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#ifndef __ASS_H__
#define __ASS_H__
#include "ass_types.h"
/// Libass "library object". Contents are private.
typedef struct ass_instance_s ass_instance_t;
/// used in ass_configure
typedef struct ass_settings_s {
int frame_width;
int frame_height;
double font_size_coeff; // font size multiplier
double line_spacing; // additional line spacing (in frame pixels)
int top_margin; // height of top margin. Everything except toptitles is shifted down by top_margin.
int bottom_margin; // height of bottom margin. (frame_height - top_margin - bottom_margin) is original video height.
double aspect; // frame aspect ratio, d_width / d_height.
} ass_settings_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; // RGBA
int dst_x, dst_y; // bitmap placement inside the video frame
struct ass_image_s* next; // linked list
} ass_image_t;
/**
* \brief initialize the library
* \return library handle or NULL if failed
*/
ass_instance_t* ass_init(void);
/**
* \brief finalize the library
* \param priv library handle
*/
void ass_done(ass_instance_t* priv);
/**
* \brief configure the library
* \param priv library handle
* \param config struct with configuration parameters. Caller is free to reuse it after this function returns.
*/
void ass_configure(ass_instance_t* priv, const ass_settings_t* config);
/**
* \brief start rendering a frame
* \param priv library
* \param track subtitle track
* \param now video timestamp in milliseconds
*/
int ass_start_frame(ass_instance_t *priv, ass_track_t* track, long long now);
/**
* \brief render a single event
* uses library, track and timestamp from the previous call to ass_start_frame
*/
int ass_render_event(ass_event_t* event);
/**
* \brief done rendering frame, give out the results
* \return a list of images for blending
*/
ass_image_t* ass_end_frame(void); // returns linked list of images to render
/**
* \brief render a frame, producing a list of ass_image_t
* \param priv library
* \param track subtitle track
* \param now video timestamp in milliseconds
* This function is equivalent to
* ass_start_frame()
* for events: start <= now < end:
* ass_render_event()
* ass_end_frame()
*/
ass_image_t* ass_render_frame(ass_instance_t *priv, ass_track_t* track, long long now);
// The following functions operate on track objects and do not need an ass_instance //
/**
* \brief allocate a new empty track object
* \return pointer to empty track
*/
ass_track_t* ass_new_track(void);
/**
* \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 Process Codec Private section of subtitle stream
* \param track target track
* \param data string to parse
* \param size length of data
*/
void ass_process_chunk(ass_track_t* track, char *data, int size);
/**
* \brief Process a chunk of subtitle stream data. In matroska, this containes 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_line(ass_track_t* track, char *data, int size, long long timecode, long long duration);
/**
* \brief Read subtitles from file.
* \param fname file name
* \return newly allocated track
*/
ass_track_t* ass_read_file(char* fname);
/**
* \brief Process embedded matroska font. Saves it to ~/.mplayer/fonts.
* \param name attachment name
* \param data binary font data
* \param data_size data size
*/
void ass_process_font(const char* name, char* data, int data_size);
/**
* \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, ms
* \param movement how many events to skip from the one currently displayed
* +2 means "the one after the next", -1 means "previous"
* \return timeshift, ms
*/
long long ass_step_sub(ass_track_t* track, long long now, int movement);
#endif
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