const int dst_buf_size = 4 * ((src_buf_size + 2) / 3);
RESERVE_BB_BUFFER(src_buf, src_buf_size + 1);
RESERVE_BB_BUFFER(dst_buf, dst_buf_size + 1);
const int dst_buf_size = 4 * ((src_buf_size + 2) / 3);
RESERVE_BB_BUFFER(src_buf, src_buf_size + 1);
RESERVE_BB_BUFFER(dst_buf, dst_buf_size + 1);