ref: 7a252eea673a83b82783aac3d3bcc53193c470cf
dir: /snd.c/
#include <u.h> #include <libc.h> #include <stdio.h> #include <thread.h> #include "quakedef.h" enum{ Nbuf = 8 }; static int afd; static int sndon; static uint wpos; static Channel *schan; static QLock sndlock; static void sproc(void *) { int n, sz; threadsetgrp(THsnd); for(;;){ if(recv(schan, nil) < 0) break; sz = shm->samplebits/8 * shm->samples; if((n = write(afd, shm->buffer, sz)) != sz) break; qlock(&sndlock); wpos += n; qunlock(&sndlock); } fprint(2, "sproc %d: %r\n", threadpid(threadid())); } qboolean SNDDMA_Init(void) { int i; sndon = 0; if((afd = open("/dev/audio", OWRITE)) < 0){ fprint(2, "open: %r\n"); return 0; } shm = &sn; shm->splitbuffer = 0; if((i = COM_CheckParm("-sndbits")) != 0) shm->samplebits = atoi(com_argv[i+1]); if(shm->samplebits != 16 && shm->samplebits != 8) shm->samplebits = 16; if((i = COM_CheckParm("-sndspeed")) != 0) shm->speed = atoi(com_argv[i+1]); else shm->speed = 44100; shm->channels = 2; if(COM_CheckParm("-sndmono") != 0) shm->channels = 1; shm->samples = 4096; shm->submission_chunk = 1; if((shm->buffer = mallocz(shm->samplebits/8 * shm->samples, 1)) == nil) sysfatal("SNDDMA_Init:mallocz: %r\n"); shm->samplepos = 0; sndon = 1; wpos = 0; if((schan = chancreate(sizeof(int), Nbuf)) == nil) sysfatal("SNDDMA_Init:chancreate: %r"); if(proccreate(sproc, nil, 8192) < 0) sysfatal("SNDDMA_Init:proccreate: %r"); return 1; } uint SNDDMA_GetDMAPos(void) { if(!sndon) return 0; qlock(&sndlock); shm->samplepos = wpos / (shm->samplebits/8); qunlock(&sndlock); return shm->samplepos; } void SNDDMA_Shutdown(void) { if(!sndon) return; threadkillgrp(THsnd); close(afd); free(shm->buffer); if(schan != nil){ chanfree(schan); schan = nil; } sndon = 0; } void SNDDMA_Submit(void) { if(nbsend(schan, nil) < 0){ fprint(2, "SNDDMA_Submit:nbsend: %r\n"); SNDDMA_Shutdown(); } }