/*
  * Copyright (c) 2011 Stefano Sabatini
  * Copyright (c) 2010 S.N. Hemanth Meenakshisundaram
  * Copyright (c) 2003 Gustavo Sverzut Barbieri <gsbarbieri@yahoo.com.br>
  *
  * 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

  * drawtext filter, based on the original vhook/drawtext.c

  * filter by Gustavo Sverzut Barbieri
  */
 

 #include "config.h"

 #if HAVE_SYS_TIME_H

 #include <sys/time.h>

 #endif

 #include <sys/types.h>

 #include <sys/stat.h>

 #include <time.h>

 #if HAVE_UNISTD_H

 #include <unistd.h>

 #endif

 #include <fenv.h>

 
 #if CONFIG_LIBFONTCONFIG
 #include <fontconfig/fontconfig.h>
 #endif

 #include "libavutil/avstring.h"

 #include "libavutil/bprint.h"

 #include "libavutil/common.h"

 #include "libavutil/file.h"

 #include "libavutil/eval.h"

 #include "libavutil/opt.h"

 #include "libavutil/random_seed.h"

 #include "libavutil/parseutils.h"

 #include "libavutil/timecode.h"

 #include "libavutil/time_internal.h"

 #include "libavutil/tree.h"

 #include "libavutil/lfg.h"

 #include "avfilter.h"
 #include "drawutils.h"

 #include "formats.h"

 #include "internal.h"

 #include "video.h"

 #if CONFIG_LIBFRIBIDI
 #include <fribidi.h>
 #endif
 

 #include <ft2build.h>
 #include FT_FREETYPE_H
 #include FT_GLYPH_H

 #include FT_STROKER_H

 static const char *const var_names[] = {

     "dar",
     "hsub", "vsub",
     "line_h", "lh",           ///< line height, same as max_glyph_h

     "main_h", "h", "H",       ///< height of the input video

     "main_w", "w", "W",       ///< width  of the input video

     "max_glyph_a", "ascent",  ///< max glyph ascent
     "max_glyph_d", "descent", ///< min glyph descent

     "max_glyph_h",            ///< max glyph height
     "max_glyph_w",            ///< max glyph width
     "n",                      ///< number of frame

     "sar",

     "t",                      ///< timestamp expressed in seconds
     "text_h", "th",           ///< height of the rendered text
     "text_w", "tw",           ///< width  of the rendered text

     "x",
     "y",

     "pict_type",

     NULL
 };
 

 static const char *const fun2_names[] = {
     "rand"

 };
 
 static double drand(void *opaque, double min, double max)
 {

     return min + (max-min) / UINT_MAX * av_lfg_get(opaque);

 }
 
 typedef double (*eval_func2)(void *, double a, double b);
 
 static const eval_func2 fun2[] = {
     drand,
     NULL
 };
 

 enum var_name {

     VAR_DAR,
     VAR_HSUB, VAR_VSUB,
     VAR_LINE_H, VAR_LH,

     VAR_MAIN_H, VAR_h, VAR_H,

     VAR_MAIN_W, VAR_w, VAR_W,

     VAR_MAX_GLYPH_A, VAR_ASCENT,
     VAR_MAX_GLYPH_D, VAR_DESCENT,

     VAR_MAX_GLYPH_H,
     VAR_MAX_GLYPH_W,
     VAR_N,

     VAR_SAR,

     VAR_T,
     VAR_TEXT_H, VAR_TH,
     VAR_TEXT_W, VAR_TW,

     VAR_X,
     VAR_Y,

     VAR_PICT_TYPE,

     VAR_VARS_NB
 };
 

 enum expansion_mode {
     EXP_NONE,
     EXP_NORMAL,
     EXP_STRFTIME,
 };
 

 typedef struct DrawTextContext {

     const AVClass *class;

     int exp_mode;                   ///< expansion mode to use for the text

     int reinit;                     ///< tells if the filter is being reinited

 #if CONFIG_LIBFONTCONFIG
     uint8_t *font;              ///< font to be used
 #endif

     uint8_t *fontfile;              ///< font to be used
     uint8_t *text;                  ///< text to be drawn

     AVBPrint expanded_text;         ///< used to contain the expanded text

     uint8_t *fontcolor_expr;        ///< fontcolor expression to evaluate
     AVBPrint expanded_fontcolor;    ///< used to contain the expanded fontcolor spec

     int ft_load_flags;              ///< flags used for loading fonts, see FT_LOAD_*
     FT_Vector *positions;           ///< positions for each element in the text

     size_t nb_positions;            ///< number of elements of positions array

     char *textfile;                 ///< file with text to be drawn

     int x;                          ///< x position to start drawing text
     int y;                          ///< y position to start drawing text

     int max_glyph_w;                ///< max glyph width

     int max_glyph_h;                ///< max glyph height

     int shadowx, shadowy;

     int borderw;                    ///< border width

     char *fontsize_expr;            ///< expression for fontsize
     AVExpr *fontsize_pexpr;         ///< parsed expressions for fontsize

     unsigned int fontsize;          ///< font size to use

     unsigned int default_fontsize;  ///< default font size to use

     int line_spacing;               ///< lines spacing in pixels

     short int draw_box;             ///< draw box around text - true or false

     int boxborderw;                 ///< box border width

     int use_kerning;                ///< font kerning is used - true/false
     int tabsize;                    ///< tab size

     int fix_bounds;                 ///< do we let it go out of frame bounds - t/f

     FFDrawContext dc;
     FFDrawColor fontcolor;          ///< foreground color
     FFDrawColor shadowcolor;        ///< shadow color

     FFDrawColor bordercolor;        ///< border color

     FFDrawColor boxcolor;           ///< background color
 

     FT_Library library;             ///< freetype font library handle
     FT_Face face;                   ///< freetype font face handle

     FT_Stroker stroker;             ///< freetype stroker handle

     struct AVTreeNode *glyphs;      ///< rendered glyphs, stored using the UTF-32 char code

     char *x_expr;                   ///< expression for x position
     char *y_expr;                   ///< expression for y position
     AVExpr *x_pexpr, *y_pexpr;      ///< parsed expressions for x and y

     int64_t basetime;               ///< base pts time in the real world for display

     double var_values[VAR_VARS_NB];

     char   *a_expr;
     AVExpr *a_pexpr;
     int alpha;

     AVLFG  prng;                    ///< random

     char       *tc_opt_string;      ///< specified timecode option string
     AVRational  tc_rate;            ///< frame rate for timecode
     AVTimecode  tc;                 ///< timecode context

     int tc24hmax;                   ///< 1 if timecode is wrapped to 24 hours, 0 otherwise

     int reload;                     ///< reload text file for each frame

     int start_number;               ///< starting frame number for n/frame_num var

 #if CONFIG_LIBFRIBIDI
     int text_shaping;               ///< 1 to shape the text before drawing it
 #endif

     AVDictionary *metadata;

 } DrawTextContext;
 
 #define OFFSET(x) offsetof(DrawTextContext, x)

 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM

 
 static const AVOption drawtext_options[]= {

     {"fontfile",    "set font file",        OFFSET(fontfile),           AV_OPT_TYPE_STRING, {.str=NULL},  CHAR_MIN, CHAR_MAX, FLAGS},
     {"text",        "set text",             OFFSET(text),               AV_OPT_TYPE_STRING, {.str=NULL},  CHAR_MIN, CHAR_MAX, FLAGS},
     {"textfile",    "set text file",        OFFSET(textfile),           AV_OPT_TYPE_STRING, {.str=NULL},  CHAR_MIN, CHAR_MAX, FLAGS},

     {"fontcolor",   "set foreground color", OFFSET(fontcolor.rgba),     AV_OPT_TYPE_COLOR,  {.str="black"}, CHAR_MIN, CHAR_MAX, FLAGS},

     {"fontcolor_expr", "set foreground color expression", OFFSET(fontcolor_expr), AV_OPT_TYPE_STRING, {.str=""}, CHAR_MIN, CHAR_MAX, FLAGS},

     {"boxcolor",    "set box color",        OFFSET(boxcolor.rgba),      AV_OPT_TYPE_COLOR,  {.str="white"}, CHAR_MIN, CHAR_MAX, FLAGS},

     {"bordercolor", "set border color",     OFFSET(bordercolor.rgba),   AV_OPT_TYPE_COLOR,  {.str="black"}, CHAR_MIN, CHAR_MAX, FLAGS},

     {"shadowcolor", "set shadow color",     OFFSET(shadowcolor.rgba),   AV_OPT_TYPE_COLOR,  {.str="black"}, CHAR_MIN, CHAR_MAX, FLAGS},

     {"box",         "set box",              OFFSET(draw_box),           AV_OPT_TYPE_BOOL,   {.i64=0},     0,        1       , FLAGS},

     {"boxborderw",  "set box border width", OFFSET(boxborderw),         AV_OPT_TYPE_INT,    {.i64=0},     INT_MIN,  INT_MAX , FLAGS},

     {"line_spacing",  "set line spacing in pixels", OFFSET(line_spacing),   AV_OPT_TYPE_INT,    {.i64=0},     INT_MIN,  INT_MAX,FLAGS},

     {"fontsize",    "set font size",        OFFSET(fontsize_expr),      AV_OPT_TYPE_STRING, {.str=NULL},  CHAR_MIN, CHAR_MAX , FLAGS},

     {"x",           "set x expression",     OFFSET(x_expr),             AV_OPT_TYPE_STRING, {.str="0"},   CHAR_MIN, CHAR_MAX, FLAGS},
     {"y",           "set y expression",     OFFSET(y_expr),             AV_OPT_TYPE_STRING, {.str="0"},   CHAR_MIN, CHAR_MAX, FLAGS},

     {"shadowx",     "set shadow x offset",  OFFSET(shadowx),            AV_OPT_TYPE_INT,    {.i64=0},     INT_MIN,  INT_MAX , FLAGS},
     {"shadowy",     "set shadow y offset",  OFFSET(shadowy),            AV_OPT_TYPE_INT,    {.i64=0},     INT_MIN,  INT_MAX , FLAGS},

     {"borderw",     "set border width",     OFFSET(borderw),            AV_OPT_TYPE_INT,    {.i64=0},     INT_MIN,  INT_MAX , FLAGS},

     {"tabsize",     "set tab size",         OFFSET(tabsize),            AV_OPT_TYPE_INT,    {.i64=4},     0,        INT_MAX , FLAGS},
     {"basetime",    "set base time",        OFFSET(basetime),           AV_OPT_TYPE_INT64,  {.i64=AV_NOPTS_VALUE}, INT64_MIN, INT64_MAX , FLAGS},

 #if CONFIG_LIBFONTCONFIG
     { "font",        "Font name",            OFFSET(font),               AV_OPT_TYPE_STRING, { .str = "Sans" },           .flags = FLAGS },
 #endif

 
     {"expansion", "set the expansion mode", OFFSET(exp_mode), AV_OPT_TYPE_INT, {.i64=EXP_NORMAL}, 0, 2, FLAGS, "expansion"},
         {"none",     "set no expansion",                    OFFSET(exp_mode), AV_OPT_TYPE_CONST, {.i64=EXP_NONE},     0, 0, FLAGS, "expansion"},
         {"normal",   "set normal expansion",                OFFSET(exp_mode), AV_OPT_TYPE_CONST, {.i64=EXP_NORMAL},   0, 0, FLAGS, "expansion"},
         {"strftime", "set strftime expansion (deprecated)", OFFSET(exp_mode), AV_OPT_TYPE_CONST, {.i64=EXP_STRFTIME}, 0, 0, FLAGS, "expansion"},
 
     {"timecode",        "set initial timecode",             OFFSET(tc_opt_string), AV_OPT_TYPE_STRING,   {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS},

     {"tc24hmax",        "set 24 hours max (timecode only)", OFFSET(tc24hmax),      AV_OPT_TYPE_BOOL,     {.i64=0},           0,        1, FLAGS},

     {"timecode_rate",   "set rate (timecode only)",         OFFSET(tc_rate),       AV_OPT_TYPE_RATIONAL, {.dbl=0},           0,  INT_MAX, FLAGS},
     {"r",               "set rate (timecode only)",         OFFSET(tc_rate),       AV_OPT_TYPE_RATIONAL, {.dbl=0},           0,  INT_MAX, FLAGS},
     {"rate",            "set rate (timecode only)",         OFFSET(tc_rate),       AV_OPT_TYPE_RATIONAL, {.dbl=0},           0,  INT_MAX, FLAGS},

     {"reload",     "reload text file for each frame",                       OFFSET(reload),     AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS},

     { "alpha",       "apply alpha while rendering", OFFSET(a_expr),      AV_OPT_TYPE_STRING, { .str = "1"     },          .flags = FLAGS },

     {"fix_bounds", "check and fix text coords to avoid clipping", OFFSET(fix_bounds), AV_OPT_TYPE_BOOL, {.i64=1}, 0, 1, FLAGS},

     {"start_number", "start frame number for n/frame_num variable", OFFSET(start_number), AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX, FLAGS},

 #if CONFIG_LIBFRIBIDI

     {"text_shaping", "attempt to shape text before drawing", OFFSET(text_shaping), AV_OPT_TYPE_BOOL, {.i64=1}, 0, 1, FLAGS},

 #endif
 

     /* FT_LOAD_* flags */

     { "ft_load_flags", "set font loading flags for libfreetype", OFFSET(ft_load_flags), AV_OPT_TYPE_FLAGS, { .i64 = FT_LOAD_DEFAULT }, 0, INT_MAX, FLAGS, "ft_load_flags" },

         { "default",                     NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_DEFAULT },                     .flags = FLAGS, .unit = "ft_load_flags" },
         { "no_scale",                    NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_NO_SCALE },                    .flags = FLAGS, .unit = "ft_load_flags" },
         { "no_hinting",                  NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_NO_HINTING },                  .flags = FLAGS, .unit = "ft_load_flags" },
         { "render",                      NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_RENDER },                      .flags = FLAGS, .unit = "ft_load_flags" },
         { "no_bitmap",                   NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_NO_BITMAP },                   .flags = FLAGS, .unit = "ft_load_flags" },
         { "vertical_layout",             NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_VERTICAL_LAYOUT },             .flags = FLAGS, .unit = "ft_load_flags" },
         { "force_autohint",              NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_FORCE_AUTOHINT },              .flags = FLAGS, .unit = "ft_load_flags" },
         { "crop_bitmap",                 NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_CROP_BITMAP },                 .flags = FLAGS, .unit = "ft_load_flags" },
         { "pedantic",                    NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_PEDANTIC },                    .flags = FLAGS, .unit = "ft_load_flags" },
         { "ignore_global_advance_width", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH }, .flags = FLAGS, .unit = "ft_load_flags" },
         { "no_recurse",                  NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_NO_RECURSE },                  .flags = FLAGS, .unit = "ft_load_flags" },
         { "ignore_transform",            NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_IGNORE_TRANSFORM },            .flags = FLAGS, .unit = "ft_load_flags" },
         { "monochrome",                  NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_MONOCHROME },                  .flags = FLAGS, .unit = "ft_load_flags" },
         { "linear_design",               NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_LINEAR_DESIGN },               .flags = FLAGS, .unit = "ft_load_flags" },
         { "no_autohint",                 NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_NO_AUTOHINT },                 .flags = FLAGS, .unit = "ft_load_flags" },

     { NULL }

 };
 

 AVFILTER_DEFINE_CLASS(drawtext);

 
 #undef __FTERRORS_H__
 #define FT_ERROR_START_LIST {
 #define FT_ERRORDEF(e, v, s) { (e), (s) },
 #define FT_ERROR_END_LIST { 0, NULL } };
 

 static const struct ft_error {

     int err;
     const char *err_msg;

 } ft_errors[] =

 #include FT_ERRORS_H
 
 #define FT_ERRMSG(e) ft_errors[e].err_msg
 

 typedef struct Glyph {

     FT_Glyph glyph;

     FT_Glyph border_glyph;

     uint32_t code;

     unsigned int fontsize;

     FT_Bitmap bitmap; ///< array holding bitmaps of font

     FT_Bitmap border_bitmap; ///< array holding bitmaps of font border

     FT_BBox bbox;
     int advance;
     int bitmap_left;
     int bitmap_top;
 } Glyph;
 

 static int glyph_cmp(const void *key, const void *b)

 {
     const Glyph *a = key, *bb = b;
     int64_t diff = (int64_t)a->code - (int64_t)bb->code;

 
     if (diff != 0)
          return diff > 0 ? 1 : -1;
     else
          return FFDIFFSIGN((int64_t)a->fontsize, (int64_t)bb->fontsize);

 }
 
 /**
  * Load glyphs corresponding to the UTF-32 codepoint code.
  */
 static int load_glyph(AVFilterContext *ctx, Glyph **glyph_ptr, uint32_t code)
 {

     DrawTextContext *s = ctx->priv;

     FT_BitmapGlyph bitmapglyph;

     Glyph *glyph;
     struct AVTreeNode *node = NULL;
     int ret;
 

     /* load glyph into s->face->glyph */
     if (FT_Load_Char(s->face, code, s->ft_load_flags))

         return AVERROR(EINVAL);
 

     glyph = av_mallocz(sizeof(*glyph));
     if (!glyph) {

         ret = AVERROR(ENOMEM);
         goto error;
     }
     glyph->code  = code;

     glyph->fontsize = s->fontsize;

     if (FT_Get_Glyph(s->face->glyph, &glyph->glyph)) {

         ret = AVERROR(EINVAL);
         goto error;
     }

     if (s->borderw) {

         glyph->border_glyph = glyph->glyph;

         if (FT_Glyph_StrokeBorder(&glyph->border_glyph, s->stroker, 0, 0) ||
             FT_Glyph_To_Bitmap(&glyph->border_glyph, FT_RENDER_MODE_NORMAL, 0, 1)) {

             ret = AVERROR_EXTERNAL;
             goto error;
         }

         bitmapglyph = (FT_BitmapGlyph) glyph->border_glyph;

         glyph->border_bitmap = bitmapglyph->bitmap;
     }

     if (FT_Glyph_To_Bitmap(&glyph->glyph, FT_RENDER_MODE_NORMAL, 0, 1)) {

         ret = AVERROR_EXTERNAL;
         goto error;
     }

     bitmapglyph = (FT_BitmapGlyph) glyph->glyph;

     glyph->bitmap      = bitmapglyph->bitmap;
     glyph->bitmap_left = bitmapglyph->left;
     glyph->bitmap_top  = bitmapglyph->top;

     glyph->advance     = s->face->glyph->advance.x >> 6;

 
     /* measure text height to calculate text_height (or the maximum text height) */

     FT_Glyph_Get_CBox(glyph->glyph, ft_glyph_bbox_pixels, &glyph->bbox);

 
     /* cache the newly created glyph */

     if (!(node = av_tree_node_alloc())) {

         ret = AVERROR(ENOMEM);
         goto error;
     }

     av_tree_insert(&s->glyphs, glyph, glyph_cmp, &node);

 
     if (glyph_ptr)
         *glyph_ptr = glyph;
     return 0;
 
 error:
     if (glyph)
         av_freep(&glyph->glyph);

     av_freep(&glyph);
     av_freep(&node);
     return ret;
 }
 

 static av_cold int set_fontsize(AVFilterContext *ctx, unsigned int fontsize)
 {
     int err;
     DrawTextContext *s = ctx->priv;
 
     if ((err = FT_Set_Pixel_Sizes(s->face, 0, fontsize))) {
         av_log(ctx, AV_LOG_ERROR, "Could not set font size to %d pixels: %s\n",
                fontsize, FT_ERRMSG(err));
         return AVERROR(EINVAL);
     }
 
     s->fontsize = fontsize;
 
     return 0;
 }
 
 static av_cold int parse_fontsize(AVFilterContext *ctx)
 {
     DrawTextContext *s = ctx->priv;
     int err;
 
     if (s->fontsize_pexpr)
         return 0;
 
     if (s->fontsize_expr == NULL)
         return AVERROR(EINVAL);
 
     if ((err = av_expr_parse(&s->fontsize_pexpr, s->fontsize_expr, var_names,
                              NULL, NULL, fun2_names, fun2, 0, ctx)) < 0)
         return err;
 
     return 0;
 }
 
 static av_cold int update_fontsize(AVFilterContext *ctx)
 {
     DrawTextContext *s = ctx->priv;
     unsigned int fontsize = s->default_fontsize;
     int err;
     double size, roundedsize;
 
     // if no fontsize specified use the default
     if (s->fontsize_expr != NULL) {
         if ((err = parse_fontsize(ctx)) < 0)
            return err;
 
         size = av_expr_eval(s->fontsize_pexpr, s->var_values, &s->prng);
 
         if (!isnan(size)) {
             roundedsize = round(size);
             // test for overflow before cast
             if (!(roundedsize > INT_MIN && roundedsize < INT_MAX)) {
                 av_log(ctx, AV_LOG_ERROR, "fontsize overflow\n");
                 return AVERROR(EINVAL);
             }
 
             fontsize = roundedsize;
         }
     }
 
     if (fontsize == 0)
         fontsize = 1;
 
     // no change
     if (fontsize == s->fontsize)
         return 0;
 
     return set_fontsize(ctx, fontsize);
 }
 

 static int load_font_file(AVFilterContext *ctx, const char *path, int index)

 {

     DrawTextContext *s = ctx->priv;

     int err;
 

     err = FT_New_Face(s->library, path, index, &s->face);

     if (err) {

 #if !CONFIG_LIBFONTCONFIG

         av_log(ctx, AV_LOG_ERROR, "Could not load font \"%s\": %s\n",
                s->fontfile, FT_ERRMSG(err));

 #endif

         return AVERROR(EINVAL);
     }
     return 0;
 }
 

 #if CONFIG_LIBFONTCONFIG
 static int load_font_fontconfig(AVFilterContext *ctx)

 {

     DrawTextContext *s = ctx->priv;

     FcConfig *fontconfig;

     FcPattern *pat, *best;

     FcResult result = FcResultMatch;
     FcChar8 *filename;

     int index;

     double size;

     int err = AVERROR(ENOENT);

     int parse_err;

 
     fontconfig = FcInitLoadConfigAndFonts();
     if (!fontconfig) {

         av_log(ctx, AV_LOG_ERROR, "impossible to init fontconfig\n");

         return AVERROR_UNKNOWN;

     }

     pat = FcNameParse(s->fontfile ? s->fontfile :

                           (uint8_t *)(intptr_t)"default");

     if (!pat) {
         av_log(ctx, AV_LOG_ERROR, "could not parse fontconfig pat");

         return AVERROR(EINVAL);
     }

 
     FcPatternAddString(pat, FC_FAMILY, s->font);

 
     parse_err = parse_fontsize(ctx);
     if (!parse_err) {
         double size = av_expr_eval(s->fontsize_pexpr, s->var_values, &s->prng);
 
         if (isnan(size)) {
             av_log(ctx, AV_LOG_ERROR, "impossible to find font information");
             return AVERROR(EINVAL);
         }
 
         FcPatternAddDouble(pat, FC_SIZE, size);
     }

 
     FcDefaultSubstitute(pat);
 

     if (!FcConfigSubstitute(fontconfig, pat, FcMatchPattern)) {
         av_log(ctx, AV_LOG_ERROR, "could not substitue fontconfig options"); /* very unlikely */

         FcPatternDestroy(pat);
         return AVERROR(ENOMEM);

     }

     best = FcFontMatch(fontconfig, pat, &result);

     FcPatternDestroy(pat);
 

     if (!best || result != FcResultMatch) {
         av_log(ctx, AV_LOG_ERROR,
                "Cannot find a valid font for the family %s\n",

                s->font);
         goto fail;

     }

     if (
         FcPatternGetInteger(best, FC_INDEX, 0, &index   ) != FcResultMatch ||
         FcPatternGetDouble (best, FC_SIZE,  0, &size    ) != FcResultMatch) {
         av_log(ctx, AV_LOG_ERROR, "impossible to find font information");

         return AVERROR(EINVAL);
     }

     if (FcPatternGetString(best, FC_FILE, 0, &filename) != FcResultMatch) {

         av_log(ctx, AV_LOG_ERROR, "No file path for %s\n",
                s->font);
         goto fail;
     }
 

     av_log(ctx, AV_LOG_INFO, "Using \"%s\"\n", filename);

     if (parse_err)
         s->default_fontsize = size + 0.5;

     err = load_font_file(ctx, filename, index);

     if (err)
         return err;
     FcConfigDestroy(fontconfig);

 fail:
     FcPatternDestroy(best);
     return err;

 }
 #endif
 
 static int load_font(AVFilterContext *ctx)
 {

     DrawTextContext *s = ctx->priv;

     int err;
 
     /* load the face, and set up the encoding, which is by default UTF-8 */

     err = load_font_file(ctx, s->fontfile, 0);

     if (!err)
         return 0;

 #if CONFIG_LIBFONTCONFIG
     err = load_font_fontconfig(ctx);

     if (!err)
         return 0;
 #endif
     return err;
 }
 

 static int load_textfile(AVFilterContext *ctx)
 {

     DrawTextContext *s = ctx->priv;

     int err;
     uint8_t *textbuf;

     uint8_t *tmp;

     size_t textbuf_size;
 

     if ((err = av_file_map(s->textfile, &textbuf, &textbuf_size, 0, ctx)) < 0) {

         av_log(ctx, AV_LOG_ERROR,
                "The text file '%s' could not be read or is empty\n",

                s->textfile);

         return err;
     }
 

     if (textbuf_size > SIZE_MAX - 1 || !(tmp = av_realloc(s->text, textbuf_size + 1))) {

         av_file_unmap(textbuf, textbuf_size);

         return AVERROR(ENOMEM);

     }
     s->text = tmp;

     memcpy(s->text, textbuf, textbuf_size);
     s->text[textbuf_size] = 0;

     av_file_unmap(textbuf, textbuf_size);
 
     return 0;
 }
 

 static inline int is_newline(uint32_t c)
 {
     return c == '\n' || c == '\r' || c == '\f' || c == '\v';
 }
 
 #if CONFIG_LIBFRIBIDI
 static int shape_text(AVFilterContext *ctx)
 {
     DrawTextContext *s = ctx->priv;
     uint8_t *tmp;
     int ret = AVERROR(ENOMEM);
     static const FriBidiFlags flags = FRIBIDI_FLAGS_DEFAULT |
                                       FRIBIDI_FLAGS_ARABIC;
     FriBidiChar *unicodestr = NULL;
     FriBidiStrIndex len;
     FriBidiParType direction = FRIBIDI_PAR_LTR;
     FriBidiStrIndex line_start = 0;
     FriBidiStrIndex line_end = 0;
     FriBidiLevel *embedding_levels = NULL;
     FriBidiArabicProp *ar_props = NULL;
     FriBidiCharType *bidi_types = NULL;
     FriBidiStrIndex i,j;
 
     len = strlen(s->text);
     if (!(unicodestr = av_malloc_array(len, sizeof(*unicodestr)))) {
         goto out;
     }
     len = fribidi_charset_to_unicode(FRIBIDI_CHAR_SET_UTF8,
                                      s->text, len, unicodestr);
 
     bidi_types = av_malloc_array(len, sizeof(*bidi_types));
     if (!bidi_types) {
         goto out;
     }
 
     fribidi_get_bidi_types(unicodestr, len, bidi_types);
 
     embedding_levels = av_malloc_array(len, sizeof(*embedding_levels));
     if (!embedding_levels) {
         goto out;
     }
 
     if (!fribidi_get_par_embedding_levels(bidi_types, len, &direction,
                                           embedding_levels)) {
         goto out;
     }
 
     ar_props = av_malloc_array(len, sizeof(*ar_props));
     if (!ar_props) {
         goto out;
     }
 
     fribidi_get_joining_types(unicodestr, len, ar_props);
     fribidi_join_arabic(bidi_types, len, embedding_levels, ar_props);
     fribidi_shape(flags, embedding_levels, len, ar_props, unicodestr);
 
     for (line_end = 0, line_start = 0; line_end < len; line_end++) {
         if (is_newline(unicodestr[line_end]) || line_end == len - 1) {
             if (!fribidi_reorder_line(flags, bidi_types,
                                       line_end - line_start + 1, line_start,
                                       direction, embedding_levels, unicodestr,
                                       NULL)) {
                 goto out;
             }
             line_start = line_end + 1;
         }
     }
 
     /* Remove zero-width fill chars put in by libfribidi */
     for (i = 0, j = 0; i < len; i++)
         if (unicodestr[i] != FRIBIDI_CHAR_FILL)
             unicodestr[j++] = unicodestr[i];
     len = j;
 
     if (!(tmp = av_realloc(s->text, (len * 4 + 1) * sizeof(*s->text)))) {
         /* Use len * 4, as a unicode character can be up to 4 bytes in UTF-8 */
         goto out;
     }
 
     s->text = tmp;
     len = fribidi_unicode_to_charset(FRIBIDI_CHAR_SET_UTF8,
                                      unicodestr, len, s->text);
     ret = 0;
 
 out:
     av_free(unicodestr);
     av_free(embedding_levels);
     av_free(ar_props);
     av_free(bidi_types);
     return ret;
 }
 #endif
 

 static av_cold int init(AVFilterContext *ctx)

 {
     int err;

     DrawTextContext *s = ctx->priv;

     Glyph *glyph;
 

     av_expr_free(s->fontsize_pexpr);
     s->fontsize_pexpr = NULL;
 
     s->fontsize = 0;
     s->default_fontsize = 16;
 

     if (!s->fontfile && !CONFIG_LIBFONTCONFIG) {

         av_log(ctx, AV_LOG_ERROR, "No font filename provided\n");
         return AVERROR(EINVAL);
     }
 

     if (s->textfile) {
         if (s->text) {

             av_log(ctx, AV_LOG_ERROR,
                    "Both text and text file provided. Please provide only one\n");
             return AVERROR(EINVAL);
         }

         if ((err = load_textfile(ctx)) < 0)

             return err;
     }
 

     if (s->reload && !s->textfile)

         av_log(ctx, AV_LOG_WARNING, "No file to reload\n");
 

     if (s->tc_opt_string) {
         int ret = av_timecode_init_from_string(&s->tc, s->tc_rate,
                                                s->tc_opt_string, ctx);

         if (ret < 0)
             return ret;

         if (s->tc24hmax)
             s->tc.flags |= AV_TIMECODE_FLAG_24HOURSMAX;
         if (!s->text)
             s->text = av_strdup("");

     }
 

     if (!s->text) {

         av_log(ctx, AV_LOG_ERROR,

                "Either text, a valid file or a timecode must be provided\n");

         return AVERROR(EINVAL);
     }
 

 #if CONFIG_LIBFRIBIDI
     if (s->text_shaping)
         if ((err = shape_text(ctx)) < 0)
             return err;
 #endif
 

     if ((err = FT_Init_FreeType(&(s->library)))) {

         av_log(ctx, AV_LOG_ERROR,
                "Could not load FreeType: %s\n", FT_ERRMSG(err));
         return AVERROR(EINVAL);
     }
 

     if ((err = load_font(ctx)) < 0)
         return err;
 
     if ((err = update_fontsize(ctx)) < 0)

         return err;

     if (s->borderw) {
         if (FT_Stroker_New(s->library, &s->stroker)) {
             av_log(ctx, AV_LOG_ERROR, "Coult not init FT stroker\n");
             return AVERROR_EXTERNAL;
         }
         FT_Stroker_Set(s->stroker, s->borderw << 6, FT_STROKER_LINECAP_ROUND,
                        FT_STROKER_LINEJOIN_ROUND, 0);
     }
 

     s->use_kerning = FT_HAS_KERNING(s->face);

 
     /* load the fallback glyph with code 0 */
     load_glyph(ctx, NULL, 0);
 
     /* set the tabsize in pixels */

     if ((err = load_glyph(ctx, &glyph, ' ')) < 0) {

         av_log(ctx, AV_LOG_ERROR, "Could not set tabsize.\n");
         return err;
     }

     s->tabsize *= glyph->advance;

     if (s->exp_mode == EXP_STRFTIME &&
         (strchr(s->text, '%') || strchr(s->text, '\\')))

         av_log(ctx, AV_LOG_WARNING, "expansion=strftime is deprecated.\n");
 

     av_bprint_init(&s->expanded_text, 0, AV_BPRINT_SIZE_UNLIMITED);

     av_bprint_init(&s->expanded_fontcolor, 0, AV_BPRINT_SIZE_UNLIMITED);

     return 0;
 }
 
 static int query_formats(AVFilterContext *ctx)
 {

     return ff_set_common_formats(ctx, ff_draw_supported_pixel_formats(0));

 }
 
 static int glyph_enu_free(void *opaque, void *elem)
 {

     Glyph *glyph = elem;
 

     FT_Done_Glyph(glyph->glyph);

     FT_Done_Glyph(glyph->border_glyph);

     av_free(elem);
     return 0;
 }
 
 static av_cold void uninit(AVFilterContext *ctx)
 {

     DrawTextContext *s = ctx->priv;

     av_expr_free(s->x_pexpr);
     av_expr_free(s->y_pexpr);

     av_expr_free(s->a_pexpr);

     av_expr_free(s->fontsize_pexpr);
 
     s->x_pexpr = s->y_pexpr = s->a_pexpr = s->fontsize_pexpr = NULL;
 

     av_freep(&s->positions);

     s->nb_positions = 0;

     av_tree_enumerate(s->glyphs, NULL, NULL, glyph_enu_free);
     av_tree_destroy(s->glyphs);

     s->glyphs = NULL;

     FT_Done_Face(s->face);

     FT_Stroker_Done(s->stroker);

     FT_Done_FreeType(s->library);

     av_bprint_finalize(&s->expanded_text, NULL);

     av_bprint_finalize(&s->expanded_fontcolor, NULL);

 }
 
 static int config_input(AVFilterLink *inlink)
 {

     AVFilterContext *ctx = inlink->dst;

     DrawTextContext *s = ctx->priv;

     int ret;
 

     ff_draw_init(&s->dc, inlink->format, FF_DRAW_PROCESS_ALPHA);

     ff_draw_color(&s->dc, &s->fontcolor,   s->fontcolor.rgba);
     ff_draw_color(&s->dc, &s->shadowcolor, s->shadowcolor.rgba);

     ff_draw_color(&s->dc, &s->bordercolor, s->bordercolor.rgba);

     ff_draw_color(&s->dc, &s->boxcolor,    s->boxcolor.rgba);
 
     s->var_values[VAR_w]     = s->var_values[VAR_W]     = s->var_values[VAR_MAIN_W] = inlink->w;
     s->var_values[VAR_h]     = s->var_values[VAR_H]     = s->var_values[VAR_MAIN_H] = inlink->h;
     s->var_values[VAR_SAR]   = inlink->sample_aspect_ratio.num ? av_q2d(inlink->sample_aspect_ratio) : 1;
     s->var_values[VAR_DAR]   = (double)inlink->w / inlink->h * s->var_values[VAR_SAR];
     s->var_values[VAR_HSUB]  = 1 << s->dc.hsub_max;
     s->var_values[VAR_VSUB]  = 1 << s->dc.vsub_max;
     s->var_values[VAR_X]     = NAN;
     s->var_values[VAR_Y]     = NAN;
     s->var_values[VAR_T]     = NAN;

     av_lfg_init(&s->prng, av_get_random_seed());

     av_expr_free(s->x_pexpr);
     av_expr_free(s->y_pexpr);

     av_expr_free(s->a_pexpr);
     s->x_pexpr = s->y_pexpr = s->a_pexpr = NULL;

     if ((ret = av_expr_parse(&s->x_pexpr, s->x_expr, var_names,

                              NULL, NULL, fun2_names, fun2, 0, ctx)) < 0 ||

         (ret = av_expr_parse(&s->y_pexpr, s->y_expr, var_names,

                              NULL, NULL, fun2_names, fun2, 0, ctx)) < 0 ||
         (ret = av_expr_parse(&s->a_pexpr, s->a_expr, var_names,

                              NULL, NULL, fun2_names, fun2, 0, ctx)) < 0)
 

         return AVERROR(EINVAL);
 

     return 0;
 }
 

 static int command(AVFilterContext *ctx, const char *cmd, const char *arg, char *res, int res_len, int flags)
 {

     DrawTextContext *s = ctx->priv;

     if (!strcmp(cmd, "reinit")) {

         int ret;

         uninit(ctx);

         s->reinit = 1;

         if ((ret = av_set_options_string(ctx, arg, "=", ":")) < 0)
             return ret;

         if ((ret = init(ctx)) < 0)

             return ret;
         return config_input(ctx->inputs[0]);

     }
 
     return AVERROR(ENOSYS);
 }
 

 static int func_pict_type(AVFilterContext *ctx, AVBPrint *bp,
                           char *fct, unsigned argc, char **argv, int tag)
 {

     DrawTextContext *s = ctx->priv;

     av_bprintf(bp, "%c", av_get_picture_type_char(s->var_values[VAR_PICT_TYPE]));

     return 0;
 }
 

 static int func_pts(AVFilterContext *ctx, AVBPrint *bp,
                     char *fct, unsigned argc, char **argv, int tag)
 {

     DrawTextContext *s = ctx->priv;

     const char *fmt;
     double pts = s->var_values[VAR_T];
     int ret;

     fmt = argc >= 1 ? argv[0] : "flt";
     if (argc >= 2) {
         int64_t delta;
         if ((ret = av_parse_time(&delta, argv[1], 1)) < 0) {
             av_log(ctx, AV_LOG_ERROR, "Invalid delta '%s'\n", argv[1]);
             return ret;
         }
         pts += (double)delta / AV_TIME_BASE;
     }
     if (!strcmp(fmt, "flt")) {

         av_bprintf(bp, "%.6f", pts);

     } else if (!strcmp(fmt, "hms")) {
         if (isnan(pts)) {
             av_bprintf(bp, " ??:??:??.???");
         } else {

             int64_t ms = llrint(pts * 1000);

             char sign = ' ';
             if (ms < 0) {
                 sign = '-';
                 ms = -ms;
             }
             av_bprintf(bp, "%c%02d:%02d:%02d.%03d", sign,
                        (int)(ms / (60 * 60 * 1000)),
                        (int)(ms / (60 * 1000)) % 60,
                        (int)(ms / 1000) % 60,

                        (int)(ms % 1000));

         }

     } else if (!strcmp(fmt, "localtime") ||
                !strcmp(fmt, "gmtime")) {
         struct tm tm;
         time_t ms = (time_t)pts;
         const char *timefmt = argc >= 3 ? argv[2] : "%Y-%m-%d %H:%M:%S";
         if (!strcmp(fmt, "localtime"))
             localtime_r(&ms, &tm);
         else
             gmtime_r(&ms, &tm);
         av_bprint_strftime(bp, timefmt, &tm);

     } else {
         av_log(ctx, AV_LOG_ERROR, "Invalid format '%s'\n", fmt);
         return AVERROR(EINVAL);
     }

     return 0;
 }
 

 static int func_frame_num(AVFilterContext *ctx, AVBPrint *bp,
                           char *fct, unsigned argc, char **argv, int tag)
 {

     DrawTextContext *s = ctx->priv;

     av_bprintf(bp, "%d", (int)s->var_values[VAR_N]);

     return 0;
 }
 

 static int func_metadata(AVFilterContext *ctx, AVBPrint *bp,
                          char *fct, unsigned argc, char **argv, int tag)
 {
     DrawTextContext *s = ctx->priv;
     AVDictionaryEntry *e = av_dict_get(s->metadata, argv[0], NULL, 0);
 
     if (e && e->value)
         av_bprintf(bp, "%s", e->value);

     else if (argc >= 2)
         av_bprintf(bp, "%s", argv[1]);

     return 0;
 }
 

 static int func_strftime(AVFilterContext *ctx, AVBPrint *bp,
                          char *fct, unsigned argc, char **argv, int tag)
 {
     const char *fmt = argc ? argv[0] : "%Y-%m-%d %H:%M:%S";
     time_t now;
     struct tm tm;
 
     time(&now);
     if (tag == 'L')
         localtime_r(&now, &tm);
     else

         tm = *gmtime_r(&now, &tm);

     av_bprint_strftime(bp, fmt, &tm);
     return 0;
 }
 

 static int func_eval_expr(AVFilterContext *ctx, AVBPrint *bp,
                           char *fct, unsigned argc, char **argv, int tag)
 {

     DrawTextContext *s = ctx->priv;

     double res;
     int ret;
 

     ret = av_expr_parse_and_eval(&res, argv[0], var_names, s->var_values,

                                  NULL, NULL, fun2_names, fun2,

                                  &s->prng, 0, ctx);

     if (ret < 0)
         av_log(ctx, AV_LOG_ERROR,
                "Expression '%s' for the expr text expansion function is not valid\n",
                argv[0]);
     else
         av_bprintf(bp, "%f", res);
 
     return ret;
 }
 

 static int func_eval_expr_int_format(AVFilterContext *ctx, AVBPrint *bp,
                           char *fct, unsigned argc, char **argv, int tag)
 {
     DrawTextContext *s = ctx->priv;
     double res;
     int intval;
     int ret;
     unsigned int positions = 0;
     char fmt_str[30] = "%";
 
     /*
      * argv[0] expression to be converted to `int`
      * argv[1] format: 'x', 'X', 'd' or 'u'
      * argv[2] positions printed (optional)
      */
 
     ret = av_expr_parse_and_eval(&res, argv[0], var_names, s->var_values,
                                  NULL, NULL, fun2_names, fun2,
                                  &s->prng, 0, ctx);
     if (ret < 0) {
         av_log(ctx, AV_LOG_ERROR,
                "Expression '%s' for the expr text expansion function is not valid\n",
                argv[0]);
         return ret;
     }
 
     if (!strchr("xXdu", argv[1][0])) {
         av_log(ctx, AV_LOG_ERROR, "Invalid format '%c' specified,"
                 " allowed values: 'x', 'X', 'd', 'u'\n", argv[1][0]);
         return AVERROR(EINVAL);
     }
 
     if (argc == 3) {
         ret = sscanf(argv[2], "%u", &positions);
         if (ret != 1) {

             av_log(ctx, AV_LOG_ERROR, "expr_int_format(): Invalid number of positions"

                     " to print: '%s'\n", argv[2]);
             return AVERROR(EINVAL);
         }
     }
 
     feclearexcept(FE_ALL_EXCEPT);
     intval = res;
     if ((ret = fetestexcept(FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW))) {
         av_log(ctx, AV_LOG_ERROR, "Conversion of floating-point result to int failed. Control register: 0x%08x. Conversion result: %d\n", ret, intval);
         return AVERROR(EINVAL);
     }
 
     if (argc == 3)
         av_strlcatf(fmt_str, sizeof(fmt_str), "0%u", positions);
     av_strlcatf(fmt_str, sizeof(fmt_str), "%c", argv[1][0]);
 
     av_log(ctx, AV_LOG_DEBUG, "Formatting value %f (expr '%s') with spec '%s'\n",
             res, argv[0], fmt_str);
 
     av_bprintf(bp, fmt_str, intval);
 
     return 0;
 }
 

 static const struct drawtext_function {
     const char *name;
     unsigned argc_min, argc_max;

     int tag;                            /**< opaque argument to func */

     int (*func)(AVFilterContext *, AVBPrint *, char *, unsigned, char **, int);
 } functions[] = {

     { "expr",      1, 1, 0,   func_eval_expr },
     { "e",         1, 1, 0,   func_eval_expr },

     { "expr_int_format", 2, 3, 0, func_eval_expr_int_format },

     { "eif",       2, 3, 0,   func_eval_expr_int_format },

     { "pict_type", 0, 0, 0,   func_pict_type },

     { "pts",       0, 3, 0,   func_pts      },

     { "gmtime",    0, 1, 'G', func_strftime },
     { "localtime", 0, 1, 'L', func_strftime },

     { "frame_num", 0, 0, 0,   func_frame_num },
     { "n",         0, 0, 0,   func_frame_num },

     { "metadata",  1, 2, 0,   func_metadata },

 };
 
 static int eval_function(AVFilterContext *ctx, AVBPrint *bp, char *fct,
                          unsigned argc, char **argv)
 {
     unsigned i;
 
     for (i = 0; i < FF_ARRAY_ELEMS(functions); i++) {
         if (strcmp(fct, functions[i].name))
             continue;
         if (argc < functions[i].argc_min) {
             av_log(ctx, AV_LOG_ERROR, "%%{%s} requires at least %d arguments\n",
                    fct, functions[i].argc_min);
             return AVERROR(EINVAL);
         }
         if (argc > functions[i].argc_max) {
             av_log(ctx, AV_LOG_ERROR, "%%{%s} requires at most %d arguments\n",
                    fct, functions[i].argc_max);
             return AVERROR(EINVAL);
         }
         break;
     }
     if (i >= FF_ARRAY_ELEMS(functions)) {
         av_log(ctx, AV_LOG_ERROR, "%%{%s} is not known\n", fct);
         return AVERROR(EINVAL);
     }
     return functions[i].func(ctx, bp, fct, argc, argv, functions[i].tag);
 }
 
 static int expand_function(AVFilterContext *ctx, AVBPrint *bp, char **rtext)
 {
     const char *text = *rtext;
     char *argv[16] = { NULL };
     unsigned argc = 0, i;
     int ret;
 
     if (*text != '{') {
         av_log(ctx, AV_LOG_ERROR, "Stray %% near '%s'\n", text);
         return AVERROR(EINVAL);
     }
     text++;
     while (1) {
         if (!(argv[argc++] = av_get_token(&text, ":}"))) {
             ret = AVERROR(ENOMEM);
             goto end;
         }
         if (!*text) {
             av_log(ctx, AV_LOG_ERROR, "Unterminated %%{} near '%s'\n", *rtext);
             ret = AVERROR(EINVAL);
             goto end;
         }
         if (argc == FF_ARRAY_ELEMS(argv))
             av_freep(&argv[--argc]); /* error will be caught later */
         if (*text == '}')
             break;
         text++;
     }
 
     if ((ret = eval_function(ctx, bp, argv[0], argc - 1, argv + 1)) < 0)
         goto end;
     ret = 0;
     *rtext = (char *)text + 1;
 
 end:
     for (i = 0; i < argc; i++)
         av_freep(&argv[i]);
     return ret;
 }
 

 static int expand_text(AVFilterContext *ctx, char *text, AVBPrint *bp)

 {
     int ret;
 
     av_bprint_clear(bp);
     while (*text) {
         if (*text == '\\' && text[1]) {
             av_bprint_chars(bp, text[1], 1);
             text += 2;
         } else if (*text == '%') {
             text++;
             if ((ret = expand_function(ctx, bp, &text)) < 0)
                 return ret;
         } else {
             av_bprint_chars(bp, *text, 1);
             text++;
         }
     }
     if (!av_bprint_is_complete(bp))
         return AVERROR(ENOMEM);
     return 0;
 }
 

 static int draw_glyphs(DrawTextContext *s, AVFrame *frame,

                        int width, int height,

                        FFDrawColor *color,
                        int x, int y, int borderw)

 {

     char *text = s->expanded_text.str;

     uint32_t code = 0;

     int i, x1, y1;

     uint8_t *p;
     Glyph *glyph = NULL;
 
     for (i = 0, p = text; *p; i++) {

         FT_Bitmap bitmap;

         Glyph dummy = { 0 };
         GET_UTF8(code, *p++, continue;);
 
         /* skip new line chars, just go to new line */
         if (code == '\n' || code == '\r' || code == '\t')
             continue;
 
         dummy.code = code;

         dummy.fontsize = s->fontsize;

         glyph = av_tree_find(s->glyphs, &dummy, glyph_cmp, NULL);

         bitmap = borderw ? glyph->border_bitmap : glyph->bitmap;
 

         if (glyph->bitmap.pixel_mode != FT_PIXEL_MODE_MONO &&
             glyph->bitmap.pixel_mode != FT_PIXEL_MODE_GRAY)
             return AVERROR(EINVAL);
 

         x1 = s->positions[i].x+s->x+x - borderw;
         y1 = s->positions[i].y+s->y+y - borderw;

         ff_blend_mask(&s->dc, color,

                       frame->data, frame->linesize, width, height,

                       bitmap.buffer, bitmap.pitch,
                       bitmap.width, bitmap.rows,
                       bitmap.pixel_mode == FT_PIXEL_MODE_MONO ? 0 : 3,

                       0, x1, y1);

     }
 
     return 0;
 }
 

 static void update_color_with_alpha(DrawTextContext *s, FFDrawColor *color, const FFDrawColor incolor)
 {
     *color = incolor;
     color->rgba[3] = (color->rgba[3] * s->alpha) / 255;
     ff_draw_color(&s->dc, color, color->rgba);

 }
 

 static void update_alpha(DrawTextContext *s)
 {
     double alpha = av_expr_eval(s->a_pexpr, s->var_values, &s->prng);
 
     if (isnan(alpha))
         return;
 
     if (alpha >= 1.0)
         s->alpha = 255;
     else if (alpha <= 0)
         s->alpha = 0;
     else
         s->alpha = 256 * alpha;
 }
 

 static int draw_text(AVFilterContext *ctx, AVFrame *frame,

                      int width, int height)
 {

     DrawTextContext *s = ctx->priv;

     AVFilterLink *inlink = ctx->inputs[0];

     uint32_t code = 0, prev_code = 0;

     int x = 0, y = 0, i = 0, ret;

     int max_text_line_w = 0, len;
     int box_w, box_h;

     char *text;

     uint8_t *p;
     int y_min = 32000, y_max = -32000;

     int x_min = 32000, x_max = -32000;

     FT_Vector delta;
     Glyph *glyph = NULL, *prev_glyph = NULL;
     Glyph dummy = { 0 };
 

     time_t now = time(0);
     struct tm ltime;

     AVBPrint *bp = &s->expanded_text;

     FFDrawColor fontcolor;
     FFDrawColor shadowcolor;
     FFDrawColor bordercolor;
     FFDrawColor boxcolor;
 

     av_bprint_clear(bp);

     if(s->basetime != AV_NOPTS_VALUE)
         now= frame->pts*av_q2d(ctx->inputs[0]->time_base) + s->basetime/1000000;

     switch (s->exp_mode) {

     case EXP_NONE:

         av_bprintf(bp, "%s", s->text);

         break;
     case EXP_NORMAL:

         if ((ret = expand_text(ctx, s->text, &s->expanded_text)) < 0)

             return ret;
         break;
     case EXP_STRFTIME:
         localtime_r(&now, &ltime);

         av_bprint_strftime(bp, s->text, &ltime);

         break;
     }

     if (s->tc_opt_string) {

         char tcbuf[AV_TIMECODE_STR_SIZE];

         av_timecode_make_string(&s->tc, tcbuf, inlink->frame_count_out);

         av_bprint_clear(bp);

         av_bprintf(bp, "%s%s", s->text, tcbuf);

     }
 

     if (!av_bprint_is_complete(bp))

         return AVERROR(ENOMEM);

     text = s->expanded_text.str;
     if ((len = s->expanded_text.len) > s->nb_positions) {
         if (!(s->positions =
               av_realloc(s->positions, len*sizeof(*s->positions))))

             return AVERROR(ENOMEM);

         s->nb_positions = len;

     }
 

     if (s->fontcolor_expr[0]) {
         /* If expression is set, evaluate and replace the static value */
         av_bprint_clear(&s->expanded_fontcolor);
         if ((ret = expand_text(ctx, s->fontcolor_expr, &s->expanded_fontcolor)) < 0)
             return ret;
         if (!av_bprint_is_complete(&s->expanded_fontcolor))
             return AVERROR(ENOMEM);
         av_log(s, AV_LOG_DEBUG, "Evaluated fontcolor is '%s'\n", s->expanded_fontcolor.str);
         ret = av_parse_color(s->fontcolor.rgba, s->expanded_fontcolor.str, -1, s);
         if (ret)
             return ret;
         ff_draw_color(&s->dc, &s->fontcolor, s->fontcolor.rgba);
     }
 

     x = 0;
     y = 0;

     if ((ret = update_fontsize(ctx)) < 0)
         return ret;
 

     /* load and cache glyphs */

     for (i = 0, p = text; *p; i++) {

         GET_UTF8(code, *p++, continue;);
 
         /* get glyph */
         dummy.code = code;

         dummy.fontsize = s->fontsize;

         glyph = av_tree_find(s->glyphs, &dummy, glyph_cmp, NULL);

         if (!glyph) {

             ret = load_glyph(ctx, &glyph, code);
             if (ret < 0)
                 return ret;

         }

 
         y_min = FFMIN(glyph->bbox.yMin, y_min);
         y_max = FFMAX(glyph->bbox.yMax, y_max);

         x_min = FFMIN(glyph->bbox.xMin, x_min);
         x_max = FFMAX(glyph->bbox.xMax, x_max);

     }

     s->max_glyph_h = y_max - y_min;
     s->max_glyph_w = x_max - x_min;

 
     /* compute and save position for each glyph */
     glyph = NULL;

     for (i = 0, p = text; *p; i++) {

         GET_UTF8(code, *p++, continue;);
 
         /* skip the \n in the sequence \r\n */
         if (prev_code == '\r' && code == '\n')
             continue;
 
         prev_code = code;
         if (is_newline(code)) {

             max_text_line_w = FFMAX(max_text_line_w, x);

             y += s->max_glyph_h + s->line_spacing;

             x = 0;

             continue;
         }
 
         /* get glyph */
         prev_glyph = glyph;
         dummy.code = code;

         dummy.fontsize = s->fontsize;

         glyph = av_tree_find(s->glyphs, &dummy, glyph_cmp, NULL);

 
         /* kerning */

         if (s->use_kerning && prev_glyph && glyph->code) {
             FT_Get_Kerning(s->face, prev_glyph->code, glyph->code,

                            ft_kerning_default, &delta);
             x += delta.x >> 6;
         }
 
         /* save position */

         s->positions[i].x = x + glyph->bitmap_left;
         s->positions[i].y = y - glyph->bitmap_top + y_max;
         if (code == '\t') x  = (x / s->tabsize + 1)*s->tabsize;

         else              x += glyph->advance;
     }
 

     max_text_line_w = FFMAX(x, max_text_line_w);
 

     s->var_values[VAR_TW] = s->var_values[VAR_TEXT_W] = max_text_line_w;
     s->var_values[VAR_TH] = s->var_values[VAR_TEXT_H] = y + s->max_glyph_h;

     s->var_values[VAR_MAX_GLYPH_W] = s->max_glyph_w;
     s->var_values[VAR_MAX_GLYPH_H] = s->max_glyph_h;
     s->var_values[VAR_MAX_GLYPH_A] = s->var_values[VAR_ASCENT ] = y_max;
     s->var_values[VAR_MAX_GLYPH_D] = s->var_values[VAR_DESCENT] = y_min;

     s->var_values[VAR_LINE_H] = s->var_values[VAR_LH] = s->max_glyph_h;

     s->x = s->var_values[VAR_X] = av_expr_eval(s->x_pexpr, s->var_values, &s->prng);
     s->y = s->var_values[VAR_Y] = av_expr_eval(s->y_pexpr, s->var_values, &s->prng);
     s->x = s->var_values[VAR_X] = av_expr_eval(s->x_pexpr, s->var_values, &s->prng);

     update_alpha(s);

     update_color_with_alpha(s, &fontcolor  , s->fontcolor  );
     update_color_with_alpha(s, &shadowcolor, s->shadowcolor);
     update_color_with_alpha(s, &bordercolor, s->bordercolor);
     update_color_with_alpha(s, &boxcolor   , s->boxcolor   );
 

     box_w = FFMIN(width - 1 , max_text_line_w);

     box_h = FFMIN(height - 1, y + s->max_glyph_h);

 
     /* draw box */

     if (s->draw_box)

         ff_blend_rectangle(&s->dc, &boxcolor,

                            frame->data, frame->linesize, width, height,

                            s->x - s->boxborderw, s->y - s->boxborderw,
                            box_w + s->boxborderw * 2, box_h + s->boxborderw * 2);

     if (s->shadowx || s->shadowy) {

         if ((ret = draw_glyphs(s, frame, width, height,

                                &shadowcolor, s->shadowx, s->shadowy, 0)) < 0)

             return ret;
     }
 

     if (s->borderw) {

         if ((ret = draw_glyphs(s, frame, width, height,

                                &bordercolor, 0, 0, s->borderw)) < 0)

             return ret;
     }

     if ((ret = draw_glyphs(s, frame, width, height,

                            &fontcolor, 0, 0, 0)) < 0)

         return ret;

 
     return 0;
 }
 

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

 {

     AVFilterContext *ctx = inlink->dst;

     AVFilterLink *outlink = ctx->outputs[0];

     DrawTextContext *s = ctx->priv;

     int ret;

     if (s->reload) {

         if ((ret = load_textfile(ctx)) < 0) {
             av_frame_free(&frame);

             return ret;

         }

 #if CONFIG_LIBFRIBIDI
         if (s->text_shaping)

             if ((ret = shape_text(ctx)) < 0) {
                 av_frame_free(&frame);

                 return ret;

             }

 #endif
     }

     s->var_values[VAR_N] = inlink->frame_count_out + s->start_number;

     s->var_values[VAR_T] = frame->pts == AV_NOPTS_VALUE ?

         NAN : frame->pts * av_q2d(inlink->time_base);

     s->var_values[VAR_PICT_TYPE] = frame->pict_type;

     s->metadata = frame->metadata;

     draw_text(ctx, frame, frame->width, frame->height);

 
     av_log(ctx, AV_LOG_DEBUG, "n:%d t:%f text_w:%d text_h:%d x:%d y:%d\n",

            (int)s->var_values[VAR_N], s->var_values[VAR_T],
            (int)s->var_values[VAR_TEXT_W], (int)s->var_values[VAR_TEXT_H],
            s->x, s->y);

     return ff_filter_frame(outlink, frame);

 }
 

 static const AVFilterPad avfilter_vf_drawtext_inputs[] = {
     {

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

     },
     { NULL }
 };
 
 static const AVFilterPad avfilter_vf_drawtext_outputs[] = {
     {
         .name = "default",
         .type = AVMEDIA_TYPE_VIDEO,
     },
     { NULL }
 };
 

 AVFilter ff_vf_drawtext = {

     .name          = "drawtext",
     .description   = NULL_IF_CONFIG_SMALL("Draw text on top of video frames using libfreetype library."),
     .priv_size     = sizeof(DrawTextContext),

     .priv_class    = &drawtext_class,

     .init          = init,
     .uninit        = uninit,
     .query_formats = query_formats,

     .inputs        = avfilter_vf_drawtext_inputs,
     .outputs       = avfilter_vf_drawtext_outputs,

     .process_command = command,

     .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,

 };