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 "config.h"
30 
31 #if HAVE_SYS_TIME_H
32 #include <sys/time.h>
33 #endif
34 #include <sys/types.h>
35 #include <sys/stat.h>
36 #include <time.h>
37 #if HAVE_UNISTD_H
38 #include <unistd.h>
39 #endif
40 
41 #ifndef __amigaos4__
42 #include <fenv.h>
43 #endif
44 
45 #if CONFIG_LIBFONTCONFIG
46 #include <fontconfig/fontconfig.h>
47 #endif
48 
49 #include "libavutil/avstring.h"
50 #include "libavutil/bprint.h"
51 #include "libavutil/common.h"
52 #include "libavutil/file.h"
53 #include "libavutil/eval.h"
54 #include "libavutil/opt.h"
55 #include "libavutil/random_seed.h"
56 #include "libavutil/parseutils.h"
57 #include "libavutil/timecode.h"
58 #include "libavutil/tree.h"
59 #include "libavutil/lfg.h"
60 #include "avfilter.h"
61 #include "drawutils.h"
62 #include "formats.h"
63 #include "internal.h"
64 #include "video.h"
65 
66 #if CONFIG_LIBFRIBIDI
67 #include <fribidi.h>
68 #endif
69 
70 #include <ft2build.h>
71 #include FT_FREETYPE_H
72 #include FT_GLYPH_H
73 #include FT_STROKER_H
74 
75 static const char *const var_names[] = {
76     "dar",
77     "hsub", "vsub",
78     "line_h", "lh",           ///< line height, same as max_glyph_h
79     "main_h", "h", "H",       ///< height of the input video
80     "main_w", "w", "W",       ///< width  of the input video
81     "max_glyph_a", "ascent",  ///< max glyph ascent
82     "max_glyph_d", "descent", ///< min glyph descent
83     "max_glyph_h",            ///< max glyph height
84     "max_glyph_w",            ///< max glyph width
85     "n",                      ///< number of frame
86     "sar",
87     "t",                      ///< timestamp expressed in seconds
88     "text_h", "th",           ///< height of the rendered text
89     "text_w", "tw",           ///< width  of the rendered text
90     "x",
91     "y",
92     "pict_type",
93     NULL
94 };
95 
96 static const char *const fun2_names[] = {
97     "rand"
98 };
99 
drand(void * opaque,double min,double max)100 static double drand(void *opaque, double min, double max)
101 {
102     return min + (max-min) / UINT_MAX * av_lfg_get(opaque);
103 }
104 
105 typedef double (*eval_func2)(void *, double a, double b);
106 
107 static const eval_func2 fun2[] = {
108     drand,
109     NULL
110 };
111 
112 enum var_name {
113     VAR_DAR,
114     VAR_HSUB, VAR_VSUB,
115     VAR_LINE_H, VAR_LH,
116     VAR_MAIN_H, VAR_h, VAR_H,
117     VAR_MAIN_W, VAR_w, VAR_W,
118     VAR_MAX_GLYPH_A, VAR_ASCENT,
119     VAR_MAX_GLYPH_D, VAR_DESCENT,
120     VAR_MAX_GLYPH_H,
121     VAR_MAX_GLYPH_W,
122     VAR_N,
123     VAR_SAR,
124     VAR_T,
125     VAR_TEXT_H, VAR_TH,
126     VAR_TEXT_W, VAR_TW,
127     VAR_X,
128     VAR_Y,
129     VAR_PICT_TYPE,
130     VAR_VARS_NB
131 };
132 
133 enum expansion_mode {
134     EXP_NONE,
135     EXP_NORMAL,
136     EXP_STRFTIME,
137 };
138 
139 typedef struct DrawTextContext {
140     const AVClass *class;
141     enum expansion_mode exp_mode;   ///< expansion mode to use for the text
142     int reinit;                     ///< tells if the filter is being reinited
143 #if CONFIG_LIBFONTCONFIG
144     uint8_t *font;              ///< font to be used
145 #endif
146     uint8_t *fontfile;              ///< font to be used
147     uint8_t *text;                  ///< text to be drawn
148     AVBPrint expanded_text;         ///< used to contain the expanded text
149     uint8_t *fontcolor_expr;        ///< fontcolor expression to evaluate
150     AVBPrint expanded_fontcolor;    ///< used to contain the expanded fontcolor spec
151     int ft_load_flags;              ///< flags used for loading fonts, see FT_LOAD_*
152     FT_Vector *positions;           ///< positions for each element in the text
153     size_t nb_positions;            ///< number of elements of positions array
154     char *textfile;                 ///< file with text to be drawn
155     int x;                          ///< x position to start drawing text
156     int y;                          ///< y position to start drawing text
157     int max_glyph_w;                ///< max glyph width
158     int max_glyph_h;                ///< max glyph height
159     int shadowx, shadowy;
160     int borderw;                    ///< border width
161     unsigned int fontsize;          ///< font size to use
162 
163     short int draw_box;             ///< draw box around text - true or false
164     int use_kerning;                ///< font kerning is used - true/false
165     int tabsize;                    ///< tab size
166     int fix_bounds;                 ///< do we let it go out of frame bounds - t/f
167 
168     FFDrawContext dc;
169     FFDrawColor fontcolor;          ///< foreground color
170     FFDrawColor shadowcolor;        ///< shadow color
171     FFDrawColor bordercolor;        ///< border color
172     FFDrawColor boxcolor;           ///< background color
173 
174     FT_Library library;             ///< freetype font library handle
175     FT_Face face;                   ///< freetype font face handle
176     FT_Stroker stroker;             ///< freetype stroker handle
177     struct AVTreeNode *glyphs;      ///< rendered glyphs, stored using the UTF-32 char code
178     char *x_expr;                   ///< expression for x position
179     char *y_expr;                   ///< expression for y position
180     AVExpr *x_pexpr, *y_pexpr;      ///< parsed expressions for x and y
181     int64_t basetime;               ///< base pts time in the real world for display
182     double var_values[VAR_VARS_NB];
183 #if FF_API_DRAWTEXT_OLD_TIMELINE
184     char   *draw_expr;              ///< expression for draw
185     AVExpr *draw_pexpr;             ///< parsed expression for draw
186     int draw;                       ///< set to zero to prevent drawing
187 #endif
188     AVLFG  prng;                    ///< random
189     char       *tc_opt_string;      ///< specified timecode option string
190     AVRational  tc_rate;            ///< frame rate for timecode
191     AVTimecode  tc;                 ///< timecode context
192     int tc24hmax;                   ///< 1 if timecode is wrapped to 24 hours, 0 otherwise
193     int reload;                     ///< reload text file for each frame
194     int start_number;               ///< starting frame number for n/frame_num var
195 #if CONFIG_LIBFRIBIDI
196     int text_shaping;               ///< 1 to shape the text before drawing it
197 #endif
198     AVDictionary *metadata;
199 } DrawTextContext;
200 
201 #define OFFSET(x) offsetof(DrawTextContext, x)
202 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
203 
204 static const AVOption drawtext_options[]= {
205     {"fontfile",    "set font file",        OFFSET(fontfile),           AV_OPT_TYPE_STRING, {.str=NULL},  CHAR_MIN, CHAR_MAX, FLAGS},
206     {"text",        "set text",             OFFSET(text),               AV_OPT_TYPE_STRING, {.str=NULL},  CHAR_MIN, CHAR_MAX, FLAGS},
207     {"textfile",    "set text file",        OFFSET(textfile),           AV_OPT_TYPE_STRING, {.str=NULL},  CHAR_MIN, CHAR_MAX, FLAGS},
208     {"fontcolor",   "set foreground color", OFFSET(fontcolor.rgba),     AV_OPT_TYPE_COLOR,  {.str="black"}, CHAR_MIN, CHAR_MAX, FLAGS},
209     {"fontcolor_expr", "set foreground color expression", OFFSET(fontcolor_expr), AV_OPT_TYPE_STRING, {.str=""}, CHAR_MIN, CHAR_MAX, FLAGS},
210     {"boxcolor",    "set box color",        OFFSET(boxcolor.rgba),      AV_OPT_TYPE_COLOR,  {.str="white"}, CHAR_MIN, CHAR_MAX, FLAGS},
211     {"bordercolor", "set border color",     OFFSET(bordercolor.rgba),   AV_OPT_TYPE_COLOR,  {.str="black"}, CHAR_MIN, CHAR_MAX, FLAGS},
212     {"shadowcolor", "set shadow color",     OFFSET(shadowcolor.rgba),   AV_OPT_TYPE_COLOR,  {.str="black"}, CHAR_MIN, CHAR_MAX, FLAGS},
213     {"box",         "set box",              OFFSET(draw_box),           AV_OPT_TYPE_INT,    {.i64=0},     0,        1       , FLAGS},
214     {"fontsize",    "set font size",        OFFSET(fontsize),           AV_OPT_TYPE_INT,    {.i64=0},     0,        INT_MAX , FLAGS},
215     {"x",           "set x expression",     OFFSET(x_expr),             AV_OPT_TYPE_STRING, {.str="0"},   CHAR_MIN, CHAR_MAX, FLAGS},
216     {"y",           "set y expression",     OFFSET(y_expr),             AV_OPT_TYPE_STRING, {.str="0"},   CHAR_MIN, CHAR_MAX, FLAGS},
217     {"shadowx",     "set x",                OFFSET(shadowx),            AV_OPT_TYPE_INT,    {.i64=0},     INT_MIN,  INT_MAX , FLAGS},
218     {"shadowy",     "set y",                OFFSET(shadowy),            AV_OPT_TYPE_INT,    {.i64=0},     INT_MIN,  INT_MAX , FLAGS},
219     {"borderw",     "set border width",     OFFSET(borderw),            AV_OPT_TYPE_INT,    {.i64=0},     INT_MIN,  INT_MAX , FLAGS},
220     {"tabsize",     "set tab size",         OFFSET(tabsize),            AV_OPT_TYPE_INT,    {.i64=4},     0,        INT_MAX , FLAGS},
221     {"basetime",    "set base time",        OFFSET(basetime),           AV_OPT_TYPE_INT64,  {.i64=AV_NOPTS_VALUE}, INT64_MIN, INT64_MAX , FLAGS},
222 #if FF_API_DRAWTEXT_OLD_TIMELINE
223     {"draw",        "if false do not draw (deprecated)", OFFSET(draw_expr), AV_OPT_TYPE_STRING, {.str=NULL},   CHAR_MIN, CHAR_MAX, FLAGS},
224 #endif
225 #if CONFIG_LIBFONTCONFIG
226     { "font",        "Font name",            OFFSET(font),               AV_OPT_TYPE_STRING, { .str = "Sans" },           .flags = FLAGS },
227 #endif
228 
229     {"expansion", "set the expansion mode", OFFSET(exp_mode), AV_OPT_TYPE_INT, {.i64=EXP_NORMAL}, 0, 2, FLAGS, "expansion"},
230         {"none",     "set no expansion",                    OFFSET(exp_mode), AV_OPT_TYPE_CONST, {.i64=EXP_NONE},     0, 0, FLAGS, "expansion"},
231         {"normal",   "set normal expansion",                OFFSET(exp_mode), AV_OPT_TYPE_CONST, {.i64=EXP_NORMAL},   0, 0, FLAGS, "expansion"},
232         {"strftime", "set strftime expansion (deprecated)", OFFSET(exp_mode), AV_OPT_TYPE_CONST, {.i64=EXP_STRFTIME}, 0, 0, FLAGS, "expansion"},
233 
234     {"timecode",        "set initial timecode",             OFFSET(tc_opt_string), AV_OPT_TYPE_STRING,   {.str=NULL}, CHAR_MIN, CHAR_MAX, FLAGS},
235     {"tc24hmax",        "set 24 hours max (timecode only)", OFFSET(tc24hmax),      AV_OPT_TYPE_INT,      {.i64=0},           0,        1, FLAGS},
236     {"timecode_rate",   "set rate (timecode only)",         OFFSET(tc_rate),       AV_OPT_TYPE_RATIONAL, {.dbl=0},           0,  INT_MAX, FLAGS},
237     {"r",               "set rate (timecode only)",         OFFSET(tc_rate),       AV_OPT_TYPE_RATIONAL, {.dbl=0},           0,  INT_MAX, FLAGS},
238     {"rate",            "set rate (timecode only)",         OFFSET(tc_rate),       AV_OPT_TYPE_RATIONAL, {.dbl=0},           0,  INT_MAX, FLAGS},
239     {"reload",     "reload text file for each frame",                       OFFSET(reload),     AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS},
240     {"fix_bounds", "if true, check and fix text coords to avoid clipping",  OFFSET(fix_bounds), AV_OPT_TYPE_INT, {.i64=1}, 0, 1, FLAGS},
241     {"start_number", "start frame number for n/frame_num variable", OFFSET(start_number), AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX, FLAGS},
242 
243 #if CONFIG_LIBFRIBIDI
244     {"text_shaping", "attempt to shape text before drawing", OFFSET(text_shaping), AV_OPT_TYPE_INT, {.i64=1}, 0, 1, FLAGS},
245 #endif
246 
247     /* FT_LOAD_* flags */
248     { "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" },
249         { "default",                     NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_DEFAULT },                     .flags = FLAGS, .unit = "ft_load_flags" },
250         { "no_scale",                    NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_NO_SCALE },                    .flags = FLAGS, .unit = "ft_load_flags" },
251         { "no_hinting",                  NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_NO_HINTING },                  .flags = FLAGS, .unit = "ft_load_flags" },
252         { "render",                      NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_RENDER },                      .flags = FLAGS, .unit = "ft_load_flags" },
253         { "no_bitmap",                   NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_NO_BITMAP },                   .flags = FLAGS, .unit = "ft_load_flags" },
254         { "vertical_layout",             NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_VERTICAL_LAYOUT },             .flags = FLAGS, .unit = "ft_load_flags" },
255         { "force_autohint",              NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_FORCE_AUTOHINT },              .flags = FLAGS, .unit = "ft_load_flags" },
256         { "crop_bitmap",                 NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_CROP_BITMAP },                 .flags = FLAGS, .unit = "ft_load_flags" },
257         { "pedantic",                    NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_PEDANTIC },                    .flags = FLAGS, .unit = "ft_load_flags" },
258         { "ignore_global_advance_width", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH }, .flags = FLAGS, .unit = "ft_load_flags" },
259         { "no_recurse",                  NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_NO_RECURSE },                  .flags = FLAGS, .unit = "ft_load_flags" },
260         { "ignore_transform",            NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_IGNORE_TRANSFORM },            .flags = FLAGS, .unit = "ft_load_flags" },
261         { "monochrome",                  NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_MONOCHROME },                  .flags = FLAGS, .unit = "ft_load_flags" },
262         { "linear_design",               NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_LINEAR_DESIGN },               .flags = FLAGS, .unit = "ft_load_flags" },
263         { "no_autohint",                 NULL, 0, AV_OPT_TYPE_CONST, { .i64 = FT_LOAD_NO_AUTOHINT },                 .flags = FLAGS, .unit = "ft_load_flags" },
264     { NULL }
265 };
266 
267 AVFILTER_DEFINE_CLASS(drawtext);
268 
269 #undef __FTERRORS_H__
270 #define FT_ERROR_START_LIST {
271 #define FT_ERRORDEF(e, v, s) { (e), (s) },
272 #define FT_ERROR_END_LIST { 0, NULL } };
273 
274 static const struct ft_error
275 {
276     int err;
277     const char *err_msg;
278 } ft_errors[] =
279 #include FT_ERRORS_H
280 
281 #define FT_ERRMSG(e) ft_errors[e].err_msg
282 
283 typedef struct Glyph {
284     FT_Glyph glyph;
285     FT_Glyph border_glyph;
286     uint32_t code;
287     FT_Bitmap bitmap; ///< array holding bitmaps of font
288     FT_Bitmap border_bitmap; ///< array holding bitmaps of font border
289     FT_BBox bbox;
290     int advance;
291     int bitmap_left;
292     int bitmap_top;
293 } Glyph;
294 
glyph_cmp(void * key,const void * b)295 static int glyph_cmp(void *key, const void *b)
296 {
297     const Glyph *a = key, *bb = b;
298     int64_t diff = (int64_t)a->code - (int64_t)bb->code;
299     return diff > 0 ? 1 : diff < 0 ? -1 : 0;
300 }
301 
302 /**
303  * Load glyphs corresponding to the UTF-32 codepoint code.
304  */
load_glyph(AVFilterContext * ctx,Glyph ** glyph_ptr,uint32_t code)305 static int load_glyph(AVFilterContext *ctx, Glyph **glyph_ptr, uint32_t code)
306 {
307     DrawTextContext *s = ctx->priv;
308     FT_BitmapGlyph bitmapglyph;
309     Glyph *glyph;
310     struct AVTreeNode *node = NULL;
311     int ret;
312 
313     /* load glyph into s->face->glyph */
314     if (FT_Load_Char(s->face, code, s->ft_load_flags))
315         return AVERROR(EINVAL);
316 
317     glyph = av_mallocz(sizeof(*glyph));
318     if (!glyph) {
319         ret = AVERROR(ENOMEM);
320         goto error;
321     }
322     glyph->code  = code;
323 
324     if (FT_Get_Glyph(s->face->glyph, &glyph->glyph)) {
325         ret = AVERROR(EINVAL);
326         goto error;
327     }
328     if (s->borderw) {
329         glyph->border_glyph = glyph->glyph;
330         if (FT_Glyph_StrokeBorder(&glyph->border_glyph, s->stroker, 0, 0) ||
331             FT_Glyph_To_Bitmap(&glyph->border_glyph, FT_RENDER_MODE_NORMAL, 0, 1)) {
332             ret = AVERROR_EXTERNAL;
333             goto error;
334         }
335         bitmapglyph = (FT_BitmapGlyph) glyph->border_glyph;
336         glyph->border_bitmap = bitmapglyph->bitmap;
337     }
338     if (FT_Glyph_To_Bitmap(&glyph->glyph, FT_RENDER_MODE_NORMAL, 0, 1)) {
339         ret = AVERROR_EXTERNAL;
340         goto error;
341     }
342     bitmapglyph = (FT_BitmapGlyph) glyph->glyph;
343 
344     glyph->bitmap      = bitmapglyph->bitmap;
345     glyph->bitmap_left = bitmapglyph->left;
346     glyph->bitmap_top  = bitmapglyph->top;
347     glyph->advance     = s->face->glyph->advance.x >> 6;
348 
349     /* measure text height to calculate text_height (or the maximum text height) */
350     FT_Glyph_Get_CBox(glyph->glyph, ft_glyph_bbox_pixels, &glyph->bbox);
351 
352     /* cache the newly created glyph */
353     if (!(node = av_tree_node_alloc())) {
354         ret = AVERROR(ENOMEM);
355         goto error;
356     }
357     av_tree_insert(&s->glyphs, glyph, glyph_cmp, &node);
358 
359     if (glyph_ptr)
360         *glyph_ptr = glyph;
361     return 0;
362 
363 error:
364     if (glyph)
365         av_freep(&glyph->glyph);
366 
367     av_freep(&glyph);
368     av_freep(&node);
369     return ret;
370 }
371 
load_font_file(AVFilterContext * ctx,const char * path,int index)372 static int load_font_file(AVFilterContext *ctx, const char *path, int index)
373 {
374     DrawTextContext *s = ctx->priv;
375     int err;
376 
377     err = FT_New_Face(s->library, path, index, &s->face);
378     if (err) {
379         av_log(ctx, AV_LOG_ERROR, "Could not load font \"%s\": %s\n",
380                s->fontfile, FT_ERRMSG(err));
381         return AVERROR(EINVAL);
382     }
383     return 0;
384 }
385 
386 #if CONFIG_LIBFONTCONFIG
load_font_fontconfig(AVFilterContext * ctx)387 static int load_font_fontconfig(AVFilterContext *ctx)
388 {
389     DrawTextContext *s = ctx->priv;
390     FcConfig *fontconfig;
391     FcPattern *pat, *best;
392     FcResult result = FcResultMatch;
393     FcChar8 *filename;
394     int index;
395     double size;
396     int err = AVERROR(ENOENT);
397 
398     fontconfig = FcInitLoadConfigAndFonts();
399     if (!fontconfig) {
400         av_log(ctx, AV_LOG_ERROR, "impossible to init fontconfig\n");
401         return AVERROR_UNKNOWN;
402     }
403     pat = FcNameParse(s->fontfile ? s->fontfile :
404                           (uint8_t *)(intptr_t)"default");
405     if (!pat) {
406         av_log(ctx, AV_LOG_ERROR, "could not parse fontconfig pat");
407         return AVERROR(EINVAL);
408     }
409 
410     FcPatternAddString(pat, FC_FAMILY, s->font);
411     if (s->fontsize)
412         FcPatternAddDouble(pat, FC_SIZE, (double)s->fontsize);
413 
414     FcDefaultSubstitute(pat);
415 
416     if (!FcConfigSubstitute(fontconfig, pat, FcMatchPattern)) {
417         av_log(ctx, AV_LOG_ERROR, "could not substitue fontconfig options"); /* very unlikely */
418         FcPatternDestroy(pat);
419         return AVERROR(ENOMEM);
420     }
421 
422     best = FcFontMatch(fontconfig, pat, &result);
423     FcPatternDestroy(pat);
424 
425     if (!best || result != FcResultMatch) {
426         av_log(ctx, AV_LOG_ERROR,
427                "Cannot find a valid font for the family %s\n",
428                s->font);
429         goto fail;
430     }
431 
432     if (
433         FcPatternGetInteger(best, FC_INDEX, 0, &index   ) != FcResultMatch ||
434         FcPatternGetDouble (best, FC_SIZE,  0, &size    ) != FcResultMatch) {
435         av_log(ctx, AV_LOG_ERROR, "impossible to find font information");
436         return AVERROR(EINVAL);
437     }
438 
439     if (FcPatternGetString(best, FC_FILE, 0, &filename) != FcResultMatch) {
440         av_log(ctx, AV_LOG_ERROR, "No file path for %s\n",
441                s->font);
442         goto fail;
443     }
444 
445     av_log(ctx, AV_LOG_INFO, "Using \"%s\"\n", filename);
446     if (!s->fontsize)
447         s->fontsize = size + 0.5;
448 
449     err = load_font_file(ctx, filename, index);
450     if (err)
451         return err;
452     FcConfigDestroy(fontconfig);
453 fail:
454     FcPatternDestroy(best);
455     return err;
456 }
457 #endif
458 
load_font(AVFilterContext * ctx)459 static int load_font(AVFilterContext *ctx)
460 {
461     DrawTextContext *s = ctx->priv;
462     int err;
463 
464     /* load the face, and set up the encoding, which is by default UTF-8 */
465     err = load_font_file(ctx, s->fontfile, 0);
466     if (!err)
467         return 0;
468 #if CONFIG_LIBFONTCONFIG
469     err = load_font_fontconfig(ctx);
470     if (!err)
471         return 0;
472 #endif
473     return err;
474 }
475 
load_textfile(AVFilterContext * ctx)476 static int load_textfile(AVFilterContext *ctx)
477 {
478     DrawTextContext *s = ctx->priv;
479     int err;
480     uint8_t *textbuf;
481     uint8_t *tmp;
482     size_t textbuf_size;
483 
484     if ((err = av_file_map(s->textfile, &textbuf, &textbuf_size, 0, ctx)) < 0) {
485         av_log(ctx, AV_LOG_ERROR,
486                "The text file '%s' could not be read or is empty\n",
487                s->textfile);
488         return err;
489     }
490 
491     if (!(tmp = av_realloc(s->text, textbuf_size + 1))) {
492         av_file_unmap(textbuf, textbuf_size);
493         return AVERROR(ENOMEM);
494     }
495     s->text = tmp;
496     memcpy(s->text, textbuf, textbuf_size);
497     s->text[textbuf_size] = 0;
498     av_file_unmap(textbuf, textbuf_size);
499 
500     return 0;
501 }
502 
is_newline(uint32_t c)503 static inline int is_newline(uint32_t c)
504 {
505     return c == '\n' || c == '\r' || c == '\f' || c == '\v';
506 }
507 
508 #if CONFIG_LIBFRIBIDI
shape_text(AVFilterContext * ctx)509 static int shape_text(AVFilterContext *ctx)
510 {
511     DrawTextContext *s = ctx->priv;
512     uint8_t *tmp;
513     int ret = AVERROR(ENOMEM);
514     static const FriBidiFlags flags = FRIBIDI_FLAGS_DEFAULT |
515                                       FRIBIDI_FLAGS_ARABIC;
516     FriBidiChar *unicodestr = NULL;
517     FriBidiStrIndex len;
518     FriBidiParType direction = FRIBIDI_PAR_LTR;
519     FriBidiStrIndex line_start = 0;
520     FriBidiStrIndex line_end = 0;
521     FriBidiLevel *embedding_levels = NULL;
522     FriBidiArabicProp *ar_props = NULL;
523     FriBidiCharType *bidi_types = NULL;
524     FriBidiStrIndex i,j;
525 
526     len = strlen(s->text);
527     if (!(unicodestr = av_malloc_array(len, sizeof(*unicodestr)))) {
528         goto out;
529     }
530     len = fribidi_charset_to_unicode(FRIBIDI_CHAR_SET_UTF8,
531                                      s->text, len, unicodestr);
532 
533     bidi_types = av_malloc_array(len, sizeof(*bidi_types));
534     if (!bidi_types) {
535         goto out;
536     }
537 
538     fribidi_get_bidi_types(unicodestr, len, bidi_types);
539 
540     embedding_levels = av_malloc_array(len, sizeof(*embedding_levels));
541     if (!embedding_levels) {
542         goto out;
543     }
544 
545     if (!fribidi_get_par_embedding_levels(bidi_types, len, &direction,
546                                           embedding_levels)) {
547         goto out;
548     }
549 
550     ar_props = av_malloc_array(len, sizeof(*ar_props));
551     if (!ar_props) {
552         goto out;
553     }
554 
555     fribidi_get_joining_types(unicodestr, len, ar_props);
556     fribidi_join_arabic(bidi_types, len, embedding_levels, ar_props);
557     fribidi_shape(flags, embedding_levels, len, ar_props, unicodestr);
558 
559     for (line_end = 0, line_start = 0; line_end < len; line_end++) {
560         if (is_newline(unicodestr[line_end]) || line_end == len - 1) {
561             if (!fribidi_reorder_line(flags, bidi_types,
562                                       line_end - line_start + 1, line_start,
563                                       direction, embedding_levels, unicodestr,
564                                       NULL)) {
565                 goto out;
566             }
567             line_start = line_end + 1;
568         }
569     }
570 
571     /* Remove zero-width fill chars put in by libfribidi */
572     for (i = 0, j = 0; i < len; i++)
573         if (unicodestr[i] != FRIBIDI_CHAR_FILL)
574             unicodestr[j++] = unicodestr[i];
575     len = j;
576 
577     if (!(tmp = av_realloc(s->text, (len * 4 + 1) * sizeof(*s->text)))) {
578         /* Use len * 4, as a unicode character can be up to 4 bytes in UTF-8 */
579         goto out;
580     }
581 
582     s->text = tmp;
583     len = fribidi_unicode_to_charset(FRIBIDI_CHAR_SET_UTF8,
584                                      unicodestr, len, s->text);
585     ret = 0;
586 
587 out:
588     av_free(unicodestr);
589     av_free(embedding_levels);
590     av_free(ar_props);
591     av_free(bidi_types);
592     return ret;
593 }
594 #endif
595 
init(AVFilterContext * ctx)596 static av_cold int init(AVFilterContext *ctx)
597 {
598     int err;
599     DrawTextContext *s = ctx->priv;
600     Glyph *glyph;
601 
602 #if FF_API_DRAWTEXT_OLD_TIMELINE
603     if (s->draw_expr)
604         av_log(ctx, AV_LOG_WARNING, "'draw' option is deprecated and will be removed soon, "
605                "you are encouraged to use the generic timeline support through the 'enable' option\n");
606 #endif
607 
608     if (!s->fontfile && !CONFIG_LIBFONTCONFIG) {
609         av_log(ctx, AV_LOG_ERROR, "No font filename provided\n");
610         return AVERROR(EINVAL);
611     }
612 
613     if (s->textfile) {
614         if (s->text) {
615             av_log(ctx, AV_LOG_ERROR,
616                    "Both text and text file provided. Please provide only one\n");
617             return AVERROR(EINVAL);
618         }
619         if ((err = load_textfile(ctx)) < 0)
620             return err;
621     }
622 
623 #if CONFIG_LIBFRIBIDI
624     if (s->text_shaping)
625         if ((err = shape_text(ctx)) < 0)
626             return err;
627 #endif
628 
629     if (s->reload && !s->textfile)
630         av_log(ctx, AV_LOG_WARNING, "No file to reload\n");
631 
632     if (s->tc_opt_string) {
633         int ret = av_timecode_init_from_string(&s->tc, s->tc_rate,
634                                                s->tc_opt_string, ctx);
635         if (ret < 0)
636             return ret;
637         if (s->tc24hmax)
638             s->tc.flags |= AV_TIMECODE_FLAG_24HOURSMAX;
639         if (!s->text)
640             s->text = av_strdup("");
641     }
642 
643     if (!s->text) {
644         av_log(ctx, AV_LOG_ERROR,
645                "Either text, a valid file or a timecode must be provided\n");
646         return AVERROR(EINVAL);
647     }
648 
649     if ((err = FT_Init_FreeType(&(s->library)))) {
650         av_log(ctx, AV_LOG_ERROR,
651                "Could not load FreeType: %s\n", FT_ERRMSG(err));
652         return AVERROR(EINVAL);
653     }
654 
655     err = load_font(ctx);
656     if (err)
657         return err;
658     if (!s->fontsize)
659         s->fontsize = 16;
660     if ((err = FT_Set_Pixel_Sizes(s->face, 0, s->fontsize))) {
661         av_log(ctx, AV_LOG_ERROR, "Could not set font size to %d pixels: %s\n",
662                s->fontsize, FT_ERRMSG(err));
663         return AVERROR(EINVAL);
664     }
665 
666     if (s->borderw) {
667         if (FT_Stroker_New(s->library, &s->stroker)) {
668             av_log(ctx, AV_LOG_ERROR, "Coult not init FT stroker\n");
669             return AVERROR_EXTERNAL;
670         }
671         FT_Stroker_Set(s->stroker, s->borderw << 6, FT_STROKER_LINECAP_ROUND,
672                        FT_STROKER_LINEJOIN_ROUND, 0);
673     }
674 
675     s->use_kerning = FT_HAS_KERNING(s->face);
676 
677     /* load the fallback glyph with code 0 */
678     load_glyph(ctx, NULL, 0);
679 
680     /* set the tabsize in pixels */
681     if ((err = load_glyph(ctx, &glyph, ' ')) < 0) {
682         av_log(ctx, AV_LOG_ERROR, "Could not set tabsize.\n");
683         return err;
684     }
685     s->tabsize *= glyph->advance;
686 
687     if (s->exp_mode == EXP_STRFTIME &&
688         (strchr(s->text, '%') || strchr(s->text, '\\')))
689         av_log(ctx, AV_LOG_WARNING, "expansion=strftime is deprecated.\n");
690 
691     av_bprint_init(&s->expanded_text, 0, AV_BPRINT_SIZE_UNLIMITED);
692     av_bprint_init(&s->expanded_fontcolor, 0, AV_BPRINT_SIZE_UNLIMITED);
693 
694     return 0;
695 }
696 
query_formats(AVFilterContext * ctx)697 static int query_formats(AVFilterContext *ctx)
698 {
699     ff_set_common_formats(ctx, ff_draw_supported_pixel_formats(0));
700     return 0;
701 }
702 
glyph_enu_free(void * opaque,void * elem)703 static int glyph_enu_free(void *opaque, void *elem)
704 {
705     Glyph *glyph = elem;
706 
707     FT_Done_Glyph(glyph->glyph);
708     FT_Done_Glyph(glyph->border_glyph);
709     av_free(elem);
710     return 0;
711 }
712 
uninit(AVFilterContext * ctx)713 static av_cold void uninit(AVFilterContext *ctx)
714 {
715     DrawTextContext *s = ctx->priv;
716 
717     av_expr_free(s->x_pexpr);
718     av_expr_free(s->y_pexpr);
719 #if FF_API_DRAWTEXT_OLD_TIMELINE
720     av_expr_free(s->draw_pexpr);
721     s->x_pexpr = s->y_pexpr = s->draw_pexpr = NULL;
722 #endif
723     av_freep(&s->positions);
724     s->nb_positions = 0;
725 
726 
727     av_tree_enumerate(s->glyphs, NULL, NULL, glyph_enu_free);
728     av_tree_destroy(s->glyphs);
729     s->glyphs = NULL;
730 
731     FT_Done_Face(s->face);
732     FT_Stroker_Done(s->stroker);
733     FT_Done_FreeType(s->library);
734 
735     av_bprint_finalize(&s->expanded_text, NULL);
736     av_bprint_finalize(&s->expanded_fontcolor, NULL);
737 }
738 
config_input(AVFilterLink * inlink)739 static int config_input(AVFilterLink *inlink)
740 {
741     AVFilterContext *ctx = inlink->dst;
742     DrawTextContext *s = ctx->priv;
743     int ret;
744 
745     ff_draw_init(&s->dc, inlink->format, 0);
746     ff_draw_color(&s->dc, &s->fontcolor,   s->fontcolor.rgba);
747     ff_draw_color(&s->dc, &s->shadowcolor, s->shadowcolor.rgba);
748     ff_draw_color(&s->dc, &s->bordercolor, s->bordercolor.rgba);
749     ff_draw_color(&s->dc, &s->boxcolor,    s->boxcolor.rgba);
750 
751     s->var_values[VAR_w]     = s->var_values[VAR_W]     = s->var_values[VAR_MAIN_W] = inlink->w;
752     s->var_values[VAR_h]     = s->var_values[VAR_H]     = s->var_values[VAR_MAIN_H] = inlink->h;
753     s->var_values[VAR_SAR]   = inlink->sample_aspect_ratio.num ? av_q2d(inlink->sample_aspect_ratio) : 1;
754     s->var_values[VAR_DAR]   = (double)inlink->w / inlink->h * s->var_values[VAR_SAR];
755     s->var_values[VAR_HSUB]  = 1 << s->dc.hsub_max;
756     s->var_values[VAR_VSUB]  = 1 << s->dc.vsub_max;
757     s->var_values[VAR_X]     = NAN;
758     s->var_values[VAR_Y]     = NAN;
759     s->var_values[VAR_T]     = NAN;
760 
761     av_lfg_init(&s->prng, av_get_random_seed());
762 
763     av_expr_free(s->x_pexpr);
764     av_expr_free(s->y_pexpr);
765 #if FF_API_DRAWTEXT_OLD_TIMELINE
766     av_expr_free(s->draw_pexpr);
767     s->x_pexpr = s->y_pexpr = s->draw_pexpr = NULL;
768 #else
769     s->x_pexpr = s->y_pexpr = NULL;
770 #endif
771 
772     if ((ret = av_expr_parse(&s->x_pexpr, s->x_expr, var_names,
773                              NULL, NULL, fun2_names, fun2, 0, ctx)) < 0 ||
774         (ret = av_expr_parse(&s->y_pexpr, s->y_expr, var_names,
775                              NULL, NULL, fun2_names, fun2, 0, ctx)) < 0)
776 
777         return AVERROR(EINVAL);
778 #if FF_API_DRAWTEXT_OLD_TIMELINE
779     if (s->draw_expr &&
780         (ret = av_expr_parse(&s->draw_pexpr, s->draw_expr, var_names,
781                              NULL, NULL, fun2_names, fun2, 0, ctx)) < 0)
782         return ret;
783 #endif
784 
785     return 0;
786 }
787 
command(AVFilterContext * ctx,const char * cmd,const char * arg,char * res,int res_len,int flags)788 static int command(AVFilterContext *ctx, const char *cmd, const char *arg, char *res, int res_len, int flags)
789 {
790     DrawTextContext *s = ctx->priv;
791 
792     if (!strcmp(cmd, "reinit")) {
793         int ret;
794         uninit(ctx);
795         s->reinit = 1;
796         if ((ret = av_set_options_string(ctx, arg, "=", ":")) < 0)
797             return ret;
798         if ((ret = init(ctx)) < 0)
799             return ret;
800         return config_input(ctx->inputs[0]);
801     }
802 
803     return AVERROR(ENOSYS);
804 }
805 
func_pict_type(AVFilterContext * ctx,AVBPrint * bp,char * fct,unsigned argc,char ** argv,int tag)806 static int func_pict_type(AVFilterContext *ctx, AVBPrint *bp,
807                           char *fct, unsigned argc, char **argv, int tag)
808 {
809     DrawTextContext *s = ctx->priv;
810 
811     av_bprintf(bp, "%c", av_get_picture_type_char(s->var_values[VAR_PICT_TYPE]));
812     return 0;
813 }
814 
func_pts(AVFilterContext * ctx,AVBPrint * bp,char * fct,unsigned argc,char ** argv,int tag)815 static int func_pts(AVFilterContext *ctx, AVBPrint *bp,
816                     char *fct, unsigned argc, char **argv, int tag)
817 {
818     DrawTextContext *s = ctx->priv;
819     const char *fmt;
820     double pts = s->var_values[VAR_T];
821     int ret;
822 
823     fmt = argc >= 1 ? argv[0] : "flt";
824     if (argc >= 2) {
825         int64_t delta;
826         if ((ret = av_parse_time(&delta, argv[1], 1)) < 0) {
827             av_log(ctx, AV_LOG_ERROR, "Invalid delta '%s'\n", argv[1]);
828             return ret;
829         }
830         pts += (double)delta / AV_TIME_BASE;
831     }
832     if (!strcmp(fmt, "flt")) {
833         av_bprintf(bp, "%.6f", s->var_values[VAR_T]);
834     } else if (!strcmp(fmt, "hms")) {
835         if (isnan(pts)) {
836             av_bprintf(bp, " ??:??:??.???");
837         } else {
838             int64_t ms = round(pts * 1000);
839             char sign = ' ';
840             if (ms < 0) {
841                 sign = '-';
842                 ms = -ms;
843             }
844             av_bprintf(bp, "%c%02d:%02d:%02d.%03d", sign,
845                        (int)(ms / (60 * 60 * 1000)),
846                        (int)(ms / (60 * 1000)) % 60,
847                        (int)(ms / 1000) % 60,
848                        (int)ms % 1000);
849         }
850     } else {
851         av_log(ctx, AV_LOG_ERROR, "Invalid format '%s'\n", fmt);
852         return AVERROR(EINVAL);
853     }
854     return 0;
855 }
856 
func_frame_num(AVFilterContext * ctx,AVBPrint * bp,char * fct,unsigned argc,char ** argv,int tag)857 static int func_frame_num(AVFilterContext *ctx, AVBPrint *bp,
858                           char *fct, unsigned argc, char **argv, int tag)
859 {
860     DrawTextContext *s = ctx->priv;
861 
862     av_bprintf(bp, "%d", (int)s->var_values[VAR_N]);
863     return 0;
864 }
865 
func_metadata(AVFilterContext * ctx,AVBPrint * bp,char * fct,unsigned argc,char ** argv,int tag)866 static int func_metadata(AVFilterContext *ctx, AVBPrint *bp,
867                          char *fct, unsigned argc, char **argv, int tag)
868 {
869     DrawTextContext *s = ctx->priv;
870     AVDictionaryEntry *e = av_dict_get(s->metadata, argv[0], NULL, 0);
871 
872     if (e && e->value)
873         av_bprintf(bp, "%s", e->value);
874     return 0;
875 }
876 
877 #if !HAVE_LOCALTIME_R
localtime_r(const time_t * t,struct tm * tm)878 static void localtime_r(const time_t *t, struct tm *tm)
879 {
880     *tm = *localtime(t);
881 }
882 #endif
883 
func_strftime(AVFilterContext * ctx,AVBPrint * bp,char * fct,unsigned argc,char ** argv,int tag)884 static int func_strftime(AVFilterContext *ctx, AVBPrint *bp,
885                          char *fct, unsigned argc, char **argv, int tag)
886 {
887     const char *fmt = argc ? argv[0] : "%Y-%m-%d %H:%M:%S";
888     time_t now;
889     struct tm tm;
890 
891     time(&now);
892     if (tag == 'L')
893         localtime_r(&now, &tm);
894     else
895         tm = *gmtime(&now);
896     av_bprint_strftime(bp, fmt, &tm);
897     return 0;
898 }
899 
func_eval_expr(AVFilterContext * ctx,AVBPrint * bp,char * fct,unsigned argc,char ** argv,int tag)900 static int func_eval_expr(AVFilterContext *ctx, AVBPrint *bp,
901                           char *fct, unsigned argc, char **argv, int tag)
902 {
903     DrawTextContext *s = ctx->priv;
904     double res;
905     int ret;
906 
907     ret = av_expr_parse_and_eval(&res, argv[0], var_names, s->var_values,
908                                  NULL, NULL, fun2_names, fun2,
909                                  &s->prng, 0, ctx);
910     if (ret < 0)
911         av_log(ctx, AV_LOG_ERROR,
912                "Expression '%s' for the expr text expansion function is not valid\n",
913                argv[0]);
914     else
915         av_bprintf(bp, "%f", res);
916 
917     return ret;
918 }
919 
func_eval_expr_int_format(AVFilterContext * ctx,AVBPrint * bp,char * fct,unsigned argc,char ** argv,int tag)920 static int func_eval_expr_int_format(AVFilterContext *ctx, AVBPrint *bp,
921                           char *fct, unsigned argc, char **argv, int tag)
922 {
923     DrawTextContext *s = ctx->priv;
924     double res;
925     int intval;
926     int ret;
927     unsigned int positions = 0;
928     char fmt_str[30] = "%";
929 
930     /*
931      * argv[0] expression to be converted to `int`
932      * argv[1] format: 'x', 'X', 'd' or 'u'
933      * argv[2] positions printed (optional)
934      */
935 
936     ret = av_expr_parse_and_eval(&res, argv[0], var_names, s->var_values,
937                                  NULL, NULL, fun2_names, fun2,
938                                  &s->prng, 0, ctx);
939     if (ret < 0) {
940         av_log(ctx, AV_LOG_ERROR,
941                "Expression '%s' for the expr text expansion function is not valid\n",
942                argv[0]);
943         return ret;
944     }
945 
946     if (!strchr("xXdu", argv[1][0])) {
947         av_log(ctx, AV_LOG_ERROR, "Invalid format '%c' specified,"
948                 " allowed values: 'x', 'X', 'd', 'u'\n", argv[1][0]);
949         return AVERROR(EINVAL);
950     }
951 
952     if (argc == 3) {
953         ret = sscanf(argv[2], "%u", &positions);
954         if (ret != 1) {
955             av_log(ctx, AV_LOG_ERROR, "expr_int_format(): Invalid number of positions"
956                     " to print: '%s'\n", argv[2]);
957             return AVERROR(EINVAL);
958         }
959     }
960 
961     feclearexcept(FE_ALL_EXCEPT);
962     intval = res;
963     if ((ret = fetestexcept(FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW))) {
964         av_log(ctx, AV_LOG_ERROR, "Conversion of floating-point result to int failed. Control register: 0x%08x. Conversion result: %d\n", ret, intval);
965         return AVERROR(EINVAL);
966     }
967 
968     if (argc == 3)
969         av_strlcatf(fmt_str, sizeof(fmt_str), "0%u", positions);
970     av_strlcatf(fmt_str, sizeof(fmt_str), "%c", argv[1][0]);
971 
972     av_log(ctx, AV_LOG_DEBUG, "Formatting value %f (expr '%s') with spec '%s'\n",
973             res, argv[0], fmt_str);
974 
975     av_bprintf(bp, fmt_str, intval);
976 
977     return 0;
978 }
979 
980 static const struct drawtext_function {
981     const char *name;
982     unsigned argc_min, argc_max;
983     int tag;                            /**< opaque argument to func */
984     int (*func)(AVFilterContext *, AVBPrint *, char *, unsigned, char **, int);
985 } functions[] = {
986     { "expr",      1, 1, 0,   func_eval_expr },
987     { "e",         1, 1, 0,   func_eval_expr },
988     { "expr_int_format", 2, 3, 0, func_eval_expr_int_format },
989     { "eif",       2, 3, 0,   func_eval_expr_int_format },
990     { "pict_type", 0, 0, 0,   func_pict_type },
991     { "pts",       0, 2, 0,   func_pts      },
992     { "gmtime",    0, 1, 'G', func_strftime },
993     { "localtime", 0, 1, 'L', func_strftime },
994     { "frame_num", 0, 0, 0,   func_frame_num },
995     { "n",         0, 0, 0,   func_frame_num },
996     { "metadata",  1, 1, 0,   func_metadata },
997 };
998 
eval_function(AVFilterContext * ctx,AVBPrint * bp,char * fct,unsigned argc,char ** argv)999 static int eval_function(AVFilterContext *ctx, AVBPrint *bp, char *fct,
1000                          unsigned argc, char **argv)
1001 {
1002     unsigned i;
1003 
1004     for (i = 0; i < FF_ARRAY_ELEMS(functions); i++) {
1005         if (strcmp(fct, functions[i].name))
1006             continue;
1007         if (argc < functions[i].argc_min) {
1008             av_log(ctx, AV_LOG_ERROR, "%%{%s} requires at least %d arguments\n",
1009                    fct, functions[i].argc_min);
1010             return AVERROR(EINVAL);
1011         }
1012         if (argc > functions[i].argc_max) {
1013             av_log(ctx, AV_LOG_ERROR, "%%{%s} requires at most %d arguments\n",
1014                    fct, functions[i].argc_max);
1015             return AVERROR(EINVAL);
1016         }
1017         break;
1018     }
1019     if (i >= FF_ARRAY_ELEMS(functions)) {
1020         av_log(ctx, AV_LOG_ERROR, "%%{%s} is not known\n", fct);
1021         return AVERROR(EINVAL);
1022     }
1023     return functions[i].func(ctx, bp, fct, argc, argv, functions[i].tag);
1024 }
1025 
expand_function(AVFilterContext * ctx,AVBPrint * bp,char ** rtext)1026 static int expand_function(AVFilterContext *ctx, AVBPrint *bp, char **rtext)
1027 {
1028     const char *text = *rtext;
1029     char *argv[16] = { NULL };
1030     unsigned argc = 0, i;
1031     int ret;
1032 
1033     if (*text != '{') {
1034         av_log(ctx, AV_LOG_ERROR, "Stray %% near '%s'\n", text);
1035         return AVERROR(EINVAL);
1036     }
1037     text++;
1038     while (1) {
1039         if (!(argv[argc++] = av_get_token(&text, ":}"))) {
1040             ret = AVERROR(ENOMEM);
1041             goto end;
1042         }
1043         if (!*text) {
1044             av_log(ctx, AV_LOG_ERROR, "Unterminated %%{} near '%s'\n", *rtext);
1045             ret = AVERROR(EINVAL);
1046             goto end;
1047         }
1048         if (argc == FF_ARRAY_ELEMS(argv))
1049             av_freep(&argv[--argc]); /* error will be caught later */
1050         if (*text == '}')
1051             break;
1052         text++;
1053     }
1054 
1055     if ((ret = eval_function(ctx, bp, argv[0], argc - 1, argv + 1)) < 0)
1056         goto end;
1057     ret = 0;
1058     *rtext = (char *)text + 1;
1059 
1060 end:
1061     for (i = 0; i < argc; i++)
1062         av_freep(&argv[i]);
1063     return ret;
1064 }
1065 
expand_text(AVFilterContext * ctx,char * text,AVBPrint * bp)1066 static int expand_text(AVFilterContext *ctx, char *text, AVBPrint *bp)
1067 {
1068     int ret;
1069 
1070     av_bprint_clear(bp);
1071     while (*text) {
1072         if (*text == '\\' && text[1]) {
1073             av_bprint_chars(bp, text[1], 1);
1074             text += 2;
1075         } else if (*text == '%') {
1076             text++;
1077             if ((ret = expand_function(ctx, bp, &text)) < 0)
1078                 return ret;
1079         } else {
1080             av_bprint_chars(bp, *text, 1);
1081             text++;
1082         }
1083     }
1084     if (!av_bprint_is_complete(bp))
1085         return AVERROR(ENOMEM);
1086     return 0;
1087 }
1088 
draw_glyphs(DrawTextContext * s,AVFrame * frame,int width,int height,FFDrawColor * color,int x,int y,int borderw)1089 static int draw_glyphs(DrawTextContext *s, AVFrame *frame,
1090                        int width, int height,
1091                        FFDrawColor *color, int x, int y, int borderw)
1092 {
1093     char *text = s->expanded_text.str;
1094     uint32_t code = 0;
1095     int i, x1, y1;
1096     uint8_t *p;
1097     Glyph *glyph = NULL;
1098 
1099     for (i = 0, p = text; *p; i++) {
1100         FT_Bitmap bitmap;
1101         Glyph dummy = { 0 };
1102         GET_UTF8(code, *p++, continue;);
1103 
1104         /* skip new line chars, just go to new line */
1105         if (code == '\n' || code == '\r' || code == '\t')
1106             continue;
1107 
1108         dummy.code = code;
1109         glyph = av_tree_find(s->glyphs, &dummy, (void *)glyph_cmp, NULL);
1110 
1111         bitmap = borderw ? glyph->border_bitmap : glyph->bitmap;
1112 
1113         if (glyph->bitmap.pixel_mode != FT_PIXEL_MODE_MONO &&
1114             glyph->bitmap.pixel_mode != FT_PIXEL_MODE_GRAY)
1115             return AVERROR(EINVAL);
1116 
1117         x1 = s->positions[i].x+s->x+x - borderw;
1118         y1 = s->positions[i].y+s->y+y - borderw;
1119 
1120         ff_blend_mask(&s->dc, color,
1121                       frame->data, frame->linesize, width, height,
1122                       bitmap.buffer, bitmap.pitch,
1123                       bitmap.width, bitmap.rows,
1124                       bitmap.pixel_mode == FT_PIXEL_MODE_MONO ? 0 : 3,
1125                       0, x1, y1);
1126     }
1127 
1128     return 0;
1129 }
1130 
draw_text(AVFilterContext * ctx,AVFrame * frame,int width,int height)1131 static int draw_text(AVFilterContext *ctx, AVFrame *frame,
1132                      int width, int height)
1133 {
1134     DrawTextContext *s = ctx->priv;
1135     AVFilterLink *inlink = ctx->inputs[0];
1136 
1137     uint32_t code = 0, prev_code = 0;
1138     int x = 0, y = 0, i = 0, ret;
1139     int max_text_line_w = 0, len;
1140     int box_w, box_h;
1141     char *text;
1142     uint8_t *p;
1143     int y_min = 32000, y_max = -32000;
1144     int x_min = 32000, x_max = -32000;
1145     FT_Vector delta;
1146     Glyph *glyph = NULL, *prev_glyph = NULL;
1147     Glyph dummy = { 0 };
1148 
1149     time_t now = time(0);
1150     struct tm ltime;
1151     AVBPrint *bp = &s->expanded_text;
1152 
1153     av_bprint_clear(bp);
1154 
1155     if(s->basetime != AV_NOPTS_VALUE)
1156         now= frame->pts*av_q2d(ctx->inputs[0]->time_base) + s->basetime/1000000;
1157 
1158     switch (s->exp_mode) {
1159     case EXP_NONE:
1160         av_bprintf(bp, "%s", s->text);
1161         break;
1162     case EXP_NORMAL:
1163         if ((ret = expand_text(ctx, s->text, &s->expanded_text)) < 0)
1164             return ret;
1165         break;
1166     case EXP_STRFTIME:
1167         localtime_r(&now, &ltime);
1168         av_bprint_strftime(bp, s->text, &ltime);
1169         break;
1170     }
1171 
1172     if (s->tc_opt_string) {
1173         char tcbuf[AV_TIMECODE_STR_SIZE];
1174         av_timecode_make_string(&s->tc, tcbuf, inlink->frame_count);
1175         av_bprint_clear(bp);
1176         av_bprintf(bp, "%s%s", s->text, tcbuf);
1177     }
1178 
1179     if (!av_bprint_is_complete(bp))
1180         return AVERROR(ENOMEM);
1181     text = s->expanded_text.str;
1182     if ((len = s->expanded_text.len) > s->nb_positions) {
1183         if (!(s->positions =
1184               av_realloc(s->positions, len*sizeof(*s->positions))))
1185             return AVERROR(ENOMEM);
1186         s->nb_positions = len;
1187     }
1188 
1189     if (s->fontcolor_expr[0]) {
1190         /* If expression is set, evaluate and replace the static value */
1191         av_bprint_clear(&s->expanded_fontcolor);
1192         if ((ret = expand_text(ctx, s->fontcolor_expr, &s->expanded_fontcolor)) < 0)
1193             return ret;
1194         if (!av_bprint_is_complete(&s->expanded_fontcolor))
1195             return AVERROR(ENOMEM);
1196         av_log(s, AV_LOG_DEBUG, "Evaluated fontcolor is '%s'\n", s->expanded_fontcolor.str);
1197         ret = av_parse_color(s->fontcolor.rgba, s->expanded_fontcolor.str, -1, s);
1198         if (ret)
1199             return ret;
1200         ff_draw_color(&s->dc, &s->fontcolor, s->fontcolor.rgba);
1201     }
1202 
1203     x = 0;
1204     y = 0;
1205 
1206     /* load and cache glyphs */
1207     for (i = 0, p = text; *p; i++) {
1208         GET_UTF8(code, *p++, continue;);
1209 
1210         /* get glyph */
1211         dummy.code = code;
1212         glyph = av_tree_find(s->glyphs, &dummy, glyph_cmp, NULL);
1213         if (!glyph) {
1214             load_glyph(ctx, &glyph, code);
1215         }
1216 
1217         y_min = FFMIN(glyph->bbox.yMin, y_min);
1218         y_max = FFMAX(glyph->bbox.yMax, y_max);
1219         x_min = FFMIN(glyph->bbox.xMin, x_min);
1220         x_max = FFMAX(glyph->bbox.xMax, x_max);
1221     }
1222     s->max_glyph_h = y_max - y_min;
1223     s->max_glyph_w = x_max - x_min;
1224 
1225     /* compute and save position for each glyph */
1226     glyph = NULL;
1227     for (i = 0, p = text; *p; i++) {
1228         GET_UTF8(code, *p++, continue;);
1229 
1230         /* skip the \n in the sequence \r\n */
1231         if (prev_code == '\r' && code == '\n')
1232             continue;
1233 
1234         prev_code = code;
1235         if (is_newline(code)) {
1236 
1237             max_text_line_w = FFMAX(max_text_line_w, x);
1238             y += s->max_glyph_h;
1239             x = 0;
1240             continue;
1241         }
1242 
1243         /* get glyph */
1244         prev_glyph = glyph;
1245         dummy.code = code;
1246         glyph = av_tree_find(s->glyphs, &dummy, glyph_cmp, NULL);
1247 
1248         /* kerning */
1249         if (s->use_kerning && prev_glyph && glyph->code) {
1250             FT_Get_Kerning(s->face, prev_glyph->code, glyph->code,
1251                            ft_kerning_default, &delta);
1252             x += delta.x >> 6;
1253         }
1254 
1255         /* save position */
1256         s->positions[i].x = x + glyph->bitmap_left;
1257         s->positions[i].y = y - glyph->bitmap_top + y_max;
1258         if (code == '\t') x  = (x / s->tabsize + 1)*s->tabsize;
1259         else              x += glyph->advance;
1260     }
1261 
1262     max_text_line_w = FFMAX(x, max_text_line_w);
1263 
1264     s->var_values[VAR_TW] = s->var_values[VAR_TEXT_W] = max_text_line_w;
1265     s->var_values[VAR_TH] = s->var_values[VAR_TEXT_H] = y + s->max_glyph_h;
1266 
1267     s->var_values[VAR_MAX_GLYPH_W] = s->max_glyph_w;
1268     s->var_values[VAR_MAX_GLYPH_H] = s->max_glyph_h;
1269     s->var_values[VAR_MAX_GLYPH_A] = s->var_values[VAR_ASCENT ] = y_max;
1270     s->var_values[VAR_MAX_GLYPH_D] = s->var_values[VAR_DESCENT] = y_min;
1271 
1272     s->var_values[VAR_LINE_H] = s->var_values[VAR_LH] = s->max_glyph_h;
1273 
1274     s->x = s->var_values[VAR_X] = av_expr_eval(s->x_pexpr, s->var_values, &s->prng);
1275     s->y = s->var_values[VAR_Y] = av_expr_eval(s->y_pexpr, s->var_values, &s->prng);
1276     s->x = s->var_values[VAR_X] = av_expr_eval(s->x_pexpr, s->var_values, &s->prng);
1277 #if FF_API_DRAWTEXT_OLD_TIMELINE
1278     if (s->draw_pexpr){
1279     s->draw = av_expr_eval(s->draw_pexpr, s->var_values, &s->prng);
1280 
1281     if(!s->draw)
1282         return 0;
1283     }
1284     if (ctx->is_disabled)
1285         return 0;
1286 #endif
1287 
1288     box_w = FFMIN(width - 1 , max_text_line_w);
1289     box_h = FFMIN(height - 1, y + s->max_glyph_h);
1290 
1291     /* draw box */
1292     if (s->draw_box)
1293         ff_blend_rectangle(&s->dc, &s->boxcolor,
1294                            frame->data, frame->linesize, width, height,
1295                            s->x, s->y, box_w, box_h);
1296 
1297     if (s->shadowx || s->shadowy) {
1298         if ((ret = draw_glyphs(s, frame, width, height,
1299                                &s->shadowcolor, s->shadowx, s->shadowy, 0)) < 0)
1300             return ret;
1301     }
1302 
1303     if (s->borderw) {
1304         if ((ret = draw_glyphs(s, frame, width, height,
1305                                &s->bordercolor, 0, 0, s->borderw)) < 0)
1306             return ret;
1307     }
1308     if ((ret = draw_glyphs(s, frame, width, height,
1309                            &s->fontcolor, 0, 0, 0)) < 0)
1310         return ret;
1311 
1312     return 0;
1313 }
1314 
filter_frame(AVFilterLink * inlink,AVFrame * frame)1315 static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
1316 {
1317     AVFilterContext *ctx = inlink->dst;
1318     AVFilterLink *outlink = ctx->outputs[0];
1319     DrawTextContext *s = ctx->priv;
1320     int ret;
1321 
1322     if (s->reload) {
1323         if ((ret = load_textfile(ctx)) < 0)
1324             return ret;
1325 #if CONFIG_LIBFRIBIDI
1326         if (s->text_shaping)
1327             if ((ret = shape_text(ctx)) < 0)
1328                 return ret;
1329 #endif
1330     }
1331 
1332     s->var_values[VAR_N] = inlink->frame_count+s->start_number;
1333     s->var_values[VAR_T] = frame->pts == AV_NOPTS_VALUE ?
1334         NAN : frame->pts * av_q2d(inlink->time_base);
1335 
1336     s->var_values[VAR_PICT_TYPE] = frame->pict_type;
1337     s->metadata = av_frame_get_metadata(frame);
1338 
1339     draw_text(ctx, frame, frame->width, frame->height);
1340 
1341     av_log(ctx, AV_LOG_DEBUG, "n:%d t:%f text_w:%d text_h:%d x:%d y:%d\n",
1342            (int)s->var_values[VAR_N], s->var_values[VAR_T],
1343            (int)s->var_values[VAR_TEXT_W], (int)s->var_values[VAR_TEXT_H],
1344            s->x, s->y);
1345 
1346     return ff_filter_frame(outlink, frame);
1347 }
1348 
1349 static const AVFilterPad avfilter_vf_drawtext_inputs[] = {
1350     {
1351         .name           = "default",
1352         .type           = AVMEDIA_TYPE_VIDEO,
1353         .filter_frame   = filter_frame,
1354         .config_props   = config_input,
1355         .needs_writable = 1,
1356     },
1357     { NULL }
1358 };
1359 
1360 static const AVFilterPad avfilter_vf_drawtext_outputs[] = {
1361     {
1362         .name = "default",
1363         .type = AVMEDIA_TYPE_VIDEO,
1364     },
1365     { NULL }
1366 };
1367 
1368 AVFilter ff_vf_drawtext = {
1369     .name          = "drawtext",
1370     .description   = NULL_IF_CONFIG_SMALL("Draw text on top of video frames using libfreetype library."),
1371     .priv_size     = sizeof(DrawTextContext),
1372     .priv_class    = &drawtext_class,
1373     .init          = init,
1374     .uninit        = uninit,
1375     .query_formats = query_formats,
1376     .inputs        = avfilter_vf_drawtext_inputs,
1377     .outputs       = avfilter_vf_drawtext_outputs,
1378     .process_command = command,
1379 #if FF_API_DRAWTEXT_OLD_TIMELINE
1380     .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL,
1381 #else
1382     .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
1383 #endif
1384 };
1385