v4l2_video_std_frame_period
v4l2_video_std_frame_period(vv->standard->id,
v4l2_video_std_frame_period(bttv_tvnorms[btv->tvnorm].v4l2_id,
v4l2_video_std_frame_period(v4l2->norm,
EXPORT_SYMBOL(v4l2_video_std_frame_period);
v4l2_video_std_frame_period(id, &vs->frameperiod);
v4l2_video_std_frame_period(std, &p->parm.capture.timeperframe);
void v4l2_video_std_frame_period(int id, struct v4l2_fract *frameperiod);