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#include <stdlib.h>
#include <stdio.h>
/* JPEG stream markers: */
#define JPEG_MARKER 0xFF
/* Start of Image, End of Image */
#define JPEG_SOI 0xD8
#define JPEG_EOI 0xD9
#define JPEG_JFIF 0xE0
/* encoding markers, quantization tables and Huffman tables */
#define JPEG_QUANT 0xDB
#define JPEG_HUFF 0xC4
/* image markers, start of frame and start of scan */
#define JPEG_SOF0 0xC0
#define JPEG_SOF1 0xC1
#define JPEG_SOF2 0xC2
#define JPEG_SOS 0xDA
void printJpegStream(FILE *f)
{
int c, l;
while(!feof(f))
{
if(fgetc(f) != JPEG_MARKER)
{
printf("Jpeg marker not found!\n");
break;
}
switch(c=fgetc(f))
{
case JPEG_SOI: printf("SOI\n"); break;
case JPEG_EOI: printf("EOI\n"); break;
case JPEG_JFIF: printf("JFIF\n"); break;
case JPEG_QUANT: printf("Quantization table\n"); break;
case JPEG_HUFF: printf("Huffman table\n"); break;
case JPEG_SOF0: printf("Start of frame 0\n"); break;
case JPEG_SOF1: printf("Start of frame 1\n"); break;
case JPEG_SOF2: printf("Start of frame 2\n"); break;
case JPEG_SOS: printf("Start of scan\n"); break;
default: printf("Unknown JPEG block: %02x\n", c);
}
if(c==JPEG_SOS)
break;
if(c != JPEG_SOI && c != JPEG_EOI)
{
l = (fgetc(f)<<8) + fgetc(f);
printf("%i bytes\n", l);
for(l-=2; l>0; --l)
fgetc(f);
}
}
}
int main(int argc, char *argv[])
{
FILE *f;
f = fopen(argv[1], "rb");
if(argc<1)
{
printf("Gimme file name\n");
exit(1);
}
if(!f)
{
printf("Couldn't open file %s!\n", argv[1]);
exit(1);
}
printJpegStream(f);
exit(0);
}
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