/*
  * Copyright (c) 2013 Paul B Mahol
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include "libavutil/imgutils.h"
 #include "libavutil/eval.h"
 #include "libavutil/opt.h"
 #include "libavutil/pixfmt.h"
 #include "avfilter.h"
 #include "bufferqueue.h"
 #include "formats.h"

 #include "framesync.h"

 #include "internal.h"
 #include "video.h"

 #include "blend.h"

 
 #define TOP    0
 #define BOTTOM 1
 

 typedef struct BlendContext {

     const AVClass *class;

     FFFrameSync fs;

     int hsub, vsub;             ///< chroma subsampling values

     int nb_planes;

     char *all_expr;
     enum BlendMode all_mode;
     double all_opacity;
 
     FilterParams params[4];

     int tblend;
     AVFrame *prev_frame;        /* only used with tblend */

 } BlendContext;
 

 static const char *const var_names[] = {   "X",   "Y",   "W",   "H",   "SW",   "SH",   "T",   "N",   "A",   "B",   "TOP",   "BOTTOM",        NULL };
 enum                                   { VAR_X, VAR_Y, VAR_W, VAR_H, VAR_SW, VAR_SH, VAR_T, VAR_N, VAR_A, VAR_B, VAR_TOP, VAR_BOTTOM, VAR_VARS_NB };
 
 typedef struct ThreadData {
     const AVFrame *top, *bottom;
     AVFrame *dst;
     AVFilterLink *inlink;
     int plane;
     int w, h;
     FilterParams *param;
 } ThreadData;
 

 #define COMMON_OPTIONS \
     { "c0_mode", "set component #0 blend mode", OFFSET(params[0].mode), AV_OPT_TYPE_INT, {.i64=0}, 0, BLEND_NB-1, FLAGS, "mode"},\
     { "c1_mode", "set component #1 blend mode", OFFSET(params[1].mode), AV_OPT_TYPE_INT, {.i64=0}, 0, BLEND_NB-1, FLAGS, "mode"},\
     { "c2_mode", "set component #2 blend mode", OFFSET(params[2].mode), AV_OPT_TYPE_INT, {.i64=0}, 0, BLEND_NB-1, FLAGS, "mode"},\
     { "c3_mode", "set component #3 blend mode", OFFSET(params[3].mode), AV_OPT_TYPE_INT, {.i64=0}, 0, BLEND_NB-1, FLAGS, "mode"},\
     { "all_mode", "set blend mode for all components", OFFSET(all_mode), AV_OPT_TYPE_INT, {.i64=-1},-1, BLEND_NB-1, FLAGS, "mode"},\
     { "addition",   "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_ADDITION},   0, 0, FLAGS, "mode" },\

     { "addition128","", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_GRAINMERGE}, 0, 0, FLAGS, "mode" },\
     { "grainmerge", "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_GRAINMERGE}, 0, 0, FLAGS, "mode" },\

     { "and",        "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_AND},        0, 0, FLAGS, "mode" },\
     { "average",    "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_AVERAGE},    0, 0, FLAGS, "mode" },\
     { "burn",       "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_BURN},       0, 0, FLAGS, "mode" },\
     { "darken",     "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_DARKEN},     0, 0, FLAGS, "mode" },\
     { "difference", "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_DIFFERENCE}, 0, 0, FLAGS, "mode" },\

     { "difference128", "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_GRAINEXTRACT}, 0, 0, FLAGS, "mode" },\
     { "grainextract", "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_GRAINEXTRACT}, 0, 0, FLAGS, "mode" },\

     { "divide",     "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_DIVIDE},     0, 0, FLAGS, "mode" },\
     { "dodge",      "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_DODGE},      0, 0, FLAGS, "mode" },\
     { "exclusion",  "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_EXCLUSION},  0, 0, FLAGS, "mode" },\

     { "extremity",  "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_EXTREMITY},  0, 0, FLAGS, "mode" },\

     { "freeze",     "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_FREEZE},     0, 0, FLAGS, "mode" },\

     { "glow",       "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_GLOW},       0, 0, FLAGS, "mode" },\

     { "hardlight",  "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_HARDLIGHT},  0, 0, FLAGS, "mode" },\

     { "hardmix",    "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_HARDMIX},    0, 0, FLAGS, "mode" },\

     { "heat",       "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_HEAT},       0, 0, FLAGS, "mode" },\

     { "lighten",    "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_LIGHTEN},    0, 0, FLAGS, "mode" },\

     { "linearlight","", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_LINEARLIGHT},0, 0, FLAGS, "mode" },\

     { "multiply",   "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_MULTIPLY},   0, 0, FLAGS, "mode" },\

     { "multiply128","", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_MULTIPLY128},0, 0, FLAGS, "mode" },\

     { "negation",   "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_NEGATION},   0, 0, FLAGS, "mode" },\
     { "normal",     "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_NORMAL},     0, 0, FLAGS, "mode" },\
     { "or",         "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_OR},         0, 0, FLAGS, "mode" },\
     { "overlay",    "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_OVERLAY},    0, 0, FLAGS, "mode" },\
     { "phoenix",    "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_PHOENIX},    0, 0, FLAGS, "mode" },\
     { "pinlight",   "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_PINLIGHT},   0, 0, FLAGS, "mode" },\
     { "reflect",    "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_REFLECT},    0, 0, FLAGS, "mode" },\
     { "screen",     "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_SCREEN},     0, 0, FLAGS, "mode" },\
     { "softlight",  "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_SOFTLIGHT},  0, 0, FLAGS, "mode" },\
     { "subtract",   "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_SUBTRACT},   0, 0, FLAGS, "mode" },\
     { "vividlight", "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_VIVIDLIGHT}, 0, 0, FLAGS, "mode" },\
     { "xor",        "", 0, AV_OPT_TYPE_CONST, {.i64=BLEND_XOR},        0, 0, FLAGS, "mode" },\
     { "c0_expr",  "set color component #0 expression", OFFSET(params[0].expr_str), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },\
     { "c1_expr",  "set color component #1 expression", OFFSET(params[1].expr_str), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },\
     { "c2_expr",  "set color component #2 expression", OFFSET(params[2].expr_str), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },\
     { "c3_expr",  "set color component #3 expression", OFFSET(params[3].expr_str), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },\
     { "all_expr", "set expression for all color components", OFFSET(all_expr), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS },\
     { "c0_opacity",  "set color component #0 opacity", OFFSET(params[0].opacity), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 1, FLAGS },\
     { "c1_opacity",  "set color component #1 opacity", OFFSET(params[1].opacity), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 1, FLAGS },\
     { "c2_opacity",  "set color component #2 opacity", OFFSET(params[2].opacity), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 1, FLAGS },\
     { "c3_opacity",  "set color component #3 opacity", OFFSET(params[3].opacity), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 1, FLAGS },\
     { "all_opacity", "set opacity for all color components", OFFSET(all_opacity), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 1, FLAGS}
 

 #define OFFSET(x) offsetof(BlendContext, x)
 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
 
 static const AVOption blend_options[] = {

     COMMON_OPTIONS,

     { NULL }

 };
 

 FRAMESYNC_DEFINE_CLASS(blend, BlendContext, fs);

 #define COPY(src)                                                            \
 static void blend_copy ## src(const uint8_t *top, ptrdiff_t top_linesize,    \
                             const uint8_t *bottom, ptrdiff_t bottom_linesize,\
                             uint8_t *dst, ptrdiff_t dst_linesize,            \

                             ptrdiff_t width, ptrdiff_t height,               \

                             FilterParams *param, double *values, int starty) \

 {                                                                            \
     av_image_copy_plane(dst, dst_linesize, src, src ## _linesize,            \

                         width, height);                                 \

 }
 

 COPY(top)

 COPY(bottom)

 
 #undef COPY
 

 static void blend_normal_8bit(const uint8_t *top, ptrdiff_t top_linesize,
                               const uint8_t *bottom, ptrdiff_t bottom_linesize,
                               uint8_t *dst, ptrdiff_t dst_linesize,

                               ptrdiff_t width, ptrdiff_t height,

                               FilterParams *param, double *values, int starty)

 {
     const double opacity = param->opacity;
     int i, j;
 

     for (i = 0; i < height; i++) {

         for (j = 0; j < width; j++) {
             dst[j] = top[j] * opacity + bottom[j] * (1. - opacity);
         }
         dst    += dst_linesize;
         top    += top_linesize;
         bottom += bottom_linesize;
     }
 }
 
 static void blend_normal_16bit(const uint8_t *_top, ptrdiff_t top_linesize,
                                   const uint8_t *_bottom, ptrdiff_t bottom_linesize,
                                   uint8_t *_dst, ptrdiff_t dst_linesize,

                                   ptrdiff_t width, ptrdiff_t height,

                                   FilterParams *param, double *values, int starty)

 {
     const uint16_t *top = (uint16_t*)_top;
     const uint16_t *bottom = (uint16_t*)_bottom;
     uint16_t *dst = (uint16_t*)_dst;
     const double opacity = param->opacity;
     int i, j;
     dst_linesize /= 2;
     top_linesize /= 2;
     bottom_linesize /= 2;
 

     for (i = 0; i < height; i++) {

         for (j = 0; j < width; j++) {
             dst[j] = top[j] * opacity + bottom[j] * (1. - opacity);
         }
         dst    += dst_linesize;
         top    += top_linesize;
         bottom += bottom_linesize;
     }
 }
 

 #define DEFINE_BLEND8(name, expr)                                              \

 static void blend_## name##_8bit(const uint8_t *top, ptrdiff_t top_linesize,         \
                                  const uint8_t *bottom, ptrdiff_t bottom_linesize,   \
                                  uint8_t *dst, ptrdiff_t dst_linesize,               \

                                  ptrdiff_t width, ptrdiff_t height,                \

                                  FilterParams *param, double *values, int starty) \

 {                                                                              \
     double opacity = param->opacity;                                           \
     int i, j;                                                                  \
                                                                                \

     for (i = 0; i < height; i++) {                                             \

         for (j = 0; j < width; j++) {                                          \
             dst[j] = top[j] + ((expr) - top[j]) * opacity;                     \
         }                                                                      \
         dst    += dst_linesize;                                                \
         top    += top_linesize;                                                \
         bottom += bottom_linesize;                                             \
     }                                                                          \
 }
 
 #define DEFINE_BLEND16(name, expr)                                             \

 static void blend_## name##_16bit(const uint8_t *_top, ptrdiff_t top_linesize,       \
                                   const uint8_t *_bottom, ptrdiff_t bottom_linesize, \
                                   uint8_t *_dst, ptrdiff_t dst_linesize,             \

                                   ptrdiff_t width, ptrdiff_t height,           \

                                   FilterParams *param, double *values, int starty)         \

 {                                                                              \
     const uint16_t *top = (uint16_t*)_top;                                     \
     const uint16_t *bottom = (uint16_t*)_bottom;                               \
     uint16_t *dst = (uint16_t*)_dst;                                           \
     double opacity = param->opacity;                                           \
     int i, j;                                                                  \
     dst_linesize /= 2;                                                         \
     top_linesize /= 2;                                                         \
     bottom_linesize /= 2;                                                      \
                                                                                \

     for (i = 0; i < height; i++) {                                             \

         for (j = 0; j < width; j++) {                                          \
             dst[j] = top[j] + ((expr) - top[j]) * opacity;                     \
         }                                                                      \
         dst    += dst_linesize;                                                \
         top    += top_linesize;                                                \
         bottom += bottom_linesize;                                             \
     }                                                                          \

 }
 
 #define A top[j]
 #define B bottom[j]
 

 #define MULTIPLY(x, a, b) ((x) * (((a) * (b)) / 255))
 #define SCREEN(x, a, b)   (255 - (x) * ((255 - (a)) * (255 - (b)) / 255))
 #define BURN(a, b)        (((a) == 0) ? (a) : FFMAX(0, 255 - ((255 - (b)) << 8) / (a)))
 #define DODGE(a, b)       (((a) == 255) ? (a) : FFMIN(255, (((b) << 8) / (255 - (a)))))

 DEFINE_BLEND8(addition,   FFMIN(255, A + B))

 DEFINE_BLEND8(grainmerge, av_clip_uint8(A + B - 128))

 DEFINE_BLEND8(average,    (A + B) / 2)
 DEFINE_BLEND8(subtract,   FFMAX(0, A - B))
 DEFINE_BLEND8(multiply,   MULTIPLY(1, A, B))

 DEFINE_BLEND8(multiply128,av_clip_uint8((A - 128) * B / 32. + 128))

 DEFINE_BLEND8(negation,   255 - FFABS(255 - A - B))

 DEFINE_BLEND8(extremity,  FFABS(255 - A - B))

 DEFINE_BLEND8(difference, FFABS(A - B))

 DEFINE_BLEND8(grainextract, av_clip_uint8(128 + A - B))

 DEFINE_BLEND8(screen,     SCREEN(1, A, B))
 DEFINE_BLEND8(overlay,    (A < 128) ? MULTIPLY(2, A, B) : SCREEN(2, A, B))
 DEFINE_BLEND8(hardlight,  (B < 128) ? MULTIPLY(2, B, A) : SCREEN(2, B, A))
 DEFINE_BLEND8(hardmix,    (A < (255 - B)) ? 0: 255)

 DEFINE_BLEND8(heat,       (A == 0) ? 0 : 255 - FFMIN(((255 - B) * (255 - B)) / A, 255))
 DEFINE_BLEND8(freeze,     (B == 0) ? 0 : 255 - FFMIN(((255 - A) * (255 - A)) / B, 255))

 DEFINE_BLEND8(darken,     FFMIN(A, B))
 DEFINE_BLEND8(lighten,    FFMAX(A, B))

 DEFINE_BLEND8(divide,     av_clip_uint8(B == 0 ? 255 : 255 * A / B))

 DEFINE_BLEND8(dodge,      DODGE(A, B))
 DEFINE_BLEND8(burn,       BURN(A, B))

 DEFINE_BLEND8(softlight,  (A > 127) ? B + (255 - B) * (A - 127.5) / 127.5 * (0.5 - fabs(B - 127.5) / 255): B - B * ((127.5 - A) / 127.5) * (0.5 - fabs(B - 127.5)/255))

 DEFINE_BLEND8(exclusion,  A + B - 2 * A * B / 255)
 DEFINE_BLEND8(pinlight,   (B < 128) ? FFMIN(A, 2 * B) : FFMAX(A, 2 * (B - 128)))
 DEFINE_BLEND8(phoenix,    FFMIN(A, B) - FFMAX(A, B) + 255)
 DEFINE_BLEND8(reflect,    (B == 255) ? B : FFMIN(255, (A * A / (255 - B))))
 DEFINE_BLEND8(glow,       (A == 255) ? A : FFMIN(255, (B * B / (255 - A))))
 DEFINE_BLEND8(and,        A & B)
 DEFINE_BLEND8(or,         A | B)
 DEFINE_BLEND8(xor,        A ^ B)
 DEFINE_BLEND8(vividlight, (A < 128) ? BURN(2 * A, B) : DODGE(2 * (A - 128), B))
 DEFINE_BLEND8(linearlight,av_clip_uint8((B < 128) ? B + 2 * A - 255 : B + 2 * (A - 128)))
 
 #undef MULTIPLY
 #undef SCREEN
 #undef BURN
 #undef DODGE
 
 #define MULTIPLY(x, a, b) ((x) * (((a) * (b)) / 65535))
 #define SCREEN(x, a, b)   (65535 - (x) * ((65535 - (a)) * (65535 - (b)) / 65535))
 #define BURN(a, b)        (((a) == 0) ? (a) : FFMAX(0, 65535 - ((65535 - (b)) << 16) / (a)))
 #define DODGE(a, b)       (((a) == 65535) ? (a) : FFMIN(65535, (((b) << 16) / (65535 - (a)))))
 
 DEFINE_BLEND16(addition,   FFMIN(65535, A + B))

 DEFINE_BLEND16(grainmerge, av_clip_uint16(A + B - 32768))

 DEFINE_BLEND16(average,    (A + B) / 2)
 DEFINE_BLEND16(subtract,   FFMAX(0, A - B))
 DEFINE_BLEND16(multiply,   MULTIPLY(1, A, B))

 DEFINE_BLEND16(multiply128, av_clip_uint16((A - 32768) * B / 8192. + 32768))

 DEFINE_BLEND16(negation,   65535 - FFABS(65535 - A - B))

 DEFINE_BLEND16(extremity,  FFABS(65535 - A - B))

 DEFINE_BLEND16(difference, FFABS(A - B))

 DEFINE_BLEND16(grainextract, av_clip_uint16(32768 + A - B))

 DEFINE_BLEND16(screen,     SCREEN(1, A, B))
 DEFINE_BLEND16(overlay,    (A < 32768) ? MULTIPLY(2, A, B) : SCREEN(2, A, B))
 DEFINE_BLEND16(hardlight,  (B < 32768) ? MULTIPLY(2, B, A) : SCREEN(2, B, A))
 DEFINE_BLEND16(hardmix,    (A < (65535 - B)) ? 0: 65535)

 DEFINE_BLEND16(heat,       (A == 0) ? 0 : 65535 - FFMIN(((65535 - B) * (65535 - B)) / A, 65535))
 DEFINE_BLEND16(freeze,     (B == 0) ? 0 : 65535 - FFMIN(((65535 - A) * (65535 - A)) / B, 65535))

 DEFINE_BLEND16(darken,     FFMIN(A, B))
 DEFINE_BLEND16(lighten,    FFMAX(A, B))

 DEFINE_BLEND16(divide,     av_clip_uint16(B == 0 ? 65535 : 65535 * A / B))

 DEFINE_BLEND16(dodge,      DODGE(A, B))
 DEFINE_BLEND16(burn,       BURN(A, B))

 DEFINE_BLEND16(softlight,  (A > 32767) ? B + (65535 - B) * (A - 32767.5) / 32767.5 * (0.5 - fabs(B - 32767.5) / 65535): B - B * ((32767.5 - A) / 32767.5) * (0.5 - fabs(B - 32767.5)/65535))

 DEFINE_BLEND16(exclusion,  A + B - 2 * A * B / 65535)
 DEFINE_BLEND16(pinlight,   (B < 32768) ? FFMIN(A, 2 * B) : FFMAX(A, 2 * (B - 32768)))
 DEFINE_BLEND16(phoenix,    FFMIN(A, B) - FFMAX(A, B) + 65535)
 DEFINE_BLEND16(reflect,    (B == 65535) ? B : FFMIN(65535, (A * A / (65535 - B))))
 DEFINE_BLEND16(glow,       (A == 65535) ? A : FFMIN(65535, (B * B / (65535 - A))))
 DEFINE_BLEND16(and,        A & B)
 DEFINE_BLEND16(or,         A | B)
 DEFINE_BLEND16(xor,        A ^ B)
 DEFINE_BLEND16(vividlight, (A < 32768) ? BURN(2 * A, B) : DODGE(2 * (A - 32768), B))
 DEFINE_BLEND16(linearlight,av_clip_uint16((B < 32768) ? B + 2 * A - 65535 : B + 2 * (A - 32768)))
 
 #define DEFINE_BLEND_EXPR(type, name, div)                                     \

 static void blend_expr_## name(const uint8_t *_top, ptrdiff_t top_linesize,          \
                                const uint8_t *_bottom, ptrdiff_t bottom_linesize,    \
                                uint8_t *_dst, ptrdiff_t dst_linesize,                \

                                ptrdiff_t width, ptrdiff_t height,              \

                                FilterParams *param, double *values, int starty) \

 {                                                                              \
     const type *top = (type*)_top;                                             \
     const type *bottom = (type*)_bottom;                                       \
     type *dst = (type*)_dst;                                                   \
     AVExpr *e = param->e;                                                      \
     int y, x;                                                                  \
     dst_linesize /= div;                                                       \
     top_linesize /= div;                                                       \
     bottom_linesize /= div;                                                    \
                                                                                \

     for (y = 0; y < height; y++) {                                             \

         values[VAR_Y] = y + starty;                                            \

         for (x = 0; x < width; x++) {                                          \
             values[VAR_X]      = x;                                            \
             values[VAR_TOP]    = values[VAR_A] = top[x];                       \
             values[VAR_BOTTOM] = values[VAR_B] = bottom[x];                    \
             dst[x] = av_expr_eval(e, values, NULL);                            \
         }                                                                      \
         dst    += dst_linesize;                                                \
         top    += top_linesize;                                                \
         bottom += bottom_linesize;                                             \
     }                                                                          \

 }
 

 DEFINE_BLEND_EXPR(uint8_t, 8bit, 1)
 DEFINE_BLEND_EXPR(uint16_t, 16bit, 2)
 

 static int filter_slice(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
 {
     ThreadData *td = arg;
     int slice_start = (td->h *  jobnr   ) / nb_jobs;
     int slice_end   = (td->h * (jobnr+1)) / nb_jobs;

     int height      = slice_end - slice_start;

     const uint8_t *top    = td->top->data[td->plane];
     const uint8_t *bottom = td->bottom->data[td->plane];
     uint8_t *dst    = td->dst->data[td->plane];
     double values[VAR_VARS_NB];
 

     values[VAR_N]  = td->inlink->frame_count_out;

     values[VAR_T]  = td->dst->pts == AV_NOPTS_VALUE ? NAN : td->dst->pts * av_q2d(td->inlink->time_base);
     values[VAR_W]  = td->w;
     values[VAR_H]  = td->h;
     values[VAR_SW] = td->w / (double)td->dst->width;
     values[VAR_SH] = td->h / (double)td->dst->height;
 
     td->param->blend(top + slice_start * td->top->linesize[td->plane],
                      td->top->linesize[td->plane],
                      bottom + slice_start * td->bottom->linesize[td->plane],
                      td->bottom->linesize[td->plane],
                      dst + slice_start * td->dst->linesize[td->plane],
                      td->dst->linesize[td->plane],

                      td->w, height, td->param, &values[0], slice_start);

     return 0;
 }
 
 static AVFrame *blend_frame(AVFilterContext *ctx, AVFrame *top_buf,
                             const AVFrame *bottom_buf)
 {

     BlendContext *s = ctx->priv;

     AVFilterLink *inlink = ctx->inputs[0];
     AVFilterLink *outlink = ctx->outputs[0];
     AVFrame *dst_buf;
     int plane;
 
     dst_buf = ff_get_video_buffer(outlink, outlink->w, outlink->h);
     if (!dst_buf)
         return top_buf;
     av_frame_copy_props(dst_buf, top_buf);
 

     for (plane = 0; plane < s->nb_planes; plane++) {
         int hsub = plane == 1 || plane == 2 ? s->hsub : 0;
         int vsub = plane == 1 || plane == 2 ? s->vsub : 0;

         int outw = AV_CEIL_RSHIFT(dst_buf->width,  hsub);
         int outh = AV_CEIL_RSHIFT(dst_buf->height, vsub);

         FilterParams *param = &s->params[plane];

         ThreadData td = { .top = top_buf, .bottom = bottom_buf, .dst = dst_buf,
                           .w = outw, .h = outh, .param = param, .plane = plane,
                           .inlink = inlink };
 

         ctx->internal->execute(ctx, filter_slice, &td, NULL, FFMIN(outh, ff_filter_get_nb_threads(ctx)));

     }
 

     if (!s->tblend)

         av_frame_free(&top_buf);

 
     return dst_buf;
 }
 

 static int blend_frame_for_dualinput(FFFrameSync *fs)
 {
     AVFilterContext *ctx = fs->parent;
     AVFrame *top_buf, *bottom_buf, *dst_buf;
     int ret;
 

     ret = ff_framesync_dualinput_get(fs, &top_buf, &bottom_buf);

     if (ret < 0)
         return ret;
     if (!bottom_buf)
         return ff_filter_frame(ctx->outputs[0], top_buf);
     dst_buf = blend_frame(ctx, top_buf, bottom_buf);
     return ff_filter_frame(ctx->outputs[0], dst_buf);
 }
 

 static av_cold int init(AVFilterContext *ctx)

 {

     BlendContext *s = ctx->priv;

     s->tblend = !strcmp(ctx->filter->name, "tblend");

     s->fs.on_event = blend_frame_for_dualinput;

     return 0;
 }
 
 static int query_formats(AVFilterContext *ctx)
 {
     static const enum AVPixelFormat pix_fmts[] = {
         AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA420P,

         AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_YUVJ422P,AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ411P,
         AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P,

         AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRAP, AV_PIX_FMT_GRAY8,
         AV_PIX_FMT_YUV420P16, AV_PIX_FMT_YUV422P16, AV_PIX_FMT_YUV444P16,
         AV_PIX_FMT_YUVA420P16, AV_PIX_FMT_YUVA422P16, AV_PIX_FMT_YUVA444P16,

         AV_PIX_FMT_GBRP16, AV_PIX_FMT_GBRAP16, AV_PIX_FMT_GRAY16,

         AV_PIX_FMT_NONE

     };
 

     AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
     if (!fmts_list)
         return AVERROR(ENOMEM);
     return ff_set_common_formats(ctx, fmts_list);

 }
 

 static av_cold void uninit(AVFilterContext *ctx)
 {

     BlendContext *s = ctx->priv;

     int i;
 

     ff_framesync_uninit(&s->fs);

     av_frame_free(&s->prev_frame);

     for (i = 0; i < FF_ARRAY_ELEMS(s->params); i++)
         av_expr_free(s->params[i].e);

 }
 

 void ff_blend_init(FilterParams *param, int is_16bit)
 {
     switch (param->mode) {
     case BLEND_ADDITION:   param->blend = is_16bit ? blend_addition_16bit   : blend_addition_8bit;   break;

     case BLEND_GRAINMERGE: param->blend = is_16bit ? blend_grainmerge_16bit : blend_grainmerge_8bit; break;

     case BLEND_AND:        param->blend = is_16bit ? blend_and_16bit        : blend_and_8bit;        break;
     case BLEND_AVERAGE:    param->blend = is_16bit ? blend_average_16bit    : blend_average_8bit;    break;
     case BLEND_BURN:       param->blend = is_16bit ? blend_burn_16bit       : blend_burn_8bit;       break;
     case BLEND_DARKEN:     param->blend = is_16bit ? blend_darken_16bit     : blend_darken_8bit;     break;
     case BLEND_DIFFERENCE: param->blend = is_16bit ? blend_difference_16bit : blend_difference_8bit; break;

     case BLEND_GRAINEXTRACT: param->blend = is_16bit ? blend_grainextract_16bit: blend_grainextract_8bit; break;

     case BLEND_DIVIDE:     param->blend = is_16bit ? blend_divide_16bit     : blend_divide_8bit;     break;
     case BLEND_DODGE:      param->blend = is_16bit ? blend_dodge_16bit      : blend_dodge_8bit;      break;
     case BLEND_EXCLUSION:  param->blend = is_16bit ? blend_exclusion_16bit  : blend_exclusion_8bit;  break;

     case BLEND_EXTREMITY:  param->blend = is_16bit ? blend_extremity_16bit  : blend_extremity_8bit;  break;

     case BLEND_FREEZE:     param->blend = is_16bit ? blend_freeze_16bit     : blend_freeze_8bit;     break;

     case BLEND_GLOW:       param->blend = is_16bit ? blend_glow_16bit       : blend_glow_8bit;       break;
     case BLEND_HARDLIGHT:  param->blend = is_16bit ? blend_hardlight_16bit  : blend_hardlight_8bit;  break;
     case BLEND_HARDMIX:    param->blend = is_16bit ? blend_hardmix_16bit    : blend_hardmix_8bit;    break;

     case BLEND_HEAT:       param->blend = is_16bit ? blend_heat_16bit       : blend_heat_8bit;       break;

     case BLEND_LIGHTEN:    param->blend = is_16bit ? blend_lighten_16bit    : blend_lighten_8bit;    break;
     case BLEND_LINEARLIGHT:param->blend = is_16bit ? blend_linearlight_16bit: blend_linearlight_8bit;break;
     case BLEND_MULTIPLY:   param->blend = is_16bit ? blend_multiply_16bit   : blend_multiply_8bit;   break;
     case BLEND_MULTIPLY128:param->blend = is_16bit ? blend_multiply128_16bit: blend_multiply128_8bit;break;
     case BLEND_NEGATION:   param->blend = is_16bit ? blend_negation_16bit   : blend_negation_8bit;   break;
     case BLEND_NORMAL:     param->blend = param->opacity == 1 ? blend_copytop :
                                           param->opacity == 0 ? blend_copybottom :
                                           is_16bit ? blend_normal_16bit     : blend_normal_8bit;     break;
     case BLEND_OR:         param->blend = is_16bit ? blend_or_16bit         : blend_or_8bit;         break;
     case BLEND_OVERLAY:    param->blend = is_16bit ? blend_overlay_16bit    : blend_overlay_8bit;    break;
     case BLEND_PHOENIX:    param->blend = is_16bit ? blend_phoenix_16bit    : blend_phoenix_8bit;    break;
     case BLEND_PINLIGHT:   param->blend = is_16bit ? blend_pinlight_16bit   : blend_pinlight_8bit;   break;
     case BLEND_REFLECT:    param->blend = is_16bit ? blend_reflect_16bit    : blend_reflect_8bit;    break;
     case BLEND_SCREEN:     param->blend = is_16bit ? blend_screen_16bit     : blend_screen_8bit;     break;
     case BLEND_SOFTLIGHT:  param->blend = is_16bit ? blend_softlight_16bit  : blend_softlight_8bit;  break;
     case BLEND_SUBTRACT:   param->blend = is_16bit ? blend_subtract_16bit   : blend_subtract_8bit;   break;
     case BLEND_VIVIDLIGHT: param->blend = is_16bit ? blend_vividlight_16bit : blend_vividlight_8bit; break;
     case BLEND_XOR:        param->blend = is_16bit ? blend_xor_16bit        : blend_xor_8bit;        break;
     }
 
     if (param->opacity == 0 && param->mode != BLEND_NORMAL) {
         param->blend = blend_copytop;
     }
 
     if (ARCH_X86)
         ff_blend_init_x86(param, is_16bit);
 }
 

 static int config_output(AVFilterLink *outlink)
 {
     AVFilterContext *ctx = outlink->src;
     AVFilterLink *toplink = ctx->inputs[TOP];

     BlendContext *s = ctx->priv;

     const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(toplink->format);

     int ret, plane, is_16bit;

     if (!s->tblend) {

         AVFilterLink *bottomlink = ctx->inputs[BOTTOM];
 
         if (toplink->format != bottomlink->format) {
             av_log(ctx, AV_LOG_ERROR, "inputs must be of same pixel format\n");
             return AVERROR(EINVAL);
         }

         if (toplink->w != bottomlink->w || toplink->h != bottomlink->h) {

             av_log(ctx, AV_LOG_ERROR, "First input link %s parameters "

                    "(size %dx%d) do not match the corresponding "
                    "second input link %s parameters (size %dx%d)\n",

                    ctx->input_pads[TOP].name, toplink->w, toplink->h,

                    ctx->input_pads[BOTTOM].name, bottomlink->w, bottomlink->h);

             return AVERROR(EINVAL);
         }

     }
 
     outlink->w = toplink->w;

     outlink->h = toplink->h;

     outlink->time_base = toplink->time_base;
     outlink->sample_aspect_ratio = toplink->sample_aspect_ratio;
     outlink->frame_rate = toplink->frame_rate;
 

     s->hsub = pix_desc->log2_chroma_w;
     s->vsub = pix_desc->log2_chroma_h;

     is_16bit = pix_desc->comp[0].depth == 16;

     s->nb_planes = av_pix_fmt_count_planes(toplink->format);

     if (!s->tblend)

         if ((ret = ff_framesync_init_dualinput(&s->fs, ctx)) < 0)

             return ret;

     for (plane = 0; plane < FF_ARRAY_ELEMS(s->params); plane++) {
         FilterParams *param = &s->params[plane];

         if (s->all_mode >= 0)
             param->mode = s->all_mode;
         if (s->all_opacity < 1)
             param->opacity = s->all_opacity;

         ff_blend_init(param, is_16bit);

         if (s->all_expr && !param->expr_str) {
             param->expr_str = av_strdup(s->all_expr);

             if (!param->expr_str)
                 return AVERROR(ENOMEM);
         }
         if (param->expr_str) {
             ret = av_expr_parse(&param->e, param->expr_str, var_names,
                                 NULL, NULL, NULL, NULL, 0, ctx);
             if (ret < 0)
                 return ret;
             param->blend = is_16bit? blend_expr_16bit : blend_expr_8bit;
         }
     }
 

     return s->tblend ? 0 : ff_framesync_configure(&s->fs);

 }
 

 #if CONFIG_BLEND_FILTER
 

 static int activate(AVFilterContext *ctx)

 {

     BlendContext *s = ctx->priv;

     return ff_framesync_activate(&s->fs);

 }
 
 static const AVFilterPad blend_inputs[] = {
     {

         .name          = "top",
         .type          = AVMEDIA_TYPE_VIDEO,

     },{

         .name          = "bottom",
         .type          = AVMEDIA_TYPE_VIDEO,

     },
     { NULL }
 };
 
 static const AVFilterPad blend_outputs[] = {
     {
         .name          = "default",
         .type          = AVMEDIA_TYPE_VIDEO,
         .config_props  = config_output,
     },
     { NULL }
 };
 

 AVFilter ff_vf_blend = {

     .name          = "blend",
     .description   = NULL_IF_CONFIG_SMALL("Blend two video frames into each other."),

     .preinit       = blend_framesync_preinit,

     .init          = init,
     .uninit        = uninit,
     .priv_size     = sizeof(BlendContext),
     .query_formats = query_formats,

     .activate      = activate,

     .inputs        = blend_inputs,
     .outputs       = blend_outputs,
     .priv_class    = &blend_class,

     .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL | AVFILTER_FLAG_SLICE_THREADS,

 };

 #endif
 
 #if CONFIG_TBLEND_FILTER
 

 static int tblend_filter_frame(AVFilterLink *inlink, AVFrame *frame)
 {

     BlendContext *s = inlink->dst->priv;

     AVFilterLink *outlink = inlink->dst->outputs[0];
 

     if (s->prev_frame) {
         AVFrame *out = blend_frame(inlink->dst, frame, s->prev_frame);
         av_frame_free(&s->prev_frame);
         s->prev_frame = frame;

         return ff_filter_frame(outlink, out);
     }

     s->prev_frame = frame;

     return 0;
 }
 
 static const AVOption tblend_options[] = {
     COMMON_OPTIONS,
     { NULL }
 };
 
 AVFILTER_DEFINE_CLASS(tblend);
 
 static const AVFilterPad tblend_inputs[] = {
     {
         .name          = "default",
         .type          = AVMEDIA_TYPE_VIDEO,
         .filter_frame  = tblend_filter_frame,
     },
     { NULL }
 };
 
 static const AVFilterPad tblend_outputs[] = {
     {
         .name          = "default",
         .type          = AVMEDIA_TYPE_VIDEO,

         .config_props  = config_output,

     },
     { NULL }
 };
 
 AVFilter ff_vf_tblend = {
     .name          = "tblend",
     .description   = NULL_IF_CONFIG_SMALL("Blend successive frames."),
     .priv_size     = sizeof(BlendContext),

     .priv_class    = &tblend_class,

     .query_formats = query_formats,
     .init          = init,
     .uninit        = uninit,
     .inputs        = tblend_inputs,
     .outputs       = tblend_outputs,
     .flags         = AVFILTER_FLAG_SLICE_THREADS,
 };

 
 #endif