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1 /*
2  * SSA/ASS common functions
3  * Copyright (c) 2010  Aurelien Jacobs <aurel@gnuage.org>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include "avcodec.h"
23 #include "ass.h"
24 #include "libavutil/avstring.h"
25 #include "libavutil/bprint.h"
26 #include "libavutil/common.h"
27 
ff_ass_subtitle_header_full(AVCodecContext * avctx,int play_res_x,int play_res_y,const char * font,int font_size,int primary_color,int secondary_color,int outline_color,int back_color,int bold,int italic,int underline,int border_style,int alignment)28 int ff_ass_subtitle_header_full(AVCodecContext *avctx,
29                                 int play_res_x, int play_res_y,
30                                 const char *font, int font_size,
31                                 int primary_color, int secondary_color,
32                                 int outline_color, int back_color,
33                                 int bold, int italic, int underline,
34                                 int border_style, int alignment)
35 {
36     avctx->subtitle_header = av_asprintf(
37              "[Script Info]\r\n"
38              "; Script generated by FFmpeg/Lavc%s\r\n"
39              "ScriptType: v4.00+\r\n"
40              "PlayResX: %d\r\n"
41              "PlayResY: %d\r\n"
42              "ScaledBorderAndShadow: yes\r\n"
43              "\r\n"
44              "[V4+ Styles]\r\n"
45 
46              /* ASSv4 header */
47              "Format: Name, "
48              "Fontname, Fontsize, "
49              "PrimaryColour, SecondaryColour, OutlineColour, BackColour, "
50              "Bold, Italic, Underline, StrikeOut, "
51              "ScaleX, ScaleY, "
52              "Spacing, Angle, "
53              "BorderStyle, Outline, Shadow, "
54              "Alignment, MarginL, MarginR, MarginV, "
55              "Encoding\r\n"
56 
57              "Style: "
58              "Default,"             /* Name */
59              "%s,%d,"               /* Font{name,size} */
60              "&H%x,&H%x,&H%x,&H%x," /* {Primary,Secondary,Outline,Back}Colour */
61              "%d,%d,%d,0,"          /* Bold, Italic, Underline, StrikeOut */
62              "100,100,"             /* Scale{X,Y} */
63              "0,0,"                 /* Spacing, Angle */
64              "%d,1,0,"              /* BorderStyle, Outline, Shadow */
65              "%d,10,10,10,"         /* Alignment, Margin[LRV] */
66              "0\r\n"                /* Encoding */
67 
68              "\r\n"
69              "[Events]\r\n"
70              "Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text\r\n",
71              !(avctx->flags & AV_CODEC_FLAG_BITEXACT) ? AV_STRINGIFY(LIBAVCODEC_VERSION) : "",
72              play_res_x, play_res_y, font, font_size,
73              primary_color, secondary_color, outline_color, back_color,
74              -bold, -italic, -underline, border_style, alignment);
75 
76     if (!avctx->subtitle_header)
77         return AVERROR(ENOMEM);
78     avctx->subtitle_header_size = strlen(avctx->subtitle_header);
79     return 0;
80 }
81 
ff_ass_subtitle_header(AVCodecContext * avctx,const char * font,int font_size,int color,int back_color,int bold,int italic,int underline,int border_style,int alignment)82 int ff_ass_subtitle_header(AVCodecContext *avctx,
83                            const char *font, int font_size,
84                            int color, int back_color,
85                            int bold, int italic, int underline,
86                            int border_style, int alignment)
87 {
88     return ff_ass_subtitle_header_full(avctx,
89                                ASS_DEFAULT_PLAYRESX, ASS_DEFAULT_PLAYRESY,
90                                font, font_size, color, color,
91                                back_color, back_color,
92                                bold, italic, underline,
93                                border_style, alignment);
94 }
95 
ff_ass_subtitle_header_default(AVCodecContext * avctx)96 int ff_ass_subtitle_header_default(AVCodecContext *avctx)
97 {
98     return ff_ass_subtitle_header(avctx, ASS_DEFAULT_FONT,
99                                ASS_DEFAULT_FONT_SIZE,
100                                ASS_DEFAULT_COLOR,
101                                ASS_DEFAULT_BACK_COLOR,
102                                ASS_DEFAULT_BOLD,
103                                ASS_DEFAULT_ITALIC,
104                                ASS_DEFAULT_UNDERLINE,
105                                ASS_DEFAULT_BORDERSTYLE,
106                                ASS_DEFAULT_ALIGNMENT);
107 }
108 
ff_ass_get_dialog(int readorder,int layer,const char * style,const char * speaker,const char * text)109 char *ff_ass_get_dialog(int readorder, int layer, const char *style,
110                         const char *speaker, const char *text)
111 {
112     return av_asprintf("%d,%d,%s,%s,0,0,0,,%s",
113                        readorder, layer, style ? style : "Default",
114                        speaker ? speaker : "", text);
115 }
116 
ff_ass_add_rect2(AVSubtitle * sub,const char * dialog,int readorder,int layer,const char * style,const char * speaker,unsigned * nb_rect_allocated)117 int ff_ass_add_rect2(AVSubtitle *sub, const char *dialog,
118                     int readorder, int layer, const char *style,
119                     const char *speaker, unsigned *nb_rect_allocated)
120 {
121     AVSubtitleRect **rects = sub->rects, *rect;
122     char *ass_str;
123     uint64_t new_nb = 0;
124 
125     if (sub->num_rects >= UINT_MAX)
126         return AVERROR(ENOMEM);
127 
128     if (nb_rect_allocated && *nb_rect_allocated <= sub->num_rects) {
129         if (sub->num_rects < UINT_MAX / 17 * 16) {
130             new_nb = sub->num_rects + sub->num_rects/16 + 1;
131         } else
132             new_nb = UINT_MAX;
133     } else if (!nb_rect_allocated)
134         new_nb = sub->num_rects + 1;
135 
136     if (new_nb) {
137         rects = av_realloc_array(rects, new_nb, sizeof(*sub->rects));
138         if (!rects)
139             return AVERROR(ENOMEM);
140         if (nb_rect_allocated)
141             *nb_rect_allocated = new_nb;
142         sub->rects = rects;
143     }
144 
145     rect       = av_mallocz(sizeof(*rect));
146     if (!rect)
147         return AVERROR(ENOMEM);
148     rects[sub->num_rects++] = rect;
149     rect->type = SUBTITLE_ASS;
150     ass_str = ff_ass_get_dialog(readorder, layer, style, speaker, dialog);
151     if (!ass_str)
152         return AVERROR(ENOMEM);
153     rect->ass = ass_str;
154     return 0;
155 }
156 
ff_ass_add_rect(AVSubtitle * sub,const char * dialog,int readorder,int layer,const char * style,const char * speaker)157 int ff_ass_add_rect(AVSubtitle *sub, const char *dialog,
158                     int readorder, int layer, const char *style,
159                     const char *speaker)
160 {
161     return ff_ass_add_rect2(sub, dialog, readorder, layer, style, speaker, NULL);
162 }
163 
ff_ass_decoder_flush(AVCodecContext * avctx)164 void ff_ass_decoder_flush(AVCodecContext *avctx)
165 {
166     FFASSDecoderContext *s = avctx->priv_data;
167     if (!(avctx->flags2 & AV_CODEC_FLAG2_RO_FLUSH_NOOP))
168         s->readorder = 0;
169 }
170 
ff_ass_bprint_text_event(AVBPrint * buf,const char * p,int size,const char * linebreaks,int keep_ass_markup)171 void ff_ass_bprint_text_event(AVBPrint *buf, const char *p, int size,
172                              const char *linebreaks, int keep_ass_markup)
173 {
174     const char *p_end = p + size;
175 
176     for (; p < p_end && *p; p++) {
177 
178         /* forced custom line breaks, not accounted as "normal" EOL */
179         if (linebreaks && strchr(linebreaks, *p)) {
180             av_bprintf(buf, "\\N");
181 
182         /* standard ASS escaping so random characters don't get mis-interpreted
183          * as ASS */
184         } else if (!keep_ass_markup && strchr("{}\\", *p)) {
185             av_bprintf(buf, "\\%c", *p);
186 
187         /* some packets might end abruptly (no \0 at the end, like for example
188          * in some cases of demuxing from a classic video container), some
189          * might be terminated with \n or \r\n which we have to remove (for
190          * consistency with those who haven't), and we also have to deal with
191          * evil cases such as \r at the end of the buffer (and no \0 terminated
192          * character) */
193         } else if (p[0] == '\n') {
194             /* some stuff left so we can insert a line break */
195             if (p < p_end - 1)
196                 av_bprintf(buf, "\\N");
197         } else if (p[0] == '\r' && p < p_end - 1 && p[1] == '\n') {
198             /* \r followed by a \n, we can skip it. We don't insert the \N yet
199              * because we don't know if it is followed by more text */
200             continue;
201 
202         /* finally, a sane character */
203         } else {
204             av_bprint_chars(buf, *p, 1);
205         }
206     }
207 }
208