ao_nas.c

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	}
	nas_data->state=event->cur_state;
	return AuTrue;
}

static AuDeviceID nas_find_device(AuServer *aud, int nch)
{
	int i;
	for (i = 0; i < AuServerNumDevices(aud); i++) {
		AuDeviceAttributes *dev = AuServerDevice(aud, i);
		if ((AuDeviceKind(dev) == AuComponentKindPhysicalOutput) &&
		     AuDeviceNumTracks(dev) == nch) {
			return AuDeviceIdentifier(dev);
		}
	}
	return AuNone;
}

static unsigned int nas_aformat_to_auformat(unsigned int *format)
{
	switch (*format) {
	case	AF_FORMAT_U8:
		return AuFormatLinearUnsigned8;
	case	AF_FORMAT_S8:
		return AuFormatLinearSigned8;
	case	AF_FORMAT_U16_LE:
		return AuFormatLinearUnsigned16LSB;
	case	AF_FORMAT_U16_BE:
		return AuFormatLinearUnsigned16MSB;
	case	AF_FORMAT_S16_LE:
		return AuFormatLinearSigned16LSB;
	case	AF_FORMAT_S16_BE:
		return AuFormatLinearSigned16MSB;
	case	AF_FORMAT_MU_LAW:
		return AuFormatULAW8;
	default:
		*format=AF_FORMAT_S16_NE;
		return nas_aformat_to_auformat(format);
	}
}

// to set/get/query special features/parameters
static int control(int cmd, void *arg)
{
	AuElementParameters aep;
	AuStatus as;
	int retval = CONTROL_UNKNOWN;

	ao_control_vol_t *vol = (ao_control_vol_t *)arg;

	switch (cmd) {
	case AOCONTROL_GET_VOLUME:

		vol->right = (float)nas_data->gain/AU_FIXED_POINT_SCALE*50;
		vol->left = vol->right;

		mp_msg(MSGT_AO, MSGL_DBG2, "ao_nas: AOCONTROL_GET_VOLUME: %08x\n", nas_data->gain);
		retval = CONTROL_OK;
		break;

	case AOCONTROL_SET_VOLUME:
		/*
		 * kn: we should have vol->left == vol->right but i don't
		 * know if something can change it outside of ao_nas
		 * so i take the mean of both values.
		 */
		nas_data->gain = AU_FIXED_POINT_SCALE*((vol->left+vol->right)/2)/50;
		mp_msg(MSGT_AO, MSGL_DBG2, "ao_nas: AOCONTROL_SET_VOLUME: %08x\n", nas_data->gain);

		aep.parameters[AuParmsMultiplyConstantConstant]=nas_data->gain;
		aep.flow = nas_data->flow;
		aep.element_num = 1;
		aep.num_parameters = AuParmsMultiplyConstant;

		AuSetElementParameters(nas_data->aud, 1, &aep, &as);
		if (as != AuSuccess) {
			nas_print_error(nas_data->aud,
			                "control(): AuSetElementParameters", as);
			retval = CONTROL_ERROR;
		} else retval = CONTROL_OK;
		break;
	};

	return retval;
}

// open & setup audio device
// return: 1=success 0=fail
static int init(int rate,int channels,int format,int flags)
{
	AuElement elms[3];
	AuStatus as;
	unsigned char auformat = nas_aformat_to_auformat(&format);
	int bytes_per_sample = channels * AuSizeofFormat(auformat);
	int buffer_size;
	char *server;

	nas_data=malloc(sizeof(struct ao_nas_data));
	memset(nas_data, 0, sizeof(struct ao_nas_data));

	mp_msg(MSGT_AO, MSGL_V, "ao2: %d Hz  %d chans  %s\n",rate,channels,
		af_fmt2str_short(format));

	ao_data.format = format;
	ao_data.samplerate = rate;
	ao_data.channels = channels;
	ao_data.outburst = NAS_FRAG_SIZE;
	ao_data.bps = rate * bytes_per_sample;
	buffer_size = ao_data.bps; /* buffer 1 second */
	/*
	 * round up to multiple of NAS_FRAG_SIZE
	 * divide by 3 first because of 2:1 split
	 */
	buffer_size = (buffer_size/3 + NAS_FRAG_SIZE-1) & ~(NAS_FRAG_SIZE-1);
	ao_data.buffersize = buffer_size*3;

	nas_data->client_buffer_size = buffer_size*2;
	nas_data->client_buffer = malloc(nas_data->client_buffer_size);
	nas_data->server_buffer_size = buffer_size;
	nas_data->server_buffer = malloc(nas_data->server_buffer_size);

	if (!bytes_per_sample) {
		mp_msg(MSGT_AO, MSGL_ERR, "ao_nas: init(): Zero bytes per sample -> nosound\n");
		return 0;
	}

	if (!(server = getenv("AUDIOSERVER")) &&
	    !(server = getenv("DISPLAY"))) {
		mp_msg(MSGT_AO, MSGL_ERR, "ao_nas: init(): AUDIOSERVER environment variable not set -> nosound\n");
		return 0;
	}

	mp_msg(MSGT_AO, MSGL_V, "ao_nas: init(): Using audioserver %s\n", server);

	nas_data->aud = AuOpenServer(server, 0, NULL, 0, NULL, NULL);
	if (!nas_data->aud) { 
		mp_msg(MSGT_AO, MSGL_ERR, "ao_nas: init(): Can't open nas audio server -> nosound\n");
		return 0;
	}

	while (channels>0) {
		nas_data->dev = nas_find_device(nas_data->aud, channels);
		if (nas_data->dev != AuNone &&
		    ((nas_data->flow = AuCreateFlow(nas_data->aud, NULL)) != 0))
			break;
		channels--;
	}

	if (nas_data->flow == 0) {
		mp_msg(MSGT_AO, MSGL_ERR, "ao_nas: init(): Can't find a suitable output device -> nosound\n");
		AuCloseServer(nas_data->aud);
		nas_data->aud = 0;
		return 0;
	}

	AuMakeElementImportClient(elms, rate, auformat, channels, AuTrue,
				buffer_size / bytes_per_sample,
				(buffer_size - NAS_FRAG_SIZE) /
				bytes_per_sample, 0, NULL);
	nas_data->gain = AuFixedPointFromFraction(1, 1);
	AuMakeElementMultiplyConstant(elms+1, 0, nas_data->gain);
	AuMakeElementExportDevice(elms+2, 1, nas_data->dev, rate,
				AuUnlimitedSamples, 0, NULL);
	AuSetElements(nas_data->aud, nas_data->flow, AuTrue, sizeof(elms)/sizeof(*elms), elms, &as);
	if (as != AuSuccess) {
		nas_print_error(nas_data->aud, "init(): AuSetElements", as);
		AuCloseServer(nas_data->aud);
		nas_data->aud = 0;
		return 0;
	}
	AuRegisterEventHandler(nas_data->aud, AuEventHandlerIDMask |
				AuEventHandlerTypeMask,
				AuEventTypeElementNotify, nas_data->flow,
				nas_event_handler, (AuPointer) nas_data);
	AuSetErrorHandler(nas_data->aud, nas_error_handler);
	nas_data->state=AuStateStop;
	nas_data->expect_underrun=0;

	pthread_mutex_init(&nas_data->buffer_mutex, NULL);
	pthread_create(&nas_data->event_thread, NULL, &nas_event_thread_start, nas_data);

	return 1;
}

// close audio device
static void uninit(int immed){

	mp_msg(MSGT_AO, MSGL_DBG3, "ao_nas: uninit()\n");

	nas_data->expect_underrun = 1;
	if (!immed)
	while (nas_data->state != AuStateStop) usleep(1000);
	nas_data->stop_thread = 1;
	pthread_join(nas_data->event_thread, NULL);
	AuCloseServer(nas_data->aud);
	nas_data->aud = 0;
	free(nas_data->client_buffer);
	free(nas_data->server_buffer);
}

// stop playing and empty buffers (for seeking/pause)
static void reset(void){
	AuStatus as;

	mp_msg(MSGT_AO, MSGL_DBG3, "ao_nas: reset()\n");

	pthread_mutex_lock(&nas_data->buffer_mutex);
	nas_data->client_buffer_used = 0;
	pthread_mutex_unlock(&nas_data->buffer_mutex);
	while (nas_data->state != AuStateStop) {
		AuStopFlow(nas_data->aud, nas_data->flow, &as);
		if (as != AuSuccess)
			nas_print_error(nas_data->aud, "reset(): AuStopFlow", as);
		usleep(1000);
	}
}

// stop playing, keep buffers (for pause)
static void audio_pause(void)
{
	AuStatus as;
	mp_msg(MSGT_AO, MSGL_DBG3, "ao_nas: audio_pause()\n");

	AuStopFlow(nas_data->aud, nas_data->flow, &as);
}

// resume playing, after audio_pause()
static void audio_resume(void)
{
	AuStatus as;

	mp_msg(MSGT_AO, MSGL_DBG3, "ao_nas: audio_resume()\n");

	AuStartFlow(nas_data->aud, nas_data->flow, &as);
	if (as != AuSuccess)
		nas_print_error(nas_data->aud,
		                "play(): AuStartFlow", as);
}


// return: how many bytes can be played without blocking
static int get_space(void)
{
	int result;
	
	mp_msg(MSGT_AO, MSGL_DBG3, "ao_nas: get_space()\n");

	pthread_mutex_lock(&nas_data->buffer_mutex);
	result = nas_data->client_buffer_size - nas_data->client_buffer_used;
	pthread_mutex_unlock(&nas_data->buffer_mutex);

	return result;
}

// plays 'len' bytes of 'data'
// it should round it down to outburst*n
// return: number of bytes played
static int play(void* data,int len,int flags)
{
	int maxbursts, playbursts, writelen;
	AuStatus as;

	mp_msg(MSGT_AO, MSGL_DBG3,
	       "ao_nas: play(%p, %d, %d)\n",
	       data, len, flags);

	if (len == 0)
		return 0;

	pthread_mutex_lock(&nas_data->buffer_mutex);
	maxbursts = (nas_data->client_buffer_size -
		     nas_data->client_buffer_used) / ao_data.outburst;
	playbursts = len / ao_data.outburst;
	writelen = (playbursts > maxbursts ? maxbursts : playbursts) *
		   ao_data.outburst;
	pthread_mutex_unlock(&nas_data->buffer_mutex);

	writelen = nas_writeBuffer(nas_data, data, writelen);

	if (nas_data->state != AuStateStart &&
	    maxbursts == playbursts) {
		mp_msg(MSGT_AO, MSGL_DBG2, "ao_nas: play(): Starting flow.\n");
		nas_data->expect_underrun = 1;
		AuStartFlow(nas_data->aud, nas_data->flow, &as);
		if (as != AuSuccess)
			nas_print_error(nas_data->aud, "play(): AuStartFlow", as);
	}

	return writelen;
}

// return: delay in seconds between first and last sample in buffer
static float get_delay(void)
{
	float result;
	
	mp_msg(MSGT_AO, MSGL_DBG3, "ao_nas: get_delay()\n");

	pthread_mutex_lock(&nas_data->buffer_mutex);
	result = ((float)(nas_data->client_buffer_used +
			  nas_data->server_buffer_used)) /
		 (float)ao_data.bps;
	pthread_mutex_unlock(&nas_data->buffer_mutex);

	return result;
}