/*
  * Copyright (c) 2014-2015 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.
  */
 
 /**
  * @todo switch to dualinput
  */
 
 #include "libavutil/avassert.h"
 #include "libavutil/imgutils.h"
 #include "libavutil/opt.h"
 #include "internal.h"
 
 #include "lavfutils.h"
 
 enum mode {
     MODE_COVER,
     MODE_BLUR,
     NB_MODES
 };
 
 typedef struct CoverContext {
     AVClass *class;
     int mode;
     char *cover_filename;
     AVFrame *cover_frame;
     int width, height;
 } CoverContext;
 
 #define OFFSET(x) offsetof(CoverContext, x)
 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
 static const AVOption cover_rect_options[] = {
     { "cover",  "cover bitmap filename",  OFFSET(cover_filename),  AV_OPT_TYPE_STRING, {.str = NULL}, .flags = FLAGS },
     { "mode", "set removal mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64 = MODE_BLUR}, 0, NB_MODES - 1, FLAGS, "mode" },
         { "cover", "cover area with bitmap", 0, AV_OPT_TYPE_CONST, {.i64 = MODE_COVER}, INT_MIN, INT_MAX, FLAGS, "mode" },
         { "blur", "blur area", 0, AV_OPT_TYPE_CONST, {.i64 = MODE_BLUR}, INT_MIN, INT_MAX, FLAGS, "mode" },
     { NULL }
 };
 

 AVFILTER_DEFINE_CLASS(cover_rect);

 
 static int query_formats(AVFilterContext *ctx)
 {
     static const enum AVPixelFormat pix_fmts[] = {
         AV_PIX_FMT_YUV420P,
         AV_PIX_FMT_YUVJ420P,
         AV_PIX_FMT_NONE
     };
 
     return ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
 }
 
 static int config_input(AVFilterLink *inlink)
 {
     return 0;
 }
 
 static void cover_rect(CoverContext *cover, AVFrame *in, int offx, int offy)
 {
     int x, y, p;
 
     for (p = 0; p < 3; p++) {
         uint8_t *data = in->data[p] + (offx>>!!p) + (offy>>!!p) * in->linesize[p];
         const uint8_t *src = cover->cover_frame->data[p];

         int w = AV_CEIL_RSHIFT(cover->cover_frame->width , !!p);
         int h = AV_CEIL_RSHIFT(cover->cover_frame->height, !!p);

         for (y = 0; y < h; y++) {
             for (x = 0; x < w; x++) {
                 data[x] = src[x];
             }
             data += in->linesize[p];
             src += cover->cover_frame->linesize[p];
         }
     }
 }
 static void blur(CoverContext *cover, AVFrame *in, int offx, int offy)
 {
     int x, y, p;
 
     for (p=0; p<3; p++) {
         int ox = offx>>!!p;
         int oy = offy>>!!p;
         int stride = in->linesize[p];
         uint8_t *data = in->data[p] + ox + oy * stride;

         int w = AV_CEIL_RSHIFT(cover->width , !!p);
         int h = AV_CEIL_RSHIFT(cover->height, !!p);
         int iw = AV_CEIL_RSHIFT(in->width , !!p);
         int ih = AV_CEIL_RSHIFT(in->height, !!p);

         for (y = 0; y < h; y++) {
             for (x = 0; x < w; x++) {
                 int c = 0;
                 int s = 0;
                 if (ox) {
                     int scale = 65536 / (x + 1);
                     s += data[-1 + y*stride] * scale;
                     c += scale;
                 }
                 if (oy) {
                     int scale = 65536 / (y + 1);
                     s += data[x - stride] * scale;
                     c += scale;
                 }
                 if (ox + w < iw) {
                     int scale = 65536 / (w - x);
                     s += data[w + y*stride] * scale;
                     c += scale;
                 }
                 if (oy + h < ih) {
                     int scale = 65536 / (h - y);
                     s += data[x + h*stride] * scale;
                     c += scale;
                 }

                 data[x + y*stride] = c ? (s + (c>>1)) / c : 0;

             }
         }
     }
 }
 
 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
 {
     AVFilterContext *ctx = inlink->dst;
     CoverContext *cover = ctx->priv;
     AVDictionaryEntry *ex, *ey, *ew, *eh;
     int x = -1, y = -1, w = -1, h = -1;
     char *xendptr = NULL, *yendptr = NULL, *wendptr = NULL, *hendptr = NULL;
 
     ex = av_dict_get(in->metadata, "lavfi.rect.x", NULL, AV_DICT_MATCH_CASE);
     ey = av_dict_get(in->metadata, "lavfi.rect.y", NULL, AV_DICT_MATCH_CASE);
     ew = av_dict_get(in->metadata, "lavfi.rect.w", NULL, AV_DICT_MATCH_CASE);
     eh = av_dict_get(in->metadata, "lavfi.rect.h", NULL, AV_DICT_MATCH_CASE);
     if (ex && ey && ew && eh) {
         x = strtol(ex->value, &xendptr, 10);
         y = strtol(ey->value, &yendptr, 10);
         w = strtol(ew->value, &wendptr, 10);
         h = strtol(eh->value, &hendptr, 10);
     }
 
     if (!xendptr || *xendptr || !yendptr || *yendptr ||
         !wendptr || *wendptr || !hendptr || !hendptr
     ) {
         return ff_filter_frame(ctx->outputs[0], in);
     }
 

     if (x < 0) {
         w += x;
         x = 0;
     }
     if (y < 0) {
         h += y;
         y = 0;
     }
     w = FFMIN(w, in->width  - x);
     h = FFMIN(h, in->height - y);
 

     if (w > in->width || h > in->height || w <= 0 || h <= 0)
         return AVERROR(EINVAL);
 
     if (cover->cover_frame) {
         if (w != cover->cover_frame->width || h != cover->cover_frame->height)
             return AVERROR(EINVAL);
     }
 
     cover->width  = w;
     cover->height = h;
 
     x = av_clip(x, 0, in->width  - w);
     y = av_clip(y, 0, in->height - h);
 
     av_frame_make_writable(in);
 
     if (cover->mode == MODE_BLUR) {
         blur (cover, in, x, y);
     } else {
         cover_rect(cover, in, x, y);
     }
     return ff_filter_frame(ctx->outputs[0], in);
 }
 
 static av_cold void uninit(AVFilterContext *ctx)
 {
     CoverContext *cover = ctx->priv;
 
     if (cover->cover_frame)
         av_freep(&cover->cover_frame->data[0]);
 }
 
 static av_cold int init(AVFilterContext *ctx)
 {
     CoverContext *cover = ctx->priv;
     int ret;
 
     if (cover->mode == MODE_COVER) {
         if (!cover->cover_filename) {
             av_log(ctx, AV_LOG_ERROR, "cover filename not set\n");
             return AVERROR(EINVAL);
         }
 
         cover->cover_frame = av_frame_alloc();
         if (!cover->cover_frame)
             return AVERROR(ENOMEM);
 
         if ((ret = ff_load_image(cover->cover_frame->data, cover->cover_frame->linesize,
                                 &cover->cover_frame->width, &cover->cover_frame->height,
                                 &cover->cover_frame->format, cover->cover_filename, ctx)) < 0)
             return ret;
 
         if (cover->cover_frame->format != AV_PIX_FMT_YUV420P && cover->cover_frame->format != AV_PIX_FMT_YUVJ420P) {
             av_log(ctx, AV_LOG_ERROR, "cover image is not a YUV420 image\n");
             return AVERROR(EINVAL);
         }
     }
 
     return 0;
 }
 
 static const AVFilterPad cover_rect_inputs[] = {
     {
         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,
         .config_props = config_input,
         .filter_frame = filter_frame,
     },
     { NULL }
 };
 
 static const AVFilterPad cover_rect_outputs[] = {
     {
         .name = "default",
         .type = AVMEDIA_TYPE_VIDEO,
     },
     { NULL }
 };
 
 AVFilter ff_vf_cover_rect = {
     .name            = "cover_rect",

     .description     = NULL_IF_CONFIG_SMALL("Find and cover a user specified object."),

     .priv_size       = sizeof(CoverContext),
     .init            = init,
     .uninit          = uninit,
     .query_formats   = query_formats,
     .inputs          = cover_rect_inputs,
     .outputs         = cover_rect_outputs,
     .priv_class      = &cover_rect_class,
 };