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PCM SUBDEVICE selection enhancements

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This commit is contained in:
Jaroslav Kysela 1999-08-22 13:34:31 +00:00
parent a234679700
commit 57631a012c
4 changed files with 83 additions and 15 deletions
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58
src/pcm/pcm.c
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@ -35,32 +35,79 @@ struct snd_pcm {
int card;
int device;
int fd;
int mode;
};
int snd_pcm_open(snd_pcm_t **handle, int card, int device, int mode)
{
int fd, ver;
return snd_pcm_open_subdevice(handle, card, device, -1, mode);
}
int snd_pcm_open_subdevice(snd_pcm_t **handle, int card, int device, int subdevice, int mode)
{
int fd, ver, err, attempt = 0;
char filename[32];
snd_pcm_t *pcm;
snd_ctl_t *ctl;
snd_pcm_playback_info_t pinfo;
snd_pcm_capture_info_t cinfo;
*handle = NULL;
if (card < 0 || card >= SND_CARDS)
return -EINVAL;
if ((err = snd_ctl_open(&ctl, card)) < 0)
return err;
__again:
if (attempt++ > 3) {
snd_ctl_close(ctl);
return -EBUSY;
}
if ((err = snd_ctl_pcm_prefer_subdevice(ctl, device, subdevice)) < 0) {
snd_ctl_close(ctl);
return err;
}
sprintf(filename, SND_FILE_PCM, card, device);
if ((fd = open(filename, mode)) < 0) {
snd_card_load(card);
if ((fd = open(filename, mode)) < 0)
return -errno;
err = -errno;
snd_ctl_close(ctl);
return err;
}
if (ioctl(fd, SND_PCM_IOCTL_PVERSION, &ver) < 0) {
err = -errno;
close(fd);
return -errno;
snd_ctl_close(ctl);
return err;
}
if (SND_PROTOCOL_INCOMPATIBLE(ver, SND_PCM_VERSION_MAX)) {
close(fd);
snd_ctl_close(ctl);
return -SND_ERROR_INCOMPATIBLE_VERSION;
}
if (subdevice >= 0 && (mode == SND_PCM_OPEN_PLAYBACK || mode == SND_PCM_OPEN_DUPLEX)) {
if (ioctl(fd, SND_PCM_IOCTL_PLAYBACK_INFO, &pinfo) < 0) {
err = -errno;
close(fd);
snd_ctl_close(ctl);
return err;
}
if (pinfo.subdevice != subdevice) {
close(fd);
goto __again;
}
}
if (subdevice >= 0 && (mode == SND_PCM_OPEN_CAPTURE || mode == SND_PCM_OPEN_DUPLEX)) {
if (ioctl(fd, SND_PCM_IOCTL_CAPTURE_INFO, &cinfo) < 0) {
err = -errno;
close(fd);
snd_ctl_close(ctl);
return err;
}
if (cinfo.subdevice != subdevice) {
close(fd);
goto __again;
}
}
pcm = (snd_pcm_t *) calloc(1, sizeof(snd_pcm_t));
if (pcm == NULL) {
close(fd);
@ -69,6 +116,7 @@ int snd_pcm_open(snd_pcm_t **handle, int card, int device, int mode)
pcm->card = card;
pcm->device = device;
pcm->fd = fd;
pcm->mode = mode;
*handle = pcm;
return 0;
}