/*

  * 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/pixdesc.h"

 #include "libavutil/parseutils.h"

 #include "avfilter.h"
 
 enum { Y, U, V, A };
 
 typedef struct {
     int x, y, w, h;
     unsigned char yuv_color[4];
     int vsub, hsub;   //< chroma subsampling
 } DrawBoxContext;
 
 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
 {
     DrawBoxContext *drawbox= ctx->priv;
     char color_str[1024] = "black";
     uint8_t rgba_color[4];
 
     drawbox->x = drawbox->y = drawbox->w = drawbox->h = 0;
 
     if (args)
         sscanf(args, "%d:%d:%d:%d:%s",
                &drawbox->x, &drawbox->y, &drawbox->w, &drawbox->h, color_str);
 

     if (av_parse_color(rgba_color, color_str, -1, ctx) < 0)

         return AVERROR(EINVAL);
 
     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 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_YUVJ444P, PIX_FMT_YUVJ422P, PIX_FMT_YUVJ420P,
         PIX_FMT_YUV440P,  PIX_FMT_YUVJ440P,
         PIX_FMT_NONE
     };
 

     avfilter_set_common_pixel_formats(ctx, avfilter_make_format_list(pix_fmts));

     return 0;
 }
 
 static int config_input(AVFilterLink *inlink)
 {
     DrawBoxContext *drawbox = inlink->dst->priv;
 
     drawbox->hsub = av_pix_fmt_descriptors[inlink->format].log2_chroma_w;
     drawbox->vsub = av_pix_fmt_descriptors[inlink->format].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_INFO, "x:%d y:%d w:%d h:%d color:0x%02X%02X%02X%02X\n",
            drawbox->w, 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 void draw_slice(AVFilterLink *inlink, int y0, int h, int slice_dir)
 {
     DrawBoxContext *drawbox = inlink->dst->priv;
     int plane, x, y, xb = drawbox->x, yb = drawbox->y;
     unsigned char *row[4];
     AVFilterBufferRef *picref = inlink->cur_buf;
 
     for (y = FFMAX(yb, y0); y < (y0 + h) && y < (yb + drawbox->h); y++) {
         row[0] = picref->data[0] + y * picref->linesize[0];
 
         for (plane = 1; plane < 3; plane++)
             row[plane] = picref->data[plane] +
                 picref->linesize[plane] * (y >> drawbox->vsub);
 
         for (x = FFMAX(xb, 0); x < (xb + drawbox->w) && x < picref->video->w; x++) {
             double alpha = (double)drawbox->yuv_color[A] / 255;
 
             if ((y - yb < 3) || (yb + drawbox->h - y < 4) ||
                 (x - xb < 3) || (xb + drawbox->w - x < 4)) {
                 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];
             }
         }
     }
 
     avfilter_draw_slice(inlink->dst->outputs[0], y0, h, 1);
 }
 
 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,
 
     .query_formats   = query_formats,
     .inputs    = (AVFilterPad[]) {{ .name             = "default",
                                     .type             = AVMEDIA_TYPE_VIDEO,
                                     .config_props     = config_input,
                                     .get_video_buffer = avfilter_null_get_video_buffer,
                                     .start_frame      = avfilter_null_start_frame,
                                     .draw_slice       = draw_slice,
                                     .end_frame        = avfilter_null_end_frame,
                                     .min_perms        = AV_PERM_WRITE | AV_PERM_READ,
                                     .rej_perms        = AV_PERM_PRESERVE },
                                   { .name = NULL}},
     .outputs   = (AVFilterPad[]) {{ .name             = "default",
                                     .type             = AVMEDIA_TYPE_VIDEO, },
                                   { .name = NULL}},
 };