionary **metadata;
334 double c[4] = {0}, ssimv = 0.0;
335 ThreadData td;
336 int ret, i;
337
338 ret = ff_framesync_dualinput_get(fs, &master, &ref);
339 if (ret < 0)
340 return ret;
341 if (ctx->is_disabled || !ref)
342 return ff_filter_frame(ctx->outputs[0], master);
343 metadata = &master->metadata;
344
345 s->nb_frames++;
346
347 td.nb_components = s->nb_components;
348 td.dsp = &s->dsp;
349 td.score = s->score;
350 td.temp = s->temp;
351 td.max = s->max;
352
353 for (int n = 0; n < s->nb_components; n++) {
354 td.main_data[n] = master->data[n];
355 td.ref_data[n] = ref->data[n];
356 td.main_linesize[n] = master->linesize[n];
357 td.ref_linesize[n] = ref->linesize[n];
358 td.planewidth[n] = s->planewidth[n];
359 td.planeheight[n] = s->planeheight[n];
360 }
361
362 ff_filter_execute(ctx, s->ssim_plane, &td, NULL,
363 FFMIN((s->planeheight[1] + 3) >> 2, s->nb_threads));
364
365 for (i = 0; i < s->nb_components; i++) {
366 for (int j = 0; j < s->nb_threads; j++)
367 c[i] += s->score[j][i];
368 c[i] = c[i] / (((s->planewidth[i] >> 2) - 1) * ((s->planeheight[i] >> 2) - 1));
369 }
370
371 for (i = 0; i < s->nb_components; i++) {
372 ssimv += s->coefs[i] * c[i];
373 s->ssim[i] += c[i];
374 }
375
376 for (i = 0; i < s->nb_components; i++) {
377 int cidx = s->is_rgb ? s->rgba_map[i] : i;
378 set_meta(metadata, "lavfi.ssim.", s->comps[i], c[cidx]);
379 }
380 s->ssim_total += ssimv;
381
382 set_meta(metadata, "lavfi.ssim.All", 0, ssimv);
383 set_meta(metadata, "lavfi.ssim.dB", 0, ssim_db(ssimv, 1.0));
384
385 if (s->stats_file) {
386 fprintf(s->stats_file, "n:%"PRId64" ", s->nb_frames);
387
388 for (i = 0; i < s->nb_components; i++) {
389 int cidx = s->is_rgb ? s->rgba_map[i] : i;
390 fprintf(s->stats_file, "%c:%f ", s->comps[i], c[cidx]);
391 }
392
393 fprintf(s->stats_file, "All:%f (%f)\n", ssimv, ssim_db(ssimv, 1.0));
394 }
395
396 return ff_filter_frame(ctx->outputs[0], master);
397 }
398
init(AVFilterContext * ctx)399 static av_cold int init(AVFilterContext *ctx)
400 {
401 SSIMContext *s = ctx->priv;
402
403 if (s->stats_file_str) {
404 if (!strcmp(s->stats_file_str, "-")) {
405 s->stats_file = stdout;
406 } else {
407 s->stats_file = avpriv_fopen_utf8(s->stats_file_str, "w");
408 if (!s->stats_file) {
409 int err = AVERROR(errno);
410 char buf[128];
411 av_strerror(err, buf, sizeof(buf));
412 av_log(ctx, AV_LOG_ERROR, "Could not open stats file %s: %s\n",
413 s->stats_file_str, buf);
414 return err;
415 }
416 }
417 }
418
419 s->fs.on_event = do_ssim;
420 return 0;
421 }
422
423 static const enum AVPixelFormat pix_fmts[] = {
424 AV_PIX_FMT_GRAY8, AV_PIX_FMT_GRAY9, AV_PIX_FMT_GRAY10,
425 AV_PIX_FMT_GRAY12, AV_PIX_FMT_GRAY14, AV_PIX_FMT_GRAY16,
426 AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV444P,
427 AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P,
428 AV_PIX_FMT_YUVJ411P, AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P,
429 AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_YUVJ444P,
430 AV_PIX_FMT_GBRP,
431 #define PF(suf) AV_PIX_FMT_YUV420##suf, AV_PIX_FMT_YUV422##suf, AV_PIX_FMT_YUV444##suf, AV_PIX_FMT_GBR##suf
432 PF(P9), PF(P10), PF(P12), PF(P14), PF(P16),
433 AV_PIX_FMT_NONE
434 };
435
config_input_ref(AVFilterLink * inlink)436 static int config_input_ref(AVFilterLink *inlink)
437 {
438 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
439 AVFilterContext *ctx = inlink->dst;
440 SSIMContext *s = ctx->priv;
441 int sum = 0, i;
442
443 s->nb_threads = ff_filter_get_nb_threads(ctx);
444 s->nb_components = desc->nb_components;
445
446 if (ctx->inputs[0]->w != ctx->inputs[1]->w ||
447 ctx->inputs[0]->h != ctx->inputs[1]->h) {
448 av_log(ctx, AV_LOG_ERROR, "Width and height of input videos must be same.\n");
449 return AVERROR(EINVAL);
450 }
451
452 s->is_rgb = ff_fill_rgba_map(s->rgba_map, inlink->format) >= 0;
453 s->comps[0] = s->is_rgb ? 'R' : 'Y';
454 s->comps[1] = s->is_rgb ? 'G' : 'U';
455 s->comps[2] = s->is_rgb ? 'B' : 'V';
456 s->comps[3] = 'A';
457
458 s->planeheight[1] = s->planeheight[2] = AV_CEIL_RSHIFT(inlink->h, desc->log2_chroma_h);
459 s->planeheight[0] = s->planeheight[3] = inlink->h;
460 s->planewidth[1] = s->planewidth[2] = AV_CEIL_RSHIFT(inlink->w, desc->log2_chroma_w);
461 s->planewidth[0] = s->planewidth[3] = inlink->w;
462 for (i = 0; i < s->nb_components; i++)
463 sum += s->planeheight[i] * s->planewidth[i];
464 for (i = 0; i < s->nb_components; i++)
465 s->coefs[i] = (double) s->planeheight[i] * s->planewidth[i] / sum;
466
467 s->temp = av_calloc(s->nb_threads, sizeof(*s->temp));
468 if (!s->temp)
469 return AVERROR(ENOMEM);
470
471 for (int t = 0; t < s->nb_threads; t++) {
472 s->temp[t] = av_calloc(2 * SUM_LEN(inlink->w), (desc->comp[0].depth > 8) ? sizeof(int64_t[4]) : sizeof(int[4]));
473 if (!s->temp[t])
474 return AVERROR(ENOMEM);
475 }
476 s->max = (1 << desc->comp[0].depth) - 1;
477
478 s->ssim_plane = desc->comp[0].depth > 8 ? ssim_plane_16bit : ssim_plane;
479 s->dsp.ssim_4x4_line = ssim_4x4xn_8bit;
480 s->dsp.ssim_end_line = ssim_endn_8bit;
481 #if ARCH_X86
482 ff_ssim_init_x86(&s->dsp);
483 #endif
484
485 s->score = av_calloc(s->nb_threads, sizeof(*s->score));
486 if (!s->score)
487 return AVERROR(ENOMEM);
488
489 for (int t = 0; t < s->nb_threads; t++) {
490 s->score[t] = av_calloc(s->nb_components, sizeof(*s->score[0]));
491 if (!s->score[t])
492 return AVERROR(ENOMEM);
493 }
494
495 return 0;
496 }
497
config_output(AVFilterLink * outlink)498 static int config_output(AVFilterLink *outlink)
499 {
500 AVFilterContext *ctx = outlink->src;
501 SSIMContext *s = ctx->priv;
502 AVFilterLink *mainlink = ctx->inputs[0];
503 int ret;
504
505 ret = ff_framesync_init_dualinput(&s->fs, ctx);
506 if (ret < 0)
507 return ret;
508 outlink->w = mainlink->w;
509 outlink->h = mainlink->h;
510 outlink->time_base = mainlink->time_base;
511 outlink->sample_aspect_ratio = mainlink->sample_aspect_ratio;
512 outlink->frame_rate = mainlink->frame_rate;
513
514 if ((ret = ff_framesync_configure(&s->fs)) < 0)
515 return ret;
516
517 outlink->time_base = s->fs.time_base;
518
519 if (av_cmp_q(mainlink->time_base, outlink->time_base) ||
520 av_cmp_q(ctx->inputs[1]->time_base, outlink->time_base))
521 av_log(ctx, AV_LOG_WARNING, "not matching timebases found between first input: %d/%d and second input %d/%d, results may be incorrect!\n",
522 mainlink->time_base.num, mainlink->time_base.den,
523 ctx->inputs[1]->time_base.num, ctx->inputs[1]->time_base.den);
524
525 return 0;
526 }
527
activate(AVFilterContext * ctx)528 static int activate(AVFilterContext *ctx)
529 {
530 SSIMContext *s = ctx->priv;
531 return ff_framesync_activate(&s->fs);
532 }
533
uninit(AVFilterContext * ctx)534 static av_cold void uninit(AVFilterContext *ctx)
535 {
536 SSIMContext *s = ctx->priv;
537
538 if (s->nb_frames > 0) {
539 char buf[256];
540 int i;
541 buf[0] = 0;
542 for (i = 0; i < s->nb_components; i++) {
543 int c = s->is_rgb ? s->rgba_map[i] : i;
544 av_strlcatf(buf, sizeof(buf), " %c:%f (%f)", s->comps[i], s->ssim[c] / s->nb_frames,
545 ssim_db(s->ssim[c], s->nb_frames));
546 }
547 av_log(ctx, AV_LOG_INFO, "SSIM%s All:%f (%f)\n", buf,
548 s->ssim_total / s->nb_frames, ssim_db(s->ssim_total, s->nb_frames));
549 }
550
551 ff_framesync_uninit(&s->fs);
552
553 if (s->stats_file && s->stats_file != stdout)
554 fclose(s->stats_file);
555
556 for (int t = 0; t < s->nb_threads && s->score; t++)
557 av_freep(&s->score[t]);
558 av_freep(&s->score);
559
560 for (int t = 0; t < s->nb_threads && s->temp; t++)
561 av_freep(&s->temp[t]);
562 av_freep(&s->temp);
563 }
564
565 static const AVFilterPad ssim_inputs[] = {
566 {
567 .name = "main",
568 .type = AVMEDIA_TYPE_VIDEO,
569 },{
570 .name = "reference",
571 .type = AVMEDIA_TYPE_VIDEO,
572 .config_props = config_input_ref,
573 },
574 };
575
576 static const AVFilterPad ssim_outputs[] = {
577 {
578 .name = "default",
579 .type = AVMEDIA_TYPE_VIDEO,
580 .config_props = config_output,
581 },
582 };
583
584 const AVFilter ff_vf_ssim = {
585 .name = "ssim",
586 .description = NULL_IF_CONFIG_SMALL("Calculate the SSIM between two video streams."),
587 .preinit = ssim_framesync_preinit,
588 .init = init,
589 .uninit = uninit,
590 .activate = activate,
591 .priv_size = sizeof(SSIMContext),
592 .priv_class = &ssim_class,
593 FILTER_INPUTS(ssim_inputs),
594 FILTER_OUTPUTS(ssim_outputs),
595 FILTER_PIXFMTS_ARRAY(pix_fmts),
596 .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL |
597 AVFILTER_FLAG_SLICE_THREADS |
598 AVFILTER_FLAG_METADATA_ONLY,
599 };
600