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The FromJPEG function

#include <stdio.h>
#include "ImgJPEG.h"
#include "ImgAlloc.h"
#include ".\JPEG\jpeglib.h"

void jpeg_FromJPEG(void*& pBuf,unsigned long& BufSz,ImgJPEGInfo& Info)
{
	jpeg_decompress_struct cinfo;
	jpeg_error_mgr jerr;

	cinfo.err = jpeg_std_error(&jerr);
	jpeg_create_decompress(&cinfo);
	
	jpeg_buffer_src(&cinfo, (unsigned char*)pBuf, BufSz);

	jpeg_read_header(&cinfo, TRUE);

	jpeg_start_decompress(&cinfo);

	Info.XDim = cinfo.image_width;
	Info.YDim = cinfo.image_height;
	Info.LineSize = (Info.XDim * 3);

	char Pack;
	char Rem = (char) (Info.LineSize % 4);

	if(Rem != 0)
	 Rem = (4 - Rem);

	Info.LineSize += Rem;

	Info.Quality = 50;

	unsigned long OutBufSz = Info.LineSize * Info.YDim;
	unsigned char* pOutBuf = (unsigned char*) img_malloc(OutBufSz);

	int row_stride = cinfo.output_width * cinfo.output_components;
	JSAMPARRAY buffer = (*cinfo.mem->alloc_sarray)	((j_common_ptr) &cinfo, JPOOL_IMAGE, row_stride, 1);

	while(cinfo.output_scanline < cinfo.output_height)
	{
		jpeg_read_scanlines(&cinfo, buffer, 1);

		unsigned char* pInsert = &(pOutBuf[((cinfo.output_height - 1) - (cinfo.output_scanline-1)) * Info.LineSize]);

		img_memcpy(pInsert,buffer[0],row_stride);
		pInsert	+= row_stride;

		for(Pack=0;Pack<Rem;Pack++)
		{
			*pInsert = 0;
			pInsert++;
		}
	}

	jpeg_finish_decompress(&cinfo);

	img_free(pBuf);
	BufSz = OutBufSz;
	pBuf = pOutBuf;
	pOutBuf = NULL;

	jpeg_destroy_decompress(&cinfo);
}
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Last modified: SolFlu  Mon, 15 Jun 2009 13:09:58 GMT