自学教程：C++ AV函数代码示例

static B jtspsscell(J jt,A w,I wf,I wcr,A*zc,A*zt){A c,t,y;B b;     I cn,*cv,j,k,m,n,p,*s,tn,*tv,*u,*u0,*v,*v0;P*wp; wp=PAV(w); s=AS(w); p=3+s[wf]; y=SPA(wp,i); s=AS(y); m=s[0]; n=s[1]; u0=AV(y); u=u0+n;  v0=u0+wf; v=v0+n; if(!m){*zt=*zc=mtv; R 1;} GATV(t,INT,2+2*m,1,0); tv=AV(t); tv[0]=tv[1]=0; tn=2; GATV(c,INT,  2*m,2,0); cv=AV(c); cv[0]=0;       cn=0; *(1+AS(c))=2; for(j=1;j<m;++j){  b=1;  for(k=0;k<wf;++k)   if(u0[k]!=u[k]){    tv[tn++]=j; tv[tn++]=j; cv[1+cn]=tn-cv[cn];    if(p==tn-cv[cn]){++cv[cn]; cv[1+cn]-=2;}     cn+=2;    cv[cn]=tn-2; u0=u; v0=v; b=0;    break;   }  if(b&&*v0!=*v){tv[tn++]=j; v0=v;}  u+=n; v+=n; } tv[tn++]=m; tv[tn++]=m; cv[1+cn]=tn-cv[cn]; if(p==tn-cv[cn]){++cv[cn]; cv[1+cn]-=2;} cn+=2; AN(t)=    *AS(t)=tn;   *zt=t;  /* cell divisions (row indices in y)            */ AN(c)=cn; *AS(c)=cn/2; *zc=c;  /* item divisions (indices in t, # of elements) */ R 1;}    /* frame: all sparse; cell: 1 or more sparse, then dense */

static REPF(jtrepzsx) {    A q,x,y;    I c,d,j,k=-1,m,p=0,*qv,*xv,*yv;    P*ap;    RZ(a&&w);    ap=PAV(a);    x=SPA(ap,x);    m=AN(x);    if(!AN(SPA(ap,a)))R repzdx(ravel(x),w,wf,wcr);    y=SPA(ap,i);    yv=AV(y);    RZ(x=cvt(INT,vec(FL,2*m,AV(x))));    xv=AV(x);    if(equ(zero,SPA(ap,e))) {        k=c=*(wf+AS(w));        if(!wf&&SPARSE&AT(w)) {            A a,y;            I m,n,q,*v;            P*wp;            wp=PAV(w);            a=SPA(wp,a);            if(AN(a)&&!*AV(a)) {                y=SPA(wp,i);                v=AS(y);                m=v[0];                n=v[1];                v=AV(y);                k=m?v[(m-1)*n]+1:0;                q=0;                DO(m, if(q==*v)++q; else if(q<*v) {                    k=q;                    break;                }            v+=n;);            }

static F2(jtpdtspmv){A ax,b,g,x,wx,y,yi,yj,z;B*bv;I m,n,s[2],*u,*v,*yv;P*ap,*wp,*zp; RZ(a&&w); ap=PAV(a); y=SPA(ap,i); yv=AV(y); s[0]=n=*AS(y); s[1]=1; GATV(yj,INT,n,2,s); if(DENSE&AT(w)){  GATV(yi,INT,n,2,s); u=AV(yi); AR(yj)=1; v=AV(yj);  DO(n, *u++=*yv++; *v++=*yv++;);

AFFENDAFFDEF(arc_tell){  AARG(fp);  AFBEGIN;  AFTCALL(VINDEX(IO(AV(fp))->io_ops, IO_tell), AV(fp));  AFEND;}

static B jtixin(J jt,A w,I s,I*i,I*n){A in,*wv;I j,k,m,*u,wd; if(AT(w)&BOX){wv=AAV(w); wd=(I)w*ARELATIVE(w); RZ(in=vi(WVR(1))); k=AN(in); u=AV(in);} else{in=w; k=AN(in)-1; u=1+AV(in);} ASSERT(1>=AR(in),EVRANK); ASSERT(k&&k<=(n?2:1),EVLENGTH); j=u[0]; j=0>j?s+j:j; m=1==k?s-j:u[1]; ASSERT(0<=j&&(!n||j<s&&j+m<=s&&0<=m),EVINDEX); *i=j; if(n)*n=m; R 1;}    /* process index file arg for index and length */

F1(bool){A b,h;I j,*v; RZ(w); if(VERB&AT(w))R ADERIV(CBOOL, basis1,0L, 0L,0L,0L); RZ(w=vi(w)); v=AV(w); DO(AN(w), j=*v++; ASSERT(-16<=j&&j<16,EVINDEX)); GA(b,BOOL,64,2,0); *AS(b)=16; *(1+AS(b))=4; MC(AV(b),booltab,64L); RZ(h=cant2(apv(AR(w),0L,1L),from(w,b))); R fdef(CBOOL,VERB, bool1,bool2, w,0L,h, 0L, RMAXL,0L,0L);}

static AFFDEF(clos_pprint){  AARG(sexpr, disp, fp);  AOARG(visithash);  AFBEGIN;  AFTCALL(arc_mkaff(c, __arc_disp_write, CNIL), CLOS_CODE(AV(sexpr)),	  AV(disp), AV(fp), AV(visithash));  AFEND;}

static AFFDEF(symbol_pprint){  AARG(sexpr, disp, fp);  AOARG(visithash);  AFBEGIN;  (void)visithash;  (void)disp;  AFTCALL(arc_mkaff(c, arc_disp, CNIL), arc_sym2name(c, AV(sexpr)), AV(fp));  AFEND;}

AFFENDstatic AFFDEF(fio_seek){  AARG(fio, offset, whence);  AFBEGIN;  if (!(FIX2INT(AV(whence)) == SEEK_SET || FIX2INT(AV(whence)) == SEEK_CUR ||	FIX2INT(AV(whence)) == SEEK_END)) {    arc_err_cstrfmt(c, "invalid seek whence argument");    ARETURN(CNIL);  }#ifdef HAVE_FSEEKO  {    long long noff;    if (__arc_val2ll(c, AV(offset), &noff)) {      ARETURN(INT2FIX(fseeko(FIODATA(AV(fio))->fp, (off_t)noff, FIX2INT(AV(whence)))));    } else {      arc_err_cstrfmt(c, "invalid seek offset");    }  }#else  {    long noff;    if (__arc_val2long(c, AV(offset), &noff)) {      ARETURN(INT2FIX(fseek(FIODATA(AV(fio))->fp, noff, FIX2INT(AV(whence)))));    } else {      arc_err_cstrfmt(c, "invalid seek offset");    }  }#endif  AFEND;}

B jtsymext(J jt,B b){A x,y;I j,m,n,s[2],*v,xn,yn;L*u; if(b){y=jt->symp; j=((MS*)y-1)->j; n=*AS(y); yn=AN(y);} else {            j=12;            n=1;      yn=0;    } m=msize[1+j];                              /* new size in bytes           */ m-=sizeof(MS)+SZI*(AH+2);                  /* less array overhead         */ m/=symcol*SZI;                             /* new # rows                  */ s[0]=m; s[1]=symcol; xn=m*symcol;          /* new pool array shape        */ GA(x,INT,xn,2,s); v=AV(x);                 /* new pool array              */ if(b)ICPY(v,AV(y),yn);                     /* copy old data to new array  */ memset(v+yn,C0,SZI*(xn-yn));               /* 0 unused area for safety    */ u=n+(L*)v; j=1+n; DO(m-n-1, u++->next=j++;);                 /* build free list extension   */

AFFENDstatic AFFDEF(xhash_apply){  AARG(tbl, key, dflt);  AFBEGIN;  AFCALL(arc_mkaff(c, arc_xhash_lookup, CNIL), AV(tbl), AV(key));  if (BOUND_P(AFCRV))    ARETURN(AFCRV);  ARETURN(AV(dflt));  AFEND;}

pj_status_t pjmedia_format_id_to_PixelFormat(pjmedia_format_id fmt_id,					     enum AVPixelFormat *pixel_format){    unsigned i;    for (i=0; i<PJ_ARRAY_SIZE(ffmpeg_fmt_table); ++i) {	const struct ffmpeg_fmt_table_t *t = &ffmpeg_fmt_table[i];	if (t->id==fmt_id && t->pf != AV(PIX_FMT_NONE)) {	    *pixel_format = t->pf;	    return PJ_SUCCESS;	}    }    *pixel_format = AV(PIX_FMT_NONE);    return PJ_ENOTFOUND;}

pj_status_t pjmedia_format_id_to_CodecID(pjmedia_format_id fmt_id,					 unsigned *codec_id){    unsigned i;    for (i=0; i<PJ_ARRAY_SIZE(ffmpeg_codec_table); ++i) {	const struct ffmpeg_codec_table_t *t = &ffmpeg_codec_table[i];	if (t->id==fmt_id && t->codec_id != AV(PIX_FMT_NONE)) {	    *codec_id = t->codec_id;	    return PJ_SUCCESS;	}    }    *codec_id = (unsigned)AV(PIX_FMT_NONE);    return PJ_ENOTFOUND;}

static DF1(case1){A u;V*sv; PREF1(case1); sv=VAV(self); RZ(u=from(df1(w,sv->g),sv->h)); ASSERT(!AR(u),EVRANK); R df1(w,*AV(u));}

static F1(jtvtokens){A t,*y,z;I n,*s;TA*x; RZ(t=tokens(vs(w))); n=AN(t); y=AAV(t); jt->tmonad=1;  GA(z,BOX,WTA*(5+n),2,0); s=AS(z); *s++=5+n; *s=WTA; x=(TA*)AV(z); x->a=mark; x->t=0; ++x; DO(n, x->a=t=*y++; x->t=0; ++x; if(t==xnam||jt->dotnames&&t==xdot)jt->tmonad=0;);

static A jtmerge1(J jt,A w,A ind){A z;B*b;C*wc,*zc;D*wd,*zd;I c,it,j,k,m,r,*s,t,*u,*wi,*zi; RZ(w&&ind); r=MAX(0,AR(w)-1); s=1+AS(w); t=AT(w); k=bp(t); m=IC(w); c=aii(w); ASSERT(!(t&SPARSE),EVNONCE); ASSERT(r==AR(ind),EVRANK); ASSERT(!ICMP(s,AS(ind),r),EVLENGTH); GA(z,t,c,r,s); if(!(AT(ind)&B01+INT))RZ(ind=cvt(INT,ind)); it=AT(ind); u=AV(ind); b=(B*)u; ASSERT(!c||1<m||!(it&B01),EVINDEX); ASSERT(!c||1!=m||!memchr(b,C1,c),EVINDEX); zi=AV(z); zc=(C*)zi; zd=(D*)zc; wi=AV(w); wc=(C*)wi; wd=(D*)wc; switch(MCASE(it,k)){  case MCASE(B01,sizeof(C)): DO(c,         *zc++=wc[*b++?i+c:i];); break;  case MCASE(B01,sizeof(I)): DO(c,         *zi++=wi[*b++?i+c:i];); break;

static DF2(case2){A u;V*sv; PREF2(case2); sv=VAV(self); RZ(u=from(df2(a,w,sv->g),sv->h)); ASSERT(!AR(u),EVRANK); R df2(a,w,*AV(u));}

static void jsig(void){ tostdout=1; suspend=1; if(debugb&&!spc()){  dhead(); jputs("ws full (can not debug suspend)"); jputc(CNL);  debugb=0; } dhead(); jputs(AV(*(jerr+AAV(qevm)))); jputc(CNL);}

static A jtcants(J jt,A a,A w,A z){A a1,q,y;B*b,*c;I*u,wr,zr;P*wp,*zp; RZ(a&&w&&z); RZ(a=grade1(a)); wr=AR(w); wp=PAV(w); a1=SPA(wp,a); zr=AR(z); zp=PAV(z); ASSERT(wr==zr,EVNONCE); RZ(b=bfi(wr,a1,1)); GA(q,B01,wr,1,0); c=BAV(q); u=AV(a); DO(wr, c[i]=b[u[i]];);

static A jtvaspc(J jt,A a,A w,C id,VF ado,I cv,I t,I zt,I af,I acr,I wf,I wcr,I f,I r){A q;I*as,*v,*ws; as=AS(a); ws=AS(w); GA(q,INT,f+r,1,0); v=AV(q); if(r>acr){ICPY(v,wf+ws,r); RZ(a=irs2(vec(INT,r-acr,acr+v),a,0L,1L,0L,jtreshape));} if(r>wcr){ICPY(v,af+as,r); RZ(w=irs2(vec(INT,r-wcr,wcr+v),w,0L,1L,0L,jtreshape));} R vasp(a,w,id,ado,cv,t,zt,af,r,wf,r,f,r);}    /* prefix agreement on cells */