int main( int nArgc, char ** papszArgv )
{
const char *pszFilename;
FILE *fp;
CEOSRecord *psRecord;
int nPosition = 0;
if( nArgc > 1 )
pszFilename = papszArgv[1];
else
pszFilename = "imag_01.dat";
fp = VSIFOpenL( pszFilename, "rb" );
if( fp == NULL )
{
fprintf( stderr, "Can't open %s at all.\n", pszFilename );
exit( 1 );
}
while( !VSIFEofL(fp)
&& (psRecord = CEOSReadRecord( fp )) != NULL )
{
printf( "%9d:%4d:%8x:%d\n",
nPosition, psRecord->nRecordNum,
psRecord->nRecordType, psRecord->nLength );
CEOSDestroyRecord( psRecord );
nPosition = (int) VSIFTellL( fp );
}
VSIFCloseL( fp );
exit( 0 );
}
CEOSImage * CEOSOpen( const char * pszFilename, const char * pszAccess )
{
VSILFILE *fp;
CEOSRecord *psRecord;
CEOSImage *psImage;
int nSeqNum, i;
GByte abyHeader[16];
/* -------------------------------------------------------------------- */
/* Try to open the imagery file. */
/* -------------------------------------------------------------------- */
fp = VSIFOpenL( pszFilename, pszAccess );
if( fp == NULL )
{
CPLError( CE_Failure, CPLE_OpenFailed,
"Failed to open CEOS file `%s' with access `%s'.\n",
pszFilename, pszAccess );
return NULL;
}
/* -------------------------------------------------------------------- */
/* Create a CEOSImage structure, and initialize it. */
/* -------------------------------------------------------------------- */
psImage = (CEOSImage *) CPLCalloc(1,sizeof(CEOSImage));
psImage->fpImage = fp;
psImage->nPixels = psImage->nLines = psImage->nBands = 0;
/* -------------------------------------------------------------------- */
/* Preread info on the first record, to establish if it is */
/* little endian. */
/* -------------------------------------------------------------------- */
VSIFReadL( abyHeader, 16, 1, fp );
VSIFSeekL( fp, 0, SEEK_SET );
if( abyHeader[0] != 0 || abyHeader[1] != 0 )
psImage->bLittleEndian = TRUE;
/* -------------------------------------------------------------------- */
/* Try to read the header record. */
/* -------------------------------------------------------------------- */
psRecord = CEOSReadRecord( psImage );
if( psRecord == NULL )
{
CEOSClose( psImage );
return NULL;
}
if( psRecord->nRecordType != CRT_IMAGE_FDR )
{
CPLError( CE_Failure, CPLE_AppDefined,
"Got a %X type record, instead of the expected\n"
"file descriptor record on file %s.\n",
psRecord->nRecordType, pszFilename );
CEOSDestroyRecord( psRecord );
CEOSClose( psImage );
return NULL;
}
/* -------------------------------------------------------------------- */
/* The sequence number should be 2 indicating this is the */
/* imagery file. */
/* -------------------------------------------------------------------- */
nSeqNum = CEOSScanInt( psRecord->pachData + 44, 4 );
if( nSeqNum != 2 )
{
CPLError( CE_Warning, CPLE_AppDefined,
"Got a %d file sequence number, instead of the expected\n"
"2 indicating imagery on file %s.\n"
"Continuing to access anyways.\n",
nSeqNum, pszFilename );
}
/* -------------------------------------------------------------------- */
/* Extract various information. */
/* -------------------------------------------------------------------- */
psImage->nImageRecCount = CEOSScanInt( psRecord->pachData+180, 6 );
psImage->nImageRecLength = CEOSScanInt( psRecord->pachData+186, 6 );
psImage->nBitsPerPixel = CEOSScanInt( psRecord->pachData+216, 4 );
psImage->nBands = CEOSScanInt( psRecord->pachData+232, 4 );
psImage->nLines = CEOSScanInt( psRecord->pachData+236, 8 );
psImage->nPixels = CEOSScanInt( psRecord->pachData+248, 8 );
psImage->nPrefixBytes = CEOSScanInt( psRecord->pachData+276, 4 );
psImage->nSuffixBytes = CEOSScanInt( psRecord->pachData+288, 4 );
if( psImage->nImageRecLength <= 0 ||
psImage->nPrefixBytes < 0 ||
psImage->nBands > INT_MAX / psImage->nImageRecLength ||
(size_t)psImage->nBands > INT_MAX / sizeof(int))
{
CEOSDestroyRecord( psRecord );
CEOSClose( psImage );
return NULL;
}
/* -------------------------------------------------------------------- */
/* Try to establish the layout of the imagery data. */
/* -------------------------------------------------------------------- */
psImage->nLineOffset = psImage->nBands * psImage->nImageRecLength;
psImage->panDataStart = (int *) VSIMalloc(sizeof(int) * psImage->nBands);
if( psImage->panDataStart == NULL )
{
CEOSDestroyRecord( psRecord );
CEOSClose( psImage );
return NULL;
}
for( i = 0; i < psImage->nBands; i++ )
{
psImage->panDataStart[i] =
psRecord->nLength + i * psImage->nImageRecLength
+ 12 + psImage->nPrefixBytes;
}
CEOSDestroyRecord( psRecord );
return psImage;
}