pcm_bluetooth.c

实现bluez蓝牙profile需要的库

					struct pollfd *pfd, unsigned int space)
{
	struct bluetooth_data *data = io->private_data;

	assert(io);

	if (space < 1)
		return 0;

	pfd[0].fd = data->stream.fd;
	pfd[0].events = POLLIN;
	pfd[0].revents = 0;

	return 1;
}

static int bluetooth_poll_revents(snd_pcm_ioplug_t *io ATTRIBUTE_UNUSED,
					struct pollfd *pfds, unsigned int nfds,
							unsigned short *revents)
{
	assert(pfds && nfds == 1 && revents);

	*revents = pfds[0].revents;

	return 0;
}

static int bluetooth_playback_poll_descriptors(snd_pcm_ioplug_t *io,
					struct pollfd *pfd, unsigned int space)
{
	struct bluetooth_data *data = io->private_data;

	DBG("");

	assert(data->pipefd[0] >= 0);

	if (space < 1)
		return 0;

	pfd[0].fd = data->pipefd[0];
	pfd[0].events = POLLIN;
	pfd[0].revents = 0;

	return 1;
}

static int bluetooth_playback_poll_revents(snd_pcm_ioplug_t *io,
					struct pollfd *pfds, unsigned int nfds,
							unsigned short *revents)
{
	static char buf[1];
	int ret;

	DBG("");

	assert(pfds);
	assert(nfds == 1);
	assert(revents);
	assert(pfds[0].fd >= 0);

	if (io->state != SND_PCM_STATE_PREPARED)
		ret = read(pfds[0].fd, buf, 1);

	*revents = (pfds[0].revents & ~POLLIN) | POLLOUT;

	return 0;
}


static snd_pcm_sframes_t bluetooth_hsp_read(snd_pcm_ioplug_t *io,
				const snd_pcm_channel_area_t *areas,
				snd_pcm_uframes_t offset, snd_pcm_uframes_t size)
{
	struct bluetooth_data *data = io->private_data;
	struct ipc_data_cfg cfg = data->cfg;
	snd_pcm_uframes_t frames_to_write, ret;
	unsigned char *buff;
	int nrecv, frame_size = 0;

	DBG("areas->step=%u areas->first=%u offset=%lu size=%lu io->nonblock=%u",
			areas->step, areas->first, offset, size, io->nonblock);

	if (data->count > 0)
		goto proceed;

	frame_size = areas->step / 8;

	nrecv = recv(data->stream.fd, data->buffer, cfg.pkt_len,
			MSG_WAITALL | (io->nonblock ? MSG_DONTWAIT : 0));

	if (nrecv < 0) {
		ret = (errno == EPIPE) ? -EIO : -errno;
		goto done;
	}

	if (nrecv != cfg.pkt_len) {
		ret = -EIO;
		SNDERR(strerror(-ret));
		goto done;
	}

	/* Increment hardware transmition pointer */
	data->hw_ptr = (data->hw_ptr + cfg.pkt_len / cfg.sample_size) %
								io->buffer_size;

proceed:
	buff = (unsigned char *) areas->addr +
			(areas->first + areas->step * offset) / 8;

	if ((data->count + size * frame_size) <= cfg.pkt_len)
		frames_to_write = size;
	else
		frames_to_write = (cfg.pkt_len - data->count) / frame_size;

	memcpy(buff, data->buffer + data->count, frame_size * frames_to_write);
	data->count += (frame_size * frames_to_write);
	data->count %= cfg.pkt_len;

	/* Return written frames count */
	ret = frames_to_write;

done:
	DBG("returning %lu", ret);
	return ret;
}

static snd_pcm_sframes_t bluetooth_hsp_write(snd_pcm_ioplug_t *io,
				const snd_pcm_channel_area_t *areas,
				snd_pcm_uframes_t offset, snd_pcm_uframes_t size)
{
	struct bluetooth_data *data = io->private_data;
	struct ipc_data_cfg cfg = data->cfg;
	snd_pcm_sframes_t ret = 0;
	snd_pcm_uframes_t frames_to_read;
	uint8_t *buff;
	int rsend, frame_size;

	DBG("areas->step=%u areas->first=%u offset=%lu, size=%lu io->nonblock=%u",
			areas->step, areas->first, offset, size, io->nonblock);

	if (io->hw_ptr > io->appl_ptr) {
		ret = bluetooth_playback_stop(io);
		if (ret == 0)
			ret = -EPIPE;
		goto done;
	}

	frame_size = areas->step / 8;
	if ((data->count + size * frame_size) <= cfg.pkt_len)
		frames_to_read = size;
	else
		frames_to_read = (cfg.pkt_len - data->count) / frame_size;

	DBG("count=%d frames_to_read=%lu", data->count, frames_to_read);

	/* Ready for more data */
	buff = (uint8_t *) areas->addr +
			(areas->first + areas->step * offset) / 8;
	memcpy(data->buffer + data->count, buff, frame_size * frames_to_read);

	/* Remember we have some frames in the pipe now */
	data->count += frames_to_read * frame_size;
	if (data->count != cfg.pkt_len) {
		ret = frames_to_read;
		goto done;
	}

	rsend = send(data->stream.fd, data->buffer, cfg.pkt_len,
			io->nonblock ? MSG_DONTWAIT : 0);
	if (rsend > 0) {
		/* Reset count pointer */
		data->count = 0;

		ret = frames_to_read;
	} else if (rsend < 0)
		ret = (errno == EPIPE) ? -EIO : -errno;
	else
		ret = -EIO;

done:
	DBG("returning %ld", ret);
	return ret;
}

static snd_pcm_sframes_t bluetooth_a2dp_read(snd_pcm_ioplug_t *io,
				const snd_pcm_channel_area_t *areas,
				snd_pcm_uframes_t offset, snd_pcm_uframes_t size)
{
	snd_pcm_uframes_t ret = 0;
	return ret;
}

static int avdtp_write(struct bluetooth_data *data)
{
	int ret = 0;
	struct rtp_header *header;
	struct rtp_payload *payload;
	struct bluetooth_a2dp *a2dp = &data->a2dp;

	header = (void *) a2dp->buffer;
	payload = (void *) (a2dp->buffer + sizeof(*header));

	memset(a2dp->buffer, 0, sizeof(*header) + sizeof(*payload));

	payload->frame_count = a2dp->frame_count;
	header->v = 2;
	header->pt = 1;
	header->sequence_number = htons(a2dp->seq_num);
	header->timestamp = htonl(a2dp->nsamples);
	header->ssrc = htonl(1);

	ret = send(data->stream.fd, a2dp->buffer, a2dp->count, MSG_DONTWAIT);
	if (ret == -1)
		ret = -errno;

	/* Reset buffer of data to send */
	a2dp->count = sizeof(struct rtp_header) + sizeof(struct rtp_payload);
	a2dp->frame_count = 0;
	a2dp->samples = 0;
	a2dp->seq_num++;

	return ret;
}

static snd_pcm_sframes_t bluetooth_a2dp_write(snd_pcm_ioplug_t *io,
				const snd_pcm_channel_area_t *areas,
				snd_pcm_uframes_t offset, snd_pcm_uframes_t size)
{
	struct bluetooth_data *data = io->private_data;
	struct bluetooth_a2dp *a2dp = &data->a2dp;
	snd_pcm_sframes_t ret = 0;
	snd_pcm_uframes_t frames_to_read;
	int frame_size, encoded;
	uint8_t *buff;

	DBG("areas->step=%u areas->first=%u offset=%lu size=%lu",
				areas->step, areas->first, offset, size);
	DBG("hw_ptr=%lu appl_ptr=%lu", io->hw_ptr, io->appl_ptr);

	if (io->hw_ptr > io->appl_ptr) {
		ret = bluetooth_playback_stop(io);
		if (ret == 0)
			ret = -EPIPE;
		goto done;
	}

	/* Check if we should autostart */
	if (io->state == SND_PCM_STATE_PREPARED) {
		snd_pcm_sw_params_t *swparams;
		snd_pcm_uframes_t threshold;

		snd_pcm_sw_params_malloc(&swparams);
		if (!snd_pcm_sw_params_current(io->pcm, swparams) &&
				!snd_pcm_sw_params_get_start_threshold(swparams, &threshold)) {
			if (io->appl_ptr >= threshold) {
				ret = snd_pcm_start(io->pcm);
				if (ret != 0)
					goto done;
			}
		}
		snd_pcm_sw_params_free(swparams);
	}

	frame_size = areas->step / 8;
	if ((data->count + size * frame_size) <= a2dp->codesize)
		frames_to_read = size;
	else
		frames_to_read = (a2dp->codesize - data->count) / frame_size;

	DBG("count=%d frames_to_read=%lu", data->count, frames_to_read);
	DBG("a2dp.count=%d cfg.pkt_len=%d", a2dp->count, data->cfg.pkt_len);

	/* FIXME: If state is not streaming then return */

	/* Ready for more data */
	buff = (uint8_t *) areas->addr +
				(areas->first + areas->step * offset) / 8;
	memcpy(data->buffer + data->count, buff, frame_size * frames_to_read);

	/* Remember we have some frames in the pipe now */
	data->count += frames_to_read * frame_size;
	if (data->count != a2dp->codesize) {
		ret = frames_to_read;
		goto done;
	}

	/* Enough data to encode (sbc wants 1k blocks) */
	encoded = sbc_encode(&(a2dp->sbc), data->buffer, a2dp->codesize);
	if (encoded <= 0) {
		DBG("Encoding error %d", encoded);
		goto done;
	}

	data->count -= encoded;

	DBG("encoded=%d  a2dp.sbc.len=%d", encoded, a2dp->sbc.len);

	if (a2dp->count + a2dp->sbc.len >= data->cfg.pkt_len) {
		ret = avdtp_write(data);
		if (ret < 0) {
			if (-ret == EPIPE)
				ret = -EIO;
			goto done;
		}
	}

	memcpy(a2dp->buffer + a2dp->count, a2dp->sbc.data, a2dp->sbc.len);
	a2dp->count += a2dp->sbc.len;
	a2dp->frame_count++;
	a2dp->samples += encoded / frame_size;
	a2dp->nsamples += encoded / frame_size;

	ret = frames_to_read;

done:
	DBG("returning %ld", ret);
	return ret;
}

static snd_pcm_ioplug_callback_t bluetooth_hsp_playback = {
	.start			= bluetooth_playback_start,
	.stop			= bluetooth_playback_stop,
	.pointer		= bluetooth_pointer,
	.close			= bluetooth_close,
	.hw_params		= bluetooth_hsp_hw_params,
	.prepare		= bluetooth_prepare,
	.transfer		= bluetooth_hsp_write,
	.poll_descriptors	= bluetooth_playback_poll_descriptors,
	.poll_revents		= bluetooth_playback_poll_revents,
};

static snd_pcm_ioplug_callback_t bluetooth_hsp_capture = {
	.start			= bluetooth_start,
	.stop			= bluetooth_stop,
	.pointer		= bluetooth_pointer,
	.close			= bluetooth_close,
	.hw_params		= bluetooth_hsp_hw_params,
	.prepare		= bluetooth_prepare,
	.transfer		= bluetooth_hsp_read,
	.poll_descriptors	= bluetooth_poll_descriptors,
	.poll_revents		= bluetooth_poll_revents,
};

static snd_pcm_ioplug_callback_t bluetooth_a2dp_playback = {
	.start			= bluetooth_playback_start,
	.stop			= bluetooth_playback_stop,
	.pointer		= bluetooth_pointer,
	.close			= bluetooth_close,
	.hw_params		= bluetooth_a2dp_hw_params,
	.prepare		= bluetooth_prepare,
	.transfer		= bluetooth_a2dp_write,
	.poll_descriptors	= bluetooth_playback_poll_descriptors,
	.poll_revents		= bluetooth_playback_poll_revents,
};

static snd_pcm_ioplug_callback_t bluetooth_a2dp_capture = {
	.start			= bluetooth_start,
	.stop			= bluetooth_stop,
	.pointer		= bluetooth_pointer,
	.close			= bluetooth_close,
	.hw_params		= bluetooth_a2dp_hw_params,
	.prepare		= bluetooth_prepare,
	.transfer		= bluetooth_a2dp_read,
	.poll_descriptors	= bluetooth_poll_descriptors,
	.poll_revents		= bluetooth_poll_revents,
};

#define ARRAY_NELEMS(a) (sizeof((a)) / sizeof((a)[0]))

static int bluetooth_hsp_hw_constraint(snd_pcm_ioplug_t *io)
{
	struct bluetooth_data *data = io->private_data;
	struct ipc_data_cfg cfg = data->cfg;
	snd_pcm_access_t access_list[] = {
		SND_PCM_ACCESS_RW_INTERLEAVED,
		/* Mmap access is really useless fo this driver, but we
		 * support it because some pieces of software out there
		 * insist on using it */
		SND_PCM_ACCESS_MMAP_INTERLEAVED
	};
	unsigned int format_list[] = {
		SND_PCM_FORMAT_S16_LE
	};
	int err, channels;

	/* access type */
	err = snd_pcm_ioplug_set_param_list(io, SND_PCM_IOPLUG_HW_ACCESS,
					ARRAY_NELEMS(access_list), access_list);
	if (err < 0)
		return err;

	/* supported formats */
	err = snd_pcm_ioplug_set_param_list(io, SND_PCM_IOPLUG_HW_FORMAT,
					ARRAY_NELEMS(format_list), format_list);
	if (err < 0)
		return err;

	/* supported channels */
	channels = cfg.mode == CFG_MODE_MONO ? 1 : 2;
	err = snd_pcm_ioplug_set_param_minmax(io, SND_PCM_IOPLUG_HW_CHANNELS,
							channels, channels);
	if (err < 0)
		return err;

	/* supported rate */
	err = snd_pcm_ioplug_set_param_minmax(io, SND_PCM_IOPLUG_HW_RATE,
							cfg.rate, cfg.rate);
	if (err < 0)
		return err;

	/* supported block size */
	err = snd_pcm_ioplug_set_param_minmax(io, SND_PCM_IOPLUG_HW_PERIOD_BYTES,
						cfg.pkt_len, cfg.pkt_len);
	if (err < 0)
		return err;

	err = snd_pcm_ioplug_set_param_minmax(io, SND_PCM_IOPLUG_HW_PERIODS,
									2, 200);
	if (err < 0)
		return err;

	return 0;
}

static int bluetooth_a2dp_hw_constraint(snd_pcm_ioplug_t *io)
{
	struct bluetooth_data *data = io->private_data;
	struct bluetooth_a2dp *a2dp = &data->a2dp;
	struct ipc_data_cfg cfg = data->cfg;
	snd_pcm_access_t access_list[] = {
		SND_PCM_ACCESS_RW_INTERLEAVED,
		/* Mmap access is really useless fo this driver, but we
		 * support it because some pieces of software out there
		 * insist on using it */
		SND_PCM_ACCESS_MMAP_INTERLEAVED
	};
	unsigned int format_list[] = {
		SND_PCM_FORMAT_S16_LE
	};
	int err, channels;

	/* access type */
	err = snd_pcm_ioplug_set_param_list(io, SND_PCM_IOPLUG_HW_ACCESS,
					ARRAY_NELEMS(access_list), access_list);
	if (err < 0)
		return err;