libavfilter/vf_ssim.c

   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/file_open.h"
  39 #include "libavutil/mem.h"
  40 #include "libavutil/opt.h"
  41 #include "libavutil/pixdesc.h"
  42 #include "avfilter.h"
  43 #include "drawutils.h"
  44 #include "filters.h"
  45 #include "framesync.h"
  46 #include "ssim.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
  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
  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
 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
 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
 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
 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
 198     for (int i = 0; i < width; i++)
 199         ssim += ssim_end1x(sum0[i][0] + sum0[i + 1][0] + sum1[i][0] + sum1[i + 1][0],
 200                            sum0[i][1] + sum0[i + 1][1] + sum1[i][1] + sum1[i + 1][1],
 201                            sum0[i][2] + sum0[i + 1][2] + sum1[i][2] + sum1[i + 1][2],
 202                            sum0[i][3] + sum0[i + 1][3] + sum1[i][3] + sum1[i + 1][3],
 203                            max);
 204     return ssim;
 205 }
 206
 207 static double ssim_endn_8bit(const int (*sum0)[4], const int (*sum1)[4], int width)
 208 {
 209     double ssim = 0.0;
 210
 211     for (int i = 0; i < width; i++)
 212         ssim += ssim_end1(sum0[i][0] + sum0[i + 1][0] + sum1[i][0] + sum1[i + 1][0],
 213                           sum0[i][1] + sum0[i + 1][1] + sum1[i][1] + sum1[i + 1][1],
 214                           sum0[i][2] + sum0[i + 1][2] + sum1[i][2] + sum1[i + 1][2],
 215                           sum0[i][3] + sum0[i + 1][3] + sum1[i][3] + sum1[i + 1][3]);
 216     return ssim;
 217 }
 218
 219 #define SUM_LEN(w) (((w) >> 2) + 3)
 220
 221 typedef struct ThreadData {
 222     const uint8_t *main_data[4];
 223     const uint8_t *ref_data[4];
 224     int main_linesize[4];
 225     int ref_linesize[4];
 226     int planewidth[4];
 227     int planeheight[4];
 228     double **score;
 229     int **temp;
 230     int nb_components;
 231     int max;
 232     SSIMDSPContext *dsp;
 233 } ThreadData;
 234
 235 static int ssim_plane_16bit(AVFilterContext *ctx, void *arg,
 236                             int jobnr, int nb_jobs)
 237 {
 238     ThreadData *td = arg;
 239     double *score = td->score[jobnr];
 240     void *temp = td->temp[jobnr];
 241     const int max = td->max;
 242
 243     for (int c = 0; c < td->nb_components; c++) {
 244         const uint8_t *main_data = td->main_data[c];
 245         const uint8_t *ref_data = td->ref_data[c];
 246         const int main_stride = td->main_linesize[c];
 247         const int ref_stride = td->ref_linesize[c];
 248         int width = td->planewidth[c];
 249         int height = td->planeheight[c];
 250         const int slice_start = ((height >> 2) * jobnr) / nb_jobs;
 251         const int slice_end = ((height >> 2) * (jobnr+1)) / nb_jobs;
 252         const int ystart = FFMAX(1, slice_start);
 253         int z = ystart - 1;
 254         double ssim = 0.0;
 255         int64_t (*sum0)[4] = temp;
 256         int64_t (*sum1)[4] = sum0 + SUM_LEN(width);
 257
 258         width >>= 2;
 259         height >>= 2;
 260
 261         for (int y = ystart; y < slice_end; y++) {
 262             for (; z <= y; z++) {
 263                 FFSWAP(void*, sum0, sum1);
 264                 ssim_4x4xn_16bit(&main_data[4 * z * main_stride], main_stride,
 265                                  &ref_data[4 * z * ref_stride], ref_stride,
 266                                  sum0, width);
 267             }
 268
 269             ssim += ssim_endn_16bit((const int64_t (*)[4])sum0, (const int64_t (*)[4])sum1, width - 1, max);
 270         }
 271
 272         score[c] = ssim;
 273     }
 274
 275     return 0;
 276 }
 277
 278 static int ssim_plane(AVFilterContext *ctx, void *arg,
 279                       int jobnr, int nb_jobs)
 280 {
 281     ThreadData *td = arg;
 282     double *score = td->score[jobnr];
 283     void *temp = td->temp[jobnr];
 284     SSIMDSPContext *dsp = td->dsp;
 285
 286     for (int c = 0; c < td->nb_components; c++) {
 287         const uint8_t *main_data = td->main_data[c];
 288         const uint8_t *ref_data = td->ref_data[c];
 289         const int main_stride = td->main_linesize[c];
 290         const int ref_stride = td->ref_linesize[c];
 291         int width = td->planewidth[c];
 292         int height = td->planeheight[c];
 293         const int slice_start = ((height >> 2) * jobnr) / nb_jobs;
 294         const int slice_end = ((height >> 2) * (jobnr+1)) / nb_jobs;
 295         const int ystart = FFMAX(1, slice_start);
 296         int z = ystart - 1;
 297         double ssim = 0.0;
 298         int (*sum0)[4] = temp;
 299         int (*sum1)[4] = sum0 + SUM_LEN(width);
 300
 301         width >>= 2;
 302         height >>= 2;
 303
 304         for (int y = ystart; y < slice_end; y++) {
 305             for (; z <= y; z++) {
 306                 FFSWAP(void*, sum0, sum1);
 307                 dsp->ssim_4x4_line(&main_data[4 * z * main_stride], main_stride,
 308                                    &ref_data[4 * z * ref_stride], ref_stride,
 309                                    sum0, width);
 310             }
 311
 312             ssim += dsp->ssim_end_line((const int (*)[4])sum0, (const int (*)[4])sum1, width - 1);
 313         }
 314
 315         score[c] = ssim;
 316     }
 317
 318     return 0;
 319 }
 320
 321 static double ssim_db(double ssim, double weight)
 322 {
 323     return (fabs(weight - ssim) > 1e-9) ? 10.0 * log10(weight / (weight - ssim)) : INFINITY;
 324 }
 325
 326 static int do_ssim(FFFrameSync *fs)
 327 {
 328     AVFilterContext *ctx = fs->parent;
 329     SSIMContext *s = ctx->priv;
 330     AVFrame *master, *ref;
 331     AVDictionary **metadata;
 332     double c[4] = {0}, ssimv = 0.0;
 333     ThreadData td;
 334     int ret, i;
 335
 336     ret = ff_framesync_dualinput_get(fs, &master, &ref);
 337     if (ret < 0)
 338         return ret;
 339     if (ctx->is_disabled || !ref)
 340         return ff_filter_frame(ctx->outputs[0], master);
 341     metadata = &master->metadata;
 342
 343     s->nb_frames++;
 344
 345     td.nb_components = s->nb_components;
 346     td.dsp = &s->dsp;
 347     td.score = s->score;
 348     td.temp = s->temp;
 349     td.max = s->max;
 350
 351     for (int n = 0; n < s->nb_components; n++) {
 352         td.main_data[n] = master->data[n];
 353         td.ref_data[n] = ref->data[n];
 354         td.main_linesize[n] = master->linesize[n];
 355         td.ref_linesize[n] = ref->linesize[n];
 356         td.planewidth[n] = s->planewidth[n];
 357         td.planeheight[n] = s->planeheight[n];
 358     }
 359
 360     if (master->color_range != ref->color_range) {
 361         av_log(ctx, AV_LOG_WARNING, "master and reference "
 362                "frames use different color ranges (%s != %s)\n",
 363                av_color_range_name(master->color_range),
 364                av_color_range_name(ref->color_range));
 365     }
 366
 367     ff_filter_execute(ctx, s->ssim_plane, &td, NULL,
 368                       FFMIN((s->planeheight[1] + 3) >> 2, s->nb_threads));
 369
 370     for (i = 0; i < s->nb_components; i++) {
 371         for (int j = 0; j < s->nb_threads; j++)
 372             c[i] += s->score[j][i];
 373         c[i] = c[i] / (((s->planewidth[i] >> 2) - 1) * ((s->planeheight[i] >> 2) - 1));
 374     }
 375
 376     for (i = 0; i < s->nb_components; i++) {
 377         ssimv += s->coefs[i] * c[i];
 378         s->ssim[i] += c[i];
 379     }
 380
 381     for (i = 0; i < s->nb_components; i++) {
 382         int cidx = s->is_rgb ? s->rgba_map[i] : i;
 383         set_meta(metadata, "lavfi.ssim.", s->comps[i], c[cidx]);
 384     }
 385     s->ssim_total += ssimv;
 386
 387     set_meta(metadata, "lavfi.ssim.All", 0, ssimv);
 388     set_meta(metadata, "lavfi.ssim.dB", 0, ssim_db(ssimv, 1.0));
 389
 390     if (s->stats_file) {
 391         fprintf(s->stats_file, "n:%"PRId64" ", s->nb_frames);
 392
 393         for (i = 0; i < s->nb_components; i++) {
 394             int cidx = s->is_rgb ? s->rgba_map[i] : i;
 395             fprintf(s->stats_file, "%c:%f ", s->comps[i], c[cidx]);
 396         }
 397
 398         fprintf(s->stats_file, "All:%f (%f)\n", ssimv, ssim_db(ssimv, 1.0));
 399     }
 400
 401     return ff_filter_frame(ctx->outputs[0], master);
 402 }
 403
 404 static av_cold int init(AVFilterContext *ctx)
 405 {
 406     SSIMContext *s = ctx->priv;
 407
 408     if (s->stats_file_str) {
 409         if (!strcmp(s->stats_file_str, "-")) {
 410             s->stats_file = stdout;
 411         } else {
 412             s->stats_file = avpriv_fopen_utf8(s->stats_file_str, "w");
 413             if (!s->stats_file) {
 414                 int err = AVERROR(errno);
 415                 av_log(ctx, AV_LOG_ERROR, "Could not open stats file %s: %s\n",
 416                        s->stats_file_str, av_err2str(err));
 417                 return err;
 418             }
 419         }
 420     }
 421
 422     s->fs.on_event = do_ssim;
 423     return 0;
 424 }
 425
 426 static const enum AVPixelFormat pix_fmts[] = {
 427     AV_PIX_FMT_GRAY8, AV_PIX_FMT_GRAY9, AV_PIX_FMT_GRAY10,
 428     AV_PIX_FMT_GRAY12, AV_PIX_FMT_GRAY14, AV_PIX_FMT_GRAY16,
 429     AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV444P,
 430     AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P,
 431     AV_PIX_FMT_YUVJ411P, AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P,
 432     AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_YUVJ444P,
 433     AV_PIX_FMT_GBRP,
 434 #define PF(suf) AV_PIX_FMT_YUV420##suf,  AV_PIX_FMT_YUV422##suf,  AV_PIX_FMT_YUV444##suf, AV_PIX_FMT_GBR##suf
 435     PF(P9), PF(P10), PF(P12), PF(P14), PF(P16),
 436     AV_PIX_FMT_NONE
 437 };
 438
 439 static int config_input_ref(AVFilterLink *inlink)
 440 {
 441     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
 442     AVFilterContext *ctx  = inlink->dst;
 443     SSIMContext *s = ctx->priv;
 444     int sum = 0;
 445
 446     s->nb_threads = ff_filter_get_nb_threads(ctx);
 447     s->nb_components = desc->nb_components;
 448
 449     if (ctx->inputs[0]->w != ctx->inputs[1]->w ||
 450         ctx->inputs[0]->h != ctx->inputs[1]->h) {
 451         av_log(ctx, AV_LOG_ERROR, "Width and height of input videos must be same.\n");
 452         return AVERROR(EINVAL);
 453     }
 454
 455     s->is_rgb = ff_fill_rgba_map(s->rgba_map, inlink->format) >= 0;
 456     s->comps[0] = s->is_rgb ? 'R' : 'Y';
 457     s->comps[1] = s->is_rgb ? 'G' : 'U';
 458     s->comps[2] = s->is_rgb ? 'B' : 'V';
 459     s->comps[3] = 'A';
 460
 461     s->planeheight[1] = s->planeheight[2] = AV_CEIL_RSHIFT(inlink->h, desc->log2_chroma_h);
 462     s->planeheight[0] = s->planeheight[3] = inlink->h;
 463     s->planewidth[1]  = s->planewidth[2]  = AV_CEIL_RSHIFT(inlink->w, desc->log2_chroma_w);
 464     s->planewidth[0]  = s->planewidth[3]  = inlink->w;
 465     for (int i = 0; i < s->nb_components; i++)
 466         sum += s->planeheight[i] * s->planewidth[i];
 467     for (int i = 0; i < s->nb_components; i++)
 468         s->coefs[i] = (double) s->planeheight[i] * s->planewidth[i] / sum;
 469
 470     s->temp = av_calloc(s->nb_threads, sizeof(*s->temp));
 471     if (!s->temp)
 472         return AVERROR(ENOMEM);
 473
 474     for (int t = 0; t < s->nb_threads; t++) {
 475         s->temp[t] = av_calloc(2 * SUM_LEN(inlink->w), (desc->comp[0].depth > 8) ? sizeof(int64_t[4]) : sizeof(int[4]));
 476         if (!s->temp[t])
 477             return AVERROR(ENOMEM);
 478     }
 479     s->max = (1 << desc->comp[0].depth) - 1;
 480
 481     s->ssim_plane = desc->comp[0].depth > 8 ? ssim_plane_16bit : ssim_plane;
 482     s->dsp.ssim_4x4_line = ssim_4x4xn_8bit;
 483     s->dsp.ssim_end_line = ssim_endn_8bit;
 484 #if ARCH_X86
 485     ff_ssim_init_x86(&s->dsp);
 486 #endif
 487
 488     s->score = av_calloc(s->nb_threads, sizeof(*s->score));
 489     if (!s->score)
 490         return AVERROR(ENOMEM);
 491
 492     for (int t = 0; t < s->nb_threads; t++) {
 493         s->score[t] = av_calloc(s->nb_components, sizeof(*s->score[0]));
 494         if (!s->score[t])
 495             return AVERROR(ENOMEM);
 496     }
 497
 498     return 0;
 499 }
 500
 501 static int config_output(AVFilterLink *outlink)
 502 {
 503     AVFilterContext *ctx = outlink->src;
 504     SSIMContext *s = ctx->priv;
 505     AVFilterLink *mainlink = ctx->inputs[0];
 506     FilterLink *il = ff_filter_link(mainlink);
 507     FilterLink *ol = ff_filter_link(outlink);
 508     int ret;
 509
 510     ret = ff_framesync_init_dualinput(&s->fs, ctx);
 511     if (ret < 0)
 512         return ret;
 513     outlink->w = mainlink->w;
 514     outlink->h = mainlink->h;
 515     outlink->time_base = mainlink->time_base;
 516     outlink->sample_aspect_ratio = mainlink->sample_aspect_ratio;
 517     ol->frame_rate = il->frame_rate;
 518
 519     if ((ret = ff_framesync_configure(&s->fs)) < 0)
 520         return ret;
 521
 522     outlink->time_base = s->fs.time_base;
 523
 524     if (av_cmp_q(mainlink->time_base, outlink->time_base) ||
 525         av_cmp_q(ctx->inputs[1]->time_base, outlink->time_base))
 526         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",
 527                mainlink->time_base.num, mainlink->time_base.den,
 528                ctx->inputs[1]->time_base.num, ctx->inputs[1]->time_base.den);
 529
 530     return 0;
 531 }
 532
 533 static int activate(AVFilterContext *ctx)
 534 {
 535     SSIMContext *s = ctx->priv;
 536     return ff_framesync_activate(&s->fs);
 537 }
 538
 539 static av_cold void uninit(AVFilterContext *ctx)
 540 {
 541     SSIMContext *s = ctx->priv;
 542
 543     if (s->nb_frames > 0) {
 544         char buf[256];
 545         buf[0] = 0;
 546         for (int i = 0; i < s->nb_components; i++) {
 547             int c = s->is_rgb ? s->rgba_map[i] : i;
 548             av_strlcatf(buf, sizeof(buf), " %c:%f (%f)", s->comps[i], s->ssim[c] / s->nb_frames,
 549                         ssim_db(s->ssim[c], s->nb_frames));
 550         }
 551         av_log(ctx, AV_LOG_INFO, "SSIM%s All:%f (%f)\n", buf,
 552                s->ssim_total / s->nb_frames, ssim_db(s->ssim_total, s->nb_frames));
 553     }
 554
 555     ff_framesync_uninit(&s->fs);
 556
 557     if (s->stats_file && s->stats_file != stdout)
 558         fclose(s->stats_file);
 559
 560     for (int t = 0; t < s->nb_threads && s->score; t++)
 561         av_freep(&s->score[t]);
 562     av_freep(&s->score);
 563
 564     for (int t = 0; t < s->nb_threads && s->temp; t++)
 565         av_freep(&s->temp[t]);
 566     av_freep(&s->temp);
 567 }
 568
 569 static const AVFilterPad ssim_inputs[] = {
 570     {
 571         .name         = "main",
 572         .type         = AVMEDIA_TYPE_VIDEO,
 573     },{
 574         .name         = "reference",
 575         .type         = AVMEDIA_TYPE_VIDEO,
 576         .config_props = config_input_ref,
 577     },
 578 };
 579
 580 static const AVFilterPad ssim_outputs[] = {
 581     {
 582         .name          = "default",
 583         .type          = AVMEDIA_TYPE_VIDEO,
 584         .config_props  = config_output,
 585     },
 586 };
 587
 588 const FFFilter ff_vf_ssim = {
 589     .p.name        = "ssim",
 590     .p.description = NULL_IF_CONFIG_SMALL("Calculate the SSIM between two video streams."),
 591     .p.priv_class  = &ssim_class,
 592     .p.flags       = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL |
 593                      AVFILTER_FLAG_SLICE_THREADS             |
 594                      AVFILTER_FLAG_METADATA_ONLY,
 595     .preinit       = ssim_framesync_preinit,
 596     .init          = init,
 597     .uninit        = uninit,
 598     .activate      = activate,
 599     .priv_size     = sizeof(SSIMContext),
 600     FILTER_INPUTS(ssim_inputs),
 601     FILTER_OUTPUTS(ssim_outputs),
 602     FILTER_PIXFMTS_ARRAY(pix_fmts),
 603 };