/**
* Internal, but used from dvd_udf.c
*
* @param device A read handle.
* @param lb_number Logical block number to start read from.
* @param block_count Number of logical blocks to read.
* @param data Pointer to buffer where read data should be stored.
* This buffer must be large enough to hold lb_number*2048 bytes.
* The pointer must be aligned to the logical block size when
* reading from a raw/O_DIRECT device.
* @param encrypted 0 if no decryption shall be performed,
* 1 if decryption shall be performed
* @param return Returns number of blocks read on success, negative on error
*/
int UDFReadBlocksRaw( dvd_reader_t *device, uint32_t lb_number,
size_t block_count, unsigned char *data,
int encrypted )
{
int ret;
if( !device->dev ) {
if(device->verbose >= 1) {
fprintf( stderr, "libdvdread: Fatal error in block read.\n" );
}
return 0;
}
ret = dvdinput_seek( device->dev, (int) lb_number );
if( ret != (int) lb_number ) {
if(device->verbose >= 1) {
fprintf( stderr,
"libdvdread: UDFReadBlocksRaw: Can't seek to block %u\n",
lb_number );
}
return 0;
}
return dvdinput_read( device->dev, (char *) data,
(int) block_count, encrypted );
}
/* Internal, but used from dvd_udf.c */
int InternalUDFReadBlocksRaw( const dvd_reader_t *device, uint32_t lb_number,
size_t block_count, unsigned char *data,
int encrypted )
{
int ret;
if( !device->dev ) {
fprintf( stderr, "libdvdread: Fatal error in block read.\n" );
return 0;
}
ret = dvdinput_seek( device->dev, (int) lb_number, encrypted & DVDCSS_SEEK_KEY );
if( ret != (int) lb_number ) {
fprintf( stderr, "libdvdread: Can't seek to block %u\n", lb_number );
return 0;
}
ret = dvdinput_read( device->dev, (char *) data,
(int) block_count, encrypted & DVDINPUT_READ_DECRYPT );
return ret;
}
/* This is using possibly several inputs and starting from an offset of '0'.
*
* Reads 'block_count' blocks from 'dvd_file' at block offset 'offset'
* into the buffer located at 'data' and if 'encrypted' is set
* descramble the data if it's encrypted. Returning either an
* negative error or the number of blocks read. */
static int DVDReadBlocksPath( const dvd_file_t *dvd_file, unsigned int offset,
size_t block_count, unsigned char *data,
int encrypted )
{
int i;
int ret, ret2, off;
ret = 0;
ret2 = 0;
for( i = 0; i < TITLES_MAX; ++i ) {
if( !dvd_file->title_sizes[ i ] ) return 0; /* Past end of file */
if( offset < dvd_file->title_sizes[ i ] ) {
if( ( offset + block_count ) <= dvd_file->title_sizes[ i ] ) {
off = dvdinput_seek( dvd_file->title_devs[ i ], (int)offset, DVDINPUT_NOFLAGS );
if( off < 0 || off != (int)offset ) {
fprintf( stderr, "libdvdread: Can't seek to block %u\n",
offset );
return off < 0 ? off : 0;
}
ret = dvdinput_read( dvd_file->title_devs[ i ], data,
(int)block_count, encrypted );
break;
} else {
size_t part1_size = dvd_file->title_sizes[ i ] - offset;
/* FIXME: Really needs to be a while loop.
* (This is only true if you try and read >1GB at a time) */
/* Read part 1 */
off = dvdinput_seek( dvd_file->title_devs[ i ], (int)offset, DVDINPUT_NOFLAGS );
if( off < 0 || off != (int)offset ) {
fprintf( stderr, "libdvdread: Can't seek to block %u\n",
offset );
return off < 0 ? off : 0;
}
ret = dvdinput_read( dvd_file->title_devs[ i ], data,
(int)part1_size, encrypted );
if( ret < 0 ) return ret;
/* FIXME: This is wrong if i is the last file in the set.
* also error from this read will not show in ret. */
/* Does the next part exist? If not then return now. */
if( i + 1 >= TITLES_MAX || !dvd_file->title_devs[ i + 1 ] )
return ret;
/* Read part 2 */
off = dvdinput_seek( dvd_file->title_devs[ i + 1 ], 0, DVDINPUT_NOFLAGS );
if( off < 0 || off != 0 ) {
fprintf( stderr, "libdvdread: Can't seek to block %d\n",
0 );
return off < 0 ? off : 0;
}
ret2 = dvdinput_read( dvd_file->title_devs[ i + 1 ],
data + ( part1_size
* (int64_t)DVD_VIDEO_LB_LEN ),
(int)(block_count - part1_size),
encrypted );
if( ret2 < 0 ) return ret2;
break;
}
} else {
offset -= dvd_file->title_sizes[ i ];
}
}
return ret + ret2;
}
