/*
  * Copyright (c) 2002 Jindrich Makovicka <makovick@gmail.com>
  * Copyright (c) 2011 Stefano Sabatini
  *
  * 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
  * Ported from MPlayer libmpcodecs/vf_delogo.c.
  */
 
 #include "libavutil/imgutils.h"
 #include "libavutil/opt.h"
 #include "libavutil/pixdesc.h"
 #include "avfilter.h"
 
 /**
  * Apply a simple delogo algorithm to the image in dst and put the
  * result in src.
  *
  * 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,
                          int logo_x, int logo_y, int logo_w, int logo_h,
                          int band, int show, int direct)
 {
     int x, y;
     int interp, dist;
     uint8_t *xdst, *xsrc;
 
     uint8_t *topleft, *botleft, *topright;
     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;
     logo_y1 = logo_y + yclipt;
     logo_y2 = logo_y + logo_h - yclipb;
 
     topleft  = src+logo_y1     * src_linesize+logo_x1;
     topright = src+logo_y1     * src_linesize+logo_x2-1;
     botleft  = src+(logo_y2-1) * src_linesize+logo_x1;
 
     dst += (logo_y1+1)*dst_linesize;
     src += (logo_y1+1)*src_linesize;
 
     if (!direct)
         av_image_copy_plane(dst, dst_linesize, src, src_linesize, w, h);
 
     for (y = logo_y1+1; y < logo_y2-1; y++) {
         for (x = logo_x1+1,
              xdst = dst+logo_x1+1,
              xsrc = src+logo_x1+1; x < logo_x2-1; x++, xdst++, xsrc++) {
             interp =
                 (topleft[src_linesize*(y-logo_y  -yclipt)]   +
                  topleft[src_linesize*(y-logo_y-1-yclipt)]   +
                  topleft[src_linesize*(y-logo_y+1-yclipt)])  * (logo_w-(x-logo_x))/logo_w
                 +
                 (topright[src_linesize*(y-logo_y-yclipt)]    +
                  topright[src_linesize*(y-logo_y-1-yclipt)]  +
                  topright[src_linesize*(y-logo_y+1-yclipt)]) * (x-logo_x)/logo_w
                 +
                 (topleft[x-logo_x-xclipl]    +
                  topleft[x-logo_x-1-xclipl]  +
                  topleft[x-logo_x+1-xclipl]) * (logo_h-(y-logo_y))/logo_h
                 +
                 (botleft[x-logo_x-xclipl]    +
                  botleft[x-logo_x-1-xclipl]  +
                  botleft[x-logo_x+1-xclipl]) * (y-logo_y)/logo_h;
             interp /= 6;
 
             if (y >= logo_y+band && y < logo_y+logo_h-band &&
                 x >= logo_x+band && x < logo_x+logo_w-band) {
                 *xdst = interp;
             } else {
                 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;
                 if (show && (dist == band-1))
                     *xdst = 0;
             }
         }
 
         dst += dst_linesize;
         src += src_linesize;
     }
 }
 
 typedef struct {
     const AVClass *class;
     int x, y, w, h, band, show;
 }  DelogoContext;
 
 #define OFFSET(x) offsetof(DelogoContext, x)
 
 static const AVOption delogo_options[]= {

     {"x",    "set logo x position",       OFFSET(x),    AV_OPT_TYPE_INT, {.dbl=-1}, -1, INT_MAX },
     {"y",    "set logo y position",       OFFSET(y),    AV_OPT_TYPE_INT, {.dbl=-1}, -1, INT_MAX },
     {"w",    "set logo width",            OFFSET(w),    AV_OPT_TYPE_INT, {.dbl=-1}, -1, INT_MAX },
     {"h",    "set logo height",           OFFSET(h),    AV_OPT_TYPE_INT, {.dbl=-1}, -1, INT_MAX },
     {"band", "set delogo area band size", OFFSET(band), AV_OPT_TYPE_INT, {.dbl= 4}, -1, INT_MAX },
     {"t",    "set delogo area band size", OFFSET(band), AV_OPT_TYPE_INT, {.dbl= 4}, -1, INT_MAX },
     {"show", "show delogo area",          OFFSET(show), AV_OPT_TYPE_INT, {.dbl= 0},  0, 1       },

     {NULL},
 };
 
 static const char *delogo_get_name(void *ctx)
 {
     return "delogo";
 }
 
 static const AVClass delogo_class = {

     .class_name = "DelogoContext",
     .item_name  = delogo_get_name,
     .option     = delogo_options,

 };
 
 static int query_formats(AVFilterContext *ctx)
 {
     enum PixelFormat pix_fmts[] = {
         PIX_FMT_YUV444P,  PIX_FMT_YUV422P,  PIX_FMT_YUV420P,
         PIX_FMT_YUV411P,  PIX_FMT_YUV410P,  PIX_FMT_YUV440P,
         PIX_FMT_YUVA420P, PIX_FMT_GRAY8,
         PIX_FMT_NONE
     };
 
     avfilter_set_common_pixel_formats(ctx, avfilter_make_format_list(pix_fmts));
     return 0;
 }
 
 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
 {
     DelogoContext *delogo = ctx->priv;
     int ret = 0;
 
     delogo->class = &delogo_class;

     av_opt_set_defaults(delogo);

 
     if (args)
         ret = sscanf(args, "%d:%d:%d:%d:%d",
                      &delogo->x, &delogo->y, &delogo->w, &delogo->h, &delogo->band);
     if (ret == 5) {
         if (delogo->band < 0)
             delogo->show = 1;
     } else if ((ret = (av_set_options_string(delogo, args, "=", ":"))) < 0) {
         av_log(ctx, AV_LOG_ERROR, "Error parsing options string: '%s'\n", args);
         return ret;
     }
 
 #define CHECK_UNSET_OPT(opt)                                            \
     if (delogo->opt == -1) {                                            \
         av_log(delogo, 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 (delogo->show)
         delogo->band = 4;
 
     av_log(ctx, AV_LOG_INFO, "x:%d y:%d, w:%d h:%d band:%d show:%d\n",
            delogo->x, delogo->y, delogo->w, delogo->h, delogo->band, delogo->show);
 
     delogo->w += delogo->band*2;
     delogo->h += delogo->band*2;
     delogo->x -= delogo->band;
     delogo->y -= delogo->band;
 
     return 0;
 }
 
 static void start_frame(AVFilterLink *inlink, AVFilterBufferRef *inpicref)
 {
     AVFilterLink *outlink = inlink->dst->outputs[0];
     AVFilterBufferRef *outpicref;
 
     if (inpicref->perms & AV_PERM_PRESERVE) {
         outpicref = avfilter_get_video_buffer(outlink, AV_PERM_WRITE,
                                               outlink->w, outlink->h);
         avfilter_copy_buffer_ref_props(outpicref, inpicref);
         outpicref->video->w = outlink->w;
         outpicref->video->h = outlink->h;
     } else
         outpicref = inpicref;
 
     outlink->out_buf = outpicref;
     avfilter_start_frame(outlink, avfilter_ref_buffer(outpicref, ~0));
 }
 
 static void null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir) { }
 
 static void end_frame(AVFilterLink *inlink)
 {
     DelogoContext *delogo = inlink->dst->priv;
     AVFilterLink *outlink = inlink->dst->outputs[0];
     AVFilterBufferRef *inpicref  = inlink ->cur_buf;
     AVFilterBufferRef *outpicref = outlink->out_buf;
     int direct = inpicref == outpicref;
     int hsub0 = av_pix_fmt_descriptors[inlink->format].log2_chroma_w;
     int vsub0 = av_pix_fmt_descriptors[inlink->format].log2_chroma_h;
     int plane;
 
     for (plane = 0; plane < 4 && inpicref->data[plane]; plane++) {
         int hsub = plane == 1 || plane == 2 ? hsub0 : 0;
         int vsub = plane == 1 || plane == 2 ? vsub0 : 0;
 
         apply_delogo(outpicref->data[plane], outpicref->linesize[plane],
                      inpicref ->data[plane], inpicref ->linesize[plane],
                      inlink->w>>hsub, inlink->h>>vsub,
                      delogo->x>>hsub, delogo->y>>vsub,
                      delogo->w>>hsub, delogo->h>>vsub,
                      delogo->band>>FFMIN(hsub, vsub),
                      delogo->show, direct);
     }
 
     avfilter_draw_slice(outlink, 0, inlink->h, 1);
     avfilter_end_frame(outlink);
     avfilter_unref_buffer(inpicref);
     if (!direct)
         avfilter_unref_buffer(outpicref);
 }
 
 AVFilter avfilter_vf_delogo = {
     .name          = "delogo",
     .description   = NULL_IF_CONFIG_SMALL("Remove logo from input video."),
     .priv_size     = sizeof(DelogoContext),
     .init          = init,
     .query_formats = query_formats,
 

     .inputs    = (const AVFilterPad[]) {{ .name       = "default",

                                     .type             = AVMEDIA_TYPE_VIDEO,
                                     .get_video_buffer = avfilter_null_get_video_buffer,
                                     .start_frame      = start_frame,
                                     .draw_slice       = null_draw_slice,
                                     .end_frame        = end_frame,
                                     .min_perms        = AV_PERM_WRITE | AV_PERM_READ,
                                     .rej_perms        = AV_PERM_PRESERVE },
                                   { .name = NULL}},

     .outputs   = (const AVFilterPad[]) {{ .name       = "default",

                                     .type             = AVMEDIA_TYPE_VIDEO, },
                                   { .name = NULL}},

 };