uint8_t *av_packet_new_side_data(AVPacket *pkt, enum AVPacketSideDataType type,
                                 int size)
{
    int elems = pkt->side_data_elems;

    if ((unsigned)elems + 1 > INT_MAX / sizeof(*pkt->side_data))
        return NULL;
    if ((unsigned)size > INT_MAX - FF_INPUT_BUFFER_PADDING_SIZE)
        return NULL;

    pkt->side_data = av_realloc(pkt->side_data,
                                (elems + 1) * sizeof(*pkt->side_data));
    if (!pkt->side_data)
        return NULL;

    pkt->side_data[elems].data = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);
    if (!pkt->side_data[elems].data)
        return NULL;
    pkt->side_data[elems].size = size;
    pkt->side_data[elems].type = type;
    pkt->side_data_elems++;

    return pkt->side_data[elems].data;
}