oplplayer/alsasnd.h

#ifdef SND_S32
#define pcms_t int32_t
#define aud_ihandle aud_handle32
#define SND_FMT SND_PCM_FORMAT_S32_LE
#else
#define pcms_t int16_t
#define aud_ihandle aud_handle16
#define SND_FMT SND_PCM_FORMAT_S16_LE
#endif

#define SND_SMPSIZE (sizeof(pcms_t))

typedef struct {
	snd_pcm_t *handle;
	uint32_t samplerate;
	uint32_t blocksize;
	uint32_t channels;
	uint32_t smppos;
	pcms_t *buffer;
	uint32_t devbufsize;
	wav_handle wav;
#ifdef SND_MSGUNDER
	uint32_t underruns;
	uint32_t lastunder;
	uint32_t pushed;
#endif
} aud_ihandle;

void
#ifdef SND_S32
wav_write32
#else
wav_write16
#endif
(wav_handle *wav, pcms_t *samples, uint32_t count) {
	if(wav->fd == NULL) {
		return;
	}
	for(int c = 0; c < (count * ((uint32_t)wav->channels)); c++) {
#ifdef SND_S32
		wav_write_uint32((wav->buffer)+(c*SND_SMPSIZE), samples[c]);
#else
		wav_write_uint16((wav->buffer)+(c*SND_SMPSIZE), samples[c]);
#endif
	}
	if(fwrite(wav->buffer, 1, SND_SMPSIZE * ((uint32_t)wav->channels) * count, wav->fd) != (SND_SMPSIZE * ((uint32_t)wav->channels) * count)) {
		fprintf(stderr, STR_WAV_EIO"\n", wav->filename);
		fclose(wav->fd);
		wav->fd = NULL;
		return;
	}
	wav->samples += count;
}

void
#ifdef SND_S32
aud_prepare32
#else
aud_prepare16
#endif
(aud_ihandle *dev) {
	if(dev->handle == NULL) {
		return;
	}
	memset(dev->buffer, 0, dev->blocksize * SND_SMPSIZE * dev->channels);
	dev->smppos = 0;
	int rc = 0;
	uint32_t tries = 0;
  	while(rc != dev->blocksize) {
		if(tries++ >= 256) {
			mid_log(STR_AUD_PREPERR);
			return;
		}
		rc = snd_pcm_writei(dev->handle, dev->buffer, dev->blocksize);
		if(rc == -EAGAIN || (rc >= 0 && (size_t)rc < dev->blocksize)) {
			snd_pcm_wait(dev->handle, 100);
		} 
		else if(rc == -EPIPE) {
			snd_pcm_prepare(dev->handle);
		}
	}
	snd_pcm_nonblock(dev->handle, 1);
	for(int z = 0; z < 16; z++) {
	 	rc = snd_pcm_writei(dev->handle, dev->buffer, dev->blocksize);
		if(rc == -EAGAIN || (rc >= 0 && (size_t)rc < dev->blocksize)) {
			snd_pcm_wait(dev->handle, 100);
		} 
		else if(rc == -EPIPE) {
			snd_pcm_prepare(dev->handle);
		}
	}
	snd_pcm_nonblock(dev->handle, 0);
}

void
#ifdef SND_S32
aud_write32
#else
aud_write16
#endif
(aud_ihandle *dev, pcms_t *data, uint32_t samples) {
	int rc;
	uint32_t blocksize = dev->blocksize;
  	while(samples > 0) {
		blocksize = samples < blocksize ? samples : blocksize;
		if(dev->handle) {
			rc = snd_pcm_writei(dev->handle, data, blocksize);
		}
		else if(dev->wav.buffer) {
#ifdef SND_S32
			wav_write32(&dev->wav, data, blocksize);
#else
			wav_write16(&dev->wav, data, blocksize);
#endif
			rc = blocksize;
		}
		else {
			fwrite(data, 1, blocksize * dev->channels * SND_SMPSIZE, stdout);
			rc = blocksize;
		}
		if(rc > 0) {
			data += rc * dev->channels;
			samples -= rc;
		}
		if(dev->handle) {
			if(rc == -EAGAIN || (rc >= 0 && (size_t)rc < blocksize)) {
				snd_pcm_wait(dev->handle, 100);
			} 
			else if(rc == -EPIPE) {
#ifdef SND_MSGUNDER
				if(dev->underruns == 0) {
					dev->lastunder = dev->pushed;
				}
				dev->underruns += 1;
#endif
				snd_pcm_prepare(dev->handle);
			}
			else if(rc < 0) {
			  	mid_log(STR_AUD_WRITERR, snd_strerror(rc), rc);
			}
#ifdef SND_MSGUNDER
			else {
			    dev->pushed += 1;
			}
			if((dev->underruns > 0) && ((dev->pushed - dev->lastunder) >= (dev->samplerate / dev->blocksize))) {
				mid_log(STR_AUD_UNDERR, dev->underruns);
				dev->underruns = 0;
			}
#endif
		}
	}
}

int
#ifdef SND_S32
aud_open_dev32
#else
aud_open_dev16
#endif
(aud_ihandle *dev, const char *devname, uint32_t samplerate, uint8_t channels, uint32_t frames, uint32_t bufsize) {
	dev->channels = channels;
	dev->samplerate = samplerate;
	dev->smppos = 0;
#ifdef SND_MSGUNDER
	dev->underruns = 0;
	dev->lastunder = 0;
	dev->pushed = 0;
#endif
	dev->handle = NULL;
	dev->buffer = NULL;
	dev->wav.buffer = NULL;
	if((devname[0] == '-') && (devname[1] == 0)) {
		dev->blocksize = frames;
		dev->devbufsize = 0;
		dev->buffer = (pcms_t*)malloc(dev->blocksize * SND_SMPSIZE * dev->channels);
		return 0;
	}
	else if((strlen(devname) >= 4) && (strcmp(devname+(strlen(devname)-4), ".wav") == 0)) {
		if(wav_open(&dev->wav, devname, samplerate, channels, SND_SMPSIZE) ^ 1) {
			return false;
		}
		dev->blocksize = frames;
		dev->devbufsize = 0;
		dev->buffer = (pcms_t*)malloc(dev->blocksize * SND_SMPSIZE * dev->channels);
		dev->wav.buffer = malloc(dev->blocksize * SND_SMPSIZE * dev->channels);
		return 0;
	}
	int rc;
	int subdir = 0;
  	snd_pcm_hw_params_t *params = NULL;
	rc = snd_pcm_open(&dev->handle, devname, SND_PCM_STREAM_PLAYBACK, 0);
	if(rc < 0) {
		fprintf(stderr, STR_AUD_OPNERR"\n", devname, snd_strerror(rc), rc);
		return 1;
	}
	snd_pcm_hw_params_alloca(&params);
	snd_pcm_hw_params_any(dev->handle, params);
	snd_pcm_hw_params_set_access(dev->handle, params, SND_PCM_ACCESS_RW_INTERLEAVED);
	if(snd_pcm_hw_params_set_format(dev->handle, params, SND_FMT) != 0) {
		snd_pcm_close(dev->handle);
    	return 2;
	}
	snd_pcm_hw_params_set_channels(dev->handle, params, dev->channels);
  	snd_pcm_hw_params_set_rate_near(dev->handle, params, &dev->samplerate, &subdir);
	snd_pcm_uframes_t framesize = frames;
  	snd_pcm_hw_params_set_period_size_near(dev->handle, params, &framesize, &subdir);
	snd_pcm_uframes_t buffersize = bufsize;
	if(bufsize > 0) {
		snd_pcm_hw_params_set_buffer_size_near(dev->handle, params, &buffersize);
	}
	rc = snd_pcm_hw_params(dev->handle, params);
  	if(rc < 0) {
    	fprintf(stderr, STR_AUD_HWERR"\n", devname, snd_strerror(rc), rc);
		snd_pcm_close(dev->handle);
    	return 1;
  	}
  	snd_pcm_hw_params_get_period_size(params, &framesize, &subdir);
	snd_pcm_hw_params_get_buffer_size(params, &buffersize);
	snd_pcm_sw_params_t *swparams;
	snd_pcm_sw_params_alloca(&swparams);
	snd_pcm_sw_params_current(dev->handle, swparams);
	// snd_pcm_sw_params_set_avail_min(dev->handle, swparams, framesize);
	// snd_pcm_sw_params_set_start_threshold(dev->handle, swparams, 0);
	// snd_pcm_sw_params_set_stop_threshold(dev->handle, swparams, buffersize);
	rc = snd_pcm_sw_params(dev->handle, swparams);
	if(rc < 0) {
    	fprintf(stderr, STR_AUD_SWERR"\n", devname, snd_strerror(rc), rc);
		snd_pcm_close(dev->handle);
    	return 1;
	}

	dev->blocksize = framesize;
	dev->devbufsize = buffersize;
  	dev->buffer = (pcms_t*)malloc(dev->blocksize * SND_SMPSIZE * dev->channels);
	snd_pcm_wait(dev->handle, -1);
#ifdef SND_S32
	aud_prepare32(dev);
#else
	aud_prepare16(dev);
#endif
	return 0;
}

void
#ifdef SND_S32
aud_push32
#else
aud_push16
#endif
(aud_ihandle *dev, pcms_t *data) {
	memcpy(&dev->buffer[dev->smppos*dev->channels], data, SND_SMPSIZE * dev->channels);
	dev->smppos++;
	if(dev->smppos == dev->blocksize) {
#ifdef SND_S32
		aud_write32(dev, dev->buffer, dev->blocksize);
#else
		aud_write16(dev, dev->buffer, dev->blocksize);
#endif
		dev->smppos = 0;
	}
}

void
#ifdef SND_S32
aud_flush32
#else
aud_flush16
#endif
(aud_ihandle *dev) {
	if(dev->smppos != 0) {
#ifdef SND_S32
		aud_write32(dev, dev->buffer, dev->smppos);
#else
		aud_write16(dev, dev->buffer, dev->smppos);
#endif
		dev->smppos = 0;
	}
}

void
#ifdef SND_S32
aud_close32
#else
aud_close16
#endif
(aud_ihandle *dev) {
	if(dev->handle) {
		snd_pcm_drain(dev->handle);
		snd_pcm_close(dev->handle);
	}
	if(dev->wav.buffer) {
		wav_close(&dev->wav);
		free(dev->wav.buffer);
	}
  	free(dev->buffer);
}

#undef pcms_t
#undef aud_ihandle
#undef SND_FMT