git.sesse.net Git - ffmpeg/blob - libavfilter/vf_lensfun.c

   1 /*
   2  * Copyright (C) 2007 by Andrew Zabolotny (author of lensfun, from which this filter derives from)
   3  * Copyright (C) 2018 Stephen Seo
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation, either version 3 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program 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
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19  */
  20
  21 /**
  22  * @file
  23  * Lensfun filter, applies lens correction with parameters from the lensfun database
  24  *
  25  * @see https://lensfun.sourceforge.net/
  26  */
  27
  28 #include <float.h>
  29 #include <math.h>
  30
  31 #include "libavutil/avassert.h"
  32 #include "libavutil/imgutils.h"
  33 #include "libavutil/opt.h"
  34 #include "libswscale/swscale.h"
  35 #include "avfilter.h"
  36 #include "formats.h"
  37 #include "internal.h"
  38 #include "video.h"
  39
  40 #include <lensfun.h>
  41
  42 #define LANCZOS_RESOLUTION 256
  43
  44 enum Mode {
  45     VIGNETTING = 0x1,
  46     GEOMETRY_DISTORTION = 0x2,
  47     SUBPIXEL_DISTORTION = 0x4
  48 };
  49
  50 enum InterpolationType {
  51     NEAREST,
  52     LINEAR,
  53     LANCZOS
  54 };
  55
  56 typedef struct VignettingThreadData {
  57     int width, height;
  58     uint8_t *data_in;
  59     int linesize_in;
  60     int pixel_composition;
  61     lfModifier *modifier;
  62 } VignettingThreadData;
  63
  64 typedef struct DistortionCorrectionThreadData {
  65     int width, height;
  66     const float *distortion_coords;
  67     const uint8_t *data_in;
  68     uint8_t *data_out;
  69     int linesize_in, linesize_out;
  70     const float *interpolation;
  71     int mode;
  72     int interpolation_type;
  73 } DistortionCorrectionThreadData;
  74
  75 typedef struct LensfunContext {
  76     const AVClass *class;
  77     const char *make, *model, *lens_model;
  78     int mode;
  79     float focal_length;
  80     float aperture;
  81     float focus_distance;
  82     float scale;
  83     int target_geometry;
  84     int reverse;
  85     int interpolation_type;
  86
  87     float *distortion_coords;
  88     float *interpolation;
  89
  90     lfLens *lens;
  91     lfCamera *camera;
  92     lfModifier *modifier;
  93 } LensfunContext;
  94
  95 #define OFFSET(x) offsetof(LensfunContext, x)
  96 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
  97 static const AVOption lensfun_options[] = {
  98     { "make", "set camera maker", OFFSET(make), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, FLAGS },
  99     { "model", "set camera model", OFFSET(model), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, FLAGS },
 100     { "lens_model", "set lens model", OFFSET(lens_model), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, FLAGS },
 101     { "mode", "set mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64=GEOMETRY_DISTORTION}, 0, VIGNETTING | GEOMETRY_DISTORTION | SUBPIXEL_DISTORTION, FLAGS, "mode" },
 102         { "vignetting", "fix lens vignetting", 0, AV_OPT_TYPE_CONST, {.i64=VIGNETTING}, 0, 0, FLAGS, "mode" },
 103         { "geometry", "correct geometry distortion", 0, AV_OPT_TYPE_CONST, {.i64=GEOMETRY_DISTORTION}, 0, 0, FLAGS, "mode" },
 104         { "subpixel", "fix chromatic aberrations", 0, AV_OPT_TYPE_CONST, {.i64=SUBPIXEL_DISTORTION}, 0, 0, FLAGS, "mode" },
 105         { "vig_geo", "fix lens vignetting and correct geometry distortion", 0, AV_OPT_TYPE_CONST, {.i64=VIGNETTING | GEOMETRY_DISTORTION}, 0, 0, FLAGS, "mode" },
 106         { "vig_subpixel", "fix lens vignetting and chromatic aberrations", 0, AV_OPT_TYPE_CONST, {.i64=VIGNETTING | SUBPIXEL_DISTORTION}, 0, 0, FLAGS, "mode" },
 107         { "distortion", "correct geometry distortion and chromatic aberrations", 0, AV_OPT_TYPE_CONST, {.i64=GEOMETRY_DISTORTION | SUBPIXEL_DISTORTION}, 0, 0, FLAGS, "mode" },
 108         { "all", NULL, 0, AV_OPT_TYPE_CONST, {.i64=VIGNETTING | GEOMETRY_DISTORTION | SUBPIXEL_DISTORTION}, 0, 0, FLAGS, "mode" },
 109     { "focal_length", "focal length of video (zoom; constant for the duration of the use of this filter)", OFFSET(focal_length), AV_OPT_TYPE_FLOAT, {.dbl=18}, 0.0, DBL_MAX, FLAGS },
 110     { "aperture", "aperture (constant for the duration of the use of this filter)", OFFSET(aperture), AV_OPT_TYPE_FLOAT, {.dbl=3.5}, 0.0, DBL_MAX, FLAGS },
 111     { "focus_distance", "focus distance (constant for the duration of the use of this filter)", OFFSET(focus_distance), AV_OPT_TYPE_FLOAT, {.dbl=1000.0f}, 0.0, DBL_MAX, FLAGS },
 112     { "scale", "scale factor applied after corrections (0.0 means automatic scaling)", OFFSET(scale), AV_OPT_TYPE_FLOAT, {.dbl=0.0}, 0.0, DBL_MAX, FLAGS },
 113     { "target_geometry", "target geometry of the lens correction (only when geometry correction is enabled)", OFFSET(target_geometry), AV_OPT_TYPE_INT, {.i64=LF_RECTILINEAR}, 0, INT_MAX, FLAGS, "lens_geometry" },
 114         { "rectilinear", "rectilinear lens (default)", 0, AV_OPT_TYPE_CONST, {.i64=LF_RECTILINEAR}, 0, 0, FLAGS, "lens_geometry" },
 115         { "fisheye", "fisheye lens", 0, AV_OPT_TYPE_CONST, {.i64=LF_FISHEYE}, 0, 0, FLAGS, "lens_geometry" },
 116         { "panoramic", "panoramic (cylindrical)", 0, AV_OPT_TYPE_CONST, {.i64=LF_PANORAMIC}, 0, 0, FLAGS, "lens_geometry" },
 117         { "equirectangular", "equirectangular", 0, AV_OPT_TYPE_CONST, {.i64=LF_EQUIRECTANGULAR}, 0, 0, FLAGS, "lens_geometry" },
 118         { "fisheye_orthographic", "orthographic fisheye", 0, AV_OPT_TYPE_CONST, {.i64=LF_FISHEYE_ORTHOGRAPHIC}, 0, 0, FLAGS, "lens_geometry" },
 119         { "fisheye_stereographic", "stereographic fisheye", 0, AV_OPT_TYPE_CONST, {.i64=LF_FISHEYE_STEREOGRAPHIC}, 0, 0, FLAGS, "lens_geometry" },
 120         { "fisheye_equisolid", "equisolid fisheye", 0, AV_OPT_TYPE_CONST, {.i64=LF_FISHEYE_EQUISOLID}, 0, 0, FLAGS, "lens_geometry" },
 121         { "fisheye_thoby", "fisheye as measured by thoby", 0, AV_OPT_TYPE_CONST, {.i64=LF_FISHEYE_THOBY}, 0, 0, FLAGS, "lens_geometry" },
 122     { "reverse", "Does reverse correction (regular image to lens distorted)", OFFSET(reverse), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS },
 123     { "interpolation", "Type of interpolation", OFFSET(interpolation_type), AV_OPT_TYPE_INT, {.i64=LINEAR}, 0, LANCZOS, FLAGS, "interpolation" },
 124         { "nearest", NULL, 0, AV_OPT_TYPE_CONST, {.i64=NEAREST}, 0, 0, FLAGS, "interpolation" },
 125         { "linear", NULL, 0, AV_OPT_TYPE_CONST, {.i64=LINEAR}, 0, 0, FLAGS, "interpolation" },
 126         { "lanczos", NULL, 0, AV_OPT_TYPE_CONST, {.i64=LANCZOS}, 0, 0, FLAGS, "interpolation" },
 127     { NULL }
 128 };
 129
 130 AVFILTER_DEFINE_CLASS(lensfun);
 131
 132 static av_cold int init(AVFilterContext *ctx)
 133 {
 134     LensfunContext *lensfun = ctx->priv;
 135     lfDatabase *db;
 136     const lfCamera **cameras;
 137     const lfLens **lenses;
 138
 139     if (!lensfun->make) {
 140         av_log(ctx, AV_LOG_FATAL, "Option \"make\" not specified\n");
 141         return AVERROR(EINVAL);
 142     } else if (!lensfun->model) {
 143         av_log(ctx, AV_LOG_FATAL, "Option \"model\" not specified\n");
 144         return AVERROR(EINVAL);
 145     } else if (!lensfun->lens_model) {
 146         av_log(ctx, AV_LOG_FATAL, "Option \"lens_model\" not specified\n");
 147         return AVERROR(EINVAL);
 148     }
 149
 150     lensfun->lens = lf_lens_create();
 151     lensfun->camera = lf_camera_create();
 152
 153     db = lf_db_create();
 154     if (lf_db_load(db) != LF_NO_ERROR) {
 155         lf_db_destroy(db);
 156         av_log(ctx, AV_LOG_FATAL, "Failed to load lensfun database\n");
 157         return AVERROR_INVALIDDATA;
 158     }
 159
 160     cameras = lf_db_find_cameras(db, lensfun->make, lensfun->model);
 161     if (cameras && *cameras) {
 162         lf_camera_copy(lensfun->camera, *cameras);
 163         av_log(ctx, AV_LOG_INFO, "Using camera %s\n", lensfun->camera->Model);
 164     } else {
 165         lf_free(cameras);
 166         lf_db_destroy(db);
 167         av_log(ctx, AV_LOG_FATAL, "Failed to find camera in lensfun database\n");
 168         return AVERROR_INVALIDDATA;
 169     }
 170     lf_free(cameras);
 171
 172     lenses = lf_db_find_lenses(db, lensfun->camera, NULL, lensfun->lens_model, 0);
 173     if (lenses && *lenses) {
 174         lf_lens_copy(lensfun->lens, *lenses);
 175         av_log(ctx, AV_LOG_INFO, "Using lens %s\n", lensfun->lens->Model);
 176     } else {
 177         lf_free(lenses);
 178         lf_db_destroy(db);
 179         av_log(ctx, AV_LOG_FATAL, "Failed to find lens in lensfun database\n");
 180         return AVERROR_INVALIDDATA;
 181     }
 182     lf_free(lenses);
 183
 184     lf_db_destroy(db);
 185     return 0;
 186 }
 187
 188 static int query_formats(AVFilterContext *ctx)
 189 {
 190     // Some of the functions provided by lensfun require pixels in RGB format
 191     static const enum AVPixelFormat fmts[] = {AV_PIX_FMT_RGB24, AV_PIX_FMT_NONE};
 192     AVFilterFormats *fmts_list = ff_make_format_list(fmts);
 193     return ff_set_common_formats(ctx, fmts_list);
 194 }
 195
 196 static float lanczos_kernel(float x)
 197 {
 198     if (x == 0.0f) {
 199         return 1.0f;
 200     } else if (x > -2.0f && x < 2.0f) {
 201         return (2.0f * sin(M_PI * x) * sin(M_PI / 2.0f * x)) / (M_PI * M_PI * x * x);
 202     } else {
 203         return 0.0f;
 204     }
 205 }
 206
 207 static int config_props(AVFilterLink *inlink)
 208 {
 209     AVFilterContext *ctx = inlink->dst;
 210     LensfunContext *lensfun = ctx->priv;
 211     int index;
 212     float a;
 213
 214     if (!lensfun->modifier) {
 215         if (lensfun->camera && lensfun->lens) {
 216             lensfun->modifier = lf_modifier_create(lensfun->lens,
 217                                                    lensfun->focal_length,
 218                                                    lensfun->camera->CropFactor,
 219                                                    inlink->w,
 220                                                    inlink->h, LF_PF_U8, lensfun->reverse);
 221             if (lensfun->mode & VIGNETTING)
 222                 lf_modifier_enable_vignetting_correction(lensfun->modifier, lensfun->aperture, lensfun->focus_distance);
 223             if (lensfun->mode & GEOMETRY_DISTORTION) {
 224                 lf_modifier_enable_distortion_correction(lensfun->modifier);
 225                 lf_modifier_enable_projection_transform(lensfun->modifier, lensfun->target_geometry);
 226                 lf_modifier_enable_scaling(lensfun->modifier, lensfun->scale);
 227             }
 228             if (lensfun->mode & SUBPIXEL_DISTORTION)
 229                 lf_modifier_enable_tca_correction(lensfun->modifier);
 230         } else {
 231             // lensfun->camera and lensfun->lens should have been initialized
 232             return AVERROR_BUG;
 233         }
 234     }
 235
 236     if (!lensfun->distortion_coords) {
 237         if (lensfun->mode & SUBPIXEL_DISTORTION) {
 238             lensfun->distortion_coords = av_malloc_array(inlink->w * inlink->h, sizeof(float) * 2 * 3);
 239             if (!lensfun->distortion_coords)
 240                 return AVERROR(ENOMEM);
 241             if (lensfun->mode & GEOMETRY_DISTORTION) {
 242                 // apply both geometry and subpixel distortion
 243                 lf_modifier_apply_subpixel_geometry_distortion(lensfun->modifier,
 244                                                                0, 0,
 245                                                                inlink->w, inlink->h,
 246                                                                lensfun->distortion_coords);
 247             } else {
 248                 // apply only subpixel distortion
 249                 lf_modifier_apply_subpixel_distortion(lensfun->modifier,
 250                                                       0, 0,
 251                                                       inlink->w, inlink->h,
 252                                                       lensfun->distortion_coords);
 253             }
 254         } else if (lensfun->mode & GEOMETRY_DISTORTION) {
 255             lensfun->distortion_coords = av_malloc_array(inlink->w * inlink->h, sizeof(float) * 2);
 256             if (!lensfun->distortion_coords)
 257                 return AVERROR(ENOMEM);
 258             // apply only geometry distortion
 259             lf_modifier_apply_geometry_distortion(lensfun->modifier,
 260                                                   0, 0,
 261                                                   inlink->w, inlink->h,
 262                                                   lensfun->distortion_coords);
 263         }
 264     }
 265
 266     if (!lensfun->interpolation)
 267         if (lensfun->interpolation_type == LANCZOS) {
 268             lensfun->interpolation = av_malloc_array(LANCZOS_RESOLUTION, sizeof(float) * 4);
 269             if (!lensfun->interpolation)
 270                 return AVERROR(ENOMEM);
 271             for (index = 0; index < 4 * LANCZOS_RESOLUTION; ++index) {
 272                 if (index == 0) {
 273                     lensfun->interpolation[index] = 1.0f;
 274                 } else {
 275                     a = sqrtf((float)index / LANCZOS_RESOLUTION);
 276                     lensfun->interpolation[index] = lanczos_kernel(a);
 277                 }
 278             }
 279         }
 280
 281     return 0;
 282 }
 283
 284 static int vignetting_filter_slice(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
 285 {
 286     const VignettingThreadData *thread_data = arg;
 287     const int slice_start = thread_data->height *  jobnr      / nb_jobs;
 288     const int slice_end   = thread_data->height * (jobnr + 1) / nb_jobs;
 289
 290     lf_modifier_apply_color_modification(thread_data->modifier,
 291                                          thread_data->data_in + slice_start * thread_data->linesize_in,
 292                                          0,
 293                                          slice_start,
 294                                          thread_data->width,
 295                                          slice_end - slice_start,
 296                                          thread_data->pixel_composition,
 297                                          thread_data->linesize_in);
 298
 299     return 0;
 300 }
 301
 302 static float square(float x)
 303 {
 304     return x * x;
 305 }
 306
 307 static int distortion_correction_filter_slice(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
 308 {
 309     const DistortionCorrectionThreadData *thread_data = arg;
 310     const int slice_start = thread_data->height *  jobnr      / nb_jobs;
 311     const int slice_end   = thread_data->height * (jobnr + 1) / nb_jobs;
 312
 313     int x, y, i, j, rgb_index;
 314     float interpolated, new_x, new_y, d, norm;
 315     int new_x_int, new_y_int;
 316     for (y = slice_start; y < slice_end; ++y)
 317         for (x = 0; x < thread_data->width; ++x)
 318             for (rgb_index = 0; rgb_index < 3; ++rgb_index) {
 319                 if (thread_data->mode & SUBPIXEL_DISTORTION) {
 320                     // subpixel (and possibly geometry) distortion correction was applied, correct distortion
 321                     switch(thread_data->interpolation_type) {
 322                     case NEAREST:
 323                         new_x_int = thread_data->distortion_coords[x * 2 * 3 + y * thread_data->width * 2 * 3 + rgb_index * 2]     + 0.5f;
 324                         new_y_int = thread_data->distortion_coords[x * 2 * 3 + y * thread_data->width * 2 * 3 + rgb_index * 2 + 1] + 0.5f;
 325                         if (new_x_int < 0 || new_x_int >= thread_data->width || new_y_int < 0 || new_y_int >= thread_data->height) {
 326                             thread_data->data_out[x * 3 + rgb_index + y * thread_data->linesize_out] = 0;
 327                         } else {
 328                             thread_data->data_out[x * 3 + rgb_index + y * thread_data->linesize_out] = thread_data->data_in[new_x_int * 3 + rgb_index + new_y_int * thread_data->linesize_in];
 329                         }
 330                         break;
 331                     case LINEAR:
 332                         interpolated = 0.0f;
 333                         new_x = thread_data->distortion_coords[x * 2 * 3 + y * thread_data->width * 2 * 3 + rgb_index * 2];
 334                         new_x_int = new_x;
 335                         new_y = thread_data->distortion_coords[x * 2 * 3 + y * thread_data->width * 2 * 3 + rgb_index * 2 + 1];
 336                         new_y_int = new_y;
 337                         if (new_x_int < 0 || new_x_int + 1 >= thread_data->width || new_y_int < 0 || new_y_int + 1 >= thread_data->height) {
 338                             thread_data->data_out[x * 3 + rgb_index + y * thread_data->linesize_out] = 0;
 339                         } else {
 340                             thread_data->data_out[x * 3 + rgb_index + y * thread_data->linesize_out] =
 341                                   thread_data->data_in[ new_x_int      * 3 + rgb_index +  new_y_int      * thread_data->linesize_in] * (new_x_int + 1 - new_x) * (new_y_int + 1 - new_y)
 342                                 + thread_data->data_in[(new_x_int + 1) * 3 + rgb_index +  new_y_int      * thread_data->linesize_in] * (new_x - new_x_int) * (new_y_int + 1 - new_y)
 343                                 + thread_data->data_in[ new_x_int      * 3 + rgb_index + (new_y_int + 1) * thread_data->linesize_in] * (new_x_int + 1 - new_x) * (new_y - new_y_int)
 344                                 + thread_data->data_in[(new_x_int + 1) * 3 + rgb_index + (new_y_int + 1) * thread_data->linesize_in] * (new_x - new_x_int) * (new_y - new_y_int);
 345                         }
 346                         break;
 347                     case LANCZOS:
 348                         interpolated = 0.0f;
 349                         norm = 0.0f;
 350                         new_x = thread_data->distortion_coords[x * 2 * 3 + y * thread_data->width * 2 * 3 + rgb_index * 2];
 351                         new_x_int = new_x;
 352                         new_y = thread_data->distortion_coords[x * 2 * 3 + y * thread_data->width * 2 * 3 + rgb_index * 2 + 1];
 353                         new_y_int = new_y;
 354                         for (j = 0; j < 4; ++j)
 355                             for (i = 0; i < 4; ++i) {
 356                                 if (new_x_int + i - 2 < 0 || new_x_int + i - 2 >= thread_data->width || new_y_int + j - 2 < 0 || new_y_int + j - 2 >= thread_data->height)
 357                                     continue;
 358                                 d = square(new_x - (new_x_int + i - 2)) * square(new_y - (new_y_int + j - 2));
 359                                 if (d >= 4.0f)
 360                                     continue;
 361                                 d = thread_data->interpolation[(int)(d * LANCZOS_RESOLUTION)];
 362                                 norm += d;
 363                                 interpolated += thread_data->data_in[(new_x_int + i - 2) * 3 + rgb_index + (new_y_int + j - 2) * thread_data->linesize_in] * d;
 364                             }
 365                         if (norm == 0.0f) {
 366                             thread_data->data_out[x * 3 + rgb_index + y * thread_data->linesize_out] = 0;
 367                         } else {
 368                             interpolated /= norm;
 369                             thread_data->data_out[x * 3 + rgb_index + y * thread_data->linesize_out] = interpolated < 0.0f ? 0.0f : interpolated > 255.0f ? 255.0f : interpolated;
 370                         }
 371                         break;
 372                     }
 373                 } else if (thread_data->mode & GEOMETRY_DISTORTION) {
 374                     // geometry distortion correction was applied, correct distortion
 375                     switch(thread_data->interpolation_type) {
 376                     case NEAREST:
 377                         new_x_int = thread_data->distortion_coords[x * 2 + y * thread_data->width * 2]     + 0.5f;
 378                         new_y_int = thread_data->distortion_coords[x * 2 + y * thread_data->width * 2 + 1] + 0.5f;
 379                         if (new_x_int < 0 || new_x_int >= thread_data->width || new_y_int < 0 || new_y_int >= thread_data->height) {
 380                             thread_data->data_out[x * 3 + rgb_index + y * thread_data->linesize_out] = 0;
 381                         } else {
 382                             thread_data->data_out[x * 3 + rgb_index + y * thread_data->linesize_out] = thread_data->data_in[new_x_int * 3 + rgb_index + new_y_int * thread_data->linesize_in];
 383                         }
 384                         break;
 385                     case LINEAR:
 386                         interpolated = 0.0f;
 387                         new_x = thread_data->distortion_coords[x * 2 + y * thread_data->width * 2];
 388                         new_x_int = new_x;
 389                         new_y = thread_data->distortion_coords[x * 2 + y * thread_data->width * 2 + 1];
 390                         new_y_int = new_y;
 391                         if (new_x_int < 0 || new_x_int + 1 >= thread_data->width || new_y_int < 0 || new_y_int + 1 >= thread_data->height) {
 392                             thread_data->data_out[x * 3 + rgb_index + y * thread_data->linesize_out] = 0;
 393                         } else {
 394                             thread_data->data_out[x * 3 + rgb_index + y * thread_data->linesize_out] =
 395                                   thread_data->data_in[ new_x_int      * 3 + rgb_index +  new_y_int      * thread_data->linesize_in] * (new_x_int + 1 - new_x) * (new_y_int + 1 - new_y)
 396                                 + thread_data->data_in[(new_x_int + 1) * 3 + rgb_index +  new_y_int      * thread_data->linesize_in] * (new_x - new_x_int) * (new_y_int + 1 - new_y)
 397                                 + thread_data->data_in[ new_x_int      * 3 + rgb_index + (new_y_int + 1) * thread_data->linesize_in] * (new_x_int + 1 - new_x) * (new_y - new_y_int)
 398                                 + thread_data->data_in[(new_x_int + 1) * 3 + rgb_index + (new_y_int + 1) * thread_data->linesize_in] * (new_x - new_x_int) * (new_y - new_y_int);
 399                         }
 400                         break;
 401                     case LANCZOS:
 402                         interpolated = 0.0f;
 403                         norm = 0.0f;
 404                         new_x = thread_data->distortion_coords[x * 2     + y * thread_data->width * 2];
 405                         new_x_int = new_x;
 406                         new_y = thread_data->distortion_coords[x * 2 + 1 + y * thread_data->width * 2];
 407                         new_y_int = new_y;
 408                         for (j = 0; j < 4; ++j)
 409                             for (i = 0; i < 4; ++i) {
 410                                 if (new_x_int + i - 2 < 0 || new_x_int + i - 2 >= thread_data->width || new_y_int + j - 2 < 0 || new_y_int + j - 2 >= thread_data->height)
 411                                     continue;
 412                                 d = square(new_x - (new_x_int + i - 2)) * square(new_y - (new_y_int + j - 2));
 413                                 if (d >= 4.0f)
 414                                     continue;
 415                                 d = thread_data->interpolation[(int)(d * LANCZOS_RESOLUTION)];
 416                                 norm += d;
 417                                 interpolated += thread_data->data_in[(new_x_int + i - 2) * 3 + rgb_index + (new_y_int + j - 2) * thread_data->linesize_in] * d;
 418                             }
 419                         if (norm == 0.0f) {
 420                             thread_data->data_out[x * 3 + rgb_index + y * thread_data->linesize_out] = 0;
 421                         } else {
 422                             interpolated /= norm;
 423                             thread_data->data_out[x * 3 + rgb_index + y * thread_data->linesize_out] = interpolated < 0.0f ? 0.0f : interpolated > 255.0f ? 255.0f : interpolated;
 424                         }
 425                         break;
 426                     }
 427                 } else {
 428                     // no distortion correction was applied
 429                     thread_data->data_out[x * 3 + rgb_index + y * thread_data->linesize_out] = thread_data->data_in[x * 3 + rgb_index + y * thread_data->linesize_in];
 430                 }
 431             }
 432
 433     return 0;
 434 }
 435
 436 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
 437 {
 438     AVFilterContext *ctx = inlink->dst;
 439     LensfunContext *lensfun = ctx->priv;
 440     AVFilterLink *outlink = ctx->outputs[0];
 441     AVFrame *out;
 442     VignettingThreadData vignetting_thread_data;
 443     DistortionCorrectionThreadData distortion_correction_thread_data;
 444
 445     if (lensfun->mode & VIGNETTING) {
 446         av_frame_make_writable(in);
 447
 448         vignetting_thread_data = (VignettingThreadData) {
 449             .width = inlink->w,
 450             .height = inlink->h,
 451             .data_in = in->data[0],
 452             .linesize_in = in->linesize[0],
 453             .pixel_composition = LF_CR_3(RED, GREEN, BLUE),
 454             .modifier = lensfun->modifier
 455         };
 456
 457         ctx->internal->execute(ctx,
 458                                vignetting_filter_slice,
 459                                &vignetting_thread_data,
 460                                NULL,
 461                                FFMIN(outlink->h, ff_filter_get_nb_threads(ctx)));
 462     }
 463
 464     if (lensfun->mode & (GEOMETRY_DISTORTION | SUBPIXEL_DISTORTION)) {
 465         out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
 466         if (!out) {
 467             av_frame_free(&in);
 468             return AVERROR(ENOMEM);
 469         }
 470         av_frame_copy_props(out, in);
 471
 472         distortion_correction_thread_data = (DistortionCorrectionThreadData) {
 473             .width = inlink->w,
 474             .height = inlink->h,
 475             .distortion_coords = lensfun->distortion_coords,
 476             .data_in = in->data[0],
 477             .data_out = out->data[0],
 478             .linesize_in = in->linesize[0],
 479             .linesize_out = out->linesize[0],
 480             .interpolation = lensfun->interpolation,
 481             .mode = lensfun->mode,
 482             .interpolation_type = lensfun->interpolation_type
 483         };
 484
 485         ctx->internal->execute(ctx,
 486                                distortion_correction_filter_slice,
 487                                &distortion_correction_thread_data,
 488                                NULL,
 489                                FFMIN(outlink->h, ff_filter_get_nb_threads(ctx)));
 490
 491         av_frame_free(&in);
 492         return ff_filter_frame(outlink, out);
 493     } else {
 494         return ff_filter_frame(outlink, in);
 495     }
 496 }
 497
 498 static av_cold void uninit(AVFilterContext *ctx)
 499 {
 500     LensfunContext *lensfun = ctx->priv;
 501
 502     if (lensfun->camera)
 503         lf_camera_destroy(lensfun->camera);
 504     if (lensfun->lens)
 505         lf_lens_destroy(lensfun->lens);
 506     if (lensfun->modifier)
 507         lf_modifier_destroy(lensfun->modifier);
 508     av_freep(&lensfun->distortion_coords);
 509     av_freep(&lensfun->interpolation);
 510 }
 511
 512 static const AVFilterPad lensfun_inputs[] = {
 513     {
 514         .name         = "default",
 515         .type         = AVMEDIA_TYPE_VIDEO,
 516         .config_props = config_props,
 517         .filter_frame = filter_frame,
 518     },
 519     { NULL }
 520 };
 521
 522 static const AVFilterPad lensfun_outputs[] = {
 523     {
 524         .name = "default",
 525         .type = AVMEDIA_TYPE_VIDEO,
 526     },
 527     { NULL }
 528 };
 529
 530 AVFilter ff_vf_lensfun = {
 531     .name          = "lensfun",
 532     .description   = NULL_IF_CONFIG_SMALL("Apply correction to an image based on info derived from the lensfun database."),
 533     .priv_size     = sizeof(LensfunContext),
 534     .init          = init,
 535     .uninit        = uninit,
 536     .query_formats = query_formats,
 537     .inputs        = lensfun_inputs,
 538     .outputs       = lensfun_outputs,
 539     .priv_class    = &lensfun_class,
 540     .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS,
 541 };