VBI_BPL
unsigned int padding = VBI_BPL - bpl;
offset = btv->vbi_fmt.fmt.count[0] * VBI_BPL;
f->samples_per_line = VBI_BPL;
f->fmt.samples_per_line = VBI_BPL;
WARN_ON(real_samples_per_line > VBI_BPL);