/*
 * Copyright 2005 by the Massachusetts Institute of Technology.
 *
 * Permission to use, copy, modify, and distribute this
 * software and its documentation for any purpose and without
 * fee is hereby granted, provided that the above copyright
 * notice appear in all copies and that both that copyright
 * notice and this permission notice appear in supporting
 * documentation, and that the name of M.I.T. not be used in
 * advertising or publicity pertaining to distribution of the
 * software without specific, written prior permission.
 * M.I.T. makes no representations about the suitability of
 * this software for any purpose.  It is provided "as is"
 * without express or implied warranty.
 */

/**
 * @description
 * This file contains functions that allow one to decode MPEG-2 compliant video. 
 * The code is based on the MPEG-2 specification (ISO/IEC 13818-2). The MPEG-2 decoding
 * is a work in progress, although it works within a limited test range. Throughout the 
 * source code, citations are made in cases where an understanding of the code would be
 * helped by looking at an outside source. The format I have chosen is 
 * (cite NUM#, LOOKUP_INFO). NUM=1 refers to ISO/IEC: 13818-2, and NUM=2 refers to the reference
 * MPEG implementation written in C, available at [www.mpeg.org].
 *
 * @author <a href="mailto:madrake@gmail.com">Matthew Drake</a>
 * @file PictureReorder.str
 * @version 1.0
 */

/**
 * @internal
 */
int->int filter PictureReorder(int width, int height) {
    int datarate = (width*height*3);
    int[(width*height*3)] databuffer;
    int next_picture_type;

    prework pop datarate {
        for (int i = 0; i < datarate; i++) {
            databuffer[i] = pop();
        }
    }

    work pop datarate push datarate {
        if (next_picture_type == 3) {
            for (int i = 0; i < datarate; i++) {
                push(pop());
            }
        } else {
            for (int i = 0; i < datarate; i++) {
                push(databuffer[i]);
                databuffer[i] = pop();
            }
        }     
    }

    handler setPictureType(int picture_coding_type) {
        next_picture_type = picture_coding_type;
    }
}