PcmDevice *
openPcmDevice (int errorLevel, const char *device) {
PcmDevice *pcm;
if ((pcm = malloc(sizeof(*pcm)))) {
if (!*device) device = PCM_OSS_DEVICE_PATH;
if ((pcm->fileDescriptor = open(device, O_WRONLY|O_NONBLOCK)) != -1) {
/* Nonblocking if snd_seq_oss is loaded with nonblock_open=1.
* There appears to be a bug in this case as write() always
* returns the full count even though large chunks of sound are
* missing. For now, therefore, force blocking output.
*/
setBlockingIo(pcm->fileDescriptor, 1);
pcm->driverVersion = 0X030000;
#ifdef OSS_GETVERSION
if (ioctl(pcm->fileDescriptor, OSS_GETVERSION, &pcm->driverVersion) == -1)
logMessage(errorLevel, "cannot get OSS driver version");
#endif /* OSS_GETVERSION */
logMessage(LOG_DEBUG, "OPSS driver version: %06X", pcm->driverVersion);
setPcmSampleRate(pcm, 8000);
setPcmChannelCount(pcm, 1);
return pcm;
} else {
logMessage(errorLevel, "cannot open PCM device: %s: %s", device, strerror(errno));
}
free(pcm);
} else {
logSystemError("PCM device allocation");
}
return NULL;
}
static int
openSoundDevice (void) {
if (!pcm) {
if (!(pcm = openPcmDevice(LOG_WARNING, opt_pcmDevice))) return 0;
speechParameters.nChannels = setPcmChannelCount(pcm, 1);
speechParameters.nSampleFreq = setPcmSampleRate(pcm, 22050);
{
typedef struct {
PcmAmplitudeFormat internal;
int external;
} FormatEntry;
static const FormatEntry formatTable[] = {
{PCM_FMT_S16L , 16},
{PCM_FMT_U8 , 8},
{PCM_FMT_UNKNOWN, 0}
};
const FormatEntry *format = formatTable;
while (format->internal != PCM_FMT_UNKNOWN) {
if (setPcmAmplitudeFormat(pcm, format->internal) == format->internal) break;
++format;
}
if (format->internal == PCM_FMT_UNKNOWN) {
logMessage(LOG_WARNING, "No supported sound format.");
closePcmDevice(pcm);
pcm = NULL;
return 0;
}
speechParameters.nBits = format->external;
}
logMessage(LOG_DEBUG, "Mikropuhe audio configuration: channels=%d rate=%d bits=%d",
speechParameters.nChannels, speechParameters.nSampleFreq, speechParameters.nBits);
}
return 1;
}
