/**

  * $Id: nrg.c,v 1.4 2007-01-31 10:58:42 nkeynes Exp $

  *

  * Nero (NRG) CD file format. File information stolen shamelessly from

  * libcdio.

  *

  * Copyright (c) 2005 Nathan Keynes.

  *

  * This program is free software; you can redistribute it and/or modify

  * it under the terms of the GNU General Public License as published by

  * the Free Software Foundation; either version 2 of the License, or

  * (at your option) any later version.

  *

  * This program 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 General Public License for more details.

  */

 #include <assert.h>

 #include <stdio.h>

 #include <errno.h>

 #include "gdrom/gdrom.h"

 #include "dream.h"

 static gboolean nrg_image_is_valid( FILE *f );

 static gdrom_disc_t nrg_image_open( const gchar *filename, FILE *f );

 struct gdrom_image_class nrg_image_class = { "Nero", "nrg", 

 					     nrg_image_is_valid, nrg_image_open };

 #define NERO_V55_ID  0x4e455235 

 #define NERO_V50_ID  0x4e45524f 

 /* Courtesy of libcdio */

 /* 5.0 or earlier */

 #define NERO_ID  0x4e45524f  /* Nero pre 5.5.x */

 #define CUES_ID  0x43554553  /* Nero pre version 5.5.x-6.x */

 #define DAOI_ID  0x44414f49

 #define ETNF_ID  0x45544e46

 #define SINF_ID  0x53494e46  /* Session information */

 #define END_ID  0x454e4421

 /* 5.5+ only */

 #define NER5_ID  0x4e455235  /* Nero version 5.5.x */

 #define CDTX_ID  0x43445458  /* CD TEXT */

 #define CUEX_ID  0x43554558  /* Nero version 5.5.x-6.x */

 #define DAOX_ID  0x44414f58  /* Nero version 5.5.x-6.x */

 #define ETN2_ID  0x45544e32

 #define MTYP_ID  0x4d545950  /* Disc Media type? */

 union nrg_footer {

     struct nrg_footer_v50 {

 	uint32_t dummy;

 	uint32_t id;

 	uint32_t offset;

     } v50;

     struct nrg_footer_v55 {

 	uint32_t id;

 	uint64_t offset;

     } v55;

 };

 struct nrg_chunk {

     uint32_t id;

     uint32_t length;

 };

 struct nrg_etnf {

     uint32_t offset;

     uint32_t length;

     uint32_t mode;

     uint32_t lba;

     uint32_t padding;

 };

 struct nrg_cues {

     uint8_t type;

     uint8_t track;

     uint8_t control;

     uint8_t pad;

     uint32_t addr;

 };

 struct nrg_daoi {

     uint32_t length;

     char mcn[14];

     uint8_t disc_mode;

     uint8_t unknown[2]; /* always 01 01? */

     uint8_t track_count;

     struct nrg_daoi_track {

 	char unknown[10];

 	uint32_t sector_size __attribute__((packed)); /* Always 0? */

 	uint8_t mode;

 	uint8_t unknown2[3]; /* Always 00 00 01? */

 	uint32_t pregap __attribute__((packed));

 	uint32_t offset __attribute__((packed));

 	uint32_t end __attribute__((packed));

     } track[0];

 } __attribute__((packed));

 /**

  * Convert an 8-bit BCD number to normal integer form. 

  * Eg, 0x79 => 79

  */

 uint8_t static bcd_to_uint8( uint8_t bcd )

 {

     return (bcd & 0x0F) + (((bcd & 0xF0)>>4)*10);

 }

 /**

  * Convert a 32 bit MSF address (BCD coded) to the

  * equivalent LBA form. 

  * Eg, 0x

  */

 uint32_t static msf_to_lba( uint32_t msf )

 {

     msf = ntohl(msf);

     int f = bcd_to_uint8(msf);

     int s = bcd_to_uint8(msf>>8);

     int m = bcd_to_uint8(msf>>16);

     return (m * 60 + s) * 75 + f;

 }

 uint32_t static nrg_track_mode( uint8_t mode )

 {

     switch( mode ) {

     case 0: return GDROM_MODE1;

     case 2: return GDROM_MODE2_XA1;

     case 3: return GDROM_MODE2;

     case 7: return GDROM_CDDA;

     default: 

 	ERROR( "Unrecognized track mode %d in Nero image", mode );

 	return -1;

     }

 }

 static gboolean nrg_image_is_valid( FILE *f )

 {

     union nrg_footer footer;

     fseek( f, -12, SEEK_END );

     fread( &footer, sizeof(footer), 1, f );

     if( ntohl(footer.v50.id) == NERO_V50_ID ) {

 	return TRUE;

     } else {

 	return FALSE;

     }

 }

 static gdrom_disc_t nrg_image_open( const gchar *filename, FILE *f )

 {

     union nrg_footer footer;

     struct nrg_chunk chunk;

     struct nrg_daoi *dao;

     gdrom_disc_t disc;

     gdrom_image_t image;

     gboolean end = FALSE;

     int session_id = 0;

     int session_track_id = 0;

     int track_id = 0;

     int cue_track_id = 0, cue_track_count = 0;

     int i;

     fseek( f, -12, SEEK_END );

     fread( &footer, sizeof(footer), 1, f );

     if( ntohl(footer.v50.id) == NERO_V50_ID ) {

 	INFO( "Loading Nero 5.0 image" );

 	fseek( f, ntohl(footer.v50.offset), SEEK_SET );

     } else if( ntohl(footer.v55.id) == NERO_V55_ID ) {

 	INFO( "Loading Nero 5.5+ image" );

 	fseek( f, ntohl(footer.v55.offset), SEEK_SET );

     } else {

 	/* Not a (recognized) Nero image */

 	return NULL;

     }

     disc = gdrom_image_new(f);

     if( disc == NULL ) {

 	fclose(f);

 	ERROR("Unable to allocate memory!");

 	return NULL;

     }

     image = (gdrom_image_t)disc;

     do {

 	fread( &chunk, sizeof(chunk), 1, f );

 	chunk.length = ntohl(chunk.length);

 	char data[chunk.length];

 	fread( data, chunk.length, 1, f );

 	switch( ntohl(chunk.id) ) {

 	case CUES_ID:

 	    cue_track_id = track_id;

 	    cue_track_count = ((chunk.length / sizeof(struct nrg_cues)) >> 1) - 1;

 	    track_id += cue_track_count;

 	    for( i=0; i<chunk.length; i+= sizeof(struct nrg_cues) ) {

 		struct nrg_cues *cue = (struct nrg_cues *)(data+i);

 		int track = 0;

 		if( cue->track == 0 )

 		    continue; /* Track 0. Leadin? always 0? */

 		if( cue->track == 0xAA ) { /* end of disc */

 		    image->track[track_id-1].sector_count =

 			msf_to_lba( cue->addr ) - image->track[track_id-1].lba;

 		} else {

 		    track = cue_track_id + bcd_to_uint8(cue->track) - 1;

 		    if( (cue->control & 0x01) == 0 ) { 

 			/* Pre-gap address. */

 			if( track != 0 ) {

 			    image->track[track-1].sector_count = 

 				msf_to_lba( cue->addr ) - image->track[track-1].lba;

 			}

 		    } else { /* Track-start address */

 			image->track[track].lba = msf_to_lba( cue->addr );

 			image->track[track].flags = cue->type;

 		    }

 		}

 	    }

 	    break;

 	case DAOI_ID:

 	    dao = (struct nrg_daoi *)data;

 	    memcpy( image->mcn, dao->mcn, 13 );

 	    image->mcn[13] = '\0';

 	    assert( dao->track_count * 30 + 22 == chunk.length );

 	    assert( dao->track_count == cue_track_count );

 	    for( i=0; i<dao->track_count; i++ ) {

 		image->track[cue_track_id].sector_size = ntohl(dao->track[i].sector_size);

 		image->track[cue_track_id].offset = ntohl(dao->track[i].offset);

 		image->track[cue_track_id].mode = nrg_track_mode( dao->track[i].mode );

 		image->track[cue_track_id].sector_count =

 		    (ntohl(dao->track[i].end) - ntohl(dao->track[i].offset))/

 		    ntohl(dao->track[i].sector_size);

 		cue_track_id++;

 	    }

 	    break;

 	case SINF_ID: 

 	    /* Data is a single 32-bit number representing number of tracks in session */

 	    i = ntohl( *(uint32_t *)data );

 	    while( i-- > 0 )

 		image->track[session_track_id++].session = session_id;

 	    session_id++;

 	    break;

 	case ETNF_ID:

 	    for( i=0; i < chunk.length; i+= 0x14 ) {

 		struct nrg_etnf *etnf = (struct nrg_etnf *)(data+i);

 		image->track[track_id].offset = ntohl(etnf->offset);

 		image->track[track_id].lba = ntohl(etnf->lba) + (i+1)*GDROM_PREGAP;

 		image->track[track_id].mode = nrg_track_mode( ntohl(etnf->mode) );

 		if( image->track[track_id].mode == -1 ) {

 		    disc->close(disc);

 		    return NULL;

 		}

 		if( image->track[track_id].mode == GDROM_CDDA )

 		    image->track[track_id].flags = 0x01;

 		else

 		    image->track[track_id].flags = 0x01 | TRACK_DATA;

 		image->track[track_id].sector_size = GDROM_SECTOR_SIZE(image->track[track_id].mode);

 		image->track[track_id].sector_count = ntohl(etnf->length) / 

 		    image->track[track_id].sector_size;

 		track_id++;

 	    }

 	    break;

 	case END_ID:

 	    end = TRUE;

 	    break;

 	}

     } while( !end );

     image->track_count = track_id;

     return disc;

 }