Functions |
vbi_export_info * | vbi_export_info_enum (int index) |
vbi_export_info * | vbi_export_info_keyword (const char *keyword) |
vbi_export_info * | vbi_export_info_export (vbi_export *) |
vbi_export * | vbi_export_new (const char *keyword, char **errstr) |
void | vbi_export_delete (vbi_export *) |
vbi_option_info * | vbi_export_option_info_enum (vbi_export *, int index) |
vbi_option_info * | vbi_export_option_info_keyword (vbi_export *, const char *keyword) |
vbi_bool | vbi_export_option_set (vbi_export *, const char *keyword,...) |
vbi_bool | vbi_export_option_get (vbi_export *, const char *keyword, vbi_option_value *value) |
vbi_bool | vbi_export_option_menu_set (vbi_export *, const char *keyword, int entry) |
vbi_bool | vbi_export_option_menu_get (vbi_export *, const char *keyword, int *entry) |
ssize_t | vbi_export_mem (vbi_export *e, void *buffer, size_t buffer_size, const vbi_page *pg) _vbi_nonnull((1)) |
void * | vbi_export_alloc (vbi_export *e, void **buffer, size_t *buffer_size, const vbi_page *pg) _vbi_nonnull((1)) |
vbi_bool | vbi_export_stdio (vbi_export *, FILE *fp, vbi_page *pg) |
vbi_bool | vbi_export_file (vbi_export *, const char *name, vbi_page *pg) |
char * | vbi_export_errstr (vbi_export *) |
Detailed Description
Once libzvbi received, decoded and formatted a Teletext or Closed Caption page you will want to render it on screen, print it as text or store it in various formats.
Fortunately you don't have to do it all by yourself. libzvbi provides export modules converting a vbi_page into the desired format or rendering directly into memory.
A minimalistic export example:
static void
{
char *errstr;
fprintf (stderr, "Cannot export as HTML: %s\n", errstr);
free (errstr);
return;
}
}
Typedef Documentation
Information about an export module.
Although export modules can be accessed by a static keyword (see vbi_export_new()) they are by definition opaque. The client can list export modules for the user and manipulate them without knowing about their availability or purpose. To do so, information about the module is necessary, given in this structure.
You can obtain this information with vbi_export_info_enum().
Enumeration Type Documentation
- Enumerator:
VBI_OPTION_BOOL |
A boolean value, either TRUE (1) or FALSE (0).
Type: | int |
Default: | vbi_option_info.def.num |
Bounds: | vbi_option_info.min.num (0) ... max.num (1), step.num (1) |
Menu: | NULL |
|
VBI_OPTION_INT |
A signed integer value.
Type: | int |
Default: | vbi_option_info.def.num |
Bounds: | vbi_option_info.min.num ... max.num, step.num |
Menu: | NULL |
When only a few discrete values rather than a range of values are permitted vbi_option_info.menu points to a vector of integers. However you must still set the option by value, not by menu index. If the value is invalid vbi_export_option_set() may fail or pick the closest possible value instead.
Type: | int |
Default: | vbi_option_info.menu.num[vbi_option_info.def.num] |
Bounds: | See vbi_option_info.menu.num[] for valid values |
Menu: | vbi_option_info.menu.num[min.num (0) ... max.num], step.num (1) |
|
VBI_OPTION_REAL |
A real value.
Type: | double |
Default: | vbi_option_info.def.dbl |
Bounds: | vbi_option_info.min.dbl ... max.dbl, step.dbl |
Menu: | NULL |
As with VBI_OPTION_INT vbi_option_info.menu may point to a set of valid values:
Type: | double |
Default: | vbi_option_info.menu.dbl[vbi_option.info.def.num] |
Bounds: | See vbi_option_info.menu.dbl[] for valid values |
Menu: | vbi_option_info.menu.dbl[min.num (0) ... max.num], step.num (1) |
|
VBI_OPTION_STRING |
A null terminated string.
Type: | char * |
Default: | vbi_option_info.def.str |
Bounds: | Not applicable |
Menu: | NULL |
As with VBI_OPTION_INT vbi_option_info.menu may point to a set of valid strings. Note that vbi_export_option_set() always expects a string for this kind of option, and it may accept strings which are not in the menu. Contrast this with VBI_OPTION_MENU , where a menu index is expected.
Type: | char * |
Default: | vbi_option_info.menu.str[vbi_option_info.def.num] |
Bounds: | Not applicable |
Menu: | vbi_option_info.menu.str[min.num (0) ... max.num], step.num (1) |
|
VBI_OPTION_MENU |
Choice between a number of named options. The value of this kind of option is the menu index. The menu strings can be localized with a dgettext("zvbi", menu.str[n]) call. For details see gettext info file.
Type: | int |
Default: | vbi_option_info.def.num |
Bounds: | vbi_option_info.min.num (0) ... max.num, step.num (1) |
Menu: | vbi_option_info.menu.str[vbi_option_info.min.num ... max.num], step.num (1). |
|
Function Documentation
- Parameters:
-
index | Index into the export module list, 0 ... n. |
Enumerates all available export modules. You should start at index 0, incrementing.
Some modules may depend on machine features or the presence of certain libraries, thus the list can vary from session to session.
- Returns:
- Static pointer to a vbi_export_info structure (no need to be freed),
NULL
if the index is out of bounds.
- Parameters:
-
Similar to vbi_export_info_enum(), but this function attempts to find an export module by keyword.
- Returns:
- Static pointer to a vbi_export_info structure,
NULL
if the named export module has not been found.
- Parameters:
-
Returns the export module info for the given export object.
- Returns:
- A static vbi_export_info pointer or
NULL
if export is NULL
.
vbi_export* vbi_export_new |
( |
const char * |
keyword, |
|
|
char ** |
errstr |
|
) |
| |
- Parameters:
-
keyword | Export module identifier as in vbi_export_info. |
errstr | If not NULL this function stores a pointer to an error description here. You must free() this string when no longer needed. |
Creates a new export module instance to export a vbi_page in the respective module format. As a special service you can initialize options by appending to the
- Parameters:
-
- Returns:
- Pointer to a newly allocated vbi_export object which must be freed by calling vbi_export_delete().
NULL
is returned and the errstr may be set (else NULL) if some problem occurred.
- Parameters:
-
This function frees all resources associated with the vbi_export object.
- Parameters:
-
export | Pointer to a initialized vbi_export object. |
index | Index in the option table 0 ... n. |
Enumerates the options available for the given export module. You should start at index 0, incrementing.
- Returns:
- Static pointer to a vbi_option_info structure,
NULL
if index is out of bounds.
vbi_bool vbi_export_option_set |
( |
vbi_export * |
export, |
|
|
const char * |
keyword, |
|
|
|
... |
|
) |
| |
- Parameters:
-
export | Pointer to a initialized vbi_export object. |
keyword | Keyword identifying the option, as in vbi_option_info. |
... | New value to set. |
Sets the value of the named option. Make sure the value is casted to the correct type (int, double, char *).
Typical usage of vbi_export_option_set():
Mind that options of type VBI_OPTION_MENU
must be set by menu entry number (int), all other options by value. If necessary it will be replaced by the closest value possible. Use function vbi_export_option_menu_set() to set options with menu by menu entry.
- Returns:
TRUE
on success, otherwise the option is not changed.
- Parameters:
-
export | Pointer to a initialized vbi_export object. |
keyword | Keyword identifying the option, as in vbi_option_info. |
value | A place to store the current option value. |
This function queries the current value of the named option. When the option is of type VBI_OPTION_STRING value.str must be freed with free() when you don't need it any longer. When the option is of type VBI_OPTION_MENU then value.num contains the selected entry.
- Returns:
TRUE
on success, otherwise value unchanged.
vbi_bool vbi_export_option_menu_set |
( |
vbi_export * |
export, |
|
|
const char * |
keyword, |
|
|
int |
entry |
|
) |
| |
- Parameters:
-
export | Pointer to a initialized vbi_export object. |
keyword | Keyword identifying the option, as in vbi_option_info. |
entry | Menu entry to be selected. |
Similar to vbi_export_option_set() this function sets the value of the named option, however it does so by number of the corresponding menu entry. Naturally this must be an option with menu.
- Returns:
TRUE
on success, otherwise the option is not changed.
vbi_bool vbi_export_option_menu_get |
( |
vbi_export * |
export, |
|
|
const char * |
keyword, |
|
|
int * |
entry |
|
) |
| |
- Parameters:
-
export | Pointer to a initialized vbi_export object. |
keyword | Keyword identifying the option, as in vbi_option_info. |
entry | A place to store the current menu entry. |
Similar to vbi_export_option_get() this function queries the current value of the named option, but returns this value as number of the corresponding menu entry. Naturally this must be an option with menu.
- Returns:
TRUE
on success, otherwise value remained unchanged.
ssize_t vbi_export_mem |
( |
vbi_export * |
e, |
|
|
void * |
buffer, |
|
|
size_t |
buffer_size, |
|
|
const vbi_page * |
pg |
|
) |
| |
- Parameters:
-
e | Initialized vbi_export object. |
buffer | Output buffer. |
buffer_size | Size of the output buffer in bytes. |
pg | Page to be exported. |
This function writes the pg contents, converted to the format selected with vbi_export_new(), into the buffer.
You can call this function repeatedly, it does not change the state of the vbi_export or vbi_page structure.
- Returns:
- On success the function returns the actual number of bytes stored in the buffer. If buffer_size is too small it returns the required size and the buffer contents are undefined. On other errors it returns -1 and the buffer contents are undefined.
- Since:
- 0.2.26
void* vbi_export_alloc |
( |
vbi_export * |
e, |
|
|
void ** |
buffer, |
|
|
size_t * |
buffer_size, |
|
|
const vbi_page * |
pg |
|
) |
| |
- Parameters:
-
e | Initialized vbi_export object. |
buffer | The address of the output buffer will be stored here. buffer can be NULL . |
buffer_size | The amount of data stored in the output buffer, in bytes, will be stored here. buffer_size can be NULL . |
pg | Page to be exported. |
This function writes the pg contents, converted to the format selected with vbi_export_new(), into a newly allocated buffer. You must free() this buffer when it is no longer needed.
You can call this function repeatedly, it does not change the state of the vbi_export or vbi_page structure.
- Returns:
- On success the function returns the address of the allocated buffer. On failure it returns
NULL
, and buffer and buffer_size remain unmodified.
- Since:
- 0.2.26
- Parameters:
-
e | Initialized vbi_export object. |
fp | Buffered i/o stream to write to. |
pg | Page to be exported. |
This function writes the pg contents, converted to the format selected with the vbi_export_new() function, into the stream fp. The caller is responsible for opening and closing the stream. Don't forget to check for i/o errors after closing. Note this function may write incomplete files when an error occurs.
You can call this function repeatedly, it does not change the state of the vbi_export or vbi_page structure.
- Returns:
FALSE
on failure, TRUE
on success.
- Parameters:
-
e | Initialized vbi_export object. |
name | File to be created. |
pg | Page to be exported. |
Writes the pg contents, converted to the format selected with vbi_export_new(), into a new file with the given name. When an error occurs after the file was opened, the function deletes the file.
You can call this function repeatedly, it does not change the state of the vbi_export or vbi_page structure.
- Returns:
FALSE
on failure, TRUE
on success.
- Parameters:
-
- Returns:
- After an export function failed, this function returns a pointer to a more detailed error description. Do not free this string. It remains valid until the next call of an export function.