static int init_table_pools(H264Context *h)
{
    const int big_mb_num    = h->mb_stride * (h->mb_height + 1) + 1;
    const int mb_array_size = h->mb_stride * h->mb_height;
    const int b4_stride     = h->mb_width * 4 + 1;
    const int b4_array_size = b4_stride * h->mb_height * 4;

    h->qscale_table_pool = av_buffer_pool_init(big_mb_num + h->mb_stride,
                                               av_buffer_allocz);
    h->mb_type_pool      = av_buffer_pool_init((big_mb_num + h->mb_stride) *
                                               sizeof(uint32_t), av_buffer_allocz);
    h->motion_val_pool   = av_buffer_pool_init(2 * (b4_array_size + 4) *
                                               sizeof(int16_t), av_buffer_allocz);
    h->ref_index_pool    = av_buffer_pool_init(4 * mb_array_size, av_buffer_allocz);

    if (!h->qscale_table_pool || !h->mb_type_pool || !h->motion_val_pool ||
        !h->ref_index_pool) {
        av_buffer_pool_uninit(&h->qscale_table_pool);
        av_buffer_pool_uninit(&h->mb_type_pool);
        av_buffer_pool_uninit(&h->motion_val_pool);
        av_buffer_pool_uninit(&h->ref_index_pool);
        return AVERROR(ENOMEM);
    }

    return 0;
}