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ass_split.h
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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 %) */
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 back_color; /**< color of the subtitle outline or shadow */
45  int bold; /**< whether text is bold (1) or not (0) */
46  int italic; /**< whether text is italic (1) or not (0) */
47  int underline; /**< whether text is underlined (1) or not (0) */
48  int alignment; /**< position of the text (left, center, top...),
49  defined after the layout of the numpad
50  (1-3 sub, 4-6 mid, 7-9 top) */
51 } ASSStyle;
52 
53 /**
54  * fields extracted from the [Events] section
55  */
56 typedef struct {
57  int layer; /**< higher numbered layers are drawn over lower numbered */
58  int start; /**< start time of the dialog in centiseconds */
59  int end; /**< end time of the dialog in centiseconds */
60  char *style; /**< name of the ASSStyle to use with this dialog */
61  char *text; /**< actual text which will be displayed as a subtitle,
62  can include style override control codes (see
63  ff_ass_split_override_codes()) */
64 } ASSDialog;
65 
66 /**
67  * structure containing the whole split ASS data
68  */
69 typedef struct {
70  ASSScriptInfo script_info; /**< general information about the SSA script*/
71  ASSStyle *styles; /**< array of split out styles */
72  int styles_count; /**< number of ASSStyle in the styles array */
73  ASSDialog *dialogs; /**< array of split out dialogs */
74  int dialogs_count; /**< number of ASSDialog in the dialogs array*/
75 } ASS;
76 
77 /**
78  * This struct can be casted to ASS to access to the split data.
79  */
80 typedef struct ASSSplitContext ASSSplitContext;
81 
82 /**
83  * Split a full ASS file or a ASS header from a string buffer and store
84  * the split structure in a newly allocated context.
85  *
86  * @param buf String containing the ASS formated data.
87  * @return Newly allocated struct containing split data.
88  */
89 ASSSplitContext *ff_ass_split(const char *buf);
90 
91 /**
92  * Split one or several ASS "Dialogue" lines from a string buffer and store
93  * them in a already initialized context.
94  *
95  * @param ctx Context previously initialized by ff_ass_split().
96  * @param buf String containing the ASS "Dialogue" lines.
97  * @param cache Set to 1 to keep all the previously split ASSDialog in
98  * the context, or set to 0 to free all the previously split
99  * ASSDialog.
100  * @param number If not NULL, the pointed integer will be set to the number
101  * of split ASSDialog.
102  * @return Pointer to the first split ASSDialog.
103  */
105  int cache, int *number);
106 
107 /**
108  * Free all the memory allocated for an ASSSplitContext.
109  *
110  * @param ctx Context previously initialized by ff_ass_split().
111  */
113 
114 
115 /**
116  * Set of callback functions corresponding to each override codes that can
117  * be encountered in a "Dialogue" Text field.
118  */
119 typedef struct {
120  /**
121  * @defgroup ass_styles ASS styles
122  * @{
123  */
124  void (*text)(void *priv, const char *text, int len);
125  void (*new_line)(void *priv, int forced);
126  void (*style)(void *priv, char style, int close);
127  void (*color)(void *priv, unsigned int /* color */, unsigned int color_id);
128  void (*alpha)(void *priv, int alpha, int alpha_id);
129  void (*font_name)(void *priv, const char *name);
130  void (*font_size)(void *priv, int size);
131  void (*alignment)(void *priv, int alignment);
132  void (*cancel_overrides)(void *priv, const char *style);
133  /** @} */
134 
135  /**
136  * @defgroup ass_functions ASS functions
137  * @{
138  */
139  void (*move)(void *priv, int x1, int y1, int x2, int y2, int t1, int t2);
140  void (*origin)(void *priv, int x, int y);
141  /** @} */
142 
143  /**
144  * @defgroup ass_end end of Dialogue Event
145  * @{
146  */
147  void (*end)(void *priv);
148  /** @} */
150 
151 /**
152  * Split override codes out of a ASS "Dialogue" Text field.
153  *
154  * @param callbacks Set of callback functions called for each override code
155  * encountered.
156  * @param priv Opaque pointer passed to the callback functions.
157  * @param buf The ASS "Dialogue" Text field to split.
158  * @return >= 0 on success otherwise an error code <0
159  */
160 int ff_ass_split_override_codes(const ASSCodesCallbacks *callbacks, void *priv,
161  const char *buf);
162 
163 /**
164  * Find an ASSStyle structure by its name.
165  *
166  * @param ctx Context previously initialized by ff_ass_split().
167  * @param style name of the style to search for.
168  * @return the ASSStyle corresponding to style, or NULL if style can't be found
169  */
170 ASSStyle *ff_ass_style_get(ASSSplitContext *ctx, const char *style);
171 
172 #endif /* AVCODEC_ASS_SPLIT_H */