CEOSDataset::~CEOSDataset()
{
FlushCache();
if( psCEOS )
CEOSClose( psCEOS );
}
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;
}
GDALDataset *CEOSDataset::Open( GDALOpenInfo * poOpenInfo )
{
CEOSImage *psCEOS;
int i;
/* -------------------------------------------------------------------- */
/* Before trying CEOSOpen() we first verify that the first */
/* record is in fact a CEOS file descriptor record. */
/* -------------------------------------------------------------------- */
if( poOpenInfo->nHeaderBytes < 100 )
return NULL;
if( poOpenInfo->pabyHeader[4] != 0x3f
|| poOpenInfo->pabyHeader[5] != 0xc0
|| poOpenInfo->pabyHeader[6] != 0x12
|| poOpenInfo->pabyHeader[7] != 0x12 )
return NULL;
/* -------------------------------------------------------------------- */
/* Try opening the dataset. */
/* -------------------------------------------------------------------- */
psCEOS = CEOSOpen( poOpenInfo->pszFilename, "rb" );
if( psCEOS == NULL )
return( NULL );
if( psCEOS->nBitsPerPixel != 8 )
{
CPLError( CE_Failure, CPLE_NotSupported,
"The CEOS driver cannot handle nBitsPerPixel = %d",
psCEOS->nBitsPerPixel );
CEOSClose(psCEOS);
return NULL;
}
if( !GDALCheckDatasetDimensions(psCEOS->nPixels, psCEOS->nBands) ||
!GDALCheckBandCount(psCEOS->nBands, FALSE) )
{
CEOSClose( psCEOS );
return NULL;
}
/* -------------------------------------------------------------------- */
/* Confirm the requested access is supported. */
/* -------------------------------------------------------------------- */
if( poOpenInfo->eAccess == GA_Update )
{
CEOSClose(psCEOS);
CPLError( CE_Failure, CPLE_NotSupported,
"The CEOS driver does not support update access to existing"
" datasets.\n" );
return NULL;
}
/* -------------------------------------------------------------------- */
/* Create a corresponding GDALDataset. */
/* -------------------------------------------------------------------- */
CEOSDataset *poDS;
poDS = new CEOSDataset();
poDS->psCEOS = psCEOS;
/* -------------------------------------------------------------------- */
/* Capture some information from the file that is of interest. */
/* -------------------------------------------------------------------- */
poDS->nRasterXSize = psCEOS->nPixels;
poDS->nRasterYSize = psCEOS->nLines;
/* -------------------------------------------------------------------- */
/* Create band information objects. */
/* -------------------------------------------------------------------- */
poDS->nBands = psCEOS->nBands;;
for( i = 0; i < poDS->nBands; i++ )
poDS->SetBand( i+1, new CEOSRasterBand( poDS, i+1 ) );
/* -------------------------------------------------------------------- */
/* Initialize any PAM information. */
/* -------------------------------------------------------------------- */
poDS->SetDescription( poOpenInfo->pszFilename );
poDS->TryLoadXML();
/* -------------------------------------------------------------------- */
/* Check for overviews. */
/* -------------------------------------------------------------------- */
poDS->oOvManager.Initialize( poDS, poOpenInfo->pszFilename );
return( poDS );
}
