ref: bce6ff4b8b16c32cbfced092983823acf3c7deb1
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);
setfcr(FPPDBL|FPRNR|FPINVAL|FPZDIV|FPOVFL);
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;
}
}