ref: dcb29f7e9714e539ce32f0aa06287471c349892f
dir: /libnpe_sdl2/audio.c/
#include "_sdl.h" enum { Aout = 2, Arec, Audiosamples = 8192, }; typedef struct Audiodev Audiodev; struct Audiodev { Lock; void (*cb)(void *, Uint8 *, int); void *userdata; char *name; Channel *wait; Uint8 *buf; int bufsz; int paused; int fd; int pid; int pidconv; int mode; }; /* FIXME extra USB audio devices? */ static Audiodev au[4] = { [0] = {.fd = -1, .mode = -1}, [1] = {.fd = -1, .mode = -1}, [Aout] = {.name = "/dev/audio", .fd = -1, .pid = -1, .mode = OWRITE}, [Arec] = {.name = "/dev/audio", .fd = -1, .pid = -1, .mode = OREAD}, }; static struct { char *spec; int ssz; /* samples size */ }fmts[AUDIO_NUM_FORMATS] = { [AUDIO_U8] = {"u8", 1}, [AUDIO_S8] = {"s8", 1}, [AUDIO_U16LSB] = {"u16", 2}, [AUDIO_S16LSB] = {"s16", 2}, [AUDIO_U16MSB] = {"U16", 2}, [AUDIO_S16MSB] = {"S16", 2}, [AUDIO_S32LSB] = {"s32", 4}, [AUDIO_S32MSB] = {"S32", 4}, [AUDIO_F32LSB] = {"f32", 4}, [AUDIO_F32MSB] = {"F32", -1}, /* FIXME big endian f32 not supported by pcmconv */ }; int SDL_GetNumAudioDevices(int iscapture) { /* FIXME look for extra USB devices? */ USED(iscapture); return 1; } char * SDL_GetAudioDeviceName(int index, int iscapture) { /* FIXME look for extra USB devices? */ USED(index); return au[iscapture ? Arec : Aout].name; } void SDL_LockAudioDevice(SDL_AudioDeviceID id) { lock(&au[id]); } void SDL_UnlockAudioDevice(SDL_AudioDeviceID id) { unlock(&au[id]); } static void audiothread(void *p) { Audiodev *a; a = p; threadsetname("%s (%s)", a->name, a->mode == OREAD ? "out" : "in"); for(;;){ if(a->mode == OREAD && readn(a->fd, a->buf, a->bufsz) != a->bufsz) break; lock(a); if(a->mode == OWRITE && a->paused) memset(a->buf, 0, a->bufsz); else a->cb(a->userdata, a->buf, a->bufsz); unlock(a); if(a->mode == OWRITE && write(a->fd, a->buf, a->bufsz) != a->bufsz) break; } lock(a); (a->mode == OWRITE ? write : read)(a->fd, a->buf, 0); chanclose(a->wait); unlock(a); threadexits(nil); } void SDL_PauseAudioDevice(SDL_AudioDeviceID id, SDL_bool pause) { Audiodev *a; a = &au[id]; if(a->paused && !pause){ if(a->pid < 0) a->pid = proccreate(audiothread, a, 4096); a->paused = 0; }else if(!a->paused && pause){ a->paused = 1; } } static int convspec(SDL_AudioSpec *s, char *spec, int n) { int ssz; ssz = -1; if(s->format < 0 || s->format >= nelem(fmts)) werrstr("invalid audio format: #%d", s->format); else if(fmts[s->format].ssz < 1) werrstr("unsupported audio format: #%d", s->format); else if(s->channels < 1) werrstr("invalid number of channels: %d", s->channels); else if(s->freq < 1) werrstr("invalid sampling rate: %d", s->freq); else if(snprint(spec, n, "%sc%dr%d", fmts[s->format].spec, s->channels, s->freq) >= n) werrstr("audio spec does not fit"); else ssz = fmts[s->format].ssz; return ssz; } SDL_AudioDeviceID SDL_OpenAudioDevice(char *dev, int rec, SDL_AudioSpec *want, SDL_AudioSpec *have, u32int change) { SDL_AudioDeviceID id; int p[2], ssz, fd; char spec[16]; Audiodev *a; /* FIXME look for extra USB devices? */ USED(dev); id = rec ? Arec : Aout; a = &au[id]; if(have == nil) have = want; *have = *want; if(have->freq < 44100 && (change & SDL_AUDIO_ALLOW_FREQUENCY_CHANGE) != 0) have->freq = 44100; if(have->format <= 0 || have->format >= nelem(fmts) || fmts[have->format].ssz < 1 && (change & SDL_AUDIO_ALLOW_FORMAT_CHANGE) != 0) have->format = AUDIO_S16; if(have->channels < 1 && (change & SDL_AUDIO_ALLOW_CHANNELS_CHANGE) != 0) have->channels = 2; if(have->samples < 2 || (have->samples & (have->samples-1)) != 0){ if(change & SDL_AUDIO_ALLOW_SAMPLES_CHANGE) have->samples = Audiosamples; else{ werrstr("invalid number of samples: %d", have->samples); goto err; } } if((ssz = convspec(have, spec, sizeof(spec))) < 1) goto err; a->userdata = have->userdata; a->cb = have->callback; a->wait = chancreate(sizeof(ulong), 0); a->bufsz = have->samples * ssz * have->channels; a->buf = malloc(a->bufsz); if(a->wait == nil || a->buf == nil){ werrstr("memory"); goto err; } a->paused = 1; a->pid = -1; a->pidconv = -1; if(have->freq != 44100 || have->format != AUDIO_S16 || have->channels != 2){ if((fd = open(a->name, a->mode)) < 0) goto err; pipe(p); if((a->pidconv = rfork(RFPROC|RFNOTEG|RFFDG|RFCENVG)) == 0){ dup(fd, rec ? 0 : 1); close(fd); dup(p[0], rec ? 1 : 0); close(p[0]); close(p[1]); //close(2); if(execl("/bin/audio/pcmconv", "pcmconv", rec ? "-o" : "-i", spec, nil) != 0) exits("%r"); }else if(a->pidconv < 0){ werrstr("pcmconv: %r"); close(fd); goto err; } a->fd = p[1]; close(p[0]); close(fd); }else if(a->fd < 0 && (a->fd = open("/dev/audio", a->mode|OCEXEC)) < 0) goto err; return id; err: werrstr("SDL_OpenAudioDevice: %r"); if(a->fd >= 0){ close(a->fd); a->fd = -1; } free(a->buf); a->buf = nil; if(a->wait != nil){ chanfree(a->wait); a->wait = nil; } return 0; } void SDL_CloseAudioDevice(SDL_AudioDeviceID id) { Audiodev *a; Waitmsg *w; int pid; a = &au[id]; if(a->fd < 0) return; lock(a); close(a->fd); unlock(a); if(a->pid >= 0) recvul(a->wait); chanfree(a->wait); free(a->buf); a->fd = -1; a->pid = -1; again: if(a->pidconv >= 0 && (w = wait()) != nil){ if(w->msg[0]) fprint(2, "SDL_CloseAudioDevice: %s: %s\n", a->name, w->msg); pid = w->pid; free(w); if(pid != a->pidconv) goto again; } }