/*
 * libiec61883 - Linux IEEE 1394 streaming media library.
 * Copyright (C) 2004 Kristian Hogsberg, Dan Dennedy, and Dan Maas.
 *
 * This file written by Kristian Hogsberg.
 * Update receive to use new raw1394 API by Dan Dennedy.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <netinet/in.h>
#include <assert.h>
#include <string.h>

#include "iec61883.h"
#include "iec61883-private.h"

#define AMDTP_MAX_PACKET_SIZE 2048

iec61883_amdtp_t
iec61883_amdtp_xmit_init (raw1394handle_t handle,
		int rate,
		int format,
		int sample_format,
		int mode,
		int dimension,
		iec61883_amdtp_xmit_t get_data, void *callback_data)
{
	int fdf, syt_interval;
	struct iec61883_amdtp *amdtp;

	amdtp = malloc (sizeof (struct iec61883_amdtp));
	if (!amdtp) {
		errno = ENOMEM;
		return NULL;
	}
	amdtp->channel = -1;

	if (format <= IEC61883_AMDTP_FORMAT_IEC958_AC3)
		amdtp->format = format;
	else {
		free (amdtp);
		return NULL;
	}

	switch (rate) {
	case 32000:
		syt_interval = 8;
		fdf = IEC61883_FDF_SFC_32KHZ;
		amdtp->iec958_rate_code = 0x0c;
		break;
	case 44100:
		syt_interval = 8;
		fdf = IEC61883_FDF_SFC_44K1HZ;
		amdtp->iec958_rate_code = 0x00;
		break;
	case 48000:
		syt_interval = 8;
		fdf = IEC61883_FDF_SFC_48KHZ;
		amdtp->iec958_rate_code = 0x04;
		break;
	case 88200:
		syt_interval = 16;
		fdf = IEC61883_FDF_SFC_88K2HZ;
		amdtp->iec958_rate_code = 0x00;
		break;
	case 96000:
		syt_interval = 16;
		fdf = IEC61883_FDF_SFC_96KHZ;
		amdtp->iec958_rate_code = 0x00;
		break;
	case 176400:
		syt_interval = 32;
		fdf = IEC61883_FDF_SFC_176K4HZ;
		amdtp->iec958_rate_code = 0x00;
		break;
	case 192000:
		syt_interval = 32;
		fdf = IEC61883_FDF_SFC_192KHZ;
		amdtp->iec958_rate_code = 0x00;
		break;

	default:
		free (amdtp);
		return NULL;
	}

	/* When using the AM824 raw subformat we can stream signals of
	 * any dimension.  The IEC958 subformat, however, only
	 * supports 2 channels.
	 */
	if (amdtp->format == IEC61883_AMDTP_FORMAT_IEC958_PCM && dimension > 2) {
		free (amdtp);
		return NULL;
	}
	else {
		amdtp->dimension = dimension;
	}

	/* reset framecounter for IEC958 mode */
	amdtp->iec958_frame_count = 0;

	amdtp->sample_format = sample_format;
	amdtp->get_data = get_data;
	amdtp->callback_data = callback_data;
	amdtp->handle = handle;
	amdtp->dimension = dimension;
	amdtp->buffer_packets = 1000;
	amdtp->prebuffer_packets = 1000;
	amdtp->irq_interval = 250;
	amdtp->synch = 0;
	amdtp->speed = RAW1394_ISO_SPEED_100;

	iec61883_cip_init (&amdtp->cip, IEC61883_FMT_AMDTP, fdf,
			   rate, dimension, syt_interval);
	iec61883_cip_set_transmission_mode (&amdtp->cip, mode);

	raw1394_set_userdata (handle, amdtp);

	return amdtp;
}

static enum raw1394_iso_disposition
amdtp_xmit_handler (raw1394handle_t handle,
		unsigned char *data, unsigned int *len,
		unsigned char *tag, unsigned char *sy,
		int cycle, unsigned int dropped)
{
	struct iec61883_amdtp *amdtp = raw1394_get_userdata (handle);
	struct iec61883_packet *packet = (struct iec61883_packet *) data;
	int nevents;
	quadlet_t *event = (quadlet_t *) packet->data;
	enum raw1394_iso_disposition result = RAW1394_ISO_OK;
	int nsamples;
	int diff_sync;
	
	assert (amdtp != NULL);
	amdtp->total_dropped += dropped;

	/* If packets got dropped, we have to resynchronize the generation
	   of SYT timestamps. Otherwise the SYT timestamps would differ
	   too much from current cycle time.
	   Unfortunately, dropped does not tell us how many packets got
	   got dropped. It just tells us that we lost packets.
	   So the only thing we can do is restarting buffering and
	   taking the current cycle count as reference. */
	if (dropped) {
		DEBUG ("dropped packets detected.");
		iec61883_cip_resync(&amdtp->cip, cycle);
	}

	/* The following is a workaround for a possible bug in the kernel
           module. It seems that after a dropped packet event, the cycle
           number passed to this handler is incorrect (does not match the
           transmission cycle) for some time. Therefore, we check whether
	   the SYT timestamp is in sync with the current cycle count. If
	   we ran out of sync, we resynchronize. */
	diff_sync = (amdtp->cip.cycle_count - cycle + 8000) % 8000;
	if (diff_sync > 5) {
		DEBUG ("lost SYT sync, resynchronizing.");
		iec61883_cip_resync(&amdtp->cip, cycle);
	}

	nevents = iec61883_cip_fill_header (handle, &amdtp->cip, packet);

	if (nevents > 0) {
		nsamples = nevents;
	}
	else {
		if (amdtp->cip.mode == IEC61883_MODE_BLOCKING_EMPTY) {
			nsamples = 0;
		}
		else {
			nsamples = amdtp->cip.syt_interval;
		}
	}

	memset (packet->data, '\0', nsamples * amdtp->dimension * sizeof (quadlet_t));

	if (nevents > 0) {
		if( amdtp->get_data (amdtp, packet->data, nevents, packet->dbc, dropped, 
				     amdtp->callback_data) < 0 ) {
			result = RAW1394_ISO_ERROR;
		}
	}

	if (result == RAW1394_ISO_OK ) {
		quadlet_t label = 0;
		int i;
		
		if (amdtp->format == IEC61883_AMDTP_FORMAT_RAW) {
			label = IEC61883_AM824_LABEL;
			switch (amdtp->sample_format) {
				case IEC61883_AMDTP_INPUT_LE24:
					label |= IEC61883_AM824_VBL_24BITS;
					break;
				case IEC61883_AMDTP_INPUT_LE20:
					label |= IEC61883_AM824_VBL_20BITS;
					break;
				case IEC61883_AMDTP_INPUT_LE16:
					label |= IEC61883_AM824_VBL_16BITS;
					break;
				default:
					break;
			}
			label = label << 24;

			for (i = 0; i < nsamples * amdtp->dimension; i++) {
				event[i] = htonl (event[i] | label);
			}
		}
		else if (amdtp->format == IEC61883_AMDTP_FORMAT_IEC958_PCM) {
			struct iec60958_data *sample;

			for (i = 0; i < nsamples * amdtp->dimension; i++) {
				sample = (struct iec60958_data *) &event[i];
				sample->label = IEC60958_LABEL;
				if (nevents == 0) {
					sample->validity = IEC60958_DATA_INVALID;
					/* Using reseved value for old
					 * SoftAcoustik SA2.0 speakers. */
					sample->pac = IEC60958_PAC_RSV;
				}
				else {
					sample->validity = IEC60958_DATA_VALID;
					if( i % 2 == 0 || amdtp->dimension == 1 ) {
						/* even --> CHANNEL 1 */
						if( amdtp->iec958_frame_count == 0 )
						{
							sample->pac = IEC60958_PAC_B;
						}
						else
						{	
							sample->pac = IEC60958_PAC_M;
						}
					}
					else {
						/* Odd --> CHANNEL 2 */
						sample->pac = IEC60958_PAC_W;
					}
				}

				sample->ch_status = 0;
				/* The parity bit is the xor of the sample bits and the channel 
				   status info bit. */
				int shift;
				u_int32_t p;
				for (shift = 16, p = sample->data ^ sample->ch_status; shift > 0; shift >>= 1)
				{
					p ^= (p >> shift);
				}
				sample->parity = p & 1;

				event[i] = htonl (event[i]);
				
				/* increase the IEC958 framecounter */
				if ((i % 2 == 1) || (amdtp->dimension == 1))
				{
					amdtp->iec958_frame_count++;
					if (amdtp->iec958_frame_count >= 192) {
						amdtp->iec958_frame_count = 0;
					}
				}
			}
		}
		else {
			/* Unsupported format. */
			result = RAW1394_ISO_ERROR;
		}

		*len = nsamples * amdtp->dimension * sizeof (quadlet_t) + 8;
		*tag = IEC61883_TAG_WITH_CIP;
		*sy = 0;
	}

	return result;
}

int
iec61883_amdtp_xmit_start (struct iec61883_amdtp *amdtp, int channel)
{
	int result = 0;
	unsigned int max_packet_size;

	assert (amdtp != NULL);
	max_packet_size = iec61883_cip_get_max_packet_size (&amdtp->cip);

	result = raw1394_iso_xmit_init (amdtp->handle, amdtp_xmit_handler,
					amdtp->buffer_packets,
					max_packet_size, channel,
					amdtp->speed, amdtp->irq_interval);
	if (result == 0) {
		amdtp->total_dropped = 0;
		amdtp->channel = channel;
		result = raw1394_iso_xmit_start (amdtp->handle, 0,
						 amdtp->prebuffer_packets);
	}

	return result;
}

iec61883_amdtp_t
iec61883_amdtp_recv_init (raw1394handle_t handle,
		iec61883_amdtp_recv_t put_data, void *callback_data)
{
	struct iec61883_amdtp *amdtp;
	
	amdtp = malloc (sizeof (struct iec61883_amdtp));
	if (!amdtp) {
		errno = ENOMEM;
		return NULL;
	}

	amdtp->channel = -1;
	amdtp->handle = handle;
	amdtp->put_data = put_data;
	amdtp->callback_data = callback_data;
	amdtp->buffer_packets = 1000;
	amdtp->irq_interval = 250;
	amdtp->synch = 0;

	raw1394_set_userdata (handle, amdtp);

	return amdtp;
}

static enum raw1394_iso_disposition
amdtp_recv_handler (raw1394handle_t handle,
		unsigned char *data,
		unsigned int len,
		unsigned char channel,
		unsigned char tag,
		unsigned char sy,
		unsigned int cycle, 
		unsigned int dropped)
{
	struct iec61883_amdtp *amdtp = raw1394_get_userdata (handle);
	enum raw1394_iso_disposition result = RAW1394_ISO_OK;
	struct iec61883_packet *packet = (struct iec61883_packet *) data;
	int label;

	assert (amdtp != NULL);
	amdtp->total_dropped += dropped;
	
	/* We only support AM824 data for the moment. */
	/* We should check the DBC value to make sure we don't miss any packet. */
	if (tag == IEC61883_TAG_WITH_CIP &&
	    packet->fmt == IEC61883_FMT_AMDTP && (
	    ((packet->fdf & ~IEC61883_FDF_SFC_MASK) == IEC61883_FDF_AM824) ||
	    ((packet->fdf & ~IEC61883_FDF_SFC_MASK) == IEC61883_FDF_AM824_CONTROLLED))) {

		/* We fill amdtp structure fields upon reception of first packet. */
		if ((amdtp->dimension < 0) && (packet->syt != 0xFFFF)) {
			amdtp->dimension = packet->dbs; /* Number of audio channels. */

			DEBUG ("FDF code = %d.", packet->fdf);

			/* Obtaining sampling rate from SFC code. */
			switch (packet->fdf & IEC61883_FDF_SFC_MASK)
			{
			case IEC61883_FDF_SFC_32KHZ:
				amdtp->rate = 32000;
				break;
			case IEC61883_FDF_SFC_44K1HZ:
				amdtp->rate = 44100;
				break;
			case IEC61883_FDF_SFC_48KHZ:
				amdtp->rate = 48000;
				break;
			case IEC61883_FDF_SFC_88K2HZ:
				amdtp->rate = 88200;
				break;
			case IEC61883_FDF_SFC_96KHZ:
				amdtp->rate = 96000;
				break;
			case IEC61883_FDF_SFC_176K4HZ:
				amdtp->rate = 176400;
				break;
			case IEC61883_FDF_SFC_192KHZ:
				amdtp->rate = 192000;
			default:
				WARN ("Unsupported SFC code (%d).",
				      packet->fdf & IEC61883_FDF_SFC_MASK);
				return RAW1394_ISO_ERROR;
			}

			label = htonl (*((quadlet_t *) packet->data)) >> 24;

			/* Checking label. */
			if ((label & ~0x03) == IEC61883_AM824_LABEL) {
				DEBUG ("Multi-bit Linear Audio (MBLA) samples.");
				/* Multi-bit Linear Audio (MBLA). */
				amdtp->format = IEC61883_AMDTP_FORMAT_RAW;

				/* Checking Valid Bit Length code. */
				switch (label & 0x03) {
				case IEC61883_AM824_VBL_24BITS:
					DEBUG ("24-bits samples.");
					amdtp->sample_format =
						IEC61883_AMDTP_INPUT_LE24;
					break;
				case IEC61883_AM824_VBL_20BITS:
					DEBUG ("20-bits samples.");
					amdtp->sample_format =
						IEC61883_AMDTP_INPUT_LE20;
					break;
				case IEC61883_AM824_VBL_16BITS:
					DEBUG ("16-bits samples.");
					amdtp->sample_format =
						IEC61883_AMDTP_INPUT_LE16;
					break;
				default:
					WARN ("Unsupported valid bit length code (%d).", label & 0x03);
					result = RAW1394_ISO_ERROR;
				}
			} else if ((label >= 0) && (label <= 0x3F)) {
				/* IEC60958 Conformant Data. */
				/* TODO: how to determine AC3 */
				amdtp->format = IEC61883_AMDTP_FORMAT_IEC958_PCM;
				amdtp->sample_format = IEC61883_AMDTP_INPUT_NA;
			} else {
				WARN ("Unsupported data format label (%d).",
				      label);
				result = RAW1394_ISO_ERROR;
			}
		}

		if ((result == RAW1394_ISO_OK) && 
				(amdtp->dimension > 0) && (packet->syt != 0xFFFF)) {
			int nsamples = (len / sizeof (quadlet_t)) - 2; /* Substracting CIP headers. */
			quadlet_t *event = (quadlet_t *) packet->data;
			int i;

			for (i = 0; i < nsamples; i++)
				event[i] = ntohl (event[i]);
				
			if (amdtp->put_data (amdtp, packet->data, nsamples, packet->dbc, dropped,
				amdtp->callback_data) < 0)
				result = RAW1394_ISO_ERROR;
		}
	}
	if (result == RAW1394_ISO_OK && dropped)
		result = RAW1394_ISO_DEFER;

	return result;
}

int
iec61883_amdtp_recv_start (struct iec61883_amdtp *amdtp, int channel)
{
	int result = 0;

	assert (amdtp != NULL);
	result = raw1394_iso_recv_init (amdtp->handle,
		amdtp_recv_handler,
		amdtp->buffer_packets,
		AMDTP_MAX_PACKET_SIZE,
		channel,
		RAW1394_DMA_PACKET_PER_BUFFER,
		amdtp->irq_interval);

	if (result == 0) {
		amdtp->total_dropped = 0;
		amdtp->channel = channel;
		amdtp->dimension = -1;	/* The audio informations in amdtp structure will be
					 * filled-in upon reception of the first isochronous
					 * packet. */

		result = raw1394_iso_recv_start (amdtp->handle, -1, -1, 0);
	}
	return result;
}

void
iec61883_amdtp_recv_stop (struct iec61883_amdtp *amdtp)
{
	assert (amdtp != NULL);
	if (amdtp->synch)
		raw1394_iso_recv_flush (amdtp->handle);
	raw1394_iso_shutdown (amdtp->handle);
}

void
iec61883_amdtp_xmit_stop (struct iec61883_amdtp *amdtp)
{
	assert (amdtp != NULL);
	if (amdtp->synch)
		raw1394_iso_xmit_sync (amdtp->handle);
	raw1394_iso_shutdown (amdtp->handle);
}

void
iec61883_amdtp_close (struct iec61883_amdtp *amdtp)
{
	assert (amdtp != NULL);
	if (amdtp->put_data)
		iec61883_amdtp_recv_stop (amdtp);
	if (amdtp->get_data)
		iec61883_amdtp_xmit_stop (amdtp);
	free (amdtp);
}

unsigned int
iec61883_amdtp_get_buffers (iec61883_amdtp_t amdtp)
{
	assert (amdtp != NULL);
	return amdtp->buffer_packets;
}

void
iec61883_amdtp_set_buffers (iec61883_amdtp_t amdtp, unsigned int packets)
{
	assert (amdtp != NULL);
	amdtp->buffer_packets = packets;
}

unsigned int
iec61883_amdtp_get_prebuffers (iec61883_amdtp_t amdtp)
{
	assert (amdtp != NULL);
	return amdtp->prebuffer_packets;
}

void
iec61883_amdtp_set_prebuffers (iec61883_amdtp_t amdtp, unsigned int packets)
{
	assert (amdtp != NULL);
	amdtp->prebuffer_packets = packets;
}

unsigned int
iec61883_amdtp_get_irq_interval (iec61883_amdtp_t amdtp)
{
	assert (amdtp != NULL);
	return amdtp->irq_interval;
}

void
iec61883_amdtp_set_irq_interval (iec61883_amdtp_t amdtp, unsigned int packets)
{
	assert (amdtp != NULL);
	amdtp->irq_interval = packets;
}

int
iec61883_amdtp_get_synch (iec61883_amdtp_t amdtp)
{
	assert (amdtp != NULL);
	return amdtp->synch;
}

void
iec61883_amdtp_set_synch (iec61883_amdtp_t amdtp, int synch)
{
	assert (amdtp != NULL);
	amdtp->synch = synch;
}

int
iec61883_amdtp_get_speed (iec61883_amdtp_t amdtp)
{
	assert (amdtp != NULL);
	return amdtp->speed;
}

void
iec61883_amdtp_set_speed (iec61883_amdtp_t amdtp, int speed)
{
	assert (amdtp != NULL);
	amdtp->speed = speed;
}

unsigned int
iec61883_amdtp_get_dropped(iec61883_amdtp_t amdtp)
{
	assert (amdtp != NULL);
	return amdtp->total_dropped;
}

void *
iec61883_amdtp_get_callback_data (iec61883_amdtp_t amdtp)
{
	assert (amdtp != NULL);
	return amdtp->callback_data;
}

int
iec61883_amdtp_get_dimension(iec61883_amdtp_t amdtp)
{
	assert (amdtp != NULL);
	return amdtp->dimension;
}

int
iec61883_amdtp_get_rate(iec61883_amdtp_t amdtp)
{
	assert (amdtp != NULL);
	return amdtp->rate;
}

enum iec61883_amdtp_format
iec61883_amdtp_get_format(iec61883_amdtp_t amdtp)
{
	assert (amdtp != NULL);
	return amdtp->format;
}

enum iec61883_amdtp_sample_format
iec61883_amdtp_get_sample_format(iec61883_amdtp_t amdtp)
{
	assert (amdtp != NULL);
	return amdtp->sample_format;
}