Aegisub/aegisub/libass/ass.h

358 lines
10 KiB
C

/*
* Copyright (C) 2006 Evgeniy Stepanov <eugeni.stepanov@gmail.com>
*
* This file is part of libass.
*
* libass is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* libass is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with libass; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef LIBASS_ASS_H
#define LIBASS_ASS_H
#include <stdio.h>
#include <stdarg.h>
#include "ass_types.h"
#define LIBASS_VERSION 0x00907000
/* Libass renderer object. Contents are private. */
typedef struct ass_renderer_s ass_renderer_t;
/* A linked list of images produced by ass renderer. */
typedef struct ass_image_s {
int w, h; // Bitmap width/height
int stride; // Bitmap stride
unsigned char *bitmap; // 1bpp stride*h alpha buffer
uint32_t color; // Bitmap color and alpha, RGBA
int dst_x, dst_y; // Bitmap placement inside the video frame
struct ass_image_s *next; // Next image, or NULL
} ass_image_t;
/* Hinting type. */
typedef enum {
ASS_HINTING_NONE = 0,
ASS_HINTING_LIGHT,
ASS_HINTING_NORMAL,
ASS_HINTING_NATIVE
} ass_hinting_t;
/**
* \brief Initialize the library.
* \return library handle or NULL if failed
*/
ass_library_t *ass_library_init(void);
/**
* \brief Finalize the library
* \param priv library handle
*/
void ass_library_done(ass_library_t *);
/**
* \brief Set private font directory.
* It is used for saving embedded fonts and also in font lookup.
*
* \param priv library handle
* \param fonts_dir private directory for font extraction
*/
void ass_set_fonts_dir(ass_library_t *priv, const char *fonts_dir);
/**
* \brief Whether fonts should be extracted from track data.
* \param priv library handle
* \param extract whether to extract fonts
*/
void ass_set_extract_fonts(ass_library_t *priv, int extract);
/**
* \brief Register style overrides with a library instance.
* The overrides should have the form [Style.]Param=Value, e.g.
* SomeStyle.Font=Arial
* ScaledBorderAndShadow=yes
*
* \param priv library handle
* \param list NULL-terminated list of strings
*/
void ass_set_style_overrides(ass_library_t *priv, char **list);
/**
* \brief Explicitly process style overrides for a track.
* \param track track handle
*/
void ass_process_force_style(ass_track_t *track);
/**
* \brief Register a callback for debug/info messages.
* If a callback is registered, it is called for every message emitted by
* libass. The callback receives a format string and a list of arguments,
* to be used for the printf family of functions. Additionally, a log level
* from 0 (FATAL errors) to 7 (verbose DEBUG) is passed. Usually, level 5
* should be used by applications.
* If no callback is set, all messages level < 5 are printed to stderr,
* prefixed with [ass].
*
* \param priv library handle
* \param msg_cb pointer to callback function
* \param data additional data, will be passed to callback
*/
void ass_set_message_cb(ass_library_t *priv,
void (*msg_cb)(int, char *, va_list *, void *),
void *data);
/**
* \brief Initialize the renderer.
* \param priv library handle
* \return renderer handle or NULL if failed
*/
ass_renderer_t *ass_renderer_init(ass_library_t *);
/**
* \brief Finalize the renderer.
* \param priv renderer handle
*/
void ass_renderer_done(ass_renderer_t *priv);
/**
* \brief Set the frame size in pixels, including margins.
* \param priv renderer handle
* \param w width
* \param h height
*/
void ass_set_frame_size(ass_renderer_t *priv, int w, int h);
/**
* \brief Set frame margins. These values may be negative if pan-and-scan
* is used.
* \param priv renderer handle
* \param t top margin
* \param b bottom margin
* \param l left margin
* \param r right margin
*/
void ass_set_margins(ass_renderer_t *priv, int t, int b, int l, int r);
/**
* \brief Whether margins should be used for placing regular events.
* \param priv renderer handle
* \param use whether to use the margins
*/
void ass_set_use_margins(ass_renderer_t *priv, int use);
/**
* \brief Set aspect ratio parameters.
* \param priv renderer handle
* \param ar physical aspect ratio
* \param par pixel ratio, e.g. width / height of the video
*/
void ass_set_aspect_ratio(ass_renderer_t *priv, double ar, double par);
/**
* \brief Set a fixed font scaling factor.
* \param priv renderer handle
* \param font_scale scaling factor, default is 1.0
*/
void ass_set_font_scale(ass_renderer_t *priv, double font_scale);
/**
* \brief Set font hinting method.
* \param priv renderer handle
* \param ht hinting method
*/
void ass_set_hinting(ass_renderer_t *priv, ass_hinting_t ht);
/**
* \brief Set line spacing. Will not be scaled with frame size.
* \param priv renderer handle
* \param line_spacing line spacing in pixels
*/
void ass_set_line_spacing(ass_renderer_t *priv, double line_spacing);
/**
* \brief Set font lookup defaults.
* \param fc whether to use fontconfig
* \param config path to fontconfig configuration file, or NULL. Only relevant
* if fontconfig is used.
* \param update whether fontconfig cache should be built/updated now. Only
* relevant if fontconfig is used.
*/
void ass_set_fonts(ass_renderer_t *priv, const char *default_font,
const char *default_family, int fc, const char *config,
int update);
/**
* \brief Update/build font cache. This needs to be called if it was
* disabled when ass_set_fonts was set.
*
* \param priv renderer handle
* \return success
*/
int ass_fonts_update(ass_renderer_t *priv);
/**
* \brief Set hard cache limits. Do not set, or set to zero, for reasonable
* defaults.
*
* \param priv renderer handle
* \param glyph_max maximum number of cached glyphs
* \param bitmap_max_size maximum bitmap cache size (in MB)
*/
void ass_set_cache_limits(ass_renderer_t *priv, int glyph_max,
int bitmap_max_size);
/**
* \brief Render a frame, producing a list of ass_image_t.
* \param priv renderer handle
* \param track subtitle track
* \param now video timestamp in milliseconds
* \param detect_change will be set to 1 if a change occured compared
* to the last invocation
*/
ass_image_t *ass_render_frame(ass_renderer_t *priv, ass_track_t *track,
long long now, int *detect_change);
/*
* The following functions operate on track objects and do not need
* an ass_renderer
*/
/**
* \brief Allocate a new empty track object.
* \param library handle
* \return pointer to empty track
*/
ass_track_t *ass_new_track(ass_library_t *);
/**
* \brief Deallocate track and all its child objects (styles and events).
* \param track track to deallocate
*/
void ass_free_track(ass_track_t *track);
/**
* \brief Allocate new style.
* \param track track
* \return newly allocated style id
*/
int ass_alloc_style(ass_track_t *track);
/**
* \brief Allocate new event.
* \param track track
* \return newly allocated event id
*/
int ass_alloc_event(ass_track_t *track);
/**
* \brief Delete a style.
* \param track track
* \param sid style id
* Deallocates style data. Does not modify track->n_styles.
*/
void ass_free_style(ass_track_t *track, int sid);
/**
* \brief Delete an event.
* \param track track
* \param eid event id
* Deallocates event data. Does not modify track->n_events.
*/
void ass_free_event(ass_track_t *track, int eid);
/**
* \brief Parse a chunk of subtitle stream data.
* \param track track
* \param data string to parse
* \param size length of data
*/
void ass_process_data(ass_track_t *track, char *data, int size);
/**
* \brief Parse Codec Private section of subtitle stream.
* \param track target track
* \param data string to parse
* \param size length of data
*/
void ass_process_codec_private(ass_track_t *track, char *data, int size);
/**
* \brief Parse a chunk of subtitle stream data. In Matroska,
* this contains exactly 1 event (or a commentary).
* \param track track
* \param data string to parse
* \param size length of data
* \param timecode starting time of the event (milliseconds)
* \param duration duration of the event (milliseconds)
*/
void ass_process_chunk(ass_track_t *track, char *data, int size,
long long timecode, long long duration);
/**
* \brief Read subtitles from file.
* \param library library handle
* \param fname file name
* \param codepage encoding (iconv format)
* \return newly allocated track
*/
ass_track_t *ass_read_file(ass_library_t *library, char *fname,
char *codepage);
/**
* \brief Read subtitles from memory.
* \param library library handle
* \param buf pointer to subtitles text
* \param bufsize size of buffer
* \param codepage encoding (iconv format)
* \return newly allocated track
*/
ass_track_t *ass_read_memory(ass_library_t *library, char *buf,
size_t bufsize, char *codepage);
/**
* \brief Read styles from file into already initialized track.
* \param fname file name
* \param codepage encoding (iconv format)
* \return 0 on success
*/
int ass_read_styles(ass_track_t *track, char *fname, char *codepage);
/**
* \brief Add a memory font.
* \param library library handle
* \param name attachment name
* \param data binary font data
* \param data_size data size
*/
void ass_add_font(ass_library_t *library, char *name, char *data,
int data_size);
/**
* \brief Remove all fonts stored in an ass_library object.
* \param library library handle
*/
void ass_clear_fonts(ass_library_t *library);
/**
* \brief Calculates timeshift from now to the start of some other subtitle
* event, depending on movement parameter.
* \param track subtitle track
* \param now current time in milliseconds
* \param movement how many events to skip from the one currently displayed
* +2 means "the one after the next", -1 means "previous"
* \return timeshift in milliseconds
*/
long long ass_step_sub(ass_track_t *track, long long now, int movement);
#endif /* LIBASS_ASS_H */