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Teletext and Closed Caption page render functions
[Exporting formatted Teletext and Closed Caption pages]


Functions

void vbi_draw_vt_page_region (vbi_page *pg, vbi_pixfmt fmt, void *canvas, int rowstride, int column, int row, int width, int height, int reveal, int flash_on)
static_inline void vbi_draw_vt_page (vbi_page *pg, vbi_pixfmt fmt, void *canvas, int reveal, int flash_on)
void vbi_draw_cc_page_region (vbi_page *pg, vbi_pixfmt fmt, void *canvas, int rowstride, int column, int row, int width, int height)
static_inline void vbi_draw_cc_page (vbi_page *pg, vbi_pixfmt fmt, void *canvas)
void vbi_get_max_rendered_size (int *w, int *h)
void vbi_get_vt_cell_size (int *w, int *h)
int vbi_print_page_region (vbi_page *pg, char *buf, int size, const char *format, vbi_bool table, vbi_bool rtl, int column, int row, int width, int height)
static_inline int vbi_print_page (vbi_page *pg, char *buf, int size, const char *format, vbi_bool table, vbi_bool ltr)
void vbi_set_brightness (vbi_decoder *vbi, int brightness)
void vbi_set_contrast (vbi_decoder *vbi, int contrast)

Detailed Description

These are functions to render Teletext and Closed Caption pages directly into memory, essentially a more direct interface to the functions of some important export modules.

Function Documentation

void vbi_draw_vt_page_region vbi_page   pg,
vbi_pixfmt    fmt,
void *    canvas,
int    rowstride,
int    column,
int    row,
int    width,
int    height,
int    reveal,
int    flash_on
 

Parameters:
pg  Source page.
fmt  Target format. For now only VBI_PIXFMT_RGBA32_LE (vbi_rgba) permitted.
canvas  Pointer to destination image (currently an array of vbi_rgba), this must be at least rowstride * height * 10 bytes large.
rowstride  canvas byte distance from line to line. If this is -1, pg->columns * 12 * sizeof(vbi_rgba) bytes will be assumed.
column  First source column, 0 ... pg->columns - 1.
row  First source row, 0 ... pg->rows - 1.
width  Number of columns to draw, 1 ... pg->columns.
height  Number of rows to draw, 1 ... pg->rows.
reveal  If FALSE, draw characters flagged 'concealed' (see vbi_char) as space (U+0020).
flash_on  If FALSE, draw characters flagged 'blink' (see vbi_char) as space (U+0020).
Draw a subsection of a Teletext vbi_page. In this mode one character occupies 12 x 10 pixels.

static_inline void vbi_draw_vt_page vbi_page   pg,
vbi_pixfmt    fmt,
void *    canvas,
int    reveal,
int    flash_on
 

Parameters:
pg  Source page.
fmt  Target format. For now only VBI_PIXFMT_RGBA32_LE (vbi_rgba) permitted.
canvas  Pointer to destination image (currently an array of vbi_rgba). This must be at least pg->columns * pg->rows * 12 * 10 * pixels large, without padding between lines.
reveal  If FALSE, draw characters flagged 'concealed' (see vbi_char) as space (U+0020).
flash_on  If FALSE, draw characters flagged 'blink' (see vbi_char) as space (U+0020).
Draw a Teletext vbi_page. In this mode one character occupies 12 x 10 pixels.

void vbi_draw_cc_page_region vbi_page   pg,
vbi_pixfmt    fmt,
void *    canvas,
int    rowstride,
int    column,
int    row,
int    width,
int    height
 

Parameters:
fmt  Target format. For now only VBI_PIXFMT_RGBA32_LE (vbi_rgba) permitted.
canvas  Pointer to destination image (currently an array of vbi_rgba), this must be at least rowstride * height * 26 bytes large.
rowstride  canvas byte distance from line to line. If this is -1, pg->columns * 16 * sizeof(vbi_rgba) bytes will be assumed.
column  First source column, 0 ... pg->columns - 1.
row  First source row, 0 ... pg->rows - 1.
width  Number of columns to draw, 1 ... pg->columns.
height  Number of rows to draw, 1 ... pg->rows.
Draw a subsection of a Closed Caption vbi_page. In this mode one character occupies 16 x 26 pixels.

static_inline void vbi_draw_cc_page vbi_page   pg,
vbi_pixfmt    fmt,
void *    canvas
 

Parameters:
pg  Source page.
fmt  Target format. For now only VBI_PIXFMT_RGBA32_LE (vbi_rgba) permitted.
canvas  Pointer to destination image (currently an array of vbi_rgba). This must be at least pg->columns * pg->rows * 16 * 26 * pixels large, without padding between lines.
Draw a Closed Caption vbi_page. In this mode one character occupies 16 x 26 pixels.

void vbi_get_max_rendered_size int *    w,
int *    h
 

Parameters:
w 
h 
Deprecated:
Character cells are 12 x 10 for Teletext and 16 x 26 for Caption. Page size is in vbi_page.

void vbi_get_vt_cell_size int *    w,
int *    h
 

Parameters:
w 
h 
Deprecated:
Character cells are 12 x 10 for Teletext and 16 x 26 for Caption.

int vbi_print_page_region vbi_page   pg,
char *    buf,
int    size,
const char *    format,
vbi_bool    table,
vbi_bool    rtl,
int    column,
int    row,
int    width,
int    height
 

Parameters:
pg  Source page.
buf  Memory location to hold the output.
size  Size of the buffer in bytes. The function fails when the data exceeds the buffer capacity.
format  Character set name for iconv() conversion, for example "ISO-8859-1".
table  Scan page in table mode, printing all characters within the source rectangle including runs of spaces at the start and end of rows. When FALSE, scan all characters from column, row to column + width - 1, row + height - 1 and all intermediate rows to their full pg->columns width. In this mode runs of spaces at the start and end of rows are collapsed into single spaces, blank lines are suppressed.
ltr  Currently ignored, please set to TRUE.
column  First source column, 0 ... pg->columns - 1.
row  First source row, 0 ... pg->rows - 1.
width  Number of columns to print, 1 ... pg->columns.
height  Number of rows to print, 1 ... pg->rows.
Print a subsection of a Teletext or Closed Caption vbi_page, rows separated by linefeeds "
", in the desired format. All character attributes and colors will be lost. Graphics characters, DRCS and all characters not representable in the target format will be replaced by spaces.

Returns:
Number of bytes written into buf, a value of zero when some error occurred. In this case buf may contain incomplete data. Note this function does not append a terminating null character.

static_inline int vbi_print_page vbi_page   pg,
char *    buf,
int    size,
const char *    format,
vbi_bool    table,
vbi_bool    ltr
 

Parameters:
pg  Source page.
buf  Memory location to hold the output.
size  Size of the buffer in bytes. The function fails when the data exceeds the buffer capacity.
format  Character set name for iconv() conversion, for example "ISO-8859-1".
table  When FALSE, runs of spaces at the start and end of rows will be collapsed into single spaces, blank lines are suppressed.
ltr  Currently ignored, please set to TRUE.
Print a Teletext or Closed Caption vbi_page, rows separated by linefeeds "
", in the desired format. All character attributes and colors will be lost. Graphics characters, DRCS and all characters not representable in the target format will be replaced by spaces.

Returns:
Number of bytes written into buf, a value of zero when some error occurred. In this case buf may contain incomplete data. Note this function does not append a terminating null character.

void vbi_set_brightness vbi_decoder *    vbi,
int    brightness
 

Parameters:
vbi  Initialized vbi decoding context.
brightness  0 dark ... 255 bright, default 128.
Change brightness of text pages, this affects the color palette of pages fetched with vbi_fetch_vt_page() and vbi_fetch_cc_page().

void vbi_set_contrast vbi_decoder *    vbi,
int    contrast
 

Parameters:
vbi  Initialized vbi decoding context.
contrast  -128 inverse ... 0 none ... 127 maximum, default 64.
Change contrast of text pages, this affects the color palette of pages fetched with vbi_fetch_vt_page() and vbi_fetch_cc_page().


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