__xtpg_get_pad_format
fmt->format = *__xtpg_get_pad_format(xtpg, sd_state, fmt->pad,
__format = __xtpg_get_pad_format(xtpg, sd_state, fmt->pad, fmt->which);
__format = __xtpg_get_pad_format(xtpg, sd_state, 1,