implement QuickTime; include "sys.m"; sys: Sys; include "quicktime.m"; init(){	sys = load Sys Sys->PATH;} open(file: string): (ref QD, string){	fd := sys->open(file, sys->OREAD);	if(fd == nil)		return (nil, "open failed"); 	r := ref QD;	r.fd = fd;	r.buf = array[DEFBUF] of byte; 	(hdr, l) := r.atomhdr();	if(hdr != "mdat")		return (nil, "not a QuickTime movie file"); 	#	# We are expecting a unified file with .data then .rsrc	#	r.skipatom(l); 	return (r, nil);} QD.atomhdr(r: self ref QD): (string, int){	b := array[8] of byte; 	if(r.readn(b, 8) != 8)		return (nil, -1); for(i := 0; i < 8; i++)sys->print("%.2ux ", int b[i]);sys->print(" %s %d\n", string b[4:8], bedword(b, 0)); 	return (string b[4:8], bedword(b, 0));} QD.skipatom(r: self ref QD, l: int): int{	return r.skip(l - AtomHDR);} QD.mvhd(q: self ref QD, l: int): string{	l -= AtomHDR;	if(l != MvhdrSIZE)		return "mvhd atom funny size"; 	b := array[l] of byte;	if(q.readn(b, l) != l)		return "short read in mvhd"; 	mvhdr := ref Mvhdr; 	mvhdr.version = bedword(b, 0);	mvhdr.create = bedword(b, 4);	mvhdr.modtime = bedword(b, 8);	mvhdr.timescale = bedword(b, 12);	mvhdr.duration = bedword(b, 16);	mvhdr.rate = bedword(b, 20);	mvhdr.vol = beword(b, 24);	mvhdr.r1 = bedword(b, 26);	mvhdr.r2 = bedword(b, 30); 	mvhdr.matrix = array[9] of int;	for(i :=0; i<9; i++)		mvhdr.matrix[i] = bedword(b, 34+i*4); 	mvhdr.r3 = beword(b, 70);	mvhdr.r4 = bedword(b, 72);	mvhdr.pvtime = bedword(b, 76);	mvhdr.posttime = bedword(b, 80);	mvhdr.seltime = bedword(b, 84);	mvhdr.seldurat = bedword(b, 88);	mvhdr.curtime = bedword(b, 92);	mvhdr.nxttkid = bedword(b, 96); 	q.mvhdr = mvhdr;	return nil;} QD.trak(q: self ref QD, l: int): string{	(tk, tkl) := q.atomhdr();	if(tk != "tkhd")		return "missing track header atom"; 	l -= tkl;	tkl -= AtomHDR;	b := array[tkl] of byte;	if(q.readn(b, tkl) != tkl)		return "short read in tkhd"; 	tkhdr := ref Tkhdr; 	tkhdr.version =	bedword(b, 0);	tkhdr.creation = bedword(b, 4);	tkhdr.modtime =	bedword(b, 8);	tkhdr.trackid =	bedword(b, 12);	tkhdr.timescale = bedword(b, 16);	tkhdr.duration = bedword(b, 20);	tkhdr.timeoff = bedword(b, 24);	tkhdr.priority = bedword(b, 28);	tkhdr.layer = beword(b, 32);	tkhdr.altgrp = beword(b, 34);	tkhdr.volume = beword(b, 36); 	tkhdr.matrix = array[9] of int;	for(i := 0; i < 9; i++)		tkhdr.matrix[i] = bedword(b, 38+i*4); 	tkhdr.width = bedword(b, 74);	tkhdr.height = bedword(b, 78); 	(md, mdl) := q.atomhdr();	if(md != "mdia")		return "missing media atom"; 	while(mdl != AtomHDR) {		(atom, atoml) := q.atomhdr();sys->print("\t%s %d\n", atom, atoml);		q.skipatom(atoml); 		mdl -= atoml;	} 	return nil;} QD.readn(r: self ref QD, b: array of byte, l: int): int{	if(r.nbyte < l) {		c := 0;		if(r.nbyte != 0) {			b[0:] = r.buf[r.ptr:];			l -= r.nbyte;			c += r.nbyte;			b = b[r.nbyte:];		}		bsize := len r.buf;		while(l != 0) {			r.nbyte = sys->read(r.fd, r.buf, bsize);			if(r.nbyte <= 0) {				r.nbyte = 0;				return -1;			}			n := l;			if(n > bsize)				n = bsize; 			r.ptr = 0;			b[0:] = r.buf[0:n];			b = b[n:];			r.nbyte -= n;			r.ptr += n;			l -= n;			c += n;		}		return c;	}	b[0:] = r.buf[r.ptr:r.ptr+l];	r.nbyte -= l;	r.ptr += l;	return l;} QD.skip(r: self ref QD, size: int): int{	if(r.nbyte != 0) {		n := size;		if(n > r.nbyte)			n = r.nbyte;		r.ptr += n;		r.nbyte -= n;		size -= n;		if(size == 0)			return 0;	}	return int sys->seek(r.fd, big size, sys->SEEKRELA);} beword(b: array of byte, o: int): int{	return 	(int b[o] << 8) | int b[o+1];} bedword(b: array of byte, o: int): int{	return	(int b[o] << 24) |		(int b[o+1] << 16) |		(int b[o+2] << 8) |		int b[o+3];}