bttv_buffer_activate_video
bttv_buffer_activate_video(btv, &new);
bttv_buffer_activate_video(btv, &new);
bttv_buffer_activate_video(btv, &idle);
bttv_buffer_activate_video(btv, &btv->curr);
int bttv_buffer_activate_video(struct bttv *btv,