/************************************************************************ * *  ring_buf.c, Buffer functions used for Reference Picture Section Mode. * *  Copyright (C) 1997  University of BC, Canada * *  Contacts:  *  Michael Gallant                   <mikeg@ee.ubc.ca> *  Guy Cote                          <guyc@ee.ubc.ca> *  Berna Erol                        <bernae@ee.ubc.ca> * *  UBC Image Processing Laboratory   http://www.ee.ubc.ca/image *  2356 Main Mall                    tel.: +1 604 822 4051 *  Vancouver BC Canada V6T1Z4        fax.: +1 604 822 5949 * ************************************************************************//* * Disclaimer of Warranty * * These software programs are available to the user without any * license fee or royalty on an "as is" basis. The University of * British Columbia disclaims any and all warranties, whether * express, implied, or statuary, including any implied warranties * or merchantability or of fitness for a particular purpose.  In no * event shall the copyright-holder be liable for any incidental, * punitive, or consequential damages of any kind whatsoever arising * from the use of these programs. * * This disclaimer of warranty extends to the user of these programs * and user's customers, employees, agents, transferees, successors, * and assigns. * * The University of British Columbia does not represent or warrant * that the programs furnished hereunder are free of infringement of * any third-party patents. * * Commercial implementations of H.263, including shareware, are * subject to royalty fees to patent holders.  Many of these patents * are general enough such that they are unavoidable regardless of * implementation design. **/#include "sim.h"#define RING_SIZE 8int   ring_pointer;                           /* pointer to last picture        */PictImage *ring_orig[RING_SIZE] = {NULL};     /* Ring buffers for original and  */PictImage *ring_recon[RING_SIZE] = {NULL};    /* reconstructed images           */int   ring_temporal_reference[RING_SIZE];     /* TR values for the pictures     */int   ring_quality[RING_SIZE];                /* Picture Quality                */  /********************************************************************** * *	Name:         GetReferencePicture *	Description:  gets the requested prediction picture from *                the ring buffer. *	 *	Input:        tr, orig, recon *         *	Returns:      0 *	Side effects:  * *	Date: 980610  Author: Guy Cote <guyc@ece.ubc.ca> * ***********************************************************************/int GetReferencePicture(int tr, PictImage *orig, PictImage *recon){  int i;    for (i = ring_pointer; i != (ring_pointer+1)%RING_SIZE;   i = (i+RING_SIZE-1)%RING_SIZE)   {    if (tr == ring_temporal_reference[i])      break;  }    if (!ring_orig[i]->lum || tr != ring_temporal_reference[i])    return -1;    memcpy(orig->lum, ring_orig[i]->lum, pels*lines);  memcpy(orig->Cr,  ring_orig[i]->Cr,  pels*lines/4);  memcpy(orig->Cb,  ring_orig[i]->Cb,  pels*lines/4);  memcpy(recon->lum,ring_recon[i]->lum, pels*lines);  memcpy(recon->Cr, ring_recon[i]->Cr,  pels*lines/4);  memcpy(recon->Cb, ring_recon[i]->Cb,  pels*lines/4);  return 0;}/********************************************************************** * *	Name:         StorePicture *	Description:  Stores a picture into the ring buffer.                   *	 *	Input:        tr, orig, recon *         *	Returns:      0 *	Side effects:  * *	Date: 980610  Author: Guy Cote <guyc@ece.ubc.ca> * ***********************************************************************/void StorePicture(int tr, PictImage *orig, PictImage *recon){    ring_pointer = (ring_pointer+1)%RING_SIZE;  if (!ring_orig[ring_pointer])   {    ring_orig[ring_pointer] = InitImage(pels*lines);    ring_recon[ring_pointer] = InitImage(pels*lines);  }  memcpy(ring_orig[ring_pointer]->lum,orig->lum,  (sizeof (char))*pels*lines);  memcpy(ring_orig[ring_pointer]->Cr, orig->Cr,   (sizeof (char))*pels*lines/4);  memcpy(ring_orig[ring_pointer]->Cb, orig->Cb,   (sizeof (char))*pels*lines/4);  memcpy(ring_recon[ring_pointer]->lum,recon->lum, (sizeof (char))*pels*lines);  memcpy(ring_recon[ring_pointer]->Cr, recon->Cr,  (sizeof (char))*pels*lines/4);  memcpy(ring_recon[ring_pointer]->Cb, recon->Cb,  (sizeof (char))*pels*lines/4);   ring_temporal_reference[ring_pointer] = tr;}