Changeset 13650

Timestamp:

02/01/08 10:52:26 (5 months ago)

Author:

retsios

Message:

Added option next to JasPer to use GDAL-JPEG2000-drivers supporting the J2k_SUBFILE mechanism, for decoding JPEG2000 sections in GRIB files.

Files:

• spike/grib/degrib18/g2clib-1.0.4/dec_jpeg2000.cpp (modified) (4 diffs)

spike/grib/degrib18/g2clib-1.0.4/dec_jpeg2000.cpp

@@ -1 +1 @@
-#include "grib2.h"
+
-#ifndef USE_JPEG2000
-int dec_jpeg2000(char *injpc,g2int bufsize,g2int *outfld) {return 0;}
-
+
+
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
+
+#ifdef USE_JPEG2000_J2KSUBFILE
+#include <gdal_pam.h>
+#else
-#include <jasper/jasper.h>
-#define JAS_1_700_2
-
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-   int dec_jpeg2000(char *injpc,g2int bufsize,g2int *outfld)
@@ -51 +105 @@
-
-{
+
+#ifdef USE_JPEG2000_J2KSUBFILE
+     
+    // J2K_SUBFILE method
+    
+    // Specifically ECW needs a few JP2 headers (the so-called "boxes") .. prepend them to the memory buffer
+    // Does Kakadu need them as well?
+    const int headersize = 40;  // 40 bytes of headers will be prepended
+    char* jpcbuf = injpc; // remember old buffer
+    injpc = (char*)malloc(bufsize + headersize); // old buffer is too small, thus allocate new buffer
+    writeJ2KHeaders(injpc); // write out the 40 header bytes
+    memcpy(injpc + headersize, jpcbuf, bufsize); // append the jpeg2000 data
+
+    // create "memory file" from buffer
+    int fileNumber = 0;
+    VSIStatBufL   sStatBuf;
+    char *pszFileName = CPLStrdup( "/vsimem/work.jp2" );
+
+    // ensure we don't overwrite an existing file accidentally
+    while ( VSIStatL( pszFileName, &sStatBuf ) == 0 ) {
+          CPLFree( pszFileName );
+          pszFileName = CPLStrdup( CPLSPrintf( "/vsimem/work%d.jp2", ++fileNumber ) );
+    }
+
+    VSIFCloseL( VSIFileFromMemBuffer( pszFileName, (unsigned char*)injpc, bufsize + headersize, TRUE ) ); // TRUE to let vsi delete the buffer when done
+
+    // Open it with a JPEG2000 driver supporting J2K_SUBFILE
+    char *pszDSName = CPLStrdup( CPLSPrintf( "J2K_SUBFILE:%d,%d,%s", 0, bufsize, pszFileName ) );
+
+    // Open memory buffer for reading 
+    GDALDataset* poJ2KDataset = (GDALDataset *)GDALOpen( pszDSName, GA_ReadOnly ); // This goes to CNCSJP2FileView
+    //GDALDataset* poJ2KDataset = (GDALDataset *)GDALOpen( "/vsimem/work.jp2", GA_ReadOnly ); // This goes to CNCSJP2File, and fails
+ 
+    if( poJ2KDataset == NULL )
+    {
+        printf("dec_jpeg2000: Unable to open JPEG2000 image within GRIB file.\n"
+                  "Is the JPEG2000 driver available?" );
+        return -3;
+    }
+
+    if( poJ2KDataset->GetRasterCount() != 1 )
+    {
+       printf("dec_jpeg2000: Found color image.  Grayscale expected.\n");
+       return (-5);
+    }
+
+    GDALRasterBand *poBand = poJ2KDataset->GetRasterBand(1);
+
+    // Fulfill administration: initialize parameters required for RasterIO
+    int nXSize = poJ2KDataset->GetRasterXSize();
+    int nYSize = poJ2KDataset->GetRasterYSize();
+    int nXOff = 0;
+    int nYOff = 0;
+    int nBufXSize = nXSize;
+    int nBufYSize = nYSize;
+    GDALDataType eBufType = GDT_Int32; // map to type of "outfld" buffer: g2int*
+    int nBandCount = 1;
+    int* panBandMap = NULL;
+    int nPixelSpace = 0;
+    int nLineSpace = 0;
+    int nBandSpace = 0;
+
+    //    Decompress the JPEG2000 into the output integer array.
+    poJ2KDataset->RasterIO( GF_Read, nXOff, nYOff, nXSize, nYSize,
+                                       outfld, nBufXSize, nBufYSize, eBufType,
+                                       nBandCount, panBandMap, 
+                                       nPixelSpace, nLineSpace, nBandSpace );
+
+    // close source file, and "unlink" it.
+    GDALClose( poJ2KDataset );
+    VSIUnlink( pszFileName );
+
+    CPLFree( pszDSName );
+    CPLFree( pszFileName );
+
+    return 0;
+
+#else /* USE_JPEG2000_J2KSUBFILE */
+
+    // JasPer method
+    
-    int ier;
-    g2int i,j,k;
@@ -71 +206 @@
-//     Decode JPEG200 codestream into jas_image_t structure.
-//       
+
-    image=jpc_decode(jpcstream,opts);
-    if ( image == 0 ) {
@@ -138 +274 @@
-
-    return 0;
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