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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 FFmpeg.
7  *
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.
12  *
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.
17  *
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
21  */
22 
23 /**
24  * @file
25  * drawtext filter, based on the original vhook/drawtext.c
26  * filter by Gustavo Sverzut Barbieri
27  */
28 
29 #include <sys/time.h>
30 #include <time.h>
31 
32 #include "config.h"
33 #include "libavutil/avstring.h"
34 #include "libavutil/bprint.h"
35 #include "libavutil/common.h"
36 #include "libavutil/file.h"
37 #include "libavutil/eval.h"
38 #include "libavutil/opt.h"
39 #include "libavutil/random_seed.h"
40 #include "libavutil/parseutils.h"
41 #include "libavutil/timecode.h"
42 #include "libavutil/tree.h"
43 #include "libavutil/lfg.h"
44 #include "avfilter.h"
45 #include "drawutils.h"
46 #include "formats.h"
47 #include "internal.h"
48 #include "video.h"
49 
50 #include <ft2build.h>
51 #include <freetype/config/ftheader.h>
52 #include FT_FREETYPE_H
53 #include FT_GLYPH_H
54 #if CONFIG_FONTCONFIG
55 #include <fontconfig/fontconfig.h>
56 #endif
57 
58 static const char *const var_names[] = {
59  "dar",
60  "hsub", "vsub",
61  "line_h", "lh", ///< line height, same as max_glyph_h
62  "main_h", "h", "H", ///< height of the input video
63  "main_w", "w", "W", ///< width of the input video
64  "max_glyph_a", "ascent", ///< max glyph ascent
65  "max_glyph_d", "descent", ///< min glyph descent
66  "max_glyph_h", ///< max glyph height
67  "max_glyph_w", ///< max glyph width
68  "n", ///< number of frame
69  "sar",
70  "t", ///< timestamp expressed in seconds
71  "text_h", "th", ///< height of the rendered text
72  "text_w", "tw", ///< width of the rendered text
73  "x",
74  "y",
75  "pict_type",
76  NULL
77 };
78 
79 static const char *const fun2_names[] = {
80  "rand"
81 };
82 
83 static double drand(void *opaque, double min, double max)
84 {
85  return min + (max-min) / UINT_MAX * av_lfg_get(opaque);
86 }
87 
88 typedef double (*eval_func2)(void *, double a, double b);
89 
90 static const eval_func2 fun2[] = {
91  drand,
92  NULL
93 };
94 
95 enum var_name {
96  VAR_DAR,
97  VAR_HSUB, VAR_VSUB,
98  VAR_LINE_H, VAR_LH,
99  VAR_MAIN_H, VAR_h, VAR_H,
100  VAR_MAIN_W, VAR_w, VAR_W,
101  VAR_MAX_GLYPH_A, VAR_ASCENT,
102  VAR_MAX_GLYPH_D, VAR_DESCENT,
103  VAR_MAX_GLYPH_H,
104  VAR_MAX_GLYPH_W,
105  VAR_N,
106  VAR_SAR,
107  VAR_T,
108  VAR_TEXT_H, VAR_TH,
109  VAR_TEXT_W, VAR_TW,
110  VAR_X,
111  VAR_Y,
112  VAR_PICT_TYPE,
113  VAR_VARS_NB
114 };
115 
116 enum expansion_mode {
117  EXP_NONE,
118  EXP_NORMAL,
119  EXP_STRFTIME,
120 };
121 
122 typedef struct {
123  const AVClass *class;
124  enum expansion_mode exp_mode; ///< expansion mode to use for the text
125  int reinit; ///< tells if the filter is being reinited
126  uint8_t *fontfile; ///< font to be used
127  uint8_t *text; ///< text to be drawn
128  AVBPrint expanded_text; ///< used to contain the expanded text
129  int ft_load_flags; ///< flags used for loading fonts, see FT_LOAD_*
130  FT_Vector *positions; ///< positions for each element in the text
131  size_t nb_positions; ///< number of elements of positions array
132  char *textfile; ///< file with text to be drawn
133  int x; ///< x position to start drawing text
134  int y; ///< y position to start drawing text
135  int max_glyph_w; ///< max glyph width
136  int max_glyph_h; ///< max glyph height
137  int shadowx, shadowy;
138  unsigned int fontsize; ///< font size to use
139 
140  short int draw_box; ///< draw box around text - true or false
141  int use_kerning; ///< font kerning is used - true/false
142  int tabsize; ///< tab size
143  int fix_bounds; ///< do we let it go out of frame bounds - t/f
144 
145  FFDrawContext dc;
146  FFDrawColor fontcolor; ///< foreground color
147  FFDrawColor shadowcolor; ///< shadow color
148  FFDrawColor boxcolor; ///< background color
149 
150  FT_Library library; ///< freetype font library handle
151  FT_Face face; ///< freetype font face handle
152  struct AVTreeNode *glyphs; ///< rendered glyphs, stored using the UTF-32 char code
153  char *x_expr; ///< expression for x position
154  char *y_expr; ///< expression for y position
155  AVExpr *x_pexpr, *y_pexpr; ///< parsed expressions for x and y
156  int64_t basetime; ///< base pts time in the real world for display
157  double var_values[VAR_VARS_NB];
158  char *draw_expr; ///< expression for draw
159  AVExpr *draw_pexpr; ///< parsed expression for draw
160  int draw; ///< set to zero to prevent drawing
161  AVLFG prng; ///< random
162  char *tc_opt_string; ///< specified timecode option string
163  AVRational tc_rate; ///< frame rate for timecode
164  AVTimecode tc; ///< timecode context
165  int tc24hmax; ///< 1 if timecode is wrapped to 24 hours, 0 otherwise
166  int reload; ///< reload text file for each frame
167  int start_number; ///< starting frame number for n/frame_num var
168  AVDictionary *metadata;
169 } DrawTextContext;
170 
171 #define OFFSET(x) offsetof(DrawTextContext, x)
172 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
173 
174 static const AVOption drawtext_options[]= {
175  {"fontfile", "set font file", OFFSET(fontfile), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS},
176  {"text", "set text", OFFSET(text), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS},
177  {"textfile", "set text file", OFFSET(textfile), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS},
178  {"fontcolor", "set foreground color", OFFSET(fontcolor.rgba), AV_OPT_TYPE_COLOR, {.str="black"}, CHAR_MIN, CHAR_MAX, FLAGS},
179  {"boxcolor", "set box color", OFFSET(boxcolor.rgba), AV_OPT_TYPE_COLOR, {.str="white"}, CHAR_MIN, CHAR_MAX, FLAGS},
180  {"shadowcolor", "set shadow color", OFFSET(shadowcolor.rgba), AV_OPT_TYPE_COLOR, {.str="black"}, CHAR_MIN, CHAR_MAX, FLAGS},
181  {"box", "set box", OFFSET(draw_box), AV_OPT_TYPE_INT, {.i64=0}, 0, 1 , FLAGS},
182  {"fontsize", "set font size", OFFSET(fontsize), AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX , FLAGS},
183  {"x", "set x expression", OFFSET(x_expr), AV_OPT_TYPE_STRING, {.str="0"}, CHAR_MIN, CHAR_MAX, FLAGS},
184  {"y", "set y expression", OFFSET(y_expr), AV_OPT_TYPE_STRING, {.str="0"}, CHAR_MIN, CHAR_MAX, FLAGS},
185  {"shadowx", "set x", OFFSET(shadowx), AV_OPT_TYPE_INT, {.i64=0}, INT_MIN, INT_MAX , FLAGS},
186  {"shadowy", "set y", OFFSET(shadowy), AV_OPT_TYPE_INT, {.i64=0}, INT_MIN, INT_MAX , FLAGS},
187  {"tabsize", "set tab size", OFFSET(tabsize), AV_OPT_TYPE_INT, {.i64=4}, 0, INT_MAX , FLAGS},
188  {"basetime", "set base time", OFFSET(basetime), AV_OPT_TYPE_INT64, {.i64=AV_NOPTS_VALUE}, INT64_MIN, INT64_MAX , FLAGS},
189  {"draw", "if false do not draw", OFFSET(draw_expr), AV_OPT_TYPE_STRING, {.str="1"}, CHAR_MIN, CHAR_MAX, FLAGS},
190 
191  {"expansion", "set the expansion mode", OFFSET(exp_mode), AV_OPT_TYPE_INT, {.i64=EXP_NORMAL}, 0, 2, FLAGS, "expansion"},
192  {"none", "set no expansion", OFFSET(exp_mode), AV_OPT_TYPE_CONST, {.i64=EXP_NONE}, 0, 0, FLAGS, "expansion"},
193  {"normal", "set normal expansion", OFFSET(exp_mode), AV_OPT_TYPE_CONST, {.i64=EXP_NORMAL}, 0, 0, FLAGS, "expansion"},
194  {"strftime", "set strftime expansion (deprecated)", OFFSET(exp_mode), AV_OPT_TYPE_CONST, {.i64=EXP_STRFTIME}, 0, 0, FLAGS, "expansion"},
195 
196  {"timecode", "set initial timecode", OFFSET(tc_opt_string), AV_OPT_TYPE_STRING, {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS},
197  {"tc24hmax", "set 24 hours max (timecode only)", OFFSET(tc24hmax), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS},
198  {"timecode_rate", "set rate (timecode only)", OFFSET(tc_rate), AV_OPT_TYPE_RATIONAL, {.dbl=0}, 0, INT_MAX, FLAGS},
199  {"r", "set rate (timecode only)", OFFSET(tc_rate), AV_OPT_TYPE_RATIONAL, {.dbl=0}, 0, INT_MAX, FLAGS},
200  {"rate", "set rate (timecode only)", OFFSET(tc_rate), AV_OPT_TYPE_RATIONAL, {.dbl=0}, 0, INT_MAX, FLAGS},
201  {"reload", "reload text file for each frame", OFFSET(reload), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS},
202  {"fix_bounds", "if true, check and fix text coords to avoid clipping", OFFSET(fix_bounds), AV_OPT_TYPE_INT, {.i64=1}, 0, 1, FLAGS},
203  {"start_number", "start frame number for n/frame_num variable", OFFSET(start_number), AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX, FLAGS},
204 
205  /* FT_LOAD_* flags */
206  { "ft_load_flags", "set font loading flags for libfreetype", OFFSET(ft_load_flags), AV_OPT_TYPE_FLAGS, { .i64 = FT_LOAD_DEFAULT | FT_LOAD_RENDER}, 0, INT_MAX, FLAGS, "ft_load_flags" },
207  { "default", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_DEFAULT }, .flags = FLAGS, .unit = "ft_load_flags" },
208  { "no_scale", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_NO_SCALE }, .flags = FLAGS, .unit = "ft_load_flags" },
209  { "no_hinting", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_NO_HINTING }, .flags = FLAGS, .unit = "ft_load_flags" },
210  { "render", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_RENDER }, .flags = FLAGS, .unit = "ft_load_flags" },
211  { "no_bitmap", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_NO_BITMAP }, .flags = FLAGS, .unit = "ft_load_flags" },
212  { "vertical_layout", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_VERTICAL_LAYOUT }, .flags = FLAGS, .unit = "ft_load_flags" },
213  { "force_autohint", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_FORCE_AUTOHINT }, .flags = FLAGS, .unit = "ft_load_flags" },
214  { "crop_bitmap", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_CROP_BITMAP }, .flags = FLAGS, .unit = "ft_load_flags" },
215  { "pedantic", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_PEDANTIC }, .flags = FLAGS, .unit = "ft_load_flags" },
216  { "ignore_global_advance_width", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH }, .flags = FLAGS, .unit = "ft_load_flags" },
217  { "no_recurse", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_NO_RECURSE }, .flags = FLAGS, .unit = "ft_load_flags" },
218  { "ignore_transform", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_IGNORE_TRANSFORM }, .flags = FLAGS, .unit = "ft_load_flags" },
219  { "monochrome", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_MONOCHROME }, .flags = FLAGS, .unit = "ft_load_flags" },
220  { "linear_design", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_LINEAR_DESIGN }, .flags = FLAGS, .unit = "ft_load_flags" },
221  { "no_autohint", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_NO_AUTOHINT }, .flags = FLAGS, .unit = "ft_load_flags" },
222  { NULL},
223 };
224 
225 AVFILTER_DEFINE_CLASS(drawtext);
226 
227 #undef __FTERRORS_H__
228 #define FT_ERROR_START_LIST {
229 #define FT_ERRORDEF(e, v, s) { (e), (s) },
230 #define FT_ERROR_END_LIST { 0, NULL } };
231 
232 struct ft_error
233 {
234  int err;
235  const char *err_msg;
236 } static ft_errors[] =
237 #include FT_ERRORS_H
238 
239 #define FT_ERRMSG(e) ft_errors[e].err_msg
240 
241 typedef struct {
242  FT_Glyph *glyph;
243  uint32_t code;
244  FT_Bitmap bitmap; ///< array holding bitmaps of font
245  FT_BBox bbox;
246  int advance;
247  int bitmap_left;
248  int bitmap_top;
249 } Glyph;
250 
251 static int glyph_cmp(void *key, const void *b)
252 {
253  const Glyph *a = key, *bb = b;
254  int64_t diff = (int64_t)a->code - (int64_t)bb->code;
255  return diff > 0 ? 1 : diff < 0 ? -1 : 0;
256 }
257 
258 /**
259  * Load glyphs corresponding to the UTF-32 codepoint code.
260  */
261 static int load_glyph(AVFilterContext *ctx, Glyph **glyph_ptr, uint32_t code)
262 {
263  DrawTextContext *s = ctx->priv;
264  Glyph *glyph;
265  struct AVTreeNode *node = NULL;
266  int ret;
267 
268  /* load glyph into s->face->glyph */
269  if (FT_Load_Char(s->face, code, s->ft_load_flags))
270  return AVERROR(EINVAL);
271 
272  /* save glyph */
273  if (!(glyph = av_mallocz(sizeof(*glyph))) ||
274  !(glyph->glyph = av_mallocz(sizeof(*glyph->glyph)))) {
275  ret = AVERROR(ENOMEM);
276  goto error;
277  }
278  glyph->code = code;
279 
280  if (FT_Get_Glyph(s->face->glyph, glyph->glyph)) {
281  ret = AVERROR(EINVAL);
282  goto error;
283  }
284 
285  glyph->bitmap = s->face->glyph->bitmap;
286  glyph->bitmap_left = s->face->glyph->bitmap_left;
287  glyph->bitmap_top = s->face->glyph->bitmap_top;
288  glyph->advance = s->face->glyph->advance.x >> 6;
289 
290  /* measure text height to calculate text_height (or the maximum text height) */
291  FT_Glyph_Get_CBox(*glyph->glyph, ft_glyph_bbox_pixels, &glyph->bbox);
292 
293  /* cache the newly created glyph */
294  if (!(node = av_tree_node_alloc())) {
295  ret = AVERROR(ENOMEM);
296  goto error;
297  }
298  av_tree_insert(&s->glyphs, glyph, glyph_cmp, &node);
299 
300  if (glyph_ptr)
301  *glyph_ptr = glyph;
302  return 0;
303 
304 error:
305  if (glyph)
306  av_freep(&glyph->glyph);
307  av_freep(&glyph);
308  av_freep(&node);
309  return ret;
310 }
311 
312 static int load_font_file(AVFilterContext *ctx, const char *path, int index,
313  const char **error)
314 {
315  DrawTextContext *s = ctx->priv;
316  int err;
317 
318  err = FT_New_Face(s->library, path, index, &s->face);
319  if (err) {
320  *error = FT_ERRMSG(err);
321  return AVERROR(EINVAL);
322  }
323  return 0;
324 }
325 
326 #if CONFIG_FONTCONFIG
327 static int load_font_fontconfig(AVFilterContext *ctx, const char **error)
328 {
329  DrawTextContext *s = ctx->priv;
330  FcConfig *fontconfig;
331  FcPattern *pattern, *fpat;
332  FcResult result = FcResultMatch;
333  FcChar8 *filename;
334  int err, index;
335  double size;
336 
337  fontconfig = FcInitLoadConfigAndFonts();
338  if (!fontconfig) {
339  *error = "impossible to init fontconfig\n";
340  return AVERROR(EINVAL);
341  }
342  pattern = FcNameParse(s->fontfile ? s->fontfile :
343  (uint8_t *)(intptr_t)"default");
344  if (!pattern) {
345  *error = "could not parse fontconfig pattern";
346  return AVERROR(EINVAL);
347  }
348  if (!FcConfigSubstitute(fontconfig, pattern, FcMatchPattern)) {
349  *error = "could not substitue fontconfig options"; /* very unlikely */
350  return AVERROR(EINVAL);
351  }
352  FcDefaultSubstitute(pattern);
353  fpat = FcFontMatch(fontconfig, pattern, &result);
354  if (!fpat || result != FcResultMatch) {
355  *error = "impossible to find a matching font";
356  return AVERROR(EINVAL);
357  }
358  if (FcPatternGetString (fpat, FC_FILE, 0, &filename) != FcResultMatch ||
359  FcPatternGetInteger(fpat, FC_INDEX, 0, &index ) != FcResultMatch ||
360  FcPatternGetDouble (fpat, FC_SIZE, 0, &size ) != FcResultMatch) {
361  *error = "impossible to find font information";
362  return AVERROR(EINVAL);
363  }
364  av_log(ctx, AV_LOG_INFO, "Using \"%s\"\n", filename);
365  if (!s->fontsize)
366  s->fontsize = size + 0.5;
367  err = load_font_file(ctx, filename, index, error);
368  if (err)
369  return err;
370  FcPatternDestroy(fpat);
371  FcPatternDestroy(pattern);
372  FcConfigDestroy(fontconfig);
373  return 0;
374 }
375 #endif
376 
377 static int load_font(AVFilterContext *ctx)
378 {
379  DrawTextContext *s = ctx->priv;
380  int err;
381  const char *error = "unknown error\n";
382 
383  /* load the face, and set up the encoding, which is by default UTF-8 */
384  err = load_font_file(ctx, s->fontfile, 0, &error);
385  if (!err)
386  return 0;
387 #if CONFIG_FONTCONFIG
388  err = load_font_fontconfig(ctx, &error);
389  if (!err)
390  return 0;
391 #endif
392  av_log(ctx, AV_LOG_ERROR, "Could not load font \"%s\": %s\n",
393  s->fontfile, error);
394  return err;
395 }
396 
397 static int load_textfile(AVFilterContext *ctx)
398 {
399  DrawTextContext *s = ctx->priv;
400  int err;
401  uint8_t *textbuf;
402  size_t textbuf_size;
403 
404  if ((err = av_file_map(s->textfile, &textbuf, &textbuf_size, 0, ctx)) < 0) {
405  av_log(ctx, AV_LOG_ERROR,
406  "The text file '%s' could not be read or is empty\n",
407  s->textfile);
408  return err;
409  }
410 
411  if (!(s->text = av_realloc(s->text, textbuf_size + 1)))
412  return AVERROR(ENOMEM);
413  memcpy(s->text, textbuf, textbuf_size);
414  s->text[textbuf_size] = 0;
415  av_file_unmap(textbuf, textbuf_size);
416 
417  return 0;
418 }
419 
420 static av_cold int init(AVFilterContext *ctx)
421 {
422  int err;
423  DrawTextContext *s = ctx->priv;
424  Glyph *glyph;
425 
426  if (!s->fontfile && !CONFIG_FONTCONFIG) {
427  av_log(ctx, AV_LOG_ERROR, "No font filename provided\n");
428  return AVERROR(EINVAL);
429  }
430 
431  if (s->textfile) {
432  if (s->text) {
433  av_log(ctx, AV_LOG_ERROR,
434  "Both text and text file provided. Please provide only one\n");
435  return AVERROR(EINVAL);
436  }
437  if ((err = load_textfile(ctx)) < 0)
438  return err;
439  }
440 
441  if (s->reload && !s->textfile)
442  av_log(ctx, AV_LOG_WARNING, "No file to reload\n");
443 
444  if (s->tc_opt_string) {
445  int ret = av_timecode_init_from_string(&s->tc, s->tc_rate,
446  s->tc_opt_string, ctx);
447  if (ret < 0)
448  return ret;
449  if (s->tc24hmax)
450  s->tc.flags |= AV_TIMECODE_FLAG_24HOURSMAX;
451  if (!s->text)
452  s->text = av_strdup("");
453  }
454 
455  if (!s->text) {
456  av_log(ctx, AV_LOG_ERROR,
457  "Either text, a valid file or a timecode must be provided\n");
458  return AVERROR(EINVAL);
459  }
460 
461  if ((err = FT_Init_FreeType(&(s->library)))) {
462  av_log(ctx, AV_LOG_ERROR,
463  "Could not load FreeType: %s\n", FT_ERRMSG(err));
464  return AVERROR(EINVAL);
465  }
466 
467  err = load_font(ctx);
468  if (err)
469  return err;
470  if (!s->fontsize)
471  s->fontsize = 16;
472  if ((err = FT_Set_Pixel_Sizes(s->face, 0, s->fontsize))) {
473  av_log(ctx, AV_LOG_ERROR, "Could not set font size to %d pixels: %s\n",
474  s->fontsize, FT_ERRMSG(err));
475  return AVERROR(EINVAL);
476  }
477 
478  s->use_kerning = FT_HAS_KERNING(s->face);
479 
480  /* load the fallback glyph with code 0 */
481  load_glyph(ctx, NULL, 0);
482 
483  /* set the tabsize in pixels */
484  if ((err = load_glyph(ctx, &glyph, ' ')) < 0) {
485  av_log(ctx, AV_LOG_ERROR, "Could not set tabsize.\n");
486  return err;
487  }
488  s->tabsize *= glyph->advance;
489 
490  if (s->exp_mode == EXP_STRFTIME &&
491  (strchr(s->text, '%') || strchr(s->text, '\\')))
492  av_log(ctx, AV_LOG_WARNING, "expansion=strftime is deprecated.\n");
493 
494  av_bprint_init(&s->expanded_text, 0, AV_BPRINT_SIZE_UNLIMITED);
495 
496  return 0;
497 }
498 
499 static int query_formats(AVFilterContext *ctx)
500 {
501  ff_set_common_formats(ctx, ff_draw_supported_pixel_formats(0));
502  return 0;
503 }
504 
505 static int glyph_enu_free(void *opaque, void *elem)
506 {
507  Glyph *glyph = elem;
508 
509  FT_Done_Glyph(*glyph->glyph);
510  av_freep(&glyph->glyph);
511  av_free(elem);
512  return 0;
513 }
514 
515 static av_cold void uninit(AVFilterContext *ctx)
516 {
517  DrawTextContext *s = ctx->priv;
518 
519  av_expr_free(s->x_pexpr);
520  av_expr_free(s->y_pexpr);
521  av_expr_free(s->draw_pexpr);
522  s->x_pexpr = s->y_pexpr = s->draw_pexpr = NULL;
523  av_freep(&s->positions);
524  s->nb_positions = 0;
525 
526 
527  av_tree_enumerate(s->glyphs, NULL, NULL, glyph_enu_free);
528  av_tree_destroy(s->glyphs);
529  s->glyphs = NULL;
530 
531  FT_Done_Face(s->face);
532  FT_Done_FreeType(s->library);
533 
534  av_bprint_finalize(&s->expanded_text, NULL);
535 }
536 
537 static inline int is_newline(uint32_t c)
538 {
539  return c == '\n' || c == '\r' || c == '\f' || c == '\v';
540 }
541 
542 static int config_input(AVFilterLink *inlink)
543 {
544  AVFilterContext *ctx = inlink->dst;
545  DrawTextContext *s = ctx->priv;
546  int ret;
547 
548  ff_draw_init(&s->dc, inlink->format, 0);
549  ff_draw_color(&s->dc, &s->fontcolor, s->fontcolor.rgba);
550  ff_draw_color(&s->dc, &s->shadowcolor, s->shadowcolor.rgba);
551  ff_draw_color(&s->dc, &s->boxcolor, s->boxcolor.rgba);
552 
553  s->var_values[VAR_w] = s->var_values[VAR_W] = s->var_values[VAR_MAIN_W] = inlink->w;
554  s->var_values[VAR_h] = s->var_values[VAR_H] = s->var_values[VAR_MAIN_H] = inlink->h;
555  s->var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ? av_q2d(inlink->sample_aspect_ratio) : 1;
556  s->var_values[VAR_DAR] = (double)inlink->w / inlink->h * s->var_values[VAR_SAR];
557  s->var_values[VAR_HSUB] = 1 << s->dc.hsub_max;
558  s->var_values[VAR_VSUB] = 1 << s->dc.vsub_max;
559  s->var_values[VAR_X] = NAN;
560  s->var_values[VAR_Y] = NAN;
561  s->var_values[VAR_T] = NAN;
562 
563  av_lfg_init(&s->prng, av_get_random_seed());
564 
565  av_expr_free(s->x_pexpr);
566  av_expr_free(s->y_pexpr);
567  av_expr_free(s->draw_pexpr);
568  s->x_pexpr = s->y_pexpr = s->draw_pexpr = NULL;
569  if ((ret = av_expr_parse(&s->x_pexpr, s->x_expr, var_names,
570  NULL, NULL, fun2_names, fun2, 0, ctx)) < 0 ||
571  (ret = av_expr_parse(&s->y_pexpr, s->y_expr, var_names,
572  NULL, NULL, fun2_names, fun2, 0, ctx)) < 0 ||
573  (ret = av_expr_parse(&s->draw_pexpr, s->draw_expr, var_names,
574  NULL, NULL, fun2_names, fun2, 0, ctx)) < 0)
575 
576  return AVERROR(EINVAL);
577 
578  return 0;
579 }
580 
581 static int command(AVFilterContext *ctx, const char *cmd, const char *arg, char *res, int res_len, int flags)
582 {
583  DrawTextContext *s = ctx->priv;
584 
585  if (!strcmp(cmd, "reinit")) {
586  int ret;
587  uninit(ctx);
588  s->reinit = 1;
589  if ((ret = init(ctx)) < 0)
590  return ret;
591  return config_input(ctx->inputs[0]);
592  }
593 
594  return AVERROR(ENOSYS);
595 }
596 
597 static int func_pict_type(AVFilterContext *ctx, AVBPrint *bp,
598  char *fct, unsigned argc, char **argv, int tag)
599 {
600  DrawTextContext *s = ctx->priv;
601 
602  av_bprintf(bp, "%c", av_get_picture_type_char(s->var_values[VAR_PICT_TYPE]));
603  return 0;
604 }
605 
606 static int func_pts(AVFilterContext *ctx, AVBPrint *bp,
607  char *fct, unsigned argc, char **argv, int tag)
608 {
609  DrawTextContext *s = ctx->priv;
610 
611  av_bprintf(bp, "%.6f", s->var_values[VAR_T]);
612  return 0;
613 }
614 
615 static int func_frame_num(AVFilterContext *ctx, AVBPrint *bp,
616  char *fct, unsigned argc, char **argv, int tag)
617 {
618  DrawTextContext *s = ctx->priv;
619 
620  av_bprintf(bp, "%d", (int)s->var_values[VAR_N]);
621  return 0;
622 }
623 
624 static int func_metadata(AVFilterContext *ctx, AVBPrint *bp,
625  char *fct, unsigned argc, char **argv, int tag)
626 {
627  DrawTextContext *s = ctx->priv;
628  AVDictionaryEntry *e = av_dict_get(s->metadata, argv[0], NULL, 0);
629 
630  if (e && e->value)
631  av_bprintf(bp, "%s", e->value);
632  return 0;
633 }
634 
635 #if !HAVE_LOCALTIME_R
636 static void localtime_r(const time_t *t, struct tm *tm)
637 {
638  *tm = *localtime(t);
639 }
640 #endif
641 
642 static int func_strftime(AVFilterContext *ctx, AVBPrint *bp,
643  char *fct, unsigned argc, char **argv, int tag)
644 {
645  const char *fmt = argc ? argv[0] : "%Y-%m-%d %H:%M:%S";
646  time_t now;
647  struct tm tm;
648 
649  time(&now);
650  if (tag == 'L')
651  localtime_r(&now, &tm);
652  else
653  tm = *gmtime(&now);
654  av_bprint_strftime(bp, fmt, &tm);
655  return 0;
656 }
657 
658 static int func_eval_expr(AVFilterContext *ctx, AVBPrint *bp,
659  char *fct, unsigned argc, char **argv, int tag)
660 {
661  DrawTextContext *s = ctx->priv;
662  double res;
663  int ret;
664 
665  ret = av_expr_parse_and_eval(&res, argv[0], var_names, s->var_values,
666  NULL, NULL, fun2_names, fun2,
667  &s->prng, 0, ctx);
668  if (ret < 0)
669  av_log(ctx, AV_LOG_ERROR,
670  "Expression '%s' for the expr text expansion function is not valid\n",
671  argv[0]);
672  else
673  av_bprintf(bp, "%f", res);
674 
675  return ret;
676 }
677 
678 static const struct drawtext_function {
679  const char *name;
680  unsigned argc_min, argc_max;
681  int tag; /**< opaque argument to func */
682  int (*func)(AVFilterContext *, AVBPrint *, char *, unsigned, char **, int);
683 } functions[] = {
684  { "expr", 1, 1, 0, func_eval_expr },
685  { "e", 1, 1, 0, func_eval_expr },
686  { "pict_type", 0, 0, 0, func_pict_type },
687  { "pts", 0, 0, 0, func_pts },
688  { "gmtime", 0, 1, 'G', func_strftime },
689  { "localtime", 0, 1, 'L', func_strftime },
690  { "frame_num", 0, 0, 0, func_frame_num },
691  { "n", 0, 0, 0, func_frame_num },
692  { "metadata", 1, 1, 0, func_metadata },
693 };
694 
695 static int eval_function(AVFilterContext *ctx, AVBPrint *bp, char *fct,
696  unsigned argc, char **argv)
697 {
698  unsigned i;
699 
700  for (i = 0; i < FF_ARRAY_ELEMS(functions); i++) {
701  if (strcmp(fct, functions[i].name))
702  continue;
703  if (argc < functions[i].argc_min) {
704  av_log(ctx, AV_LOG_ERROR, "%%{%s} requires at least %d arguments\n",
705  fct, functions[i].argc_min);
706  return AVERROR(EINVAL);
707  }
708  if (argc > functions[i].argc_max) {
709  av_log(ctx, AV_LOG_ERROR, "%%{%s} requires at most %d arguments\n",
710  fct, functions[i].argc_max);
711  return AVERROR(EINVAL);
712  }
713  break;
714  }
715  if (i >= FF_ARRAY_ELEMS(functions)) {
716  av_log(ctx, AV_LOG_ERROR, "%%{%s} is not known\n", fct);
717  return AVERROR(EINVAL);
718  }
719  return functions[i].func(ctx, bp, fct, argc, argv, functions[i].tag);
720 }
721 
722 static int expand_function(AVFilterContext *ctx, AVBPrint *bp, char **rtext)
723 {
724  const char *text = *rtext;
725  char *argv[16] = { NULL };
726  unsigned argc = 0, i;
727  int ret;
728 
729  if (*text != '{') {
730  av_log(ctx, AV_LOG_ERROR, "Stray %% near '%s'\n", text);
731  return AVERROR(EINVAL);
732  }
733  text++;
734  while (1) {
735  if (!(argv[argc++] = av_get_token(&text, ":}"))) {
736  ret = AVERROR(ENOMEM);
737  goto end;
738  }
739  if (!*text) {
740  av_log(ctx, AV_LOG_ERROR, "Unterminated %%{} near '%s'\n", *rtext);
741  ret = AVERROR(EINVAL);
742  goto end;
743  }
744  if (argc == FF_ARRAY_ELEMS(argv))
745  av_freep(&argv[--argc]); /* error will be caught later */
746  if (*text == '}')
747  break;
748  text++;
749  }
750 
751  if ((ret = eval_function(ctx, bp, argv[0], argc - 1, argv + 1)) < 0)
752  goto end;
753  ret = 0;
754  *rtext = (char *)text + 1;
755 
756 end:
757  for (i = 0; i < argc; i++)
758  av_freep(&argv[i]);
759  return ret;
760 }
761 
762 static int expand_text(AVFilterContext *ctx)
763 {
764  DrawTextContext *s = ctx->priv;
765  char *text = s->text;
766  AVBPrint *bp = &s->expanded_text;
767  int ret;
768 
769  av_bprint_clear(bp);
770  while (*text) {
771  if (*text == '\\' && text[1]) {
772  av_bprint_chars(bp, text[1], 1);
773  text += 2;
774  } else if (*text == '%') {
775  text++;
776  if ((ret = expand_function(ctx, bp, &text)) < 0)
777  return ret;
778  } else {
779  av_bprint_chars(bp, *text, 1);
780  text++;
781  }
782  }
783  if (!av_bprint_is_complete(bp))
784  return AVERROR(ENOMEM);
785  return 0;
786 }
787 
788 static int draw_glyphs(DrawTextContext *s, AVFrame *frame,
789  int width, int height, const uint8_t rgbcolor[4], FFDrawColor *color, int x, int y)
790 {
791  char *text = s->expanded_text.str;
792  uint32_t code = 0;
793  int i, x1, y1;
794  uint8_t *p;
795  Glyph *glyph = NULL;
796 
797  for (i = 0, p = text; *p; i++) {
798  Glyph dummy = { 0 };
799  GET_UTF8(code, *p++, continue;);
800 
801  /* skip new line chars, just go to new line */
802  if (code == '\n' || code == '\r' || code == '\t')
803  continue;
804 
805  dummy.code = code;
806  glyph = av_tree_find(s->glyphs, &dummy, (void *)glyph_cmp, NULL);
807 
808  if (glyph->bitmap.pixel_mode != FT_PIXEL_MODE_MONO &&
809  glyph->bitmap.pixel_mode != FT_PIXEL_MODE_GRAY)
810  return AVERROR(EINVAL);
811 
812  x1 = s->positions[i].x+s->x+x;
813  y1 = s->positions[i].y+s->y+y;
814 
815  ff_blend_mask(&s->dc, color,
816  frame->data, frame->linesize, width, height,
817  glyph->bitmap.buffer, glyph->bitmap.pitch,
818  glyph->bitmap.width, glyph->bitmap.rows,
819  glyph->bitmap.pixel_mode == FT_PIXEL_MODE_MONO ? 0 : 3,
820  0, x1, y1);
821  }
822 
823  return 0;
824 }
825 
826 static int draw_text(AVFilterContext *ctx, AVFrame *frame,
827  int width, int height)
828 {
829  DrawTextContext *s = ctx->priv;
830  AVFilterLink *inlink = ctx->inputs[0];
831 
832  uint32_t code = 0, prev_code = 0;
833  int x = 0, y = 0, i = 0, ret;
834  int max_text_line_w = 0, len;
835  int box_w, box_h;
836  char *text = s->text;
837  uint8_t *p;
838  int y_min = 32000, y_max = -32000;
839  int x_min = 32000, x_max = -32000;
840  FT_Vector delta;
841  Glyph *glyph = NULL, *prev_glyph = NULL;
842  Glyph dummy = { 0 };
843 
844  time_t now = time(0);
845  struct tm ltime;
846  AVBPrint *bp = &s->expanded_text;
847 
848  av_bprint_clear(bp);
849 
850  if(s->basetime != AV_NOPTS_VALUE)
851  now= frame->pts*av_q2d(ctx->inputs[0]->time_base) + s->basetime/1000000;
852 
853  switch (s->exp_mode) {
854  case EXP_NONE:
855  av_bprintf(bp, "%s", s->text);
856  break;
857  case EXP_NORMAL:
858  if ((ret = expand_text(ctx)) < 0)
859  return ret;
860  break;
861  case EXP_STRFTIME:
862  localtime_r(&now, &ltime);
863  av_bprint_strftime(bp, s->text, &ltime);
864  break;
865  }
866 
867  if (s->tc_opt_string) {
868  char tcbuf[AV_TIMECODE_STR_SIZE];
869  av_timecode_make_string(&s->tc, tcbuf, inlink->frame_count);
870  av_bprint_clear(bp);
871  av_bprintf(bp, "%s%s", s->text, tcbuf);
872  }
873 
874  if (!av_bprint_is_complete(bp))
875  return AVERROR(ENOMEM);
876  text = s->expanded_text.str;
877  if ((len = s->expanded_text.len) > s->nb_positions) {
878  if (!(s->positions =
879  av_realloc(s->positions, len*sizeof(*s->positions))))
880  return AVERROR(ENOMEM);
881  s->nb_positions = len;
882  }
883 
884  x = 0;
885  y = 0;
886 
887  /* load and cache glyphs */
888  for (i = 0, p = text; *p; i++) {
889  GET_UTF8(code, *p++, continue;);
890 
891  /* get glyph */
892  dummy.code = code;
893  glyph = av_tree_find(s->glyphs, &dummy, glyph_cmp, NULL);
894  if (!glyph) {
895  load_glyph(ctx, &glyph, code);
896  }
897 
898  y_min = FFMIN(glyph->bbox.yMin, y_min);
899  y_max = FFMAX(glyph->bbox.yMax, y_max);
900  x_min = FFMIN(glyph->bbox.xMin, x_min);
901  x_max = FFMAX(glyph->bbox.xMax, x_max);
902  }
903  s->max_glyph_h = y_max - y_min;
904  s->max_glyph_w = x_max - x_min;
905 
906  /* compute and save position for each glyph */
907  glyph = NULL;
908  for (i = 0, p = text; *p; i++) {
909  GET_UTF8(code, *p++, continue;);
910 
911  /* skip the \n in the sequence \r\n */
912  if (prev_code == '\r' && code == '\n')
913  continue;
914 
915  prev_code = code;
916  if (is_newline(code)) {
917 
918  max_text_line_w = FFMAX(max_text_line_w, x);
919  y += s->max_glyph_h;
920  x = 0;
921  continue;
922  }
923 
924  /* get glyph */
925  prev_glyph = glyph;
926  dummy.code = code;
927  glyph = av_tree_find(s->glyphs, &dummy, glyph_cmp, NULL);
928 
929  /* kerning */
930  if (s->use_kerning && prev_glyph && glyph->code) {
931  FT_Get_Kerning(s->face, prev_glyph->code, glyph->code,
932  ft_kerning_default, &delta);
933  x += delta.x >> 6;
934  }
935 
936  /* save position */
937  s->positions[i].x = x + glyph->bitmap_left;
938  s->positions[i].y = y - glyph->bitmap_top + y_max;
939  if (code == '\t') x = (x / s->tabsize + 1)*s->tabsize;
940  else x += glyph->advance;
941  }
942 
943  max_text_line_w = FFMAX(x, max_text_line_w);
944 
945  s->var_values[VAR_TW] = s->var_values[VAR_TEXT_W] = max_text_line_w;
946  s->var_values[VAR_TH] = s->var_values[VAR_TEXT_H] = y + s->max_glyph_h;
947 
948  s->var_values[VAR_MAX_GLYPH_W] = s->max_glyph_w;
949  s->var_values[VAR_MAX_GLYPH_H] = s->max_glyph_h;
950  s->var_values[VAR_MAX_GLYPH_A] = s->var_values[VAR_ASCENT ] = y_max;
951  s->var_values[VAR_MAX_GLYPH_D] = s->var_values[VAR_DESCENT] = y_min;
952 
953  s->var_values[VAR_LINE_H] = s->var_values[VAR_LH] = s->max_glyph_h;
954 
955  s->x = s->var_values[VAR_X] = av_expr_eval(s->x_pexpr, s->var_values, &s->prng);
956  s->y = s->var_values[VAR_Y] = av_expr_eval(s->y_pexpr, s->var_values, &s->prng);
957  s->x = s->var_values[VAR_X] = av_expr_eval(s->x_pexpr, s->var_values, &s->prng);
958  s->draw = av_expr_eval(s->draw_pexpr, s->var_values, &s->prng);
959 
960  if(!s->draw)
961  return 0;
962 
963  box_w = FFMIN(width - 1 , max_text_line_w);
964  box_h = FFMIN(height - 1, y + s->max_glyph_h);
965 
966  /* draw box */
967  if (s->draw_box)
968  ff_blend_rectangle(&s->dc, &s->boxcolor,
969  frame->data, frame->linesize, width, height,
970  s->x, s->y, box_w, box_h);
971 
972  if (s->shadowx || s->shadowy) {
973  if ((ret = draw_glyphs(s, frame, width, height, s->shadowcolor.rgba,
974  &s->shadowcolor, s->shadowx, s->shadowy)) < 0)
975  return ret;
976  }
977 
978  if ((ret = draw_glyphs(s, frame, width, height, s->fontcolor.rgba,
979  &s->fontcolor, 0, 0)) < 0)
980  return ret;
981 
982  return 0;
983 }
984 
985 static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
986 {
987  AVFilterContext *ctx = inlink->dst;
988  AVFilterLink *outlink = ctx->outputs[0];
989  DrawTextContext *s = ctx->priv;
990  int ret;
991 
992  if (s->reload)
993  if ((ret = load_textfile(ctx)) < 0)
994  return ret;
995 
996  s->var_values[VAR_N] = inlink->frame_count+s->start_number;
997  s->var_values[VAR_T] = frame->pts == AV_NOPTS_VALUE ?
998  NAN : frame->pts * av_q2d(inlink->time_base);
999 
1000  s->var_values[VAR_PICT_TYPE] = frame->pict_type;
1001  s->metadata = av_frame_get_metadata(frame);
1002 
1003  draw_text(ctx, frame, frame->width, frame->height);
1004 
1005  av_log(ctx, AV_LOG_DEBUG, "n:%d t:%f text_w:%d text_h:%d x:%d y:%d\n",
1006  (int)s->var_values[VAR_N], s->var_values[VAR_T],
1007  (int)s->var_values[VAR_TEXT_W], (int)s->var_values[VAR_TEXT_H],
1008  s->x, s->y);
1009 
1010  return ff_filter_frame(outlink, frame);
1011 }
1012 
1013 static const AVFilterPad avfilter_vf_drawtext_inputs[] = {
1014  {
1015  .name = "default",
1016  .type = AVMEDIA_TYPE_VIDEO,
1017  .get_video_buffer = ff_null_get_video_buffer,
1018  .filter_frame = filter_frame,
1019  .config_props = config_input,
1020  .needs_writable = 1,
1021  },
1022  { NULL }
1023 };
1024 
1025 static const AVFilterPad avfilter_vf_drawtext_outputs[] = {
1026  {
1027  .name = "default",
1028  .type = AVMEDIA_TYPE_VIDEO,
1029  },
1030  { NULL }
1031 };
1032 
1033 AVFilter avfilter_vf_drawtext = {
1034  .name = "drawtext",
1035  .description = NULL_IF_CONFIG_SMALL("Draw text on top of video frames using libfreetype library."),
1036  .priv_size = sizeof(DrawTextContext),
1037  .priv_class = &drawtext_class,
1038  .init = init,
1039  .uninit = uninit,
1040  .query_formats = query_formats,
1041 
1042  .inputs = avfilter_vf_drawtext_inputs,
1043  .outputs = avfilter_vf_drawtext_outputs,
1044  .process_command = command,
1045 };
Generated on Wed Jul 10 2013 23:48:10 for FFmpeg by   doxygen 1.8.2