X-Git-Url: https://git.creatis.insa-lyon.fr/pubgit/?a=blobdiff_plain;f=src%2FgdcmJpeg.cxx;h=640522d97487363cbae36852c6bb2efaf981ea04;hb=f045e95a9d0b82e8c4bd687710bd4a15323fbf55;hp=120656ed2bda9ae7c50becda980b7c713eadd6f2;hpb=a5d92ab54014d69e1c37116eb923dc3c5dc2e21f;p=gdcm.git diff --git a/src/gdcmJpeg.cxx b/src/gdcmJpeg.cxx index 120656ed..640522d9 100644 --- a/src/gdcmJpeg.cxx +++ b/src/gdcmJpeg.cxx @@ -1,404 +1,399 @@ -#include "iddcmjpeg.h" -#include - -static ClbJpeg* ClbJpegAlloc(void); -static void ClbJpegInit (ClbJpeg *); -static int ClbJpegDecodeDiff(ClbJpeg *); -static BOOL ClbJpegDecodeData(ClbJpeg *); -static int ClbJpegReadBit(ClbJpeg *); -static BOOL ClbJpegReadHeader(ClbJpeg *); -static BOOL ClbJpegStart(ClbJpeg *,FILE *); -static BOOL ClbJpegFillHuffTable(ClbJpeg *); - - - - -void _IdDcmJpegFree(ClbJpeg *jpg) -{ - free(jpg->DataImg); - free(jpg); +// gdcmJpeg.cxx +//----------------------------------------------------------------------------- +#include +#include "gdcmFile.h" + +#define BITS_IN_JSAMPLE 8 + +/* +DICOM provides a mechanism for supporting the use of JPEG Image Compression +through the Encapsulated Format (see PS 3.3 of the DICOM Standard). +Annex A defines a number of Transfer Syntaxes which reference +the JPEG Standard and provide a number of lossless (bit preserving) +and lossy compression schemes. +In order to facilitate interoperability of implementations conforming +to the DICOM Standard which elect to use one or more +of the Transfer Syntaxes for JPEG Image Compression, the following policy is specified: + + Any implementation which conforms to the DICOM Standard and has elected + to support any one of the Transfer Syntaxes for lossless JPEG Image Compression, + shall support the following lossless compression: + The subset (first-order horizontal prediction [Selection Value 1) of JPEG Process 14 + (DPCM, non-hierarchical with Huffman coding) (see Annex F of the DICOM Standard). + + Any implementation which conforms to the DICOM Standard and has elected + to support any one of the Transfer Syntaxes for 8-bit lossy JPEG Image Compression, + shall support the JPEG Baseline Compression (coding Process 1). + + Any implementation which conforms to the DICOM Standard and has elected + to support any one of the Transfer Syntaxes for 12-bit lossy JPEG Image Compression, + shall support the JPEG Compression Process 4. + +Note: The DICOM conformance statement shall differentiate between implementations +that can simply receive JPEG encoded images and those that can receive and process +JPEG encoded images (see PS 3.2 of the DICOM Standard). + +The use of the DICOM Encapsulated Format to support JPEG Compressed Pixel Data +implies that the Data Elements which are related to the Native Format Pixel Data encoding +(e.g. Bits Allocated, Bits Stored, High Bit, Pixel Representation, Rows, Columns, etc.) +shall contain values which are consistent with the characteristics +of the uncompressed pixel data from which the compressed Data Stream was derived. +The Pixel Data characteristics included in the JPEG Interchange Format +shall be used to decode the compressed data stream. + +Run Length Encoding Compression + +DICOM provides a mechanism for supporting the use of Run Length Encoding (RLE) +Compression which is a byte oriented lossless compression scheme through +the encapsulated Format (see PS 3.3 of this Standard). +Annex G of the DICOM Standard defines RLE Compression and its Transfer Syntax. + +Note: The RLE Compression algorithm described in Annex G +of the DICOM Standard is the compression used in +the TIFF 6.0 specification known as the "PackBits" scheme. + +The use of the DICOM Encapsulated Format to support RLE Compressed Pixel Data +implies that the Data Elements which are related to the Native Format Pixel Data encoding ( +e.g. Bits Allocated, Bits Stored, High Bit, Pixel Representation, Rows, Columns, etc.) +shall contain values which are consistent with the characteristics +of the uncompressed pixel data from which the compressed data is derived +*/ + +/* + * is used for the optional error recovery mechanism shown in + * the second part of the example. + */ + +/* + * Include file for users of JPEG library. + * You will need to have included system headers that define at least + * the typedefs FILE and size_t before you can include jpeglib.h. + * (stdio.h is sufficient on ANSI-conforming systems.) + * You may also wish to include "jerror.h". + */ + +extern "C" { +#include "jpeglib.h" +#include } - -ClbJpeg * _IdDcmJpegRead (FILE * fp){ -ClbJpeg * jpg=NULL; - jpg=ClbJpegAlloc(); - if(!jpg) - return(NULL); - ClbJpegInit (jpg); - if(!ClbJpegStart(jpg, fp)) - return (NULL); - return (jpg); +/******************** JPEG DECOMPRESSION SAMPLE INTERFACE *******************/ + +/* This half of the example shows how to read data from the JPEG decompressor. + * It's a bit more refined than the above, in that we show: + * (a) how to modify the JPEG library's standard error-reporting behavior; + * (b) how to allocate workspace using the library's memory manager. + * + * Just to make this example a little different from the first one, we'll + * assume that we do not intend to put the whole image into an in-memory + * buffer, but to send it line-by-line someplace else. We need a one- + * scanline-high JSAMPLE array as a work buffer, and we will let the JPEG + * memory manager allocate it for us. This approach is actually quite useful + * because we don't need to remember to deallocate the buffer separately: it + * will go away automatically when the JPEG object is cleaned up. + */ + +/* + * ERROR HANDLING: + * + * The JPEG library's standard error handler (jerror.c) is divided into + * several "methods" which you can override individually. This lets you + * adjust the behavior without duplicating a lot of code, which you might + * have to update with each future release. + * + * Our example here shows how to override the "error_exit" method so that + * control is returned to the library's caller when a fatal error occurs, + * rather than calling exit() as the standard error_exit method does. + * + * We use C's setjmp/longjmp facility to return control. This means that the + * routine which calls the JPEG library must first execute a setjmp() call to + * establish the return point. We want the replacement error_exit to do a + * longjmp(). But we need to make the setjmp buffer accessible to the + * error_exit routine. To do this, we make a private extension of the + * standard JPEG error handler object. (If we were using C++, we'd say we + * were making a subclass of the regular error handler.) + * + * Here's the extended error handler struct: + */ + +//----------------------------------------------------------------------------- +struct my_error_mgr { + struct jpeg_error_mgr pub; /* "public" fields */ + jmp_buf setjmp_buffer; /* for return to caller */ +}; + +//----------------------------------------------------------------------------- +typedef struct my_error_mgr * my_error_ptr; + +/* + * Here's the routine that will replace the standard error_exit method: + */ +METHODDEF(void) my_error_exit (j_common_ptr cinfo) { + /* cinfo->err really points to a my_error_mgr struct, so coerce pointer */ + my_error_ptr myerr = (my_error_ptr) cinfo->err; + + /* Always display the message. */ + /* We could postpone this until after returning, if we chose. */ + (*cinfo->err->output_message) (cinfo); + + /* Return control to the setjmp point */ + longjmp(myerr->setjmp_buffer, 1); } - - -static void ClbJpegInit (ClbJpeg *jpg) { -int n; - for (n=0;n<256;n++) - { - jpg->lHuffTable[n].HufCode=0; - jpg->lHuffTable[n].HufSz=0; - jpg->lHuffTable[n].HufVal=0; - } - jpg->ValCurByte=0; - jpg->PosCurBit=10; - jpg->MarkerFound=0; - jpg->RestartInterval=0; -} - -static ClbJpeg *ClbJpegAlloc(void) { -ClbJpeg * jpg; - jpg = (ClbJpeg *)malloc(sizeof(ClbJpeg)); - ClbJpegInit(jpg); -return jpg; -} +//----------------------------------------------------------------------------- +/* + * Sample routine for JPEG decompression. We assume that the source file name + * is passed in. We want to return 1 on success, 0 on error. + */ + /** + * \ingroup gdcmFile + * \brief routine for JPEG decompression + * @param fp pointer to an already open file descriptor + * 8 significant bits per pixel + * @param image_buffer to receive uncompressed pixels + * @return 1 on success, 0 on error + */ + +bool gdcmFile::gdcm_read_JPEG_file (FILE *fp,void * image_buffer) { + char *pimage; + + /* This struct contains the JPEG decompression parameters and pointers to + * working space (which is allocated as needed by the JPEG library). + */ + struct jpeg_decompress_struct cinfo; + + /* -------------- inside, we found : + * JDIMENSION image_width; // input image width + * JDIMENSION image_height; // input image height + * int input_components; // nb of color components in input image + * J_COLOR_SPACE in_color_space; // colorspace of input image + * double input_gamma; // image gamma of input image + * -------------- */ + + /* We use our private extension JPEG error handler. + * Note that this struct must live as long as the main JPEG parameter + * struct, to avoid dangling-pointer problems. + */ + struct my_error_mgr jerr; + /* More stuff */ + + JSAMPARRAY buffer; /* Output row buffer */ + + // rappel : + // ------ + // typedef unsigned char JSAMPLE; + // typedef JSAMPLE FAR *JSAMPROW; /* ptr to one image row of pixel samples. */ + // typedef JSAMPROW *JSAMPARRAY; /* ptr to some rows (a 2-D sample array) */ + // typedef JSAMPARRAY *JSAMPIMAGE; /* a 3-D sample array: top index is color */ + + int row_stride; /* physical row width in output buffer */ + +#ifdef GDCM_DEBUG + printf("entree dans gdcmFile::gdcm_read_JPEG_file12, depuis gdcmJpeg\n"); +#endif //GDCM_DEBUG + + /* In this example we want to open the input file before doing anything else, + * so that the setjmp() error recovery below can assume the file is open. + * VERY IMPORTANT: use "b" option to fopen() if you are on a machine that + * requires it in order to read binary files. + */ + + /* Step 1: allocate and initialize JPEG decompression object */ +#ifdef GDCM_DEBUG + printf("Entree Step 1\n"); +#endif //GDCM_DEBUG + + /* We set up the normal JPEG error routines, then override error_exit. */ + + cinfo.err = jpeg_std_error(&jerr.pub); + jerr.pub.error_exit = my_error_exit; + + /* Establish the setjmp return context for my_error_exit to use. */ + if (setjmp(jerr.setjmp_buffer)) { + /* If we get here, the JPEG code has signaled an error. + * We need to clean up the JPEG object, close the input file, and return. + */ + jpeg_destroy_decompress(&cinfo); + return 0; + } + /* Now we can initialize the JPEG decompression object. */ + jpeg_create_decompress(&cinfo); + + /* Step 2: specify data source (eg, a file) */ +#ifdef GDCM_DEBUG + printf("Entree Step 2\n"); +#endif //GDCM_DEBUG + + jpeg_stdio_src(&cinfo, fp); + + /* Step 3: read file parameters with jpeg_read_header() */ +#ifdef GDCM_DEBUG + printf("Entree Step 3\n"); +#endif //GDCM_DEBUG + + (void) jpeg_read_header(&cinfo, TRUE); + + /* We can ignore the return value from jpeg_read_header since + * (a) suspension is not possible with the stdio data source, and + * (b) we passed TRUE to reject a tables-only JPEG file as an error. + * See libjpeg.doc for more info. + */ + +#ifdef GDCM_DEBUG + printf("--------------Header contents :----------------\n"); + printf("image_width %d image_height %d\n", + cinfo.image_width , cinfo.image_height); + printf("bits of precision in image data %d \n", + cinfo.output_components); + printf("nb of color components returned %d \n", + cinfo.data_precision); +#endif //GDCM_DEBUG + + + /* + * JDIMENSION image_width; // input image width + * JDIMENSION image_height; // input image height + * int output_components; // # of color components returned + * J_COLOR_SPACE in_color_space; // colorspace of input image + * double input_gamma; // image gamma of input image + * int data_precision; // bits of precision in image data + */ + + /* Step 4: set parameters for decompression */ +#ifdef GDCM_DEBUG + printf("Entree Step 4\n"); +#endif //GDCM_DEBUG + /* In this example, we don't need to change any of the defaults set by + * jpeg_read_header(), so we do nothing here. + */ + + /* Step 5: Start decompressor */ +#ifdef GDCM_DEBUG + printf("Entree Step 5\n"); +#endif GDCM_DEBUG + + (void) jpeg_start_decompress(&cinfo); + /* We can ignore the return value since suspension is not possible + * with the stdio data source. + */ + + /* We may need to do some setup of our own at this point before reading + * the data. After jpeg_start_decompress() we have the correct scaled + * output image dimensions available, as well as the output colormap + * if we asked for color quantization. + * In this example, we need to make an output work buffer of the right size. + */ + + /* JSAMPLEs per row in output buffer */ + row_stride = cinfo.output_width * cinfo.output_components; + +#ifdef GDCM_DEBUG + printf ("cinfo.output_width %d cinfo.output_components %d row_stride %d\n", + cinfo.output_width, cinfo.output_components,row_stride); +#endif //GDCM_DEBUG + + /* Make a one-row-high sample array that will go away when done with image */ + buffer = (*cinfo.mem->alloc_sarray) + ((j_common_ptr) &cinfo, JPOOL_IMAGE, row_stride, 1); + + /* Step 6: while (scan lines remain to be read) */ +#ifdef GDCM_DEBUG + printf("Entree Step 6\n"); +#endif //GDCM_DEBUG + /* jpeg_read_scanlines(...); */ + + /* Here we use the library's state variable cinfo.output_scanline as the + * loop counter, so that we don't have to keep track ourselves. + */ +#ifdef GDCM_DEBUG + printf ("cinfo.output_height %d cinfo.output_width %d\n", + cinfo.output_height,cinfo.output_width); +#endif //GDCM_DEBUG + pimage=(char *)image_buffer; + + while (cinfo.output_scanline < cinfo.output_height) { + /* jpeg_read_scanlines expects an array of pointers to scanlines. + * Here the array is only one element long, but you could ask for + * more than one scanline at a time if that's more convenient. + */ + + // l'image est deja allouée (et passée en param) + // on ecrit directement les pixels + // (on DEVRAIT pouvoir) + + //(void) jpeg_read_scanlines(&cinfo, pimage, 1); + + (void) jpeg_read_scanlines(&cinfo, buffer, 1); + + if ( BITS_IN_JSAMPLE == 8) { + memcpy( pimage, buffer[0],row_stride); + pimage+=row_stride; + } else { + memcpy( pimage, buffer[0],row_stride*2 ); // FIXME : *2 car 16 bits?!? + pimage+=row_stride*2; // FIXME : *2 car 16 bits?!? + } + } + + /* Step 7: Finish decompression */ +#ifdef GDCM_DEBUG + printf("Entree Step 7\n"); +#endif //GDCM_DEBUG + (void) jpeg_finish_decompress(&cinfo); + + /* We can ignore the return value since suspension is not possible + * with the stdio data source. + */ -static BOOL ClbJpegFillHuffTable(ClbJpeg *jpg) -{ - unsigned char c; - //int testindex=0; - int n=0; - int NiDHT=0; - int indexY=0; - int k, Code, Si, i; - - for (c=0;c<255;c++) - jpg->RawDHTstart[c]=0; - - c=fgetc(jpg->infp); - - - jpg->MaxHuffSz=0; - jpg->MaxHuffVal=0; - - for (n=1;n<17;n++) - { - jpg->RawDHT[n]=fgetc(jpg->infp); - NiDHT+=jpg->RawDHT[n]; - if (jpg->RawDHT[n]!=0) - jpg->MaxHuffSz=n; - } - - for(n=1;n<16;n++) - { - if(jpg->RawDHT[n]>0) - { - jpg->RawDHTstart[n]=indexY+1; - for (i=1;i<(jpg->RawDHT[n]+1);i++) - { - indexY+=1; - c=fgetc(jpg->infp); - jpg->lHuffTable[indexY].HufVal=c; - jpg->MaxHuffVal=c; - jpg->lHuffTable[indexY].HufSz=n; - } - } - } - k=1; - Code=0; - - Si=jpg->lHuffTable[k].HufSz; - - while(1) - { - if (k>=NiDHT) break; - while( Si==jpg->lHuffTable[k].HufSz) - { - jpg->lHuffTable[k].HufCode=Code; - Code+=1; - k+=1; - } - if (klHuffTable[k].HufSz>Si) - { - Code=Code<<1; - Si+=1; - } - } - } - - return 1; -} + /* Step 8: Release JPEG decompression object */ - +#ifdef GDCM_DEBUG + printf("Entree Step 8\n"); +#endif //GDCM_DEBUG -static BOOL ClbJpegStart(ClbJpeg *jpg, FILE *inputfp) -{ - jpg->infp=inputfp; - if (!ClbJpegReadHeader(jpg)) return 0; - //printf("sortie ClbJpegReadHeader\n"); - if (!ClbJpegDecodeData(jpg)) return 0; - //printf("sortie ClbJpegDecodeData\n"); - return 1; -} + /* This is an important step since it will release a good deal of memory. */ -static BOOL ClbJpegReadHeader(ClbJpeg *jpg) -{ - unsigned char gr; - unsigned char el; - unsigned char l2; - unsigned char l1; - unsigned int sztag; - long ouca=0; - BOOL HeaderEnd=0; - BOOL isLossLess=0; - - int tp; - - gr=fgetc(jpg->infp); //FF - el=fgetc(jpg->infp); //D8 - - while(!HeaderEnd) - { - gr=fgetc(jpg->infp); - if(gr!=0xFF) return 0; - el=fgetc(jpg->infp); - - if ( (el==0xFF) || (el==0x01) || (el==0xD8) ||(el==0xD9) ||( (el>=0xD0) && (el<=0xD7) )) - ; - else - { - l1=fgetc(jpg->infp); - l2=fgetc(jpg->infp); - sztag=(l1*256)+l2-2; //tag lengh - ouca=ftell(jpg->infp); - - if (el==0xC3) - { - jpg->lSof.precision=fgetc(jpg->infp); - - l1=fgetc(jpg->infp); - l2=fgetc(jpg->infp); - jpg->lSof.Himg=(l1*256)+l2; - - l1=fgetc(jpg->infp); - l2=fgetc(jpg->infp); - jpg->lSof.Wimg=(l1*256)+l2; - - jpg->lSof.NbComponent=fgetc(jpg->infp); - - jpg->lSof.SofTabPos=ftell(jpg->infp); - - isLossLess=1; // TRUE - } - - if (el==0xC4) - { - ClbJpegFillHuffTable(jpg); - } - if (el==0xDA) - { - jpg->lSos.CompCount=fgetc(jpg->infp); - for (tp=0;tplSos.CompCount;tp++) - { - jpg->lSos.CompId=fgetc(jpg->infp); - jpg->lSos.CompDc=fgetc(jpg->infp); - } - jpg->lSos.SpectralSelStart=fgetc(jpg->infp); - jpg->lSos.SpectralSelEnd=fgetc(jpg->infp); - jpg->lSos.SuccessiveAp=fgetc(jpg->infp); - jpg->lSos.Sospttrans=(jpg->lSos.SuccessiveAp & 16); - HeaderEnd=1; - } - if (el==0xDD) - { - l1=fgetc(jpg->infp); - l2=fgetc(jpg->infp); - jpg->RestartInterval=(l1*256)+l2; - } - - fseek(jpg->infp,(ouca+sztag),0); - } - } - - if (!isLossLess) return 0; - return 1; + jpeg_destroy_decompress(&cinfo); -} + /* After finish_decompress, we can close the input file. + * Here we postpone it until after no more JPEG errors are possible, + * so as to simplify the setjmp error logic above. (Actually, I don't + * think that jpeg_destroy can do an error exit, but why assume anything...) + */ -static int ClbJpegReadBit(ClbJpeg *jpg) -{ - int r=0; - unsigned char c; - if(jpg->PosCurBit>8) // need lire octet suivant - { - jpg->ValCurByte=fgetc(jpg->infp); - if (jpg->ValCurByte==0xFF) - { - c=fgetc(jpg->infp);// est 00 ou restart marker: a skiper - if (c!=0) - { - jpg->ValCurByte=fgetc(jpg->infp); - jpg->PosCurBit=1; - jpg->MarkerFound=1; - return 0; - } - } - jpg->PosCurBit=2; - return (jpg->ValCurByte>>7); - } - else - { - r=(1&(jpg->ValCurByte>>(8-jpg->PosCurBit))); - jpg->PosCurBit+=1; - return r; - } -} + /* At this point you may want to check to see whether any corrupt-data + * warnings occurred (test whether jerr.pub.num_warnings is nonzero). + */ + /* And we're done! */ -static BOOL ClbJpegDecodeData(ClbJpeg *jpg) -{ - int iX,iY; - int lbInc=0; - unsigned int mask; - - int lPredicted=(1<<(jpg->lSof.precision-1-jpg->lSos.Sospttrans)); - - jpg->ValCurByte=jpg->lSos.SuccessiveAp; - jpg->PosCurBit=9; - - if (jpg->lSof.precision==8) - mask=0xFF; - if (jpg->lSof.precision==12) - mask=0xFFF; - if (jpg->lSof.precision==16) - mask=0xFFFF; - - jpg->DataImg=(int*)malloc(jpg->lSof.Himg*jpg->lSof.Wimg*sizeof(*jpg->DataImg)); - memset( jpg->DataImg,0,(jpg->lSof.Himg*jpg->lSof.Wimg*sizeof(*jpg->DataImg))); - - if (!jpg->RestartInterval) - { - for(iX=0;iXlSof.Wimg;iX++) // lit première ligne - { - lbInc+=1; - if (lbInc>1) - lPredicted= jpg->DataImg[lbInc-1]; - jpg->DataImg[lbInc]=lPredicted+ClbJpegDecodeDiff(jpg); - - if ( jpg->DataImg[lbInc] > ((1<<(jpg->lSof.precision))-1) ) - jpg->DataImg[lbInc]= jpg->DataImg[lbInc]&mask; - if ( jpg->DataImg[lbInc]<0) - jpg->DataImg[lbInc]= jpg->DataImg[lbInc]&mask; - } - - for (iY=1;iYlSof.Himg;iY++) //lit la suite - { - lbInc+=1; - if (lbInc>(jpg->lSof.Himg*jpg->lSof.Wimg-1)) break; - lPredicted= jpg->DataImg[lbInc-jpg->lSof.Wimg]; // se base % premier é ligne d'avant - jpg->DataImg[lbInc]=lPredicted+ClbJpegDecodeDiff(jpg); - - if ( jpg->DataImg[lbInc] > ((1<<(jpg->lSof.precision))-1) ) - jpg->DataImg[lbInc]= jpg->DataImg[lbInc]&mask; - if ( jpg->DataImg[lbInc]<0) - jpg->DataImg[lbInc]= jpg->DataImg[lbInc]&mask; - - for(iX=1;iXlSof.Wimg;iX++) - { - lbInc+=1; - if (lbInc>(jpg->lSof.Himg*jpg->lSof.Wimg-1)) break; - if (jpg->lSos.SpectralSelStart==7) // si spectral - lPredicted=( jpg->DataImg[lbInc-1]+ jpg->DataImg[lbInc-jpg->lSof.Wimg])>>1; - else - lPredicted= jpg->DataImg[lbInc-1]; // se base%pixel juste avant - jpg->DataImg[lbInc]=lPredicted+ClbJpegDecodeDiff(jpg); - - if ( jpg->DataImg[lbInc] > ((1<<(jpg->lSof.precision))-1) ) - jpg->DataImg[lbInc]= jpg->DataImg[lbInc]&mask; - if ( jpg->DataImg[lbInc]<0) - jpg->DataImg[lbInc]= jpg->DataImg[lbInc]&mask; - - } - } - } - else // il y a un define interval - { - while(1) - { - jpg->MarkerFound=0; - lPredicted=(1<<(jpg->lSof.precision - 1 - jpg->lSos.Sospttrans)); - for (iY=0;iYRestartInterval;iY++) - { - jpg->DataImg[lbInc]=lPredicted+ClbJpegDecodeDiff(jpg); - - if ( jpg->DataImg[lbInc] > ((1<<(jpg->lSof.precision))-1) ) - jpg->DataImg[lbInc]= jpg->DataImg[lbInc]&mask; - if ( jpg->DataImg[lbInc]<0) - jpg->DataImg[lbInc]= jpg->DataImg[lbInc]&mask; - - lbInc+=1; - if (lbInc>(jpg->lSof.Himg*jpg->lSof.Wimg-1)) return 1; - - if (jpg->lSos.SpectralSelStart==7) // si spectral - lPredicted=( jpg->DataImg[lbInc-1]+ jpg->DataImg[lbInc-jpg->lSof.Wimg])>>1; - else - lPredicted= jpg->DataImg[lbInc-1]; - } - while (!jpg->MarkerFound) - { - ClbJpegReadBit(jpg); // skip bits restant avant restart marker - } - } - } - return 1; + return(true); } -static int ClbJpegDecodeDiff(ClbJpeg *jpg) -{ - int lInput; - int lInputBits; - int lHufVal; - int lDiff; - int lI; - int resultat; - lHufVal = 666; - lInput = 0; - lInputBits = 0; - - - while (1) - { - lInputBits+=1; - lInput=(lInput<<1)+ClbJpegReadBit(jpg); - if (jpg->RawDHT[lInputBits]!=0) - { - for(lI=jpg->RawDHTstart[lInputBits];lI<(jpg->RawDHTstart[lInputBits]+jpg->RawDHT[lInputBits]);lI++) - { - if (lInput==jpg->lHuffTable[lI].HufCode) - lHufVal=jpg->lHuffTable[lI].HufVal; - } - } - if (lInputBits>=jpg->MaxHuffSz) - lHufVal=jpg->MaxHuffVal; - if (lHufVal<255) break; - } - if (lHufVal==0) resultat= 0; - - if ( (lHufVal>0) && (lHufVal<16)) - { - lDiff=0; - if( ClbJpegReadBit(jpg)==1) - { - for (lI=1;lI