#include <u.h>#include <libc.h>#include "stream.h" extern Streamops ivfops, mcops, audops; static struct {	char *name;	Streamops *o;}ops[] = {	{"ivf", &ivfops},	{"mc", &mcops},	{"audio", &audops},}; Stream *Sopen(char *filename, int *num){	int i, failed;	Stream *s;	char *f; 	*num = 0;	for(i = 0; i < nelem(ops); i++){		failed = 0;		if((s = ops[i].o->open(filename, num, &failed)) != nil){			f = utfrrune(filename, '/');			if(f == nil)				f = filename;			else				f++;			snprint(s->info, sizeof(s->info), "%s [%s]", ops[i].name, f);			s->t₀ = Zt₀;			return s;		}		if(failed){			werrstr("%s: %r", ops[i].name);			return nil;		}	} 	werrstr("unknown format"); 	return nil;} voidSclose(Stream *s){	if(s == nil || s->type < 0)		return;	s->ops.close(s);	s->type = -1;	if(s->freeaux != nil)		s->freeaux(s->aux);} intSread(Stream *s, Streamframe *f){	int res; 	if(s == nil || s->type < 0){		werrstr("invalid stream");		return -1;	}	if((res = s->ops.read(s, f)) == 0){		if(s->t₀ == Zt₀)			s->t₀ = f->timestamp;		/*		 * timestamps going backwards means clock wasn't monotonically		 * increasing. perhaps nanosec() or nsec() is to blame.		 * just work around it in any case, instead of hanging without		 * displaying any frames.		 */		if(f->timestamp > s->t₀)			f->timestamp -= s->t₀;		else			f->timestamp = 0;	} 	return res;}