dvd_reader.c

有关mpeg2的deocde代码

/*
 * Copyright (C) 2001, 2002, 2003 Billy Biggs <[e-mail]>,
 *                                H錵an Hjort <[e-mail]>,
 *                                Bj鰎n Englund <[e-mail]>
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
 */

#include "config.h"

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/time.h> /* For the timing of dvdcss_title crack. */
#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>
#include <dirent.h>
 
#if defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) || defined(__bsdi__)|| defined(__DARWIN__)
#define SYS_BSD 1
#endif

#if defined(__sun)
#include <sys/mnttab.h>
#elif defined(SYS_BSD)
#include <fstab.h>
#elif defined(__linux__)
#include <mntent.h>
#endif

#include "dvd_udf.h"
#include "dvd_input.h"
#include "dvd_reader.h"
#include "md5.h"

#define DEFAULT_UDF_CACHE_LEVEL 1

struct dvd_reader_s {
    /* Basic information. */
    int isImageFile;
  
    /* Hack for keeping track of the css status. 
     * 0: no css, 1: perhaps (need init of keys), 2: have done init */
    int css_state;
    int css_title; /* Last title that we have called dvdinpute_title for. */

    /* Information required for an image file. */
    dvd_input_t dev;

    /* Information required for a directory path drive. */
    char *path_root;
  
    /* Filesystem cache */
    int udfcache_level; /* 0 - turned off, 1 - on */
    void *udfcache;
};

struct dvd_file_s {
    /* Basic information. */
    dvd_reader_t *dvd;
  
    /* Hack for selecting the right css title. */
    int css_title;

    /* Information required for an image file. */
    uint32_t lb_start;
    uint32_t seek_pos;

    /* Information required for a directory path drive. */
    size_t title_sizes[ 9 ];
    dvd_input_t title_devs[ 9 ];

    /* Calculated at open-time, size in blocks. */
    ssize_t filesize;
};

/**
 * Set the level of caching on udf
 * level = 0 (no caching)
 * level = 1 (caching filesystem info)
 */
int DVDUDFCacheLevel(dvd_reader_t *device, int level)
{
  struct dvd_reader_s *dev = (struct dvd_reader_s *)device;
  
  if(level > 0) {
    level = 1;
  } else if(level < 0) {
    return dev->udfcache_level;
  }

  dev->udfcache_level = level;
  
  return level;
}

void *GetUDFCacheHandle(dvd_reader_t *device)
{
  struct dvd_reader_s *dev = (struct dvd_reader_s *)device;
  
  return dev->udfcache;
}

void SetUDFCacheHandle(dvd_reader_t *device, void *cache)
{
  struct dvd_reader_s *dev = (struct dvd_reader_s *)device;

  dev->udfcache = cache;
}



/* Loop over all titles and call dvdcss_title to crack the keys. */
static int initAllCSSKeys( dvd_reader_t *dvd )
{
    struct timeval all_s, all_e;
    struct timeval t_s, t_e;
    char filename[ MAX_UDF_FILE_NAME_LEN ];
    uint32_t start, len;
    int title;
	
    char *nokeys_str = getenv("DVDREAD_NOKEYS");
    if(nokeys_str != NULL)
      return 0;
    
    fprintf( stderr, "\n" );
    fprintf( stderr, "libdvdread: Attempting to retrieve all CSS keys\n" );
    fprintf( stderr, "libdvdread: This can take a _long_ time, "
	     "please be patient\n\n" );
	
    gettimeofday(&all_s, NULL);
	
    for( title = 0; title < 100; title++ ) {
	gettimeofday( &t_s, NULL );
	if( title == 0 ) {
	    sprintf( filename, "/VIDEO_TS/VIDEO_TS.VOB" );
	} else {
	    sprintf( filename, "/VIDEO_TS/VTS_%02d_%d.VOB", title, 0 );
	}
	start = UDFFindFile( dvd, filename, &len );
	if( start != 0 && len != 0 ) {
	    /* Perform CSS key cracking for this title. */
	    fprintf( stderr, "libdvdread: Get key for %s at 0x%08x\n", 
		     filename, start );
	    if( dvdinput_title( dvd->dev, (int)start ) < 0 ) {
		fprintf( stderr, "libdvdread: Error cracking CSS key for %s (0x%08x)\n", filename, start);
	    }
	    gettimeofday( &t_e, NULL );
	    fprintf( stderr, "libdvdread: Elapsed time %ld\n",  
		     (long int) t_e.tv_sec - t_s.tv_sec );
	}
	    
	if( title == 0 ) continue;
	    
	gettimeofday( &t_s, NULL );
	sprintf( filename, "/VIDEO_TS/VTS_%02d_%d.VOB", title, 1 );
	start = UDFFindFile( dvd, filename, &len );
	if( start == 0 || len == 0 ) break;
	    
	/* Perform CSS key cracking for this title. */
	fprintf( stderr, "libdvdread: Get key for %s at 0x%08x\n", 
		 filename, start );
	if( dvdinput_title( dvd->dev, (int)start ) < 0 ) {
	    fprintf( stderr, "libdvdread: Error cracking CSS key for %s (0x%08x)!!\n", filename, start);
	}
	gettimeofday( &t_e, NULL );
	fprintf( stderr, "libdvdread: Elapsed time %ld\n",  
		 (long int) t_e.tv_sec - t_s.tv_sec );
    }
    title--;
    
    fprintf( stderr, "libdvdread: Found %d VTS's\n", title );
    gettimeofday(&all_e, NULL);
    fprintf( stderr, "libdvdread: Elapsed time %ld\n",  
	     (long int) all_e.tv_sec - all_s.tv_sec );
    
    return 0;
}



/**
 * Open a DVD image or block device file.
 */
static dvd_reader_t *DVDOpenImageFile( const char *location, int have_css )
{
    dvd_reader_t *dvd;
    dvd_input_t dev;
    
    dev = dvdinput_open( location );
    if( !dev ) {
	fprintf( stderr, "libdvdread: Can't open %s for reading\n", location );
	return 0;
    }

    dvd = (dvd_reader_t *) malloc( sizeof( dvd_reader_t ) );
    if( !dvd ) return 0;
    dvd->isImageFile = 1;
    dvd->dev = dev;
    dvd->path_root = 0;
    
    dvd->udfcache_level = DEFAULT_UDF_CACHE_LEVEL;
    dvd->udfcache = NULL;

    if( have_css ) {
      /* Only if DVDCSS_METHOD = title, a bit if it's disc or if
       * DVDCSS_METHOD = key but region missmatch. Unfortunaly we
       * don't have that information. */
    
      dvd->css_state = 1; /* Need key init. */
    }
    dvd->css_title = 0;
    
    return dvd;
}

static dvd_reader_t *DVDOpenPath( const char *path_root )
{
    dvd_reader_t *dvd;

    dvd = (dvd_reader_t *) malloc( sizeof( dvd_reader_t ) );
    if( !dvd ) return 0;
    dvd->isImageFile = 0;
    dvd->dev = 0;
    dvd->path_root = strdup( path_root );

    dvd->udfcache_level = DEFAULT_UDF_CACHE_LEVEL;
    dvd->udfcache = NULL;
    
    dvd->css_state = 0; /* Only used in the UDF path */
    dvd->css_title = 0; /* Only matters in the UDF path */

    return dvd;
}

#if defined(__sun)
/* /dev/rdsk/c0t6d0s0 (link to /devices/...)
   /vol/dev/rdsk/c0t6d0/??
   /vol/rdsk/<name> */
static char *sun_block2char( const char *path )
{
    char *new_path;

    /* Must contain "/dsk/" */ 
    if( !strstr( path, "/dsk/" ) ) return (char *) strdup( path );

    /* Replace "/dsk/" with "/rdsk/" */
    new_path = malloc( strlen(path) + 2 );
    strcpy( new_path, path );
    strcpy( strstr( new_path, "/dsk/" ), "" );
    strcat( new_path, "/rdsk/" );
    strcat( new_path, strstr( path, "/dsk/" ) + strlen( "/dsk/" ) );

    return new_path;
}
#endif

#if defined(SYS_BSD)
/* FreeBSD /dev/(r)(a)cd0c (a is for atapi), recomended to _not_ use r
   OpenBSD /dev/rcd0c, it needs to be the raw device
   NetBSD  /dev/rcd0[d|c|..] d for x86, c (for non x86), perhaps others
   Darwin  /dev/rdisk0,  it needs to be the raw device
   BSD/OS  /dev/sr0c (if not mounted) or /dev/rsr0c ('c' any letter will do) */
static char *bsd_block2char( const char *path )
{
    char *new_path;

    /* If it doesn't start with "/dev/" or does start with "/dev/r" exit */ 
    if( !strncmp( path, "/dev/",  5 ) || strncmp( path, "/dev/r", 6 ) ) 
      return (char *) strdup( path );

    /* Replace "/dev/" with "/dev/r" */
    new_path = malloc( strlen(path) + 2 );
    strcpy( new_path, "/dev/r" );
    strcat( new_path, path + strlen( "/dev/" ) );

    return new_path;
}
#endif

dvd_reader_t *DVDOpen( const char *path )
{
    struct stat fileinfo;
    int ret, have_css;
    char *dev_name = 0;

    if( path == NULL )
      return 0;

    ret = stat( path, &fileinfo );
    if( ret < 0 ) {
	/* If we can't stat the file, give up */
	fprintf( stderr, "libdvdread: Can't stat %s\n", path );
	perror("");
	return 0;
    }

    /* Try to open libdvdcss or fall back to standard functions */
    have_css = dvdinput_setup();

    /* First check if this is a block/char device or a file*/
    if( S_ISBLK( fileinfo.st_mode ) || 
	S_ISCHR( fileinfo.st_mode ) || 
	S_ISREG( fileinfo.st_mode ) ) {

	/**
	 * Block devices and regular files are assumed to be DVD-Video images.
	 */
#if defined(__sun)
	return DVDOpenImageFile( sun_block2char( path ), have_css );
#elif defined(SYS_BSD)
	return DVDOpenImageFile( bsd_block2char( path ), have_css );
#else
	return DVDOpenImageFile( path, have_css );
#endif

    } else if( S_ISDIR( fileinfo.st_mode ) ) {
	dvd_reader_t *auth_drive = 0;
	char *path_copy;
#if defined(SYS_BSD)
	struct fstab* fe;
#elif defined(__sun) || defined(__linux__)
	FILE *mntfile;
#endif

	/* XXX: We should scream real loud here. */
	if( !(path_copy = strdup( path ) ) ) return 0;

	/* Resolve any symlinks and get the absolut dir name. */
	{
	    char *new_path;
	    int cdir = open( ".", O_RDONLY );
	    
	    if( cdir >= 0 ) {
		chdir( path_copy );
		new_path = getcwd( NULL, PATH_MAX );
		fchdir( cdir );
		close( cdir );
		if( new_path ) {
		    free( path_copy );
		    path_copy = new_path;
		}
	    }
	}
	
	/**
	 * If we're being asked to open a directory, check if that directory
	 * is the mountpoint for a DVD-ROM which we can use instead.
	 */

	if( strlen( path_copy ) > 1 ) {
	    if( path_copy[ strlen( path_copy ) - 1 ] == '/' ) 
		path_copy[ strlen( path_copy ) - 1 ] = '\0';
	}