/*
  * Copyright (c) 2002 Michael Niedermayer <michaelni@gmx.at>
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 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 General Public License for more details.
  *
  * You should have received a copy of the GNU 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.
  */
 
 /**
  * @file
  * Shape Adaptive Blur filter, ported from MPlayer libmpcodecs/vf_sab.c
  */
 
 #include "libavutil/opt.h"
 #include "libavutil/pixdesc.h"
 #include "libswscale/swscale.h"
 
 #include "avfilter.h"
 #include "formats.h"
 #include "internal.h"
 

 typedef struct FilterParam {

     float radius;
     float pre_filter_radius;
     float strength;
     float quality;
     struct SwsContext *pre_filter_context;
     uint8_t *pre_filter_buf;
     int pre_filter_linesize;
     int dist_width;
     int dist_linesize;
     int *dist_coeff;
 #define COLOR_DIFF_COEFF_SIZE 512
     int color_diff_coeff[COLOR_DIFF_COEFF_SIZE];
 } FilterParam;
 

 typedef struct SabContext {

     const AVClass *class;
     FilterParam  luma;
     FilterParam  chroma;
     int          hsub;
     int          vsub;
     unsigned int sws_flags;
 } SabContext;
 
 static int query_formats(AVFilterContext *ctx)
 {
     static const enum AVPixelFormat pix_fmts[] = {
         AV_PIX_FMT_YUV420P,
         AV_PIX_FMT_YUV410P,
         AV_PIX_FMT_YUV444P,
         AV_PIX_FMT_YUV422P,
         AV_PIX_FMT_YUV411P,
         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);

 }
 
 #define RADIUS_MIN 0.1
 #define RADIUS_MAX 4.0
 
 #define PRE_FILTER_RADIUS_MIN 0.1
 #define PRE_FILTER_RADIUS_MAX 2.0
 
 #define STRENGTH_MIN 0.1
 #define STRENGTH_MAX 100.0
 
 #define OFFSET(x) offsetof(SabContext, x)
 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
 
 static const AVOption sab_options[] = {
     { "luma_radius",            "set luma radius", OFFSET(luma.radius), AV_OPT_TYPE_FLOAT, {.dbl=1.0}, RADIUS_MIN, RADIUS_MAX, .flags=FLAGS },
     { "lr"         ,            "set luma radius", OFFSET(luma.radius), AV_OPT_TYPE_FLOAT, {.dbl=1.0}, RADIUS_MIN, RADIUS_MAX, .flags=FLAGS },
     { "luma_pre_filter_radius", "set luma pre-filter radius", OFFSET(luma.pre_filter_radius), AV_OPT_TYPE_FLOAT, {.dbl=1.0}, PRE_FILTER_RADIUS_MIN, PRE_FILTER_RADIUS_MAX, .flags=FLAGS },
     { "lpfr",                   "set luma pre-filter radius", OFFSET(luma.pre_filter_radius), AV_OPT_TYPE_FLOAT, {.dbl=1.0}, PRE_FILTER_RADIUS_MIN, PRE_FILTER_RADIUS_MAX, .flags=FLAGS },
     { "luma_strength",          "set luma strength", OFFSET(luma.strength), AV_OPT_TYPE_FLOAT, {.dbl=1.0}, STRENGTH_MIN, STRENGTH_MAX, .flags=FLAGS },
     { "ls",                     "set luma strength", OFFSET(luma.strength), AV_OPT_TYPE_FLOAT, {.dbl=1.0}, STRENGTH_MIN, STRENGTH_MAX, .flags=FLAGS },
 
     { "chroma_radius",            "set chroma radius", OFFSET(chroma.radius), AV_OPT_TYPE_FLOAT, {.dbl=RADIUS_MIN-1}, RADIUS_MIN-1, RADIUS_MAX, .flags=FLAGS },
     { "cr",                       "set chroma radius", OFFSET(chroma.radius), AV_OPT_TYPE_FLOAT, {.dbl=RADIUS_MIN-1}, RADIUS_MIN-1, RADIUS_MAX, .flags=FLAGS },
     { "chroma_pre_filter_radius", "set chroma pre-filter radius",  OFFSET(chroma.pre_filter_radius), AV_OPT_TYPE_FLOAT, {.dbl=PRE_FILTER_RADIUS_MIN-1},
                                   PRE_FILTER_RADIUS_MIN-1, PRE_FILTER_RADIUS_MAX, .flags=FLAGS },
     { "cpfr",                     "set chroma pre-filter radius",  OFFSET(chroma.pre_filter_radius), AV_OPT_TYPE_FLOAT, {.dbl=PRE_FILTER_RADIUS_MIN-1},
                                   PRE_FILTER_RADIUS_MIN-1, PRE_FILTER_RADIUS_MAX, .flags=FLAGS },
     { "chroma_strength",          "set chroma strength", OFFSET(chroma.strength), AV_OPT_TYPE_FLOAT, {.dbl=STRENGTH_MIN-1}, STRENGTH_MIN-1, STRENGTH_MAX, .flags=FLAGS },
     { "cs",                       "set chroma strength", OFFSET(chroma.strength), AV_OPT_TYPE_FLOAT, {.dbl=STRENGTH_MIN-1}, STRENGTH_MIN-1, STRENGTH_MAX, .flags=FLAGS },
 
     { NULL }
 };
 
 AVFILTER_DEFINE_CLASS(sab);
 
 static av_cold int init(AVFilterContext *ctx)
 {

     SabContext *s = ctx->priv;

 
     /* make chroma default to luma values, if not explicitly set */

     if (s->chroma.radius < RADIUS_MIN)
         s->chroma.radius = s->luma.radius;
     if (s->chroma.pre_filter_radius < PRE_FILTER_RADIUS_MIN)
         s->chroma.pre_filter_radius = s->luma.pre_filter_radius;
     if (s->chroma.strength < STRENGTH_MIN)
         s->chroma.strength = s->luma.strength;

     s->luma.quality = s->chroma.quality = 3.0;
     s->sws_flags = SWS_POINT;

 
     av_log(ctx, AV_LOG_VERBOSE,
            "luma_radius:%f luma_pre_filter_radius::%f luma_strength:%f "
            "chroma_radius:%f chroma_pre_filter_radius:%f chroma_strength:%f\n",

            s->luma  .radius, s->luma  .pre_filter_radius, s->luma  .strength,
            s->chroma.radius, s->chroma.pre_filter_radius, s->chroma.strength);

     return 0;
 }
 
 static void close_filter_param(FilterParam *f)
 {
     if (f->pre_filter_context) {
         sws_freeContext(f->pre_filter_context);
         f->pre_filter_context = NULL;
     }
     av_freep(&f->pre_filter_buf);
     av_freep(&f->dist_coeff);
 }
 
 static av_cold void uninit(AVFilterContext *ctx)
 {

     SabContext *s = ctx->priv;

     close_filter_param(&s->luma);
     close_filter_param(&s->chroma);

 }
 
 static int open_filter_param(FilterParam *f, int width, int height, unsigned int sws_flags)
 {
     SwsVector *vec;
     SwsFilter sws_f;
     int i, x, y;
     int linesize = FFALIGN(width, 8);
 
     f->pre_filter_buf = av_malloc(linesize * height);
     if (!f->pre_filter_buf)
         return AVERROR(ENOMEM);
 
     f->pre_filter_linesize = linesize;
     vec = sws_getGaussianVec(f->pre_filter_radius, f->quality);
     sws_f.lumH = sws_f.lumV = vec;
     sws_f.chrH = sws_f.chrV = NULL;
     f->pre_filter_context = sws_getContext(width, height, AV_PIX_FMT_GRAY8,
                                            width, height, AV_PIX_FMT_GRAY8,
                                            sws_flags, &sws_f, NULL, NULL);
     sws_freeVec(vec);
 
     vec = sws_getGaussianVec(f->strength, 5.0);
     for (i = 0; i < COLOR_DIFF_COEFF_SIZE; i++) {
         double d;
         int index = i-COLOR_DIFF_COEFF_SIZE/2 + vec->length/2;
 
         if (index < 0 || index >= vec->length) d = 0.0;
         else                                   d = vec->coeff[index];
 
         f->color_diff_coeff[i] = (int)(d/vec->coeff[vec->length/2]*(1<<12) + 0.5);
     }
     sws_freeVec(vec);
 
     vec = sws_getGaussianVec(f->radius, f->quality);
     f->dist_width    = vec->length;
     f->dist_linesize = FFALIGN(vec->length, 8);

     f->dist_coeff    = av_malloc_array(f->dist_width, f->dist_linesize * sizeof(*f->dist_coeff));

     if (!f->dist_coeff) {
         sws_freeVec(vec);

         return AVERROR(ENOMEM);

     }

 
     for (y = 0; y < vec->length; y++) {
         for (x = 0; x < vec->length; x++) {
             double d = vec->coeff[x] * vec->coeff[y];
             f->dist_coeff[x + y*f->dist_linesize] = (int)(d*(1<<10) + 0.5);
         }
     }
     sws_freeVec(vec);
 
     return 0;
 }
 
 static int config_props(AVFilterLink *inlink)
 {

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

     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
     int ret;
 

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

     close_filter_param(&s->luma);
     ret = open_filter_param(&s->luma, inlink->w, inlink->h, s->sws_flags);

     if (ret < 0)
         return ret;
 

     close_filter_param(&s->chroma);
     ret = open_filter_param(&s->chroma,

                             AV_CEIL_RSHIFT(inlink->w, s->hsub),
                             AV_CEIL_RSHIFT(inlink->h, s->vsub), s->sws_flags);

     return ret;
 }
 
 #define NB_PLANES 4
 
 static void blur(uint8_t       *dst, const int dst_linesize,
                  const uint8_t *src, const int src_linesize,
                  const int w, const int h, FilterParam *fp)
 {
     int x, y;
     FilterParam f = *fp;
     const int radius = f.dist_width/2;
 
     const uint8_t * const src2[NB_PLANES] = { src };
     int          src2_linesize[NB_PLANES] = { src_linesize };
     uint8_t     *dst2[NB_PLANES] = { f.pre_filter_buf };
     int dst2_linesize[NB_PLANES] = { f.pre_filter_linesize };
 
     sws_scale(f.pre_filter_context, src2, src2_linesize, 0, h, dst2, dst2_linesize);
 
 #define UPDATE_FACTOR do {                                              \
         int factor;                                                     \
         factor = f.color_diff_coeff[COLOR_DIFF_COEFF_SIZE/2 + pre_val - \
                  f.pre_filter_buf[ix + iy*f.pre_filter_linesize]] * f.dist_coeff[dx + dy*f.dist_linesize]; \
         sum += src[ix + iy*src_linesize] * factor;                      \
         div += factor;                                                  \
     } while (0)
 
     for (y = 0; y < h; y++) {
         for (x = 0; x < w; x++) {
             int sum = 0;
             int div = 0;
             int dy;
             const int pre_val = f.pre_filter_buf[x + y*f.pre_filter_linesize];
             if (x >= radius && x < w - radius) {
                 for (dy = 0; dy < radius*2 + 1; dy++) {
                     int dx;
                     int iy = y+dy - radius;

                     iy = avpriv_mirror(iy, h-1);

 
                     for (dx = 0; dx < radius*2 + 1; dx++) {
                         const int ix = x+dx - radius;
                         UPDATE_FACTOR;
                     }
                 }
             } else {
                 for (dy = 0; dy < radius*2+1; dy++) {
                     int dx;
                     int iy = y+dy - radius;

                     iy = avpriv_mirror(iy, h-1);

 
                     for (dx = 0; dx < radius*2 + 1; dx++) {
                         int ix = x+dx - radius;

                         ix = avpriv_mirror(ix, w-1);

                         UPDATE_FACTOR;
                     }
                 }
             }
             dst[x + y*dst_linesize] = (sum + div/2) / div;
         }
     }
 }
 
 static int filter_frame(AVFilterLink *inlink, AVFrame *inpic)
 {

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

     AVFilterLink *outlink = inlink->dst->outputs[0];
     AVFrame *outpic;
 
     outpic = ff_get_video_buffer(outlink, outlink->w, outlink->h);
     if (!outpic) {
         av_frame_free(&inpic);
         return AVERROR(ENOMEM);
     }
     av_frame_copy_props(outpic, inpic);
 
     blur(outpic->data[0], outpic->linesize[0], inpic->data[0],  inpic->linesize[0],

          inlink->w, inlink->h, &s->luma);

     if (inpic->data[2]) {

         int cw = AV_CEIL_RSHIFT(inlink->w, s->hsub);
         int ch = AV_CEIL_RSHIFT(inlink->h, s->vsub);

         blur(outpic->data[1], outpic->linesize[1], inpic->data[1], inpic->linesize[1], cw, ch, &s->chroma);
         blur(outpic->data[2], outpic->linesize[2], inpic->data[2], inpic->linesize[2], cw, ch, &s->chroma);

     }
 
     av_frame_free(&inpic);
     return ff_filter_frame(outlink, outpic);
 }
 
 static const AVFilterPad sab_inputs[] = {
     {
         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,
         .filter_frame = filter_frame,
         .config_props = config_props,
     },
     { NULL }
 };
 
 static const AVFilterPad sab_outputs[] = {
     {
         .name = "default",
         .type = AVMEDIA_TYPE_VIDEO,
     },
     { NULL }
 };
 

 AVFilter ff_vf_sab = {

     .name          = "sab",
     .description   = NULL_IF_CONFIG_SMALL("Apply shape adaptive blur."),
     .priv_size     = sizeof(SabContext),
     .init          = init,
     .uninit        = uninit,
     .query_formats = query_formats,
     .inputs        = sab_inputs,
     .outputs       = sab_outputs,
     .priv_class    = &sab_class,
     .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
 };