ZVBI Library
0.2.33
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Raw vbi decoder context. More...
Data Structures | |
struct | _vbi_raw_decoder_job |
Data Fields | |
int | scanning |
vbi_pixfmt | sampling_format |
int | sampling_rate |
int | bytes_per_line |
int | offset |
int | start [2] |
int | count [2] |
vbi_bool | interlaced |
vbi_bool | synchronous |
pthread_mutex_t | mutex |
unsigned int | services |
int | num_jobs |
int8_t * | pattern |
struct vbi_raw_decoder::_vbi_raw_decoder_job | jobs [8] |
Raw vbi decoder context.
Only the sampling parameters are public. See vbi_raw_decoder_parameters() and vbi_raw_decoder_add_services() for usage.
int vbi_raw_decoder::scanning |
Either 525 (M/NTSC, M/PAL) or 625 (PAL, SECAM), describing the scan line system all line numbers refer to.
vbi_pixfmt vbi_raw_decoder::sampling_format |
Format of the raw vbi data.
int vbi_raw_decoder::sampling_rate |
Sampling rate in Hz, the number of samples or pixels captured per second.
int vbi_raw_decoder::bytes_per_line |
Number of samples or pixels captured per scan line, in bytes. This determines the raw vbi image width and you want it large enough to cover all data transmitted in the line (with headroom).
int vbi_raw_decoder::offset |
The distance from 0H (leading edge hsync, half amplitude point) to the first sample (pixel) captured, in samples (pixels). You want an offset small enough not to miss the start of the data transmitted.
int vbi_raw_decoder::start[2] |
First scan line to be captured, first and second field respectively, according to the ITU-R line numbering scheme (see vbi_sliced). Set to zero if the exact line number isn't known.
int vbi_raw_decoder::count[2] |
Number of scan lines captured, first and second field respectively. This can be zero if only data from one field is required. The sum count[0] + count[1] determines the raw vbi image height.
vbi_bool vbi_raw_decoder::interlaced |
In the raw vbi image, normally all lines of the second field are supposed to follow all lines of the first field. When this flag is set, the scan lines of first and second field will be interleaved in memory. This implies count[0] and count[1] are equal.
vbi_bool vbi_raw_decoder::synchronous |
Fields must be stored in temporal order, i. e. as the lines have been captured. It is assumed that the first field is also stored first in memory, however if the hardware cannot reliable distinguish fields this flag shall be cleared, which disables decoding of data services depending on the field number.