Functions | |
vbi_bool | vbi_raw_video_image (uint8_t *raw, unsigned long raw_size, const vbi_sampling_par *sp, int blank_level, int black_level, int white_level, unsigned int pixel_mask, vbi_bool swap_fields, const vbi_sliced *sliced, unsigned int n_sliced_lines) |
vbi_bool | vbi_raw_add_noise (uint8_t *raw, const vbi_sampling_par *sp, unsigned int min_freq, unsigned int max_freq, unsigned int amplitude, unsigned int seed) |
vbi_bool | vbi_raw_vbi_image (uint8_t *raw, unsigned long raw_size, const vbi_sampling_par *sp, int blank_level, int white_level, vbi_bool swap_fields, const vbi_sliced *sliced, unsigned int n_sliced_lines) |
These are functions converting sliced VBI data to raw VBI images as transmitted in the vertical blanking interval of analog video standards. They are mainly intended for tests of the libzvbi bit slicer and raw VBI decoder.
|
|
|
To produce realistic noise min_freq = 0, max_freq = 5e6 and amplitude = 20 to 50 seems appropriate.
|
|
The function encodes sliced data as is, e.g. without adding or checking parity bits, without checking if the line number is correct for the respective data service, or if the signal will fit completely in the given space (sp->offset and sp->samples_per_line at sp->sampling_rate). Apart of the payload the generated video signal is invariable and attempts to be faithful to related standards. You can only change the characteristics of the assumed capture device. Sync pulses and color bursts and not generated if the sampling parameters extend to this area.
|