Functions to decode data transmissions in Teletext Independent Data Line packets (EN 300 708 section 6).
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Detailed Description
Functions to decode data transmissions in Teletext Independent Data Line packets (EN 300 708 section 6).
Define Documentation
#define VBI_IDL_DATA_LOST (1 << 0) |
Data was lost (not received or uncorrectable) between the current and previous call.
#define VBI_IDL_DEPENDENT (1 << 3) |
IDL Format A flag (EN 300 708 section 6.5.2): The data may require the use of data in other channels or with other service packet addresses as defined by the application.
Typedef Documentation
IDL demultiplexer context.
The contents of this structure are private.
Call vbi_idl_demux_new() to allocate an IDL demultiplexer context.
- Parameters:
-
| dx | IDL demultiplexer returned by vbi_idl_a_demux_new() and given to vbi_idl_demux_feed(). |
| buffer | Pointer to received user data. |
| n_bytes | Number of bytes in the buffer. Can be 0 if the decoded packet did not contain user data. |
| flags | VBI_IDL_DATA_LOST , VBI_IDL_DEPENDENT . |
| user_data | User pointer passed to vbi_idl_demux_new(). |
The vbi_idl_demux_feed() function calls a function of this type after successfully decoding an IDL packet.
- Returns:
- FALSE to abort vbi_idl_demux_feed() and return FALSE.
Function Documentation
- Parameters:
-
Resets the IDL demux context, useful for example after a channel change.
- Since:
- 0.2.14
vbi_bool vbi_idl_demux_feed |
( |
vbi_idl_demux * |
dx, |
|
|
const uint8_t |
buffer[42] | |
|
) |
| | |
- Parameters:
-
This function takes a stream of Teletext packets, filters out packets of the desired data channel and address and calls the output function given to vbi_idl_a_demux_new() when new user data is available.
- Returns:
- FALSE if the packet contained incorrectable errors.
- Since:
- 0.2.14
- Parameters:
-
Frees all resources associated with dx.
- Since:
- 0.2.14
- Parameters:
-
| channel | Filter out packets of this channel. |
| address | Filter out packets with this service data address. |
| callback | Function to be called by vbi_idl_demux_feed() when new data is available. |
| user_data | User pointer passed through to callback function. |
Allocates a new Independent Data Line format A (EN 300 708 section 6.5) demultiplexer.
- Returns:
- Pointer to newly allocated IDL demultiplexer which must be freed with vbi_idl_demux_delete() when done.
NULL
on failure (out of memory).
- Since:
- 0.2.14