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