MPEG2标准的编解码器

/* motion.c, motion estimation */ /* Copyright (C) 1996, MPEG Software Simulation Group. All Rights Reserved. */ /* * Disclaimer of Warranty * * These software programs are available to the user without any license fee or * royalty on an "as is" basis. The MPEG Software Simulation Group 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 MPEG Software Simulation Group does not represent or warrant that the * programs furnished hereunder are free of infringement of any third-party * patents. * * Commercial implementations of MPEG-1 and MPEG-2 video, 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 <stdio.h> #include "config.h" #include "global.h" /* private prototypes */ static void frame_ME _ANSI_ARGS_((unsigned char *oldorg, unsigned char *neworg, unsigned char *oldref, unsigned char *newref, unsigned char *cur, int i, int j, int sxf, int syf, int sxb, int syb, struct mbinfo *mbi)); static void field_ME _ANSI_ARGS_((unsigned char *oldorg, unsigned char *neworg, unsigned char *oldref, unsigned char *newref, unsigned char *cur, unsigned char *curref, int i, int j, int sxf, int syf, int sxb, int syb, struct mbinfo *mbi, int secondfield, int ipflag)); static void frame_estimate _ANSI_ARGS_((unsigned char *org, unsigned char *ref, unsigned char *mb, int i, int j, int sx, int sy, int *iminp, int *jminp, int *imintp, int *jmintp, int *iminbp, int *jminbp, int *dframep, int *dfieldp, int *tselp, int *bselp, int imins[2][2], int jmins[2][2])); static void field_estimate _ANSI_ARGS_((unsigned char *toporg, unsigned char *topref, unsigned char *botorg, unsigned char *botref, unsigned char *mb, int i, int j, int sx, int sy, int ipflag, int *iminp, int *jminp, int *imin8up, int *jmin8up, int *imin8lp, int *jmin8lp, int *dfieldp, int *d8p, int *selp, int *sel8up, int *sel8lp, int *iminsp, int *jminsp, int *dsp)); static void dpframe_estimate _ANSI_ARGS_((unsigned char *ref, unsigned char *mb, int i, int j, int iminf[2][2], int jminf[2][2], int *iminp, int *jminp, int *imindmvp, int *jmindmvp, int *dmcp, int *vmcp)); static void dpfield_estimate _ANSI_ARGS_((unsigned char *topref, unsigned char *botref, unsigned char *mb, int i, int j, int imins, int jmins, int *imindmvp, int *jmindmvp, int *dmcp, int *vmcp)); static int fullsearch _ANSI_ARGS_((unsigned char *org, unsigned char *ref, unsigned char *blk, int lx, int i0, int j0, int sx, int sy, int h, int xmax, int ymax, int *iminp, int *jminp)); static int dist1 _ANSI_ARGS_((unsigned char *blk1, unsigned char *blk2, int lx, int hx, int hy, int h, int distlim)); static int dist2 _ANSI_ARGS_((unsigned char *blk1, unsigned char *blk2, int lx, int hx, int hy, int h)); static int bdist1 _ANSI_ARGS_((unsigned char *pf, unsigned char *pb, unsigned char *p2, int lx, int hxf, int hyf, int hxb, int hyb, int h)); static int bdist2 _ANSI_ARGS_((unsigned char *pf, unsigned char *pb, unsigned char *p2, int lx, int hxf, int hyf, int hxb, int hyb, int h)); static int variance _ANSI_ARGS_((unsigned char *p, int lx)); /* * motion estimation for progressive and interlaced frame pictures * * oldorg: source frame for forward prediction (used for P and B frames) * neworg: source frame for backward prediction (B frames only) * oldref: reconstructed frame for forward prediction (P and B frames) * newref: reconstructed frame for backward prediction (B frames only) * cur: current frame (the one for which the prediction is formed) * sxf,syf: forward search window (frame coordinates) * sxb,syb: backward search window (frame coordinates) * mbi: pointer to macroblock info structure * * results: * mbi-> * mb_type: 0, MB_INTRA, MB_FORWARD, MB_BACKWARD, MB_FORWARD|MB_BACKWARD * MV[][][]: motion vectors (frame format) * mv_field_sel: top/bottom field (for field prediction) * motion_type: MC_FRAME, MC_FIELD * * uses global vars: pict_type, frame_pred_dct */ void motion_estimation(oldorg,neworg,oldref,newref,cur,curref, sxf,syf,sxb,syb,mbi,secondfield,ipflag) unsigned char *oldorg,*neworg,*oldref,*newref,*cur,*curref; int sxf,syf,sxb,syb; struct mbinfo *mbi; int secondfield,ipflag; { int i, j; /* loop through all macroblocks of the picture */ for (j=0; j<height2; j+=16) { for (i=0; i<width; i+=16) { if (pict_struct==FRAME_PICTURE) frame_ME(oldorg,neworg,oldref,newref,cur,i,j,sxf,syf,sxb,syb,mbi); else field_ME(oldorg,neworg,oldref,newref,cur,curref,i,j,sxf,syf,sxb,syb, mbi,secondfield,ipflag); mbi++; } if (!quiet) { putc('.',stderr); fflush(stderr); } } if (!quiet) putc('\n',stderr); } static void frame_ME(oldorg,neworg,oldref,newref,cur,i,j,sxf,syf,sxb,syb,mbi) unsigned char *oldorg,*neworg,*oldref,*newref,*cur; int i,j,sxf,syf,sxb,syb; struct mbinfo *mbi; { int imin,jmin,iminf,jminf,iminr,jminr; int imint,jmint,iminb,jminb; int imintf,jmintf,iminbf,jminbf; int imintr,jmintr,iminbr,jminbr; int var,v0; int dmc,dmcf,dmcr,dmci,vmc,vmcf,vmcr,vmci; int dmcfield,dmcfieldf,dmcfieldr,dmcfieldi; int tsel,bsel,tself,bself,tselr,bselr; unsigned char *mb; int imins[2][2],jmins[2][2]; int imindp,jmindp,imindmv,jmindmv,dmc_dp,vmc_dp; mb = cur + i + width*j; var = variance(mb,width); if (pict_type==I_TYPE) mbi->mb_type = MB_INTRA; else if (pict_type==P_TYPE) { if (frame_pred_dct) { dmc = fullsearch(oldorg,oldref,mb, width,i,j,sxf,syf,16,width,height,&imin,&jmin); vmc = dist2(oldref+(imin>>1)+width*(jmin>>1),mb, width,imin&1,jmin&1,16); mbi->motion_type = MC_FRAME; } else { frame_estimate(oldorg,oldref,mb,i,j,sxf,syf, &imin,&jmin,&imint,&jmint,&iminb,&jminb, &dmc,&dmcfield,&tsel,&bsel,imins,jmins); if (M==1) dpframe_estimate(oldref,mb,i,j>>1,imins,jmins, &imindp,&jmindp,&imindmv,&jmindmv,&dmc_dp,&vmc_dp); /* select between dual prime, frame and field prediction */ if (M==1 && dmc_dp<dmc && dmc_dp<dmcfield) { mbi->motion_type = MC_DMV; dmc = dmc_dp; vmc = vmc_dp; } else if (dmc<=dmcfield) { mbi->motion_type = MC_FRAME; vmc = dist2(oldref+(imin>>1)+width*(jmin>>1),mb, width,imin&1,jmin&1,16); } else { mbi->motion_type = MC_FIELD; dmc = dmcfield; vmc = dist2(oldref+(tsel?width:0)+(imint>>1)+(width<<1)*(jmint>>1), mb,width<<1,imint&1,jmint&1,8); vmc+= dist2(oldref+(bsel?width:0)+(iminb>>1)+(width<<1)*(jminb>>1), mb+width,width<<1,iminb&1,jminb&1,8); } } /* select between intra or non-intra coding: * * selection is based on intra block variance (var) vs. * prediction error variance (vmc) * * blocks with small prediction error are always coded non-intra * even if variance is smaller (is this reasonable?) */ if (vmc>var && vmc>=9*256) mbi->mb_type = MB_INTRA; else { /* select between MC / No-MC * * use No-MC if var(No-MC) <= 1.25*var(MC) * (i.e slightly biased towards No-MC) * * blocks with small prediction error are always coded as No-MC * (requires no mot