/*

  * Copyright (c) 2008 Affine Systems, Inc (Michael Sullivan, Bobby Impollonia)

  *
  * 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
  */
 
 /**
  * @file
  * Box drawing filter. Also a nice template for a filter that needs to
  * write in the input frame.
  */
 
 #include "libavutil/colorspace.h"

 #include "libavutil/common.h"

 #include "libavutil/opt.h"

 #include "libavutil/pixdesc.h"

 #include "libavutil/parseutils.h"

 #include "avfilter.h"

 #include "formats.h"

 #include "internal.h"

 #include "video.h"

 
 enum { Y, U, V, A };
 
 typedef struct {

     const AVClass *class;

     int x, y, w, h, thickness;

     char *color_str;

     unsigned char yuv_color[4];

     int invert_color; ///< invert luma color

     int vsub, hsub;   ///< chroma subsampling

 } DrawBoxContext;
 

 #define OFFSET(x) offsetof(DrawBoxContext, x)
 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
 
 static const AVOption drawbox_options[] = {
     { "x",           "set the box top-left corner x position", OFFSET(x), AV_OPT_TYPE_INT, {.i64=0}, INT_MIN, INT_MAX, FLAGS },
     { "y",           "set the box top-left corner y position", OFFSET(y), AV_OPT_TYPE_INT, {.i64=0}, INT_MIN, INT_MAX, FLAGS },

     { "width",       "set the box width",  OFFSET(w), AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX, FLAGS },

     { "w",           "set the box width",  OFFSET(w), AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX, FLAGS },

     { "height",      "set the box height", OFFSET(h), AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX, FLAGS },
     { "h",           "set the box height", OFFSET(h), AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX, FLAGS },

     { "color",       "set the box edge color", OFFSET(color_str), AV_OPT_TYPE_STRING, {.str="black"}, CHAR_MIN, CHAR_MAX, FLAGS },
     { "c",           "set the box edge color", OFFSET(color_str), AV_OPT_TYPE_STRING, {.str="black"}, CHAR_MIN, CHAR_MAX, FLAGS },

     { "thickness",   "set the box maximum thickness", OFFSET(thickness), AV_OPT_TYPE_INT, {.i64=4}, 0, INT_MAX, FLAGS },
     { "t",           "set the box maximum thickness", OFFSET(thickness), AV_OPT_TYPE_INT, {.i64=4}, 0, INT_MAX, FLAGS },

     {NULL},
 };
 
 AVFILTER_DEFINE_CLASS(drawbox);
 

 static av_cold int init(AVFilterContext *ctx, const char *args)

 {

     DrawBoxContext *drawbox = ctx->priv;

     uint8_t rgba_color[4];

     static const char *shorthand[] = { "x", "y", "w", "h", "color", "thickness", NULL };

     int ret;

     drawbox->class = &drawbox_class;
     av_opt_set_defaults(drawbox);

     if ((ret = av_opt_set_from_string(drawbox, args, shorthand, "=", ":")) < 0)
         return ret;

     if (!strcmp(drawbox->color_str, "invert"))
         drawbox->invert_color = 1;
     else if (av_parse_color(rgba_color, drawbox->color_str, -1, ctx) < 0)

         return AVERROR(EINVAL);
 

     if (!drawbox->invert_color) {
         drawbox->yuv_color[Y] = RGB_TO_Y_CCIR(rgba_color[0], rgba_color[1], rgba_color[2]);
         drawbox->yuv_color[U] = RGB_TO_U_CCIR(rgba_color[0], rgba_color[1], rgba_color[2], 0);
         drawbox->yuv_color[V] = RGB_TO_V_CCIR(rgba_color[0], rgba_color[1], rgba_color[2], 0);
         drawbox->yuv_color[A] = rgba_color[3];
     }

 
     return 0;
 }
 

 static av_cold void uninit(AVFilterContext *ctx)
 {
     DrawBoxContext *drawbox = ctx->priv;
     av_opt_free(drawbox);
 }
 

 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_YUVJ444P, AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ420P,
         AV_PIX_FMT_YUV440P,  AV_PIX_FMT_YUVJ440P,
         AV_PIX_FMT_NONE

     };
 

     ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));

     return 0;
 }
 
 static int config_input(AVFilterLink *inlink)
 {
     DrawBoxContext *drawbox = inlink->dst->priv;

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

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

 
     if (drawbox->w == 0) drawbox->w = inlink->w;
     if (drawbox->h == 0) drawbox->h = inlink->h;
 

     av_log(inlink->dst, AV_LOG_VERBOSE, "x:%d y:%d w:%d h:%d color:0x%02X%02X%02X%02X\n",

            drawbox->x, drawbox->y, drawbox->w, drawbox->h,

            drawbox->yuv_color[Y], drawbox->yuv_color[U], drawbox->yuv_color[V], drawbox->yuv_color[A]);
 
     return 0;
 }
 

 static int filter_frame(AVFilterLink *inlink, AVFilterBufferRef *frame)

 {
     DrawBoxContext *drawbox = inlink->dst->priv;
     int plane, x, y, xb = drawbox->x, yb = drawbox->y;
     unsigned char *row[4];
 

     for (y = FFMAX(yb, 0); y < frame->video->h && y < (yb + drawbox->h); y++) {
         row[0] = frame->data[0] + y * frame->linesize[0];

 
         for (plane = 1; plane < 3; plane++)

             row[plane] = frame->data[plane] +
                  frame->linesize[plane] * (y >> drawbox->vsub);

         if (drawbox->invert_color) {

             for (x = FFMAX(xb, 0); x < xb + drawbox->w && x < frame->video->w; x++)

                 if ((y - yb < drawbox->thickness-1) || (yb + drawbox->h - y < drawbox->thickness) ||
                     (x - xb < drawbox->thickness-1) || (xb + drawbox->w - x < drawbox->thickness))

                     row[0][x] = 0xff - row[0][x];
         } else {

             for (x = FFMAX(xb, 0); x < xb + drawbox->w && x < frame->video->w; x++) {

                 double alpha = (double)drawbox->yuv_color[A] / 255;
 

                 if ((y - yb < drawbox->thickness-1) || (yb + drawbox->h - y < drawbox->thickness) ||
                     (x - xb < drawbox->thickness-1) || (xb + drawbox->w - x < drawbox->thickness)) {

                     row[0][x                 ] = (1 - alpha) * row[0][x                 ] + alpha * drawbox->yuv_color[Y];
                     row[1][x >> drawbox->hsub] = (1 - alpha) * row[1][x >> drawbox->hsub] + alpha * drawbox->yuv_color[U];
                     row[2][x >> drawbox->hsub] = (1 - alpha) * row[2][x >> drawbox->hsub] + alpha * drawbox->yuv_color[V];
                 }

             }
         }
     }
 

     return ff_filter_frame(inlink->dst->outputs[0], frame);

 }
 

 static const AVFilterPad avfilter_vf_drawbox_inputs[] = {
     {
         .name             = "default",
         .type             = AVMEDIA_TYPE_VIDEO,
         .config_props     = config_input,
         .get_video_buffer = ff_null_get_video_buffer,

         .filter_frame     = filter_frame,

         .min_perms        = AV_PERM_WRITE | AV_PERM_READ,
     },
     { NULL }
 };
 
 static const AVFilterPad avfilter_vf_drawbox_outputs[] = {
     {
         .name = "default",
         .type = AVMEDIA_TYPE_VIDEO,
     },
     { NULL }
 };
 

 AVFilter avfilter_vf_drawbox = {
     .name      = "drawbox",
     .description = NULL_IF_CONFIG_SMALL("Draw a colored box on the input video."),
     .priv_size = sizeof(DrawBoxContext),
     .init      = init,

     .uninit    = uninit,

 
     .query_formats   = query_formats,

     .inputs    = avfilter_vf_drawbox_inputs,
     .outputs   = avfilter_vf_drawbox_outputs,

     .priv_class = &drawbox_class,

 };