rand_seed = *(int*)input_buffer_ptr;
moving_input_ptr = (BYTE*)((int*)input_buffer_ptr + 1);

RAM: .... [8bit][8bit][8bit][8bit][8bit][8bit][8bit][8bit][8bit][8bit] ....

.... [8bit][8bit][8bit][8bit][8bit][8bit][8bit][8bit][8bit][8bit] ....
           ^
      input_buffer_ptr

(int*)input_buffer_ptr; // casts this pointer to int*,
     //so now you treat data under this pointer as 4 bytes integer

*(int*)input_buffer_ptr; // operator * before pointer gets data under
          //that pointer, in this case, integer (4 bytes).

.... [8bit][8bit][8bit][8bit][8bit][8bit][8bit][8bit][8bit][8bit] ....
           |      random_seed     |

(int*)input_buffer_ptr + 1
//    ^                     ^
// casting to int*      moving pointer to size of int (4 bytes)

.... [8bit][8bit][8bit][8bit][8bit][8bit][8bit][8bit][8bit][8bit] ....
                                   ^
                         ((int*)input_buffer_ptr + 1)

(BYTE*)((int*)input_buffer_ptr + 1);
// ^
// casting pointer to BYTE*, so it points to the same place
// but now treated as one byte pointer.

*(BYTE*)((int*)input_buffer_ptr + 1);

.... [8bit][8bit][8bit][8bit][8bit][8bit][8bit][8bit][8bit][8bit] ....
                                   |    |
                                     ^
                      *(BYTE*)((int*)input_buffer_ptr + 1)