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>
6 * This file is part of FFmpeg.
8 * FFmpeg 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.
13 * FFmpeg 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.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 * drawtext filter, based on the original vhook/drawtext.c
26 * filter by Gustavo Sverzut Barbieri
33 #include "libavutil/avstring.h"
34 #include "libavutil/file.h"
35 #include "libavutil/eval.h"
36 #include "libavutil/opt.h"
37 #include "libavutil/random_seed.h"
38 #include "libavutil/parseutils.h"
39 #include "libavutil/timecode.h"
40 #include "libavutil/tree.h"
41 #include "libavutil/lfg.h"
43 #include "drawutils.h"
48 #include <freetype/config/ftheader.h>
49 #include FT_FREETYPE_H
52 static const char *const var_names[] = {
53 "main_w", "w", "W", ///< width of the input video
54 "main_h", "h", "H", ///< height of the input video
55 "tw", "text_w", ///< width of the rendered text
56 "th", "text_h", ///< height of the rendered text
57 "max_glyph_w", ///< max glyph width
58 "max_glyph_h", ///< max glyph height
59 "max_glyph_a", "ascent", ///< max glyph ascent
60 "max_glyph_d", "descent", ///< min glyph descent
61 "line_h", "lh", ///< line height, same as max_glyph_h
68 "n", ///< number of frame
69 "t", ///< timestamp expressed in seconds
73 static const char *const fun2_names[] = {
77 static double drand(void *opaque, double min, double max)
79 return min + (max-min) / UINT_MAX * av_lfg_get(opaque);
82 typedef double (*eval_func2)(void *, double a, double b);
84 static const eval_func2 fun2[] = {
90 VAR_MAIN_W, VAR_w, VAR_W,
91 VAR_MAIN_H, VAR_h, VAR_H,
96 VAR_MAX_GLYPH_A, VAR_ASCENT,
97 VAR_MAX_GLYPH_D, VAR_DESCENT,
111 const AVClass *class;
112 int reinit; ///< tells if the filter is being reinited
113 uint8_t *fontfile; ///< font to be used
114 uint8_t *text; ///< text to be drawn
115 uint8_t *expanded_text; ///< used to contain the strftime()-expanded text
116 size_t expanded_text_size; ///< size in bytes of the expanded_text buffer
117 int ft_load_flags; ///< flags used for loading fonts, see FT_LOAD_*
118 FT_Vector *positions; ///< positions for each element in the text
119 size_t nb_positions; ///< number of elements of positions array
120 char *textfile; ///< file with text to be drawn
121 int x; ///< x position to start drawing text
122 int y; ///< y position to start drawing text
123 int max_glyph_w; ///< max glyph width
124 int max_glyph_h; ///< max glyph height
125 int shadowx, shadowy;
126 unsigned int fontsize; ///< font size to use
127 char *fontcolor_string; ///< font color as string
128 char *boxcolor_string; ///< box color as string
129 char *shadowcolor_string; ///< shadow color as string
131 short int draw_box; ///< draw box around text - true or false
132 int use_kerning; ///< font kerning is used - true/false
133 int tabsize; ///< tab size
134 int fix_bounds; ///< do we let it go out of frame bounds - t/f
137 FFDrawColor fontcolor; ///< foreground color
138 FFDrawColor shadowcolor; ///< shadow color
139 FFDrawColor boxcolor; ///< background color
141 FT_Library library; ///< freetype font library handle
142 FT_Face face; ///< freetype font face handle
143 struct AVTreeNode *glyphs; ///< rendered glyphs, stored using the UTF-32 char code
144 char *x_expr; ///< expression for x position
145 char *y_expr; ///< expression for y position
146 AVExpr *x_pexpr, *y_pexpr; ///< parsed expressions for x and y
147 int64_t basetime; ///< base pts time in the real world for display
148 double var_values[VAR_VARS_NB];
151 int draw; ///< set to zero to prevent drawing
152 AVLFG prng; ///< random
153 char *tc_opt_string; ///< specified timecode option string
154 AVRational tc_rate; ///< frame rate for timecode
155 AVTimecode tc; ///< timecode context
156 int tc24hmax; ///< 1 if timecode is wrapped to 24 hours, 0 otherwise
160 #define OFFSET(x) offsetof(DrawTextContext, x)
162 static const AVOption drawtext_options[]= {
163 {"fontfile", "set font file", OFFSET(fontfile), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX },
164 {"text", "set text", OFFSET(text), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX },
165 {"textfile", "set text file", OFFSET(textfile), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX },
166 {"fontcolor", "set foreground color", OFFSET(fontcolor_string), AV_OPT_TYPE_STRING, {.str="black"}, CHAR_MIN, CHAR_MAX },
167 {"boxcolor", "set box color", OFFSET(boxcolor_string), AV_OPT_TYPE_STRING, {.str="white"}, CHAR_MIN, CHAR_MAX },
168 {"shadowcolor", "set shadow color", OFFSET(shadowcolor_string), AV_OPT_TYPE_STRING, {.str="black"}, CHAR_MIN, CHAR_MAX },
169 {"box", "set box", OFFSET(draw_box), AV_OPT_TYPE_INT, {.dbl=0}, 0, 1 },
170 {"fontsize", "set font size", OFFSET(fontsize), AV_OPT_TYPE_INT, {.dbl=16}, 1, INT_MAX },
171 {"x", "set x expression", OFFSET(x_expr), AV_OPT_TYPE_STRING, {.str="0"}, CHAR_MIN, CHAR_MAX },
172 {"y", "set y expression", OFFSET(y_expr), AV_OPT_TYPE_STRING, {.str="0"}, CHAR_MIN, CHAR_MAX },
173 {"shadowx", "set x", OFFSET(shadowx), AV_OPT_TYPE_INT, {.dbl=0}, INT_MIN, INT_MAX },
174 {"shadowy", "set y", OFFSET(shadowy), AV_OPT_TYPE_INT, {.dbl=0}, INT_MIN, INT_MAX },
175 {"tabsize", "set tab size", OFFSET(tabsize), AV_OPT_TYPE_INT, {.dbl=4}, 0, INT_MAX },
176 {"basetime", "set base time", OFFSET(basetime), AV_OPT_TYPE_INT64, {.dbl=AV_NOPTS_VALUE}, INT64_MIN, INT64_MAX },
177 {"draw", "if false do not draw", OFFSET(d_expr), AV_OPT_TYPE_STRING, {.str="1"}, CHAR_MIN, CHAR_MAX },
178 {"timecode", "set initial timecode", OFFSET(tc_opt_string), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX },
179 {"tc24hmax", "set 24 hours max (timecode only)", OFFSET(tc24hmax), AV_OPT_TYPE_INT, {.dbl=0}, 0, 1 },
180 {"r", "set rate (timecode only)", OFFSET(tc_rate), AV_OPT_TYPE_RATIONAL, {.dbl=0}, 0, INT_MAX },
181 {"rate", "set rate (timecode only)", OFFSET(tc_rate), AV_OPT_TYPE_RATIONAL, {.dbl=0}, 0, INT_MAX },
182 {"fix_bounds", "if true, check and fix text coords to avoid clipping",
183 OFFSET(fix_bounds), AV_OPT_TYPE_INT, {.dbl=1}, 0, 1 },
185 /* FT_LOAD_* flags */
186 {"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" },
187 {"default", "set default", 0, AV_OPT_TYPE_CONST, {.dbl=FT_LOAD_DEFAULT}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
188 {"no_scale", "set no_scale", 0, AV_OPT_TYPE_CONST, {.dbl=FT_LOAD_NO_SCALE}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
189 {"no_hinting", "set no_hinting", 0, AV_OPT_TYPE_CONST, {.dbl=FT_LOAD_NO_HINTING}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
190 {"render", "set render", 0, AV_OPT_TYPE_CONST, {.dbl=FT_LOAD_RENDER}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
191 {"no_bitmap", "set no_bitmap", 0, AV_OPT_TYPE_CONST, {.dbl=FT_LOAD_NO_BITMAP}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
192 {"vertical_layout", "set vertical_layout", 0, AV_OPT_TYPE_CONST, {.dbl=FT_LOAD_VERTICAL_LAYOUT}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
193 {"force_autohint", "set force_autohint", 0, AV_OPT_TYPE_CONST, {.dbl=FT_LOAD_FORCE_AUTOHINT}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
194 {"crop_bitmap", "set crop_bitmap", 0, AV_OPT_TYPE_CONST, {.dbl=FT_LOAD_CROP_BITMAP}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
195 {"pedantic", "set pedantic", 0, AV_OPT_TYPE_CONST, {.dbl=FT_LOAD_PEDANTIC}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
196 {"ignore_global_advance_width", "set ignore_global_advance_width", 0, AV_OPT_TYPE_CONST, {.dbl=FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
197 {"no_recurse", "set no_recurse", 0, AV_OPT_TYPE_CONST, {.dbl=FT_LOAD_NO_RECURSE}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
198 {"ignore_transform", "set ignore_transform", 0, AV_OPT_TYPE_CONST, {.dbl=FT_LOAD_IGNORE_TRANSFORM}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
199 {"monochrome", "set monochrome", 0, AV_OPT_TYPE_CONST, {.dbl=FT_LOAD_MONOCHROME}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
200 {"linear_design", "set linear_design", 0, AV_OPT_TYPE_CONST, {.dbl=FT_LOAD_LINEAR_DESIGN}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
201 {"no_autohint", "set no_autohint", 0, AV_OPT_TYPE_CONST, {.dbl=FT_LOAD_NO_AUTOHINT}, INT_MIN, INT_MAX, 0, "ft_load_flags" },
205 static const char *drawtext_get_name(void *ctx)
210 static const AVClass drawtext_class = {
216 #undef __FTERRORS_H__
217 #define FT_ERROR_START_LIST {
218 #define FT_ERRORDEF(e, v, s) { (e), (s) },
219 #define FT_ERROR_END_LIST { 0, NULL } };
225 } static ft_errors[] =
228 #define FT_ERRMSG(e) ft_errors[e].err_msg
233 FT_Bitmap bitmap; ///< array holding bitmaps of font
240 static int glyph_cmp(void *key, const void *b)
242 const Glyph *a = key, *bb = b;
243 int64_t diff = (int64_t)a->code - (int64_t)bb->code;
244 return diff > 0 ? 1 : diff < 0 ? -1 : 0;
248 * Load glyphs corresponding to the UTF-32 codepoint code.
250 static int load_glyph(AVFilterContext *ctx, Glyph **glyph_ptr, uint32_t code)
252 DrawTextContext *dtext = ctx->priv;
254 struct AVTreeNode *node = NULL;
257 /* load glyph into dtext->face->glyph */
258 if (FT_Load_Char(dtext->face, code, dtext->ft_load_flags))
259 return AVERROR(EINVAL);
262 if (!(glyph = av_mallocz(sizeof(*glyph))) ||
263 !(glyph->glyph = av_mallocz(sizeof(*glyph->glyph)))) {
264 ret = AVERROR(ENOMEM);
269 if (FT_Get_Glyph(dtext->face->glyph, glyph->glyph)) {
270 ret = AVERROR(EINVAL);
274 glyph->bitmap = dtext->face->glyph->bitmap;
275 glyph->bitmap_left = dtext->face->glyph->bitmap_left;
276 glyph->bitmap_top = dtext->face->glyph->bitmap_top;
277 glyph->advance = dtext->face->glyph->advance.x >> 6;
279 /* measure text height to calculate text_height (or the maximum text height) */
280 FT_Glyph_Get_CBox(*glyph->glyph, ft_glyph_bbox_pixels, &glyph->bbox);
282 /* cache the newly created glyph */
283 if (!(node = av_mallocz(av_tree_node_size))) {
284 ret = AVERROR(ENOMEM);
287 av_tree_insert(&dtext->glyphs, glyph, glyph_cmp, &node);
295 av_freep(&glyph->glyph);
301 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
304 DrawTextContext *dtext = ctx->priv;
307 dtext->class = &drawtext_class;
308 av_opt_set_defaults(dtext);
310 if ((err = (av_set_options_string(dtext, args, "=", ":"))) < 0) {
311 av_log(ctx, AV_LOG_ERROR, "Error parsing options string: '%s'\n", args);
315 if (!dtext->fontfile) {
316 av_log(ctx, AV_LOG_ERROR, "No font filename provided\n");
317 return AVERROR(EINVAL);
320 if (dtext->textfile) {
325 av_log(ctx, AV_LOG_ERROR,
326 "Both text and text file provided. Please provide only one\n");
327 return AVERROR(EINVAL);
329 if ((err = av_file_map(dtext->textfile, &textbuf, &textbuf_size, 0, ctx)) < 0) {
330 av_log(ctx, AV_LOG_ERROR,
331 "The text file '%s' could not be read or is empty\n",
336 if (!(dtext->text = av_malloc(textbuf_size+1)))
337 return AVERROR(ENOMEM);
338 memcpy(dtext->text, textbuf, textbuf_size);
339 dtext->text[textbuf_size] = 0;
340 av_file_unmap(textbuf, textbuf_size);
343 if (dtext->tc_opt_string) {
344 int ret = av_timecode_init_from_string(&dtext->tc, dtext->tc_rate,
345 dtext->tc_opt_string, ctx);
349 dtext->tc.flags |= AV_TIMECODE_FLAG_24HOURSMAX;
351 dtext->text = av_strdup("");
355 av_log(ctx, AV_LOG_ERROR,
356 "Either text, a valid file or a timecode must be provided\n");
357 return AVERROR(EINVAL);
360 if ((err = av_parse_color(dtext->fontcolor.rgba, dtext->fontcolor_string, -1, ctx))) {
361 av_log(ctx, AV_LOG_ERROR,
362 "Invalid font color '%s'\n", dtext->fontcolor_string);
366 if ((err = av_parse_color(dtext->boxcolor.rgba, dtext->boxcolor_string, -1, ctx))) {
367 av_log(ctx, AV_LOG_ERROR,
368 "Invalid box color '%s'\n", dtext->boxcolor_string);
372 if ((err = av_parse_color(dtext->shadowcolor.rgba, dtext->shadowcolor_string, -1, ctx))) {
373 av_log(ctx, AV_LOG_ERROR,
374 "Invalid shadow color '%s'\n", dtext->shadowcolor_string);
378 if ((err = FT_Init_FreeType(&(dtext->library)))) {
379 av_log(ctx, AV_LOG_ERROR,
380 "Could not load FreeType: %s\n", FT_ERRMSG(err));
381 return AVERROR(EINVAL);
384 /* load the face, and set up the encoding, which is by default UTF-8 */
385 if ((err = FT_New_Face(dtext->library, dtext->fontfile, 0, &dtext->face))) {
386 av_log(ctx, AV_LOG_ERROR, "Could not load fontface from file '%s': %s\n",
387 dtext->fontfile, FT_ERRMSG(err));
388 return AVERROR(EINVAL);
390 if ((err = FT_Set_Pixel_Sizes(dtext->face, 0, dtext->fontsize))) {
391 av_log(ctx, AV_LOG_ERROR, "Could not set font size to %d pixels: %s\n",
392 dtext->fontsize, FT_ERRMSG(err));
393 return AVERROR(EINVAL);
396 dtext->use_kerning = FT_HAS_KERNING(dtext->face);
398 /* load the fallback glyph with code 0 */
399 load_glyph(ctx, NULL, 0);
401 /* set the tabsize in pixels */
402 if ((err = load_glyph(ctx, &glyph, ' ')) < 0) {
403 av_log(ctx, AV_LOG_ERROR, "Could not set tabsize.\n");
406 dtext->tabsize *= glyph->advance;
411 static int query_formats(AVFilterContext *ctx)
413 avfilter_set_common_pixel_formats(ctx, ff_draw_supported_pixel_formats(0));
417 static int glyph_enu_free(void *opaque, void *elem)
423 static av_cold void uninit(AVFilterContext *ctx)
425 DrawTextContext *dtext = ctx->priv;
427 av_expr_free(dtext->x_pexpr); dtext->x_pexpr = NULL;
428 av_expr_free(dtext->y_pexpr); dtext->y_pexpr = NULL;
430 av_freep(&dtext->boxcolor_string);
431 av_freep(&dtext->expanded_text);
432 av_freep(&dtext->fontcolor_string);
433 av_freep(&dtext->fontfile);
434 av_freep(&dtext->shadowcolor_string);
435 av_freep(&dtext->text);
436 av_freep(&dtext->x_expr);
437 av_freep(&dtext->y_expr);
439 av_freep(&dtext->positions);
440 dtext->nb_positions = 0;
442 av_tree_enumerate(dtext->glyphs, NULL, NULL, glyph_enu_free);
443 av_tree_destroy(dtext->glyphs);
444 dtext->glyphs = NULL;
446 FT_Done_Face(dtext->face);
447 FT_Done_FreeType(dtext->library);
450 static inline int is_newline(uint32_t c)
452 return c == '\n' || c == '\r' || c == '\f' || c == '\v';
455 static int config_input(AVFilterLink *inlink)
457 AVFilterContext *ctx = inlink->dst;
458 DrawTextContext *dtext = ctx->priv;
461 ff_draw_init(&dtext->dc, inlink->format, 0);
462 ff_draw_color(&dtext->dc, &dtext->fontcolor, dtext->fontcolor.rgba);
463 ff_draw_color(&dtext->dc, &dtext->shadowcolor, dtext->shadowcolor.rgba);
464 ff_draw_color(&dtext->dc, &dtext->boxcolor, dtext->boxcolor.rgba);
466 dtext->var_values[VAR_w] = dtext->var_values[VAR_W] = dtext->var_values[VAR_MAIN_W] = inlink->w;
467 dtext->var_values[VAR_h] = dtext->var_values[VAR_H] = dtext->var_values[VAR_MAIN_H] = inlink->h;
468 dtext->var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ? av_q2d(inlink->sample_aspect_ratio) : 1;
469 dtext->var_values[VAR_DAR] = (double)inlink->w / inlink->h * dtext->var_values[VAR_SAR];
470 dtext->var_values[VAR_HSUB] = 1 << dtext->dc.hsub_max;
471 dtext->var_values[VAR_VSUB] = 1 << dtext->dc.vsub_max;
472 dtext->var_values[VAR_X] = NAN;
473 dtext->var_values[VAR_Y] = NAN;
475 dtext->var_values[VAR_N] = 0;
476 dtext->var_values[VAR_T] = NAN;
478 av_lfg_init(&dtext->prng, av_get_random_seed());
480 if ((ret = av_expr_parse(&dtext->x_pexpr, dtext->x_expr, var_names,
481 NULL, NULL, fun2_names, fun2, 0, ctx)) < 0 ||
482 (ret = av_expr_parse(&dtext->y_pexpr, dtext->y_expr, var_names,
483 NULL, NULL, fun2_names, fun2, 0, ctx)) < 0 ||
484 (ret = av_expr_parse(&dtext->d_pexpr, dtext->d_expr, var_names,
485 NULL, NULL, fun2_names, fun2, 0, ctx)) < 0)
487 return AVERROR(EINVAL);
492 static int command(AVFilterContext *ctx, const char *cmd, const char *arg, char *res, int res_len, int flags)
494 DrawTextContext *dtext = ctx->priv;
496 if (!strcmp(cmd, "reinit")) {
500 if ((ret = init(ctx, arg, NULL)) < 0)
502 return config_input(ctx->inputs[0]);
505 return AVERROR(ENOSYS);
508 static int draw_glyphs(DrawTextContext *dtext, AVFilterBufferRef *picref,
509 int width, int height, const uint8_t rgbcolor[4], FFDrawColor *color, int x, int y)
511 char *text = dtext->expanded_text;
517 for (i = 0, p = text; *p; i++) {
519 GET_UTF8(code, *p++, continue;);
521 /* skip new line chars, just go to new line */
522 if (code == '\n' || code == '\r' || code == '\t')
526 glyph = av_tree_find(dtext->glyphs, &dummy, (void *)glyph_cmp, NULL);
528 if (glyph->bitmap.pixel_mode != FT_PIXEL_MODE_MONO &&
529 glyph->bitmap.pixel_mode != FT_PIXEL_MODE_GRAY)
530 return AVERROR(EINVAL);
532 x1 = dtext->positions[i].x+dtext->x+x;
533 y1 = dtext->positions[i].y+dtext->y+y;
535 ff_blend_mask(&dtext->dc, color,
536 picref->data, picref->linesize, width, height,
537 glyph->bitmap.buffer, glyph->bitmap.pitch,
538 glyph->bitmap.width, glyph->bitmap.rows,
539 glyph->bitmap.pixel_mode == FT_PIXEL_MODE_MONO ? 0 : 3,
546 static int draw_text(AVFilterContext *ctx, AVFilterBufferRef *picref,
547 int width, int height)
549 DrawTextContext *dtext = ctx->priv;
550 uint32_t code = 0, prev_code = 0;
551 int x = 0, y = 0, i = 0, ret;
552 int max_text_line_w = 0, len;
554 char *text = dtext->text;
556 int y_min = 32000, y_max = -32000;
557 int x_min = 32000, x_max = -32000;
559 Glyph *glyph = NULL, *prev_glyph = NULL;
562 time_t now = time(0);
564 uint8_t *buf = dtext->expanded_text;
565 int buf_size = dtext->expanded_text_size;
567 if(dtext->basetime != AV_NOPTS_VALUE)
568 now= picref->pts*av_q2d(ctx->inputs[0]->time_base) + dtext->basetime/1000000;
571 buf_size = 2*strlen(dtext->text)+1;
572 buf = av_malloc(buf_size);
576 localtime_r(&now, <ime);
578 if(strchr(dtext->text, '%'))
579 ltime= *localtime(&now);
584 if (strftime(buf, buf_size, dtext->text, <ime) != 0 || *buf == 0)
587 } while ((buf = av_realloc(buf, buf_size)));
589 if (dtext->tc_opt_string) {
590 char tcbuf[AV_TIMECODE_STR_SIZE];
591 av_timecode_make_string(&dtext->tc, tcbuf, dtext->frame_id++);
592 buf = av_asprintf("%s%s", dtext->text, tcbuf);
596 return AVERROR(ENOMEM);
597 text = dtext->expanded_text = buf;
598 dtext->expanded_text_size = buf_size;
599 if ((len = strlen(text)) > dtext->nb_positions) {
600 if (!(dtext->positions =
601 av_realloc(dtext->positions, len*sizeof(*dtext->positions))))
602 return AVERROR(ENOMEM);
603 dtext->nb_positions = len;
609 /* load and cache glyphs */
610 for (i = 0, p = text; *p; i++) {
611 GET_UTF8(code, *p++, continue;);
615 glyph = av_tree_find(dtext->glyphs, &dummy, glyph_cmp, NULL);
617 load_glyph(ctx, &glyph, code);
620 y_min = FFMIN(glyph->bbox.yMin, y_min);
621 y_max = FFMAX(glyph->bbox.yMax, y_max);
622 x_min = FFMIN(glyph->bbox.xMin, x_min);
623 x_max = FFMAX(glyph->bbox.xMax, x_max);
625 dtext->max_glyph_h = y_max - y_min;
626 dtext->max_glyph_w = x_max - x_min;
628 /* compute and save position for each glyph */
630 for (i = 0, p = text; *p; i++) {
631 GET_UTF8(code, *p++, continue;);
633 /* skip the \n in the sequence \r\n */
634 if (prev_code == '\r' && code == '\n')
638 if (is_newline(code)) {
639 max_text_line_w = FFMAX(max_text_line_w, x);
640 y += dtext->max_glyph_h;
648 glyph = av_tree_find(dtext->glyphs, &dummy, glyph_cmp, NULL);
651 if (dtext->use_kerning && prev_glyph && glyph->code) {
652 FT_Get_Kerning(dtext->face, prev_glyph->code, glyph->code,
653 ft_kerning_default, &delta);
658 dtext->positions[i].x = x + glyph->bitmap_left;
659 dtext->positions[i].y = y - glyph->bitmap_top + y_max;
660 if (code == '\t') x = (x / dtext->tabsize + 1)*dtext->tabsize;
661 else x += glyph->advance;
664 max_text_line_w = FFMAX(x, max_text_line_w);
666 dtext->var_values[VAR_TW] = dtext->var_values[VAR_TEXT_W] = max_text_line_w;
667 dtext->var_values[VAR_TH] = dtext->var_values[VAR_TEXT_H] = y + dtext->max_glyph_h;
669 dtext->var_values[VAR_MAX_GLYPH_W] = dtext->max_glyph_w;
670 dtext->var_values[VAR_MAX_GLYPH_H] = dtext->max_glyph_h;
671 dtext->var_values[VAR_MAX_GLYPH_A] = dtext->var_values[VAR_ASCENT ] = y_max;
672 dtext->var_values[VAR_MAX_GLYPH_D] = dtext->var_values[VAR_DESCENT] = y_min;
674 dtext->var_values[VAR_LINE_H] = dtext->var_values[VAR_LH] = dtext->max_glyph_h;
676 dtext->x = dtext->var_values[VAR_X] = av_expr_eval(dtext->x_pexpr, dtext->var_values, &dtext->prng);
677 dtext->y = dtext->var_values[VAR_Y] = av_expr_eval(dtext->y_pexpr, dtext->var_values, &dtext->prng);
678 dtext->x = dtext->var_values[VAR_X] = av_expr_eval(dtext->x_pexpr, dtext->var_values, &dtext->prng);
679 dtext->draw = av_expr_eval(dtext->d_pexpr, dtext->var_values, &dtext->prng);
684 box_w = FFMIN(width - 1 , max_text_line_w);
685 box_h = FFMIN(height - 1, y + dtext->max_glyph_h);
689 ff_blend_rectangle(&dtext->dc, &dtext->boxcolor,
690 picref->data, picref->linesize, width, height,
691 dtext->x, dtext->y, box_w, box_h);
693 if (dtext->shadowx || dtext->shadowy) {
694 if ((ret = draw_glyphs(dtext, picref, width, height, dtext->shadowcolor.rgba,
695 &dtext->shadowcolor, dtext->shadowx, dtext->shadowy)) < 0)
699 if ((ret = draw_glyphs(dtext, picref, width, height, dtext->fontcolor.rgba,
700 &dtext->fontcolor, 0, 0)) < 0)
706 static void null_draw_slice(AVFilterLink *link, int y, int h, int slice_dir) { }
708 static void end_frame(AVFilterLink *inlink)
710 AVFilterContext *ctx = inlink->dst;
711 AVFilterLink *outlink = ctx->outputs[0];
712 DrawTextContext *dtext = ctx->priv;
713 AVFilterBufferRef *picref = inlink->cur_buf;
715 dtext->var_values[VAR_T] = picref->pts == AV_NOPTS_VALUE ?
716 NAN : picref->pts * av_q2d(inlink->time_base);
718 draw_text(ctx, picref, picref->video->w, picref->video->h);
720 av_log(ctx, AV_LOG_DEBUG, "n:%d t:%f text_w:%d text_h:%d x:%d y:%d\n",
721 (int)dtext->var_values[VAR_N], dtext->var_values[VAR_T],
722 (int)dtext->var_values[VAR_TEXT_W], (int)dtext->var_values[VAR_TEXT_H],
725 dtext->var_values[VAR_N] += 1.0;
727 avfilter_draw_slice(outlink, 0, picref->video->h, 1);
728 avfilter_end_frame(outlink);
731 AVFilter avfilter_vf_drawtext = {
733 .description = NULL_IF_CONFIG_SMALL("Draw text on top of video frames using libfreetype library."),
734 .priv_size = sizeof(DrawTextContext),
737 .query_formats = query_formats,
739 .inputs = (const AVFilterPad[]) {{ .name = "default",
740 .type = AVMEDIA_TYPE_VIDEO,
741 .get_video_buffer = avfilter_null_get_video_buffer,
742 .start_frame = avfilter_null_start_frame,
743 .draw_slice = null_draw_slice,
744 .end_frame = end_frame,
745 .config_props = config_input,
746 .min_perms = AV_PERM_WRITE |
748 .rej_perms = AV_PERM_PRESERVE },
750 .outputs = (const AVFilterPad[]) {{ .name = "default",
751 .type = AVMEDIA_TYPE_VIDEO, },
753 .process_command = command,