ref: be9670c51e39ac12eb42dabb0ff30831f0d47401
dir: /dec.c/
#include <u.h> #include <libc.h> #include <thread.h> #include <draw.h> #include "dat.h" #include "fncs.h" /* Proc argument structs */ typedef struct { int outpipe; char *file; Channel *cpid; } Decodearg; typedef struct { int inpipe; Channel *ctl; } Writearg; void decodeproc(void *arg) { Decodearg *a = arg; int nfd; nfd = open("/dev/null", OREAD|OWRITE); dup(nfd, 0); dup(nfd, 2); dup(a->outpipe, 1); close(nfd); close(a->outpipe); procexecl(a->cpid, "/bin/play", "play", "-o", "/fd/1", a->file, nil); } void writethread(void *arg) { int afd; int bufsize; int n; enum cmsg msg; char *buf; Writearg *a = arg; Channel *c = a->ctl; int inpipe = a->inpipe; afd = open("/dev/audio", OWRITE); if(afd < 0) sysfatal("could not open audio device"); bufsize = iounit(afd); /* * On native plan9 installs this will return 0, * so we default to the default iosize. */ if(bufsize == 0) bufsize = 8192; buf = emalloc(bufsize); for(;;){ if(nbrecv(c, &msg) != 0) switch(msg){ case STOP: free(buf); close(afd); threadexits(nil); break; case PAUSE: /* Block until we get a START message */ while(msg != START) recv(c, &msg); break; } n = read(inpipe, buf, bufsize); write(afd, buf, n); yield(); } } enum{ QUEUE, CTL, WAIT, }; void ctlproc(void *arg) { Channel **chans = arg; Channel *q = chans[0]; Channel *c = chans[1]; Channel *pop = chans[2]; Channel *w = threadwaitchan(); free(chans); char *path; enum cmsg msg; Waitmsg *wmsg; Decodearg a; Writearg wr; int p[2]; /* This allows for the main thread to kill the decoder on exit */ extern int decpid = -1; Alt alts[] = { {q, &path, CHANRCV}, {c, &msg, CHANRCV}, {w, &wmsg, CHANRCV}, {nil, nil, CHANEND}, }; pipe(p); a.cpid = chancreate(sizeof(int), 0); a.outpipe = p[0]; wr.ctl = chancreate(sizeof(enum cmsg), 0); wr.inpipe = p[1]; /* Start first song to stop blocks on writethread read */ a.file = recvp(q); procrfork(decodeproc, &a, 8192, RFFDG); recv(a.cpid, &decpid); threadcreate(writethread, &wr, 8192); for(;;){ switch(alt(alts)){ case WAIT: if(strstr(wmsg->msg, "eof")){ decpid = -1; send(pop, nil); } free(wmsg); break; case CTL: if(msg == NEXT){ killgrp(decpid); decpid = -1; send(pop, nil); }else send(wr.ctl, &msg); break; case QUEUE: a.file = path; if(decpid != -1) killgrp(decpid); procrfork(decodeproc, &a, 8192, RFFDG); recv(a.cpid, &decpid); break; default: goto cleanup; } } cleanup: if(decpid != -1) killgrp(decpid); chanfree(wr.ctl); chanfree(a.cpid); close(p[0]); close(p[1]); } /* * Spawns the decoder processes. * q is a queue for next songs. chan char* * c is for sending control messages. chan enum cmsg * nil msg is sent over pop on song change. */ void spawndec(Channel **q, Channel **c, Channel **pop) { Channel **chans = emalloc(sizeof(Channel*) * 3); if(*q == nil) *q = chancreate(sizeof(char*), 0); if(*c == nil) *c = chancreate(sizeof(enum cmsg), 0); if(*pop == nil) *pop = chancreate(sizeof(char), 0); chans[0] = *q; chans[1] = *c; chans[2] = *pop; procrfork(ctlproc, chans, 8192, RFFDG); }