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1 /*
2  * SSA/ASS spliting 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 #ifndef AVCODEC_ASS_SPLIT_H
23 #define AVCODEC_ASS_SPLIT_H
24 
25 /**
26  * fields extracted from the [Script Info] section
27  */
28 typedef struct {
29     char *script_type;    /**< SSA script format version (eg. v4.00) */
30     char *collisions;     /**< how subtitles are moved to prevent collisions */
31     int   play_res_x;     /**< video width that ASS coords are referring to */
32     int   play_res_y;     /**< video height that ASS coords are referring to */
33     float timer;          /**< time multiplier to apply to SSA clock (in %) */
34 } ASSScriptInfo;
35 
36 /**
37  * fields extracted from the [V4(+) Styles] section
38  */
39 typedef struct {
40     char *name;           /**< name of the tyle (case sensitive) */
41     char *font_name;      /**< font face (case sensitive) */
42     int   font_size;      /**< font height */
43     int   primary_color;  /**< color that a subtitle will normally appear in */
44     int   secondary_color;
45     int   outline_color;  /**< color for outline in ASS, called tertiary in SSA */
46     int   back_color;     /**< color of the subtitle outline or shadow */
47     int   bold;           /**< whether text is bold (1) or not (0) */
48     int   italic;         /**< whether text is italic (1) or not (0) */
49     int   underline;      /**< whether text is underlined (1) or not (0) */
50     int   strikeout;
51     float scalex;
52     float scaley;
53     float spacing;
54     float angle;
55     int   border_style;
56     float outline;
57     float shadow;
58     int   alignment;      /**< position of the text (left, center, top...),
59                                defined after the layout of the numpad
60                                (1-3 sub, 4-6 mid, 7-9 top) */
61     int   margin_l;
62     int   margin_r;
63     int   margin_v;
64     int   alpha_level;
65     int   encoding;
66 } ASSStyle;
67 
68 /**
69  * fields extracted from the [Events] section
70  */
71 typedef struct {
72     int   readorder;
73     int   layer;    /**< higher numbered layers are drawn over lower numbered */
74     int   start;    /**< start time of the dialog in centiseconds */
75     int   end;      /**< end time of the dialog in centiseconds */
76     char *style;    /**< name of the ASSStyle to use with this dialog */
77     char *name;
78     int   margin_l;
79     int   margin_r;
80     int   margin_v;
81     char *effect;
82     char *text;     /**< actual text which will be displayed as a subtitle,
83                          can include style override control codes (see
84                          ff_ass_split_override_codes()) */
85 } ASSDialog;
86 
87 /**
88  * structure containing the whole split ASS data
89  */
90 typedef struct {
91     ASSScriptInfo script_info;   /**< general information about the SSA script*/
92     ASSStyle     *styles;        /**< array of split out styles */
93     int           styles_count;  /**< number of ASSStyle in the styles array */
94     ASSDialog    *dialogs;       /**< array of split out dialogs */
95     int           dialogs_count; /**< number of ASSDialog in the dialogs array*/
96 } ASS;
97 
98 /**
99  * This struct can be casted to ASS to access to the split data.
100  */
101 typedef struct ASSSplitContext ASSSplitContext;
102 
103 /**
104  * Split a full ASS file or a ASS header from a string buffer and store
105  * the split structure in a newly allocated context.
106  *
107  * @param buf String containing the ASS formatted data.
108  * @return Newly allocated struct containing split data.
109  */
110 ASSSplitContext *ff_ass_split(const char *buf);
111 
112 /**
113  * Split one or several ASS "Dialogue" lines from a string buffer and store
114  * them in an already initialized context.
115  *
116  * @param ctx Context previously initialized by ff_ass_split().
117  * @param buf String containing the ASS "Dialogue" lines.
118  * @param cache Set to 1 to keep all the previously split ASSDialog in
119  *              the context, or set to 0 to free all the previously split
120  *              ASSDialog.
121  * @param number If not NULL, the pointed integer will be set to the number
122  *               of split ASSDialog.
123  * @return Pointer to the first split ASSDialog.
124  */
125 ASSDialog *ff_ass_split_dialog(ASSSplitContext *ctx, const char *buf,
126                                int cache, int *number);
127 
128 /**
129  * Free a dialogue obtained from ff_ass_split_dialog2().
130  */
131 void ff_ass_free_dialog(ASSDialog **dialogp);
132 
133 /**
134  * Split one ASS Dialogue line from a string buffer.
135  *
136  * @param ctx Context previously initialized by ff_ass_split().
137  * @param buf String containing the ASS "Dialogue" line.
138  * @return Pointer to the split ASSDialog. Must be freed with ff_ass_free_dialog()
139  */
140 ASSDialog *ff_ass_split_dialog2(ASSSplitContext *ctx, const char *buf);
141 
142 /**
143  * Free all the memory allocated for an ASSSplitContext.
144  *
145  * @param ctx Context previously initialized by ff_ass_split().
146  */
147 void ff_ass_split_free(ASSSplitContext *ctx);
148 
149 
150 /**
151  * Set of callback functions corresponding to each override codes that can
152  * be encountered in a "Dialogue" Text field.
153  */
154 typedef struct {
155     /**
156      * @defgroup ass_styles    ASS styles
157      * @{
158      */
159     void (*text)(void *priv, const char *text, int len);
160     void (*new_line)(void *priv, int forced);
161     void (*style)(void *priv, char style, int close);
162     void (*color)(void *priv, unsigned int /* color */, unsigned int color_id);
163     void (*alpha)(void *priv, int alpha, int alpha_id);
164     void (*font_name)(void *priv, const char *name);
165     void (*font_size)(void *priv, int size);
166     void (*alignment)(void *priv, int alignment);
167     void (*cancel_overrides)(void *priv, const char *style);
168     /** @} */
169 
170     /**
171      * @defgroup ass_functions    ASS functions
172      * @{
173      */
174     void (*move)(void *priv, int x1, int y1, int x2, int y2, int t1, int t2);
175     void (*origin)(void *priv, int x, int y);
176     /** @} */
177 
178     /**
179      * @defgroup ass_end    end of Dialogue Event
180      * @{
181      */
182     void (*end)(void *priv);
183     /** @} */
184 } ASSCodesCallbacks;
185 
186 /**
187  * Split override codes out of a ASS "Dialogue" Text field.
188  *
189  * @param callbacks Set of callback functions called for each override code
190  *                  encountered.
191  * @param priv Opaque pointer passed to the callback functions.
192  * @param buf The ASS "Dialogue" Text field to split.
193  * @return >= 0 on success otherwise an error code <0
194  */
195 int ff_ass_split_override_codes(const ASSCodesCallbacks *callbacks, void *priv,
196                                 const char *buf);
197 
198 /**
199  * Find an ASSStyle structure by its name.
200  *
201  * @param ctx Context previously initialized by ff_ass_split().
202  * @param style name of the style to search for.
203  * @return the ASSStyle corresponding to style, or NULL if style can't be found
204  */
205 ASSStyle *ff_ass_style_get(ASSSplitContext *ctx, const char *style);
206 
207 #endif /* AVCODEC_ASS_SPLIT_H */
208