/*

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

  * Copyright (c) 2013 Andrey Utkin <andrey.krieger.utkin gmail 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 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 and grid drawing filters. 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/eval.h"

 #include "libavutil/pixdesc.h"

 #include "libavutil/parseutils.h"

 #include "avfilter.h"

 #include "formats.h"

 #include "internal.h"

 #include "video.h"

 static const char *const var_names[] = {
     "dar",
     "hsub", "vsub",
     "in_h", "ih",      ///< height of the input video
     "in_w", "iw",      ///< width  of the input video
     "sar",
     "x",
     "y",
     "h",              ///< height of the rendered box
     "w",              ///< width  of the rendered box
     "t",

     "fill",

     NULL
 };
 

 enum { Y, U, V, A };
 

 enum var_name {
     VAR_DAR,
     VAR_HSUB, VAR_VSUB,
     VAR_IN_H, VAR_IH,
     VAR_IN_W, VAR_IW,
     VAR_SAR,
     VAR_X,
     VAR_Y,
     VAR_H,
     VAR_W,
     VAR_T,

     VAR_MAX,

     VARS_NB
 };
 

 typedef struct DrawBoxContext {

     const AVClass *class;

     int x, y, w, h;

     int thickness;

     char *color_str;

     unsigned char yuv_color[4];

     int invert_color; ///< invert luma color

     int vsub, hsub;   ///< chroma subsampling

     char *x_expr, *y_expr; ///< expression for x and y
     char *w_expr, *h_expr; ///< expression for width and height
     char *t_expr;          ///< expression for thickness

     int have_alpha;

 } DrawBoxContext;
 

 static const int NUM_EXPR_EVALS = 5;
 

 static av_cold int init(AVFilterContext *ctx)

 {

     DrawBoxContext *s = ctx->priv;

     uint8_t rgba_color[4];
 

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

         return AVERROR(EINVAL);
 

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

     }

 
     return 0;
 }
 
 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_YUVA420P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA444P,

         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 int config_input(AVFilterLink *inlink)
 {

     AVFilterContext *ctx = inlink->dst;
     DrawBoxContext *s = ctx->priv;

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

     double var_values[VARS_NB], res;
     char *expr;
     int ret;

     int i;

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

     s->have_alpha = desc->flags & AV_PIX_FMT_FLAG_ALPHA;

     var_values[VAR_IN_H] = var_values[VAR_IH] = inlink->h;
     var_values[VAR_IN_W] = var_values[VAR_IW] = inlink->w;
     var_values[VAR_SAR]  = inlink->sample_aspect_ratio.num ? av_q2d(inlink->sample_aspect_ratio) : 1;
     var_values[VAR_DAR]  = (double)inlink->w / inlink->h * var_values[VAR_SAR];
     var_values[VAR_HSUB] = s->hsub;
     var_values[VAR_VSUB] = s->vsub;
     var_values[VAR_X] = NAN;
     var_values[VAR_Y] = NAN;
     var_values[VAR_H] = NAN;
     var_values[VAR_W] = NAN;
     var_values[VAR_T] = NAN;
 

     for (i = 0; i <= NUM_EXPR_EVALS; i++) {

         /* evaluate expressions, fail on last iteration */

         var_values[VAR_MAX] = inlink->w;

         if ((ret = av_expr_parse_and_eval(&res, (expr = s->x_expr),
                                           var_names, var_values,
                                           NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0 && i == NUM_EXPR_EVALS)
             goto fail;
         s->x = var_values[VAR_X] = res;
 

         var_values[VAR_MAX] = inlink->h;

         if ((ret = av_expr_parse_and_eval(&res, (expr = s->y_expr),
                                           var_names, var_values,
                                           NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0 && i == NUM_EXPR_EVALS)
             goto fail;
         s->y = var_values[VAR_Y] = res;
 

         var_values[VAR_MAX] = inlink->w - s->x;

         if ((ret = av_expr_parse_and_eval(&res, (expr = s->w_expr),
                                           var_names, var_values,
                                           NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0 && i == NUM_EXPR_EVALS)
             goto fail;
         s->w = var_values[VAR_W] = res;
 

         var_values[VAR_MAX] = inlink->h - s->y;

         if ((ret = av_expr_parse_and_eval(&res, (expr = s->h_expr),
                                           var_names, var_values,
                                           NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0 && i == NUM_EXPR_EVALS)
             goto fail;
         s->h = var_values[VAR_H] = res;
 

         var_values[VAR_MAX] = INT_MAX;

         if ((ret = av_expr_parse_and_eval(&res, (expr = s->t_expr),
                                           var_names, var_values,
                                           NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0 && i == NUM_EXPR_EVALS)
             goto fail;
         s->thickness = var_values[VAR_T] = res;
     }
 
     /* if w or h are zero, use the input w/h */
     s->w = (s->w > 0) ? s->w : inlink->w;
     s->h = (s->h > 0) ? s->h : inlink->h;
 
     /* sanity check width and height */
     if (s->w <  0 || s->h <  0) {
         av_log(ctx, AV_LOG_ERROR, "Size values less than 0 are not acceptable.\n");
         return AVERROR(EINVAL);
     }

     av_log(ctx, AV_LOG_VERBOSE, "x:%d y:%d w:%d h:%d color:0x%02X%02X%02X%02X\n",

            s->x, s->y, s->w, s->h,

            s->yuv_color[Y], s->yuv_color[U], s->yuv_color[V], s->yuv_color[A]);

 
     return 0;

 
 fail:

     av_log(ctx, AV_LOG_ERROR,

            "Error when evaluating the expression '%s'.\n",
            expr);
     return ret;

 }
 

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

 {

     DrawBoxContext *s = inlink->dst->priv;
     int plane, x, y, xb = s->x, yb = s->y;

     unsigned char *row[4];
 

     if (s->have_alpha) {
         for (y = FFMAX(yb, 0); y < frame->height && y < (yb + s->h); y++) {
             row[0] = frame->data[0] + y * frame->linesize[0];
             row[3] = frame->data[3] + y * frame->linesize[3];
 
             for (plane = 1; plane < 3; plane++)
                 row[plane] = frame->data[plane] +
                      frame->linesize[plane] * (y >> s->vsub);
 
             if (s->invert_color) {
                 for (x = FFMAX(xb, 0); x < xb + s->w && x < frame->width; x++)
                     if ((y - yb < s->thickness) || (yb + s->h - 1 - y < s->thickness) ||
                         (x - xb < s->thickness) || (xb + s->w - 1 - x < s->thickness))
                         row[0][x] = 0xff - row[0][x];
             } else {
                 for (x = FFMAX(xb, 0); x < xb + s->w && x < frame->width; x++) {
                     if ((y - yb < s->thickness) || (yb + s->h - 1 - y < s->thickness) ||
                         (x - xb < s->thickness) || (xb + s->w - 1 - x < s->thickness)) {
                         row[0][x           ] = s->yuv_color[Y];
                         row[1][x >> s->hsub] = s->yuv_color[U];
                         row[2][x >> s->hsub] = s->yuv_color[V];
                         row[3][x           ] = s->yuv_color[A];
                     }
                 }
             }
         }
     } else {

         for (y = FFMAX(yb, 0); y < frame->height && y < (yb + s->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 >> s->vsub);
 
             if (s->invert_color) {
                 for (x = FFMAX(xb, 0); x < xb + s->w && x < frame->width; x++)
                     if ((y - yb < s->thickness) || (yb + s->h - 1 - y < s->thickness) ||
                         (x - xb < s->thickness) || (xb + s->w - 1 - x < s->thickness))
                         row[0][x] = 0xff - row[0][x];
             } else {
                 for (x = FFMAX(xb, 0); x < xb + s->w && x < frame->width; x++) {
                     double alpha = (double)s->yuv_color[A] / 255;
 
                     if ((y - yb < s->thickness) || (yb + s->h - 1 - y < s->thickness) ||
                         (x - xb < s->thickness) || (xb + s->w - 1 - x < s->thickness)) {
                         row[0][x                 ] = (1 - alpha) * row[0][x                 ] + alpha * s->yuv_color[Y];
                         row[1][x >> s->hsub] = (1 - alpha) * row[1][x >> s->hsub] + alpha * s->yuv_color[U];
                         row[2][x >> s->hsub] = (1 - alpha) * row[2][x >> s->hsub] + alpha * s->yuv_color[V];
                     }

                 }

             }
         }
     }
 

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

 }
 

 #define OFFSET(x) offsetof(DrawBoxContext, x)

 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
 

 #if CONFIG_DRAWBOX_FILTER
 

 static const AVOption drawbox_options[] = {

     { "x",         "set horizontal position of the left box edge", OFFSET(x_expr),    AV_OPT_TYPE_STRING, { .str="0" },       CHAR_MIN, CHAR_MAX, FLAGS },
     { "y",         "set vertical position of the top box edge",    OFFSET(y_expr),    AV_OPT_TYPE_STRING, { .str="0" },       CHAR_MIN, CHAR_MAX, FLAGS },
     { "width",     "set width of the box",                         OFFSET(w_expr),    AV_OPT_TYPE_STRING, { .str="0" },       CHAR_MIN, CHAR_MAX, FLAGS },
     { "w",         "set width of the box",                         OFFSET(w_expr),    AV_OPT_TYPE_STRING, { .str="0" },       CHAR_MIN, CHAR_MAX, FLAGS },
     { "height",    "set height of the box",                        OFFSET(h_expr),    AV_OPT_TYPE_STRING, { .str="0" },       CHAR_MIN, CHAR_MAX, FLAGS },
     { "h",         "set height of the box",                        OFFSET(h_expr),    AV_OPT_TYPE_STRING, { .str="0" },       CHAR_MIN, CHAR_MAX, FLAGS },

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

     { "thickness", "set the box thickness",                        OFFSET(t_expr),    AV_OPT_TYPE_STRING, { .str="3" },       CHAR_MIN, CHAR_MAX, FLAGS },
     { "t",         "set the box thickness",                        OFFSET(t_expr),    AV_OPT_TYPE_STRING, { .str="3" },       CHAR_MIN, CHAR_MAX, FLAGS },

     { NULL }

 };
 

 AVFILTER_DEFINE_CLASS(drawbox);

 static const AVFilterPad drawbox_inputs[] = {

     {

         .name           = "default",
         .type           = AVMEDIA_TYPE_VIDEO,
         .config_props   = config_input,
         .filter_frame   = filter_frame,
         .needs_writable = 1,

     },
     { NULL }
 };
 

 static const AVFilterPad drawbox_outputs[] = {

     {
         .name = "default",
         .type = AVMEDIA_TYPE_VIDEO,
     },
     { NULL }
 };
 

 AVFilter ff_vf_drawbox = {

     .name          = "drawbox",
     .description   = NULL_IF_CONFIG_SMALL("Draw a colored box on the input video."),
     .priv_size     = sizeof(DrawBoxContext),
     .priv_class    = &drawbox_class,
     .init          = init,
     .query_formats = query_formats,
     .inputs        = drawbox_inputs,
     .outputs       = drawbox_outputs,
     .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,

 };

 #endif /* CONFIG_DRAWBOX_FILTER */
 
 #if CONFIG_DRAWGRID_FILTER
 static av_pure av_always_inline int pixel_belongs_to_grid(DrawBoxContext *drawgrid, int x, int y)
 {
     // x is horizontal (width) coord,
     // y is vertical (height) coord
     int x_modulo;
     int y_modulo;
 
     // Abstract from the offset
     x -= drawgrid->x;
     y -= drawgrid->y;
 
     x_modulo = x % drawgrid->w;
     y_modulo = y % drawgrid->h;
 
     // If x or y got negative, fix values to preserve logics
     if (x_modulo < 0)
         x_modulo += drawgrid->w;
     if (y_modulo < 0)
         y_modulo += drawgrid->h;
 
     return x_modulo < drawgrid->thickness  // Belongs to vertical line
         || y_modulo < drawgrid->thickness;  // Belongs to horizontal line
 }
 
 static int drawgrid_filter_frame(AVFilterLink *inlink, AVFrame *frame)
 {
     DrawBoxContext *drawgrid = inlink->dst->priv;
     int plane, x, y;
     uint8_t *row[4];
 

     if (drawgrid->have_alpha) {
         for (y = 0; y < frame->height; y++) {
             row[0] = frame->data[0] + y * frame->linesize[0];
             row[3] = frame->data[3] + y * frame->linesize[3];
 
             for (plane = 1; plane < 3; plane++)
                 row[plane] = frame->data[plane] +
                      frame->linesize[plane] * (y >> drawgrid->vsub);
 
             if (drawgrid->invert_color) {
                 for (x = 0; x < frame->width; x++)
                     if (pixel_belongs_to_grid(drawgrid, x, y))
                         row[0][x] = 0xff - row[0][x];
             } else {
                 for (x = 0; x < frame->width; x++) {
                     if (pixel_belongs_to_grid(drawgrid, x, y)) {
                         row[0][x                  ] = drawgrid->yuv_color[Y];
                         row[1][x >> drawgrid->hsub] = drawgrid->yuv_color[U];
                         row[2][x >> drawgrid->hsub] = drawgrid->yuv_color[V];
                         row[3][x                  ] = drawgrid->yuv_color[A];
                     }
                 }
             }
         }
     } else {

         for (y = 0; y < frame->height; 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 >> drawgrid->vsub);
 
             if (drawgrid->invert_color) {
                 for (x = 0; x < frame->width; x++)
                     if (pixel_belongs_to_grid(drawgrid, x, y))
                         row[0][x] = 0xff - row[0][x];
             } else {
                 for (x = 0; x < frame->width; x++) {
                     double alpha = (double)drawgrid->yuv_color[A] / 255;
 
                     if (pixel_belongs_to_grid(drawgrid, x, y)) {
                         row[0][x                  ] = (1 - alpha) * row[0][x                  ] + alpha * drawgrid->yuv_color[Y];
                         row[1][x >> drawgrid->hsub] = (1 - alpha) * row[1][x >> drawgrid->hsub] + alpha * drawgrid->yuv_color[U];
                         row[2][x >> drawgrid->hsub] = (1 - alpha) * row[2][x >> drawgrid->hsub] + alpha * drawgrid->yuv_color[V];
                     }

                 }
             }
         }
     }
 
     return ff_filter_frame(inlink->dst->outputs[0], frame);
 }
 
 static const AVOption drawgrid_options[] = {

     { "x",         "set horizontal offset",   OFFSET(x_expr),    AV_OPT_TYPE_STRING, { .str="0" },       CHAR_MIN, CHAR_MAX, FLAGS },
     { "y",         "set vertical offset",     OFFSET(y_expr),    AV_OPT_TYPE_STRING, { .str="0" },       CHAR_MIN, CHAR_MAX, FLAGS },
     { "width",     "set width of grid cell",  OFFSET(w_expr),    AV_OPT_TYPE_STRING, { .str="0" },       CHAR_MIN, CHAR_MAX, FLAGS },
     { "w",         "set width of grid cell",  OFFSET(w_expr),    AV_OPT_TYPE_STRING, { .str="0" },       CHAR_MIN, CHAR_MAX, FLAGS },
     { "height",    "set height of grid cell", OFFSET(h_expr),    AV_OPT_TYPE_STRING, { .str="0" },       CHAR_MIN, CHAR_MAX, FLAGS },
     { "h",         "set height of grid cell", OFFSET(h_expr),    AV_OPT_TYPE_STRING, { .str="0" },       CHAR_MIN, CHAR_MAX, FLAGS },

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

     { "thickness", "set grid line thickness", OFFSET(t_expr),    AV_OPT_TYPE_STRING, {.str="1"},         CHAR_MIN, CHAR_MAX, FLAGS },
     { "t",         "set grid line thickness", OFFSET(t_expr),    AV_OPT_TYPE_STRING, {.str="1"},         CHAR_MIN, CHAR_MAX, FLAGS },

     { NULL }
 };
 
 AVFILTER_DEFINE_CLASS(drawgrid);
 
 static const AVFilterPad drawgrid_inputs[] = {
     {
         .name           = "default",
         .type           = AVMEDIA_TYPE_VIDEO,
         .config_props   = config_input,
         .filter_frame   = drawgrid_filter_frame,
         .needs_writable = 1,
     },
     { NULL }
 };
 
 static const AVFilterPad drawgrid_outputs[] = {
     {
         .name = "default",
         .type = AVMEDIA_TYPE_VIDEO,
     },
     { NULL }
 };
 

 AVFilter ff_vf_drawgrid = {

     .name          = "drawgrid",
     .description   = NULL_IF_CONFIG_SMALL("Draw a colored grid on the input video."),
     .priv_size     = sizeof(DrawBoxContext),
     .priv_class    = &drawgrid_class,
     .init          = init,
     .query_formats = query_formats,
     .inputs        = drawgrid_inputs,
     .outputs       = drawgrid_outputs,
     .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
 };
 
 #endif  /* CONFIG_DRAWGRID_FILTER */