/*

    File: file_dv.c

    Copyright (C) 2006-2007 Christophe GRENIER <grenier@cgsecurity.org>
  
    This software 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.
  
    You should have received a copy of the GNU General Public License along
    with this program; if not, write the Free Software Foundation, Inc., 51
    Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#include <stdio.h>
#include "types.h"
#include "filegen.h"

static void register_header_check_dv(file_stat_t *file_stat);
static int header_check_dv(const unsigned char *buffer, const unsigned int buffer_size, const unsigned int safe_header_only, const file_recovery_t *file_recovery, file_recovery_t *file_recovery_new);
static int data_check_dv(const unsigned char *buffer, const unsigned int buffer_size, file_recovery_t *file_recovery);

const file_hint_t file_hint_dv= {
  .extension="dv",
  .description="DIF Digital Video",
  .min_header_distance=0,
  .max_filesize=PHOTOREC_MAX_FILE_SIZE,
  .recover=1,
  .enable_by_default=1,
  .register_header_check=&register_header_check_dv
};
static const unsigned char dv_header[3]= {0x1f, 0x07, 0x00};

static void register_header_check_dv(file_stat_t *file_stat)
{
  register_header_check(0, dv_header,sizeof(dv_header), &header_check_dv, file_stat);
}

static int header_check_dv(const unsigned char *buffer, const unsigned int buffer_size, const unsigned int safe_header_only, const file_recovery_t *file_recovery, file_recovery_t *file_recovery_new)
{
  if(file_recovery!=NULL && file_recovery->file_stat!=NULL && file_recovery->file_stat->file_hint==&file_hint_dv)
    return 0;
  /* The header may be only 3 bytes */
  if(buffer[0]==0x1f && buffer[1]==0x07 && buffer[2]==0x00 && buffer[5]==0x78 && buffer[6]==0x78 && buffer[7]==0x78)
  {
    /* NTSC */
    reset_file_recovery(file_recovery_new);
    file_recovery_new->extension=file_hint_dv.extension;
    file_recovery_new->data_check=data_check_dv;
    file_recovery_new->file_check=&file_check_size;
    return 1;
  }
  return 0;
}

static int data_check_dv(const unsigned char *buffer, const unsigned int buffer_size, file_recovery_t *file_recovery)
{
  while(file_recovery->calculated_file_size + buffer_size/2  >= file_recovery->file_size &&
      file_recovery->calculated_file_size + 8 < file_recovery->file_size + buffer_size/2)
  {
    const unsigned int i=file_recovery->calculated_file_size - file_recovery->file_size + buffer_size/2;
    if(buffer[i]==0x1f && buffer[i+1]==0x07 && buffer[i+2]==0x00 &&
	buffer[i+5]==0x78 && buffer[i+6]==0x78 && buffer[i+7]==0x78)
      file_recovery->calculated_file_size+=120000;
    else
      return 2;
  }
  return 1;
}