static void mov_current_sample_dec(MOVStreamContext *sc)
{
    sc->current_sample--;
    sc->current_index--;
    if (sc->index_ranges &&
        sc->current_index < sc->current_index_range->start &&
        sc->current_index_range > sc->index_ranges) {
        sc->current_index_range--;
        sc->current_index = sc->current_index_range->end - 1;
    }
}