/*
  * Copyright (c) 2002 Jindrich Makovicka <makovick@gmail.com>
  * Copyright (c) 2011 Stefano Sabatini

  * Copyright (c) 2013, 2015 Jean Delvare <jdelvare@suse.com>

  *
  * 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
  * A very simple tv station logo remover

  * Originally imported from MPlayer libmpcodecs/vf_delogo.c,
  * the algorithm was later improved.

  */
 

 #include "libavutil/common.h"

 #include "libavutil/imgutils.h"
 #include "libavutil/opt.h"
 #include "libavutil/pixdesc.h"
 #include "avfilter.h"

 #include "formats.h"

 #include "internal.h"

 #include "video.h"

 
 /**

  * Apply a simple delogo algorithm to the image in src and put the
  * result in dst.

  *
  * The algorithm is only applied to the region specified by the logo
  * parameters.
  *
  * @param w      width of the input image
  * @param h      height of the input image
  * @param logo_x x coordinate of the top left corner of the logo region
  * @param logo_y y coordinate of the top left corner of the logo region
  * @param logo_w width of the logo
  * @param logo_h height of the logo
  * @param band   the size of the band around the processed area
  * @param show   show a rectangle around the processed area, useful for
  *               parameters tweaking
  * @param direct if non-zero perform in-place processing
  */
 static void apply_delogo(uint8_t *dst, int dst_linesize,
                          uint8_t *src, int src_linesize,

                          int w, int h, AVRational sar,

                          int logo_x, int logo_y, int logo_w, int logo_h,

                          unsigned int band, int show, int direct)

 {

     int x, y;

     uint64_t interp, weightl, weightr, weightt, weightb, weight;

     uint8_t *xdst, *xsrc;
 
     uint8_t *topleft, *botleft, *topright;

     unsigned int left_sample, right_sample;

     int xclipl, xclipr, yclipt, yclipb;
     int logo_x1, logo_x2, logo_y1, logo_y2;
 
     xclipl = FFMAX(-logo_x, 0);
     xclipr = FFMAX(logo_x+logo_w-w, 0);
     yclipt = FFMAX(-logo_y, 0);
     yclipb = FFMAX(logo_y+logo_h-h, 0);
 
     logo_x1 = logo_x + xclipl;

     logo_x2 = logo_x + logo_w - xclipr - 1;

     logo_y1 = logo_y + yclipt;

     logo_y2 = logo_y + logo_h - yclipb - 1;

     topleft  = src+logo_y1 * src_linesize+logo_x1;
     topright = src+logo_y1 * src_linesize+logo_x2;
     botleft  = src+logo_y2 * src_linesize+logo_x1;

 
     if (!direct)
         av_image_copy_plane(dst, dst_linesize, src, src_linesize, w, h);
 

     dst += (logo_y1 + 1) * dst_linesize;
     src += (logo_y1 + 1) * src_linesize;

     for (y = logo_y1+1; y < logo_y2; y++) {

         left_sample = topleft[src_linesize*(y-logo_y1)]   +
                       topleft[src_linesize*(y-logo_y1-1)] +
                       topleft[src_linesize*(y-logo_y1+1)];
         right_sample = topright[src_linesize*(y-logo_y1)]   +
                        topright[src_linesize*(y-logo_y1-1)] +
                        topright[src_linesize*(y-logo_y1+1)];
 

         for (x = logo_x1+1,
              xdst = dst+logo_x1+1,

              xsrc = src+logo_x1+1; x < logo_x2; x++, xdst++, xsrc++) {

             if (show && (y == logo_y1+1 || y == logo_y2-1 ||
                          x == logo_x1+1 || x == logo_x2-1)) {

                 *xdst = 0;
                 continue;
             }
 

             /* Weighted interpolation based on relative distances, taking SAR into account */

             weightl = (uint64_t)              (logo_x2-x) * (y-logo_y1) * (logo_y2-y) * sar.den;
             weightr = (uint64_t)(x-logo_x1)               * (y-logo_y1) * (logo_y2-y) * sar.den;
             weightt = (uint64_t)(x-logo_x1) * (logo_x2-x)               * (logo_y2-y) * sar.num;
             weightb = (uint64_t)(x-logo_x1) * (logo_x2-x) * (y-logo_y1)               * sar.num;

             interp =

                 left_sample * weightl

                 +

                 right_sample * weightr

                 +

                 (topleft[x-logo_x1]    +
                  topleft[x-logo_x1-1]  +
                  topleft[x-logo_x1+1]) * weightt

                 +

                 (botleft[x-logo_x1]    +
                  botleft[x-logo_x1-1]  +
                  botleft[x-logo_x1+1]) * weightb;

             weight = (weightl + weightr + weightt + weightb) * 3U;
             interp = ROUNDED_DIV(interp, weight);

 
             if (y >= logo_y+band && y < logo_y+logo_h-band &&
                 x >= logo_x+band && x < logo_x+logo_w-band) {
                 *xdst = interp;
             } else {

                 unsigned dist = 0;
 

                 if      (x < logo_x+band)
                     dist = FFMAX(dist, logo_x-x+band);
                 else if (x >= logo_x+logo_w-band)
                     dist = FFMAX(dist, x-(logo_x+logo_w-1-band));
 
                 if      (y < logo_y+band)
                     dist = FFMAX(dist, logo_y-y+band);
                 else if (y >= logo_y+logo_h-band)
                     dist = FFMAX(dist, y-(logo_y+logo_h-1-band));
 
                 *xdst = (*xsrc*dist + interp*(band-dist))/band;
             }
         }
 
         dst += dst_linesize;
         src += src_linesize;
     }
 }
 

 typedef struct DelogoContext {

     const AVClass *class;
     int x, y, w, h, band, show;
 }  DelogoContext;
 
 #define OFFSET(x) offsetof(DelogoContext, x)

 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM

 
 static const AVOption delogo_options[]= {

     { "x",    "set logo x position",       OFFSET(x),    AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, FLAGS },
     { "y",    "set logo y position",       OFFSET(y),    AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, FLAGS },
     { "w",    "set logo width",            OFFSET(w),    AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, FLAGS },
     { "h",    "set logo height",           OFFSET(h),    AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, FLAGS },

 #if LIBAVFILTER_VERSION_MAJOR < 7
     /* Actual default value for band/t is 1, set in init */
     { "band", "set delogo area band size", OFFSET(band), AV_OPT_TYPE_INT, { .i64 =  0 },  0, INT_MAX, FLAGS },
     { "t",    "set delogo area band size", OFFSET(band), AV_OPT_TYPE_INT, { .i64 =  0 },  0, INT_MAX, FLAGS },
 #endif

     { "show", "show delogo area",          OFFSET(show), AV_OPT_TYPE_BOOL,{ .i64 =  0 },  0, 1,       FLAGS },

     { NULL }

 };
 

 AVFILTER_DEFINE_CLASS(delogo);

 
 static int query_formats(AVFilterContext *ctx)
 {

     static const enum AVPixelFormat pix_fmts[] = {

         AV_PIX_FMT_YUV444P,  AV_PIX_FMT_YUV422P,  AV_PIX_FMT_YUV420P,
         AV_PIX_FMT_YUV411P,  AV_PIX_FMT_YUV410P,  AV_PIX_FMT_YUV440P,
         AV_PIX_FMT_YUVA420P, AV_PIX_FMT_GRAY8,
         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 int init(AVFilterContext *ctx)

 {

     DelogoContext *s = ctx->priv;

 
 #define CHECK_UNSET_OPT(opt)                                            \

     if (s->opt == -1) {                                            \
         av_log(s, AV_LOG_ERROR, "Option %s was not set.\n", #opt); \

         return AVERROR(EINVAL);                                         \
     }
     CHECK_UNSET_OPT(x);
     CHECK_UNSET_OPT(y);
     CHECK_UNSET_OPT(w);
     CHECK_UNSET_OPT(h);
 

 #if LIBAVFILTER_VERSION_MAJOR < 7
     if (s->band == 0) { /* Unset, use default */
         av_log(ctx, AV_LOG_WARNING, "Note: default band value was changed from 4 to 1.\n");
         s->band = 1;
     } else if (s->band != 1) {
         av_log(ctx, AV_LOG_WARNING, "Option band is deprecated.\n");
     }
 #else
     s->band = 1;
 #endif

     av_log(ctx, AV_LOG_VERBOSE, "x:%d y:%d, w:%d h:%d band:%d show:%d\n",

            s->x, s->y, s->w, s->h, s->band, s->show);

     s->w += s->band*2;
     s->h += s->band*2;
     s->x -= s->band;
     s->y -= s->band;

 
     return 0;
 }
 

 static int config_input(AVFilterLink *inlink)
 {
     DelogoContext *s = inlink->dst->priv;
 
     /* Check whether the logo area fits in the frame */
     if (s->x + (s->band - 1) < 0 || s->x + s->w - (s->band*2 - 2) > inlink->w ||
         s->y + (s->band - 1) < 0 || s->y + s->h - (s->band*2 - 2) > inlink->h) {
         av_log(s, AV_LOG_ERROR, "Logo area is outside of the frame.\n");
         return AVERROR(EINVAL);
     }
 
     return 0;
 }
 

 static int filter_frame(AVFilterLink *inlink, AVFrame *in)

 {

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

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

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

     AVFrame *out;

     int hsub0 = desc->log2_chroma_w;
     int vsub0 = desc->log2_chroma_h;

     int direct = 0;

     int plane;

     AVRational sar;

     if (av_frame_is_writable(in)) {

         direct = 1;
         out = in;
     } else {

         out = ff_get_video_buffer(outlink, outlink->w, outlink->h);

         if (!out) {

             av_frame_free(&in);

             return AVERROR(ENOMEM);
         }

         av_frame_copy_props(out, in);

     }
 

     sar = in->sample_aspect_ratio;
     /* Assume square pixels if SAR is unknown */
     if (!sar.num)
         sar.num = sar.den = 1;
 

     for (plane = 0; plane < desc->nb_components; plane++) {

         int hsub = plane == 1 || plane == 2 ? hsub0 : 0;
         int vsub = plane == 1 || plane == 2 ? vsub0 : 0;
 

         apply_delogo(out->data[plane], out->linesize[plane],
                      in ->data[plane], in ->linesize[plane],

                      AV_CEIL_RSHIFT(inlink->w, hsub),
                      AV_CEIL_RSHIFT(inlink->h, vsub),

                      sar, s->x>>hsub, s->y>>vsub,

                      /* Up and left borders were rounded down, inject lost bits
                       * into width and height to avoid error accumulation */

                      AV_CEIL_RSHIFT(s->w + (s->x & ((1<<hsub)-1)), hsub),
                      AV_CEIL_RSHIFT(s->h + (s->y & ((1<<vsub)-1)), vsub),

                      s->band>>FFMIN(hsub, vsub),
                      s->show, direct);

     }
 

     if (!direct)

         av_frame_free(&in);

 
     return ff_filter_frame(outlink, out);

 }
 

 static const AVFilterPad avfilter_vf_delogo_inputs[] = {
     {

         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,
         .filter_frame = filter_frame,

         .config_props = config_input,

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

 AVFilter ff_vf_delogo = {

     .name          = "delogo",
     .description   = NULL_IF_CONFIG_SMALL("Remove logo from input video."),
     .priv_size     = sizeof(DelogoContext),

     .priv_class    = &delogo_class,

     .init          = init,
     .query_formats = query_formats,

     .inputs        = avfilter_vf_delogo_inputs,
     .outputs       = avfilter_vf_delogo_outputs,
     .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,

 };