vf_drawtext.c
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1 /*
2  * Copyright (c) 2011 Stefano Sabatini
3  * Copyright (c) 2010 S.N. Hemanth Meenakshisundaram
4  * Copyright (c) 2003 Gustavo Sverzut Barbieri <gsbarbieri@yahoo.com.br>
5  *
6  * This file is part of Libav.
7  *
8  * Libav is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * Libav is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with Libav; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
29 #include <sys/time.h>
30 #include <time.h>
31 
32 #include "libavutil/colorspace.h"
33 #include "libavutil/file.h"
34 #include "libavutil/eval.h"
35 #include "libavutil/opt.h"
36 #include "libavutil/mathematics.h"
37 #include "libavutil/random_seed.h"
38 #include "libavutil/parseutils.h"
39 #include "libavutil/pixdesc.h"
40 #include "libavutil/tree.h"
41 #include "libavutil/lfg.h"
42 #include "avfilter.h"
43 #include "drawutils.h"
44 
45 #undef time
46 
47 #include <ft2build.h>
48 #include <freetype/config/ftheader.h>
49 #include FT_FREETYPE_H
50 #include FT_GLYPH_H
51 
52 static const char *var_names[] = {
53  "E",
54  "PHI",
55  "PI",
56  "main_w", "W",
57  "main_h", "H",
58  "text_w", "w",
59  "text_h", "h",
60  "x",
61  "y",
62  "n",
63  "t",
64  NULL
65 };
66 
67 static const char *fun2_names[] = {
68  "rand",
69 };
70 
71 static double drand(void *opaque, double min, double max)
72 {
73  return min + (max-min) / UINT_MAX * av_lfg_get(opaque);
74 }
75 
76 typedef double (*eval_func2)(void *, double a, double b);
77 
78 static const eval_func2 fun2[] = {
79  drand,
80  NULL
81 };
82 
83 enum var_name {
96 };
97 
98 typedef struct {
99  const AVClass *class;
100  uint8_t *fontfile;
101  uint8_t *text;
102  uint8_t *expanded_text;
105  FT_Vector *positions;
106  size_t nb_positions;
107  char *textfile;
108  int x, y;
109  int w, h;
110  int shadowx, shadowy;
111  unsigned int fontsize;
115  uint8_t fontcolor[4];
116  uint8_t boxcolor[4];
117  uint8_t shadowcolor[4];
118  uint8_t fontcolor_rgba[4];
119  uint8_t boxcolor_rgba[4];
120  uint8_t shadowcolor_rgba[4];
121 
122  short int draw_box;
124  int tabsize;
125 
126  FT_Library library;
127  FT_Face face;
128  struct AVTreeNode *glyphs;
129  int hsub, vsub;
131  int pixel_step[4];
132  uint8_t rgba_map[4];
133  uint8_t *box_line[4];
134  char *x_expr, *y_expr;
135  AVExpr *x_pexpr, *y_pexpr;
136  double var_values[VAR_VARS_NB];
137  char *d_expr;
139  int draw;
142 
143 #define OFFSET(x) offsetof(DrawTextContext, x)
144 
145 static const AVOption drawtext_options[]= {
146 {"fontfile", "set font file", OFFSET(fontfile), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX },
147 {"text", "set text", OFFSET(text), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX },
148 {"textfile", "set text file", OFFSET(textfile), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX },
149 {"fontcolor","set foreground color", OFFSET(fontcolor_string), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX },
150 {"boxcolor", "set box color", OFFSET(boxcolor_string), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX },
151 {"shadowcolor", "set shadow color", OFFSET(shadowcolor_string), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX },
152 {"box", "set box", OFFSET(draw_box), AV_OPT_TYPE_INT, {.dbl=0}, 0, 1 },
153 {"fontsize", "set font size", OFFSET(fontsize), AV_OPT_TYPE_INT, {.dbl=16}, 1, 72 },
154 {"x", "set x", OFFSET(x_expr), AV_OPT_TYPE_STRING, {.str="0"}, CHAR_MIN, CHAR_MAX },
155 {"y", "set y", OFFSET(y_expr), AV_OPT_TYPE_STRING, {.str="0"}, CHAR_MIN, CHAR_MAX },
156 {"shadowx", "set x", OFFSET(shadowx), AV_OPT_TYPE_INT, {.dbl=0}, INT_MIN, INT_MAX },
157 {"shadowy", "set y", OFFSET(shadowy), AV_OPT_TYPE_INT, {.dbl=0}, INT_MIN, INT_MAX },
158 {"tabsize", "set tab size", OFFSET(tabsize), AV_OPT_TYPE_INT, {.dbl=4}, 0, INT_MAX },
159 {"draw", "if false do not draw", OFFSET(d_expr), AV_OPT_TYPE_STRING, {.str="1"}, CHAR_MIN, CHAR_MAX },
160 
161 /* FT_LOAD_* flags */
162 {"ft_load_flags", "set font loading flags for libfreetype", OFFSET(ft_load_flags), AV_OPT_TYPE_FLAGS, {.dbl=FT_LOAD_DEFAULT|FT_LOAD_RENDER}, 0, INT_MAX, 0, "ft_load_flags" },
163 {"default", "set default", 0, AV_OPT_TYPE_CONST, {FT_LOAD_DEFAULT}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
164 {"no_scale", "set no_scale", 0, AV_OPT_TYPE_CONST, {FT_LOAD_NO_SCALE}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
165 {"no_hinting", "set no_hinting", 0, AV_OPT_TYPE_CONST, {FT_LOAD_NO_HINTING}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
166 {"render", "set render", 0, AV_OPT_TYPE_CONST, {FT_LOAD_RENDER}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
167 {"no_bitmap", "set no_bitmap", 0, AV_OPT_TYPE_CONST, {FT_LOAD_NO_BITMAP}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
168 {"vertical_layout", "set vertical_layout", 0, AV_OPT_TYPE_CONST, {FT_LOAD_VERTICAL_LAYOUT}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
169 {"force_autohint", "set force_autohint", 0, AV_OPT_TYPE_CONST, {FT_LOAD_FORCE_AUTOHINT}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
170 {"crop_bitmap", "set crop_bitmap", 0, AV_OPT_TYPE_CONST, {FT_LOAD_CROP_BITMAP}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
171 {"pedantic", "set pedantic", 0, AV_OPT_TYPE_CONST, {FT_LOAD_PEDANTIC}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
172 {"ignore_global_advance_width", "set ignore_global_advance_width", 0, AV_OPT_TYPE_CONST, {FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
173 {"no_recurse", "set no_recurse", 0, AV_OPT_TYPE_CONST, {FT_LOAD_NO_RECURSE}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
174 {"ignore_transform", "set ignore_transform", 0, AV_OPT_TYPE_CONST, {FT_LOAD_IGNORE_TRANSFORM}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
175 {"monochrome", "set monochrome", 0, AV_OPT_TYPE_CONST, {FT_LOAD_MONOCHROME}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
176 {"linear_design", "set linear_design", 0, AV_OPT_TYPE_CONST, {FT_LOAD_LINEAR_DESIGN}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
177 {"no_autohint", "set no_autohint", 0, AV_OPT_TYPE_CONST, {FT_LOAD_NO_AUTOHINT}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
178 {NULL},
179 };
180 
181 static const char *drawtext_get_name(void *ctx)
182 {
183  return "drawtext";
184 }
185 
186 static const AVClass drawtext_class = {
187  "DrawTextContext",
189  drawtext_options
190 };
191 
192 #undef __FTERRORS_H__
193 #define FT_ERROR_START_LIST {
194 #define FT_ERRORDEF(e, v, s) { (e), (s) },
195 #define FT_ERROR_END_LIST { 0, NULL } };
196 
197 struct ft_error
198 {
199  int err;
200  const char *err_msg;
201 } static ft_errors[] =
202 #include FT_ERRORS_H
203 
204 #define FT_ERRMSG(e) ft_errors[e].err_msg
205 
206 typedef struct {
207  FT_Glyph *glyph;
208  uint32_t code;
209  FT_Bitmap bitmap;
210  FT_BBox bbox;
211  int advance;
212  int bitmap_left;
213  int bitmap_top;
214 } Glyph;
215 
216 static int glyph_cmp(void *key, const void *b)
217 {
218  const Glyph *a = key, *bb = b;
219  int64_t diff = (int64_t)a->code - (int64_t)bb->code;
220  return diff > 0 ? 1 : diff < 0 ? -1 : 0;
221 }
222 
226 static int load_glyph(AVFilterContext *ctx, Glyph **glyph_ptr, uint32_t code)
227 {
228  DrawTextContext *dtext = ctx->priv;
229  Glyph *glyph;
230  struct AVTreeNode *node = NULL;
231  int ret;
232 
233  /* load glyph into dtext->face->glyph */
234  if (FT_Load_Char(dtext->face, code, dtext->ft_load_flags))
235  return AVERROR(EINVAL);
236 
237  /* save glyph */
238  if (!(glyph = av_mallocz(sizeof(*glyph))) ||
239  !(glyph->glyph = av_mallocz(sizeof(*glyph->glyph)))) {
240  ret = AVERROR(ENOMEM);
241  goto error;
242  }
243  glyph->code = code;
244 
245  if (FT_Get_Glyph(dtext->face->glyph, glyph->glyph)) {
246  ret = AVERROR(EINVAL);
247  goto error;
248  }
249 
250  glyph->bitmap = dtext->face->glyph->bitmap;
251  glyph->bitmap_left = dtext->face->glyph->bitmap_left;
252  glyph->bitmap_top = dtext->face->glyph->bitmap_top;
253  glyph->advance = dtext->face->glyph->advance.x >> 6;
254 
255  /* measure text height to calculate text_height (or the maximum text height) */
256  FT_Glyph_Get_CBox(*glyph->glyph, ft_glyph_bbox_pixels, &glyph->bbox);
257 
258  /* cache the newly created glyph */
259  if (!(node = av_mallocz(av_tree_node_size))) {
260  ret = AVERROR(ENOMEM);
261  goto error;
262  }
263  av_tree_insert(&dtext->glyphs, glyph, glyph_cmp, &node);
264 
265  if (glyph_ptr)
266  *glyph_ptr = glyph;
267  return 0;
268 
269 error:
270  if (glyph)
271  av_freep(&glyph->glyph);
272  av_freep(&glyph);
273  av_freep(&node);
274  return ret;
275 }
276 
277 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
278 {
279  int err;
280  DrawTextContext *dtext = ctx->priv;
281  Glyph *glyph;
282 
283  dtext->class = &drawtext_class;
284  av_opt_set_defaults(dtext);
285  dtext->fontcolor_string = av_strdup("black");
286  dtext->boxcolor_string = av_strdup("white");
287  dtext->shadowcolor_string = av_strdup("black");
288 
289  if ((err = (av_set_options_string(dtext, args, "=", ":"))) < 0) {
290  av_log(ctx, AV_LOG_ERROR, "Error parsing options string: '%s'\n", args);
291  return err;
292  }
293 
294  if (!dtext->fontfile) {
295  av_log(ctx, AV_LOG_ERROR, "No font filename provided\n");
296  return AVERROR(EINVAL);
297  }
298 
299  if (dtext->textfile) {
300  uint8_t *textbuf;
301  size_t textbuf_size;
302 
303  if (dtext->text) {
304  av_log(ctx, AV_LOG_ERROR,
305  "Both text and text file provided. Please provide only one\n");
306  return AVERROR(EINVAL);
307  }
308  if ((err = av_file_map(dtext->textfile, &textbuf, &textbuf_size, 0, ctx)) < 0) {
309  av_log(ctx, AV_LOG_ERROR,
310  "The text file '%s' could not be read or is empty\n",
311  dtext->textfile);
312  return err;
313  }
314 
315  if (!(dtext->text = av_malloc(textbuf_size+1)))
316  return AVERROR(ENOMEM);
317  memcpy(dtext->text, textbuf, textbuf_size);
318  dtext->text[textbuf_size] = 0;
319  av_file_unmap(textbuf, textbuf_size);
320  }
321 
322  if (!dtext->text) {
323  av_log(ctx, AV_LOG_ERROR,
324  "Either text or a valid file must be provided\n");
325  return AVERROR(EINVAL);
326  }
327 
328  if ((err = av_parse_color(dtext->fontcolor_rgba, dtext->fontcolor_string, -1, ctx))) {
329  av_log(ctx, AV_LOG_ERROR,
330  "Invalid font color '%s'\n", dtext->fontcolor_string);
331  return err;
332  }
333 
334  if ((err = av_parse_color(dtext->boxcolor_rgba, dtext->boxcolor_string, -1, ctx))) {
335  av_log(ctx, AV_LOG_ERROR,
336  "Invalid box color '%s'\n", dtext->boxcolor_string);
337  return err;
338  }
339 
340  if ((err = av_parse_color(dtext->shadowcolor_rgba, dtext->shadowcolor_string, -1, ctx))) {
341  av_log(ctx, AV_LOG_ERROR,
342  "Invalid shadow color '%s'\n", dtext->shadowcolor_string);
343  return err;
344  }
345 
346  if ((err = FT_Init_FreeType(&(dtext->library)))) {
347  av_log(ctx, AV_LOG_ERROR,
348  "Could not load FreeType: %s\n", FT_ERRMSG(err));
349  return AVERROR(EINVAL);
350  }
351 
352  /* load the face, and set up the encoding, which is by default UTF-8 */
353  if ((err = FT_New_Face(dtext->library, dtext->fontfile, 0, &dtext->face))) {
354  av_log(ctx, AV_LOG_ERROR, "Could not load fontface from file '%s': %s\n",
355  dtext->fontfile, FT_ERRMSG(err));
356  return AVERROR(EINVAL);
357  }
358  if ((err = FT_Set_Pixel_Sizes(dtext->face, 0, dtext->fontsize))) {
359  av_log(ctx, AV_LOG_ERROR, "Could not set font size to %d pixels: %s\n",
360  dtext->fontsize, FT_ERRMSG(err));
361  return AVERROR(EINVAL);
362  }
363 
364  dtext->use_kerning = FT_HAS_KERNING(dtext->face);
365 
366  /* load the fallback glyph with code 0 */
367  load_glyph(ctx, NULL, 0);
368 
369  /* set the tabsize in pixels */
370  if ((err = load_glyph(ctx, &glyph, ' ') < 0)) {
371  av_log(ctx, AV_LOG_ERROR, "Could not set tabsize.\n");
372  return err;
373  }
374  dtext->tabsize *= glyph->advance;
375 
376 #if !HAVE_LOCALTIME_R
377  av_log(ctx, AV_LOG_WARNING, "strftime() expansion unavailable!\n");
378 #endif
379 
380  return 0;
381 }
382 
384 {
385  static const enum PixelFormat pix_fmts[] = {
393  };
394 
396  return 0;
397 }
398 
399 static int glyph_enu_free(void *opaque, void *elem)
400 {
401  av_free(elem);
402  return 0;
403 }
404 
405 static av_cold void uninit(AVFilterContext *ctx)
406 {
407  DrawTextContext *dtext = ctx->priv;
408  int i;
409 
410  av_freep(&dtext->fontfile);
411  av_freep(&dtext->text);
412  av_freep(&dtext->expanded_text);
413  av_freep(&dtext->fontcolor_string);
414  av_freep(&dtext->boxcolor_string);
415  av_freep(&dtext->positions);
416  av_freep(&dtext->shadowcolor_string);
418  av_tree_destroy(dtext->glyphs);
419  dtext->glyphs = 0;
420  FT_Done_Face(dtext->face);
421  FT_Done_FreeType(dtext->library);
422 
423  for (i = 0; i < 4; i++) {
424  av_freep(&dtext->box_line[i]);
425  dtext->pixel_step[i] = 0;
426  }
427 
428 }
429 
430 static inline int is_newline(uint32_t c)
431 {
432  return c == '\n' || c == '\r' || c == '\f' || c == '\v';
433 }
434 
436 {
437  DrawTextContext *dtext = ctx->priv;
438  uint32_t code = 0, prev_code = 0;
439  int x = 0, y = 0, i = 0, ret;
440  int text_height, baseline;
441  char *text = dtext->text;
442  uint8_t *p;
443  int str_w = 0, len;
444  int y_min = 32000, y_max = -32000;
445  FT_Vector delta;
446  Glyph *glyph = NULL, *prev_glyph = NULL;
447  Glyph dummy = { 0 };
448  int width = ctx->inputs[0]->w;
449  int height = ctx->inputs[0]->h;
450 
451 #if HAVE_LOCALTIME_R
452  time_t now = time(0);
453  struct tm ltime;
454  uint8_t *buf = dtext->expanded_text;
455  int buf_size = dtext->expanded_text_size;
456 
457  if (!buf)
458  buf_size = 2*strlen(dtext->text)+1;
459 
460  localtime_r(&now, &ltime);
461 
462  while ((buf = av_realloc(buf, buf_size))) {
463  *buf = 1;
464  if (strftime(buf, buf_size, dtext->text, &ltime) != 0 || *buf == 0)
465  break;
466  buf_size *= 2;
467  }
468 
469  if (!buf)
470  return AVERROR(ENOMEM);
471  text = dtext->expanded_text = buf;
472  dtext->expanded_text_size = buf_size;
473 #endif
474 
475  if ((len = strlen(text)) > dtext->nb_positions) {
476  FT_Vector *p = av_realloc(dtext->positions,
477  len * sizeof(*dtext->positions));
478  if (!p) {
479  av_freep(dtext->positions);
480  dtext->nb_positions = 0;
481  return AVERROR(ENOMEM);
482  } else {
483  dtext->positions = p;
484  dtext->nb_positions = len;
485  }
486  }
487 
488  /* load and cache glyphs */
489  for (i = 0, p = text; *p; i++) {
490  GET_UTF8(code, *p++, continue;);
491 
492  /* get glyph */
493  dummy.code = code;
494  glyph = av_tree_find(dtext->glyphs, &dummy, glyph_cmp, NULL);
495  if (!glyph)
496  ret = load_glyph(ctx, &glyph, code);
497  if (ret) return ret;
498 
499  y_min = FFMIN(glyph->bbox.yMin, y_min);
500  y_max = FFMAX(glyph->bbox.yMax, y_max);
501  }
502  text_height = y_max - y_min;
503  baseline = y_max;
504 
505  /* compute and save position for each glyph */
506  glyph = NULL;
507  for (i = 0, p = text; *p; i++) {
508  GET_UTF8(code, *p++, continue;);
509 
510  /* skip the \n in the sequence \r\n */
511  if (prev_code == '\r' && code == '\n')
512  continue;
513 
514  prev_code = code;
515  if (is_newline(code)) {
516  str_w = FFMAX(str_w, x - dtext->x);
517  y += text_height;
518  x = 0;
519  continue;
520  }
521 
522  /* get glyph */
523  prev_glyph = glyph;
524  dummy.code = code;
525  glyph = av_tree_find(dtext->glyphs, &dummy, glyph_cmp, NULL);
526 
527  /* kerning */
528  if (dtext->use_kerning && prev_glyph && glyph->code) {
529  FT_Get_Kerning(dtext->face, prev_glyph->code, glyph->code,
530  ft_kerning_default, &delta);
531  x += delta.x >> 6;
532  }
533 
534  if (x + glyph->bbox.xMax >= width) {
535  str_w = FFMAX(str_w, x);
536  y += text_height;
537  x = 0;
538  }
539 
540  /* save position */
541  dtext->positions[i].x = x + glyph->bitmap_left;
542  dtext->positions[i].y = y - glyph->bitmap_top + baseline;
543  if (code == '\t') x = (x / dtext->tabsize + 1)*dtext->tabsize;
544  else x += glyph->advance;
545  }
546 
547  str_w = FFMIN(width - 1, FFMAX(str_w, x));
548  y = FFMIN(y + text_height, height - 1);
549 
550  dtext->w = str_w;
551  dtext->h = y;
552 
553  return 0;
554 }
555 
556 
557 static int config_input(AVFilterLink *inlink)
558 {
559  AVFilterContext *ctx = inlink->dst;
560  DrawTextContext *dtext = ctx->priv;
561  const AVPixFmtDescriptor *pix_desc = &av_pix_fmt_descriptors[inlink->format];
562  int ret;
563 
564  dtext->hsub = pix_desc->log2_chroma_w;
565  dtext->vsub = pix_desc->log2_chroma_h;
566 
567  dtext->var_values[VAR_E ] = M_E;
568  dtext->var_values[VAR_PHI] = M_PHI;
569  dtext->var_values[VAR_PI ] = M_PI;
570 
571  dtext->var_values[VAR_MAIN_W] =
572  dtext->var_values[VAR_MW] = ctx->inputs[0]->w;
573  dtext->var_values[VAR_MAIN_H] =
574  dtext->var_values[VAR_MH] = ctx->inputs[0]->h;
575 
576  dtext->var_values[VAR_X] = 0;
577  dtext->var_values[VAR_Y] = 0;
578  dtext->var_values[VAR_N] = 0;
579  dtext->var_values[VAR_T] = NAN;
580 
581  av_lfg_init(&dtext->prng, av_get_random_seed());
582 
583  if ((ret = av_expr_parse(&dtext->x_pexpr, dtext->x_expr, var_names,
584  NULL, NULL, fun2_names, fun2, 0, ctx)) < 0 ||
585  (ret = av_expr_parse(&dtext->y_pexpr, dtext->y_expr, var_names,
586  NULL, NULL, fun2_names, fun2, 0, ctx)) < 0 ||
587  (ret = av_expr_parse(&dtext->d_pexpr, dtext->d_expr, var_names,
588  NULL, NULL, fun2_names, fun2, 0, ctx)) < 0)
589  return AVERROR(EINVAL);
590 
591  if ((ret =
593  inlink->w, dtext->boxcolor,
594  inlink->format, dtext->boxcolor_rgba,
595  &dtext->is_packed_rgb, dtext->rgba_map)) < 0)
596  return ret;
597 
598  if (!dtext->is_packed_rgb) {
599  uint8_t *rgba = dtext->fontcolor_rgba;
600  dtext->fontcolor[0] = RGB_TO_Y_CCIR(rgba[0], rgba[1], rgba[2]);
601  dtext->fontcolor[1] = RGB_TO_U_CCIR(rgba[0], rgba[1], rgba[2], 0);
602  dtext->fontcolor[2] = RGB_TO_V_CCIR(rgba[0], rgba[1], rgba[2], 0);
603  dtext->fontcolor[3] = rgba[3];
604  rgba = dtext->shadowcolor_rgba;
605  dtext->shadowcolor[0] = RGB_TO_Y_CCIR(rgba[0], rgba[1], rgba[2]);
606  dtext->shadowcolor[1] = RGB_TO_U_CCIR(rgba[0], rgba[1], rgba[2], 0);
607  dtext->shadowcolor[2] = RGB_TO_V_CCIR(rgba[0], rgba[1], rgba[2], 0);
608  dtext->shadowcolor[3] = rgba[3];
609  }
610 
611  dtext->draw = 1;
612 
613  return dtext_prepare_text(ctx);
614 }
615 
616 #define GET_BITMAP_VAL(r, c) \
617  bitmap->pixel_mode == FT_PIXEL_MODE_MONO ? \
618  (bitmap->buffer[(r) * bitmap->pitch + ((c)>>3)] & (0x80 >> ((c)&7))) * 255 : \
619  bitmap->buffer[(r) * bitmap->pitch + (c)]
620 
621 #define SET_PIXEL_YUV(picref, yuva_color, val, x, y, hsub, vsub) { \
622  luma_pos = ((x) ) + ((y) ) * picref->linesize[0]; \
623  alpha = yuva_color[3] * (val) * 129; \
624  picref->data[0][luma_pos] = (alpha * yuva_color[0] + (255*255*129 - alpha) * picref->data[0][luma_pos] ) >> 23; \
625  if (((x) & ((1<<(hsub)) - 1)) == 0 && ((y) & ((1<<(vsub)) - 1)) == 0) {\
626  chroma_pos1 = ((x) >> (hsub)) + ((y) >> (vsub)) * picref->linesize[1]; \
627  chroma_pos2 = ((x) >> (hsub)) + ((y) >> (vsub)) * picref->linesize[2]; \
628  picref->data[1][chroma_pos1] = (alpha * yuva_color[1] + (255*255*129 - alpha) * picref->data[1][chroma_pos1]) >> 23; \
629  picref->data[2][chroma_pos2] = (alpha * yuva_color[2] + (255*255*129 - alpha) * picref->data[2][chroma_pos2]) >> 23; \
630  }\
631 }
632 
633 static inline int draw_glyph_yuv(AVFilterBufferRef *picref, FT_Bitmap *bitmap, unsigned int x,
634  unsigned int y, unsigned int width, unsigned int height,
635  const uint8_t yuva_color[4], int hsub, int vsub)
636 {
637  int r, c, alpha;
638  unsigned int luma_pos, chroma_pos1, chroma_pos2;
639  uint8_t src_val;
640 
641  for (r = 0; r < bitmap->rows && r+y < height; r++) {
642  for (c = 0; c < bitmap->width && c+x < width; c++) {
643  /* get intensity value in the glyph bitmap (source) */
644  src_val = GET_BITMAP_VAL(r, c);
645  if (!src_val)
646  continue;
647 
648  SET_PIXEL_YUV(picref, yuva_color, src_val, c+x, y+r, hsub, vsub);
649  }
650  }
651 
652  return 0;
653 }
654 
655 #define SET_PIXEL_RGB(picref, rgba_color, val, x, y, pixel_step, r_off, g_off, b_off, a_off) { \
656  p = picref->data[0] + (x) * pixel_step + ((y) * picref->linesize[0]); \
657  alpha = rgba_color[3] * (val) * 129; \
658  *(p+r_off) = (alpha * rgba_color[0] + (255*255*129 - alpha) * *(p+r_off)) >> 23; \
659  *(p+g_off) = (alpha * rgba_color[1] + (255*255*129 - alpha) * *(p+g_off)) >> 23; \
660  *(p+b_off) = (alpha * rgba_color[2] + (255*255*129 - alpha) * *(p+b_off)) >> 23; \
661 }
662 
663 static inline int draw_glyph_rgb(AVFilterBufferRef *picref, FT_Bitmap *bitmap,
664  unsigned int x, unsigned int y,
665  unsigned int width, unsigned int height, int pixel_step,
666  const uint8_t rgba_color[4], const uint8_t rgba_map[4])
667 {
668  int r, c, alpha;
669  uint8_t *p;
670  uint8_t src_val;
671 
672  for (r = 0; r < bitmap->rows && r+y < height; r++) {
673  for (c = 0; c < bitmap->width && c+x < width; c++) {
674  /* get intensity value in the glyph bitmap (source) */
675  src_val = GET_BITMAP_VAL(r, c);
676  if (!src_val)
677  continue;
678 
679  SET_PIXEL_RGB(picref, rgba_color, src_val, c+x, y+r, pixel_step,
680  rgba_map[0], rgba_map[1], rgba_map[2], rgba_map[3]);
681  }
682  }
683 
684  return 0;
685 }
686 
687 static inline void drawbox(AVFilterBufferRef *picref, unsigned int x, unsigned int y,
688  unsigned int width, unsigned int height,
689  uint8_t *line[4], int pixel_step[4], uint8_t color[4],
690  int hsub, int vsub, int is_rgba_packed, uint8_t rgba_map[4])
691 {
692  int i, j, alpha;
693 
694  if (color[3] != 0xFF) {
695  if (is_rgba_packed) {
696  uint8_t *p;
697  for (j = 0; j < height; j++)
698  for (i = 0; i < width; i++)
699  SET_PIXEL_RGB(picref, color, 255, i+x, y+j, pixel_step[0],
700  rgba_map[0], rgba_map[1], rgba_map[2], rgba_map[3]);
701  } else {
702  unsigned int luma_pos, chroma_pos1, chroma_pos2;
703  for (j = 0; j < height; j++)
704  for (i = 0; i < width; i++)
705  SET_PIXEL_YUV(picref, color, 255, i+x, y+j, hsub, vsub);
706  }
707  } else {
708  ff_draw_rectangle(picref->data, picref->linesize,
709  line, pixel_step, hsub, vsub,
710  x, y, width, height);
711  }
712 }
713 
714 static int draw_glyphs(DrawTextContext *dtext, AVFilterBufferRef *picref,
715  int width, int height, const uint8_t rgbcolor[4], const uint8_t yuvcolor[4], int x, int y)
716 {
717  char *text = HAVE_LOCALTIME_R ? dtext->expanded_text : dtext->text;
718  uint32_t code = 0;
719  int i;
720  uint8_t *p;
721  Glyph *glyph = NULL;
722 
723  for (i = 0, p = text; *p; i++) {
724  Glyph dummy = { 0 };
725  GET_UTF8(code, *p++, continue;);
726 
727  /* skip new line chars, just go to new line */
728  if (code == '\n' || code == '\r' || code == '\t')
729  continue;
730 
731  dummy.code = code;
732  glyph = av_tree_find(dtext->glyphs, &dummy, (void *)glyph_cmp, NULL);
733 
734  if (glyph->bitmap.pixel_mode != FT_PIXEL_MODE_MONO &&
735  glyph->bitmap.pixel_mode != FT_PIXEL_MODE_GRAY)
736  return AVERROR(EINVAL);
737 
738  if (dtext->is_packed_rgb) {
739  draw_glyph_rgb(picref, &glyph->bitmap,
740  dtext->positions[i].x+x, dtext->positions[i].y+y, width, height,
741  dtext->pixel_step[0], rgbcolor, dtext->rgba_map);
742  } else {
743  draw_glyph_yuv(picref, &glyph->bitmap,
744  dtext->positions[i].x+x, dtext->positions[i].y+y, width, height,
745  yuvcolor, dtext->hsub, dtext->vsub);
746  }
747  }
748 
749  return 0;
750 }
751 
752 static int draw_text(AVFilterContext *ctx, AVFilterBufferRef *picref,
753  int width, int height)
754 {
755  DrawTextContext *dtext = ctx->priv;
756  int ret;
757 
758  /* draw box */
759  if (dtext->draw_box)
760  drawbox(picref, dtext->x, dtext->y, dtext->w, dtext->h,
761  dtext->box_line, dtext->pixel_step, dtext->boxcolor,
762  dtext->hsub, dtext->vsub, dtext->is_packed_rgb,
763  dtext->rgba_map);
764 
765  if (dtext->shadowx || dtext->shadowy) {
766  if ((ret = draw_glyphs(dtext, picref, width, height,
767  dtext->shadowcolor_rgba,
768  dtext->shadowcolor,
769  dtext->x + dtext->shadowx,
770  dtext->y + dtext->shadowy)) < 0)
771  return ret;
772  }
773 
774  if ((ret = draw_glyphs(dtext, picref, width, height,
775  dtext->fontcolor_rgba,
776  dtext->fontcolor,
777  dtext->x,
778  dtext->y)) < 0)
779  return ret;
780 
781  return 0;
782 }
783 
784 static void null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir) { }
785 
786 static inline int normalize_double(int *n, double d)
787 {
788  int ret = 0;
789 
790  if (isnan(d)) {
791  ret = AVERROR(EINVAL);
792  } else if (d > INT_MAX || d < INT_MIN) {
793  *n = d > INT_MAX ? INT_MAX : INT_MIN;
794  ret = AVERROR(EINVAL);
795  } else
796  *n = round(d);
797 
798  return ret;
799 }
800 
801 static void start_frame(AVFilterLink *inlink, AVFilterBufferRef *inpicref)
802 {
803  AVFilterContext *ctx = inlink->dst;
804  DrawTextContext *dtext = ctx->priv;
805  int fail = 0;
806 
807  if (dtext_prepare_text(ctx) < 0) {
808  av_log(ctx, AV_LOG_ERROR, "Can't draw text\n");
809  fail = 1;
810  }
811 
812  dtext->var_values[VAR_T] = inpicref->pts == AV_NOPTS_VALUE ?
813  NAN : inpicref->pts * av_q2d(inlink->time_base);
814  dtext->var_values[VAR_X] =
815  av_expr_eval(dtext->x_pexpr, dtext->var_values, &dtext->prng);
816  dtext->var_values[VAR_Y] =
817  av_expr_eval(dtext->y_pexpr, dtext->var_values, &dtext->prng);
818  dtext->var_values[VAR_X] =
819  av_expr_eval(dtext->x_pexpr, dtext->var_values, &dtext->prng);
820 
821  dtext->draw = fail ? 0 :
822  av_expr_eval(dtext->d_pexpr, dtext->var_values, &dtext->prng);
823 
824  normalize_double(&dtext->x, dtext->var_values[VAR_X]);
825  normalize_double(&dtext->y, dtext->var_values[VAR_Y]);
826 
827  if (dtext->x < 0) dtext->x = 0;
828  if (dtext->y < 0) dtext->y = 0;
829  if ((unsigned)dtext->x + (unsigned)dtext->w > inlink->w)
830  dtext->x = inlink->w - dtext->w;
831  if ((unsigned)dtext->y + (unsigned)dtext->h > inlink->h)
832  dtext->y = inlink->h - dtext->h;
833 
834  dtext->x &= ~((1 << dtext->hsub) - 1);
835  dtext->y &= ~((1 << dtext->vsub) - 1);
836 
837  av_dlog(ctx, "n:%d t:%f x:%d y:%d x+w:%d y+h:%d\n",
838  (int)dtext->var_values[VAR_N], dtext->var_values[VAR_T],
839  dtext->x, dtext->y, dtext->x+dtext->w, dtext->y+dtext->h);
840 
841  avfilter_start_frame(inlink->dst->outputs[0], inpicref);
842 }
843 
844 static void end_frame(AVFilterLink *inlink)
845 {
846  AVFilterLink *outlink = inlink->dst->outputs[0];
847  AVFilterBufferRef *picref = inlink->cur_buf;
848  DrawTextContext *dtext = inlink->dst->priv;
849 
850  if (dtext->draw)
851  draw_text(inlink->dst, picref, picref->video->w, picref->video->h);
852 
853  dtext->var_values[VAR_N] += 1.0;
854 
855  avfilter_draw_slice(outlink, 0, picref->video->h, 1);
856  avfilter_end_frame(outlink);
857 }
858 
860  .name = "drawtext",
861  .description = NULL_IF_CONFIG_SMALL("Draw text on top of video frames using libfreetype library."),
862  .priv_size = sizeof(DrawTextContext),
863  .init = init,
864  .uninit = uninit,
866 
867  .inputs = (AVFilterPad[]) {{ .name = "default",
868  .type = AVMEDIA_TYPE_VIDEO,
869  .get_video_buffer = avfilter_null_get_video_buffer,
870  .start_frame = start_frame,
871  .draw_slice = null_draw_slice,
872  .end_frame = end_frame,
873  .config_props = config_input,
874  .min_perms = AV_PERM_WRITE |
875  AV_PERM_READ,
876  .rej_perms = AV_PERM_PRESERVE },
877  { .name = NULL}},
878  .outputs = (AVFilterPad[]) {{ .name = "default",
879  .type = AVMEDIA_TYPE_VIDEO, },
880  { .name = NULL}},
881 };