From f4cc8f1906c41a06cd69878094427fe21f7d2912 Mon Sep 17 00:00:00 2001
From: Oliver Schinagl <oliver@schinagl.nl>
Date: Thu, 2 Jun 2005 12:44:58 +0000
Subject: Update for reading

---
 src/jpeg.c | 71 +++++++++++++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 54 insertions(+), 17 deletions(-)

diff --git a/src/jpeg.c b/src/jpeg.c
index 5c779ea..c90fe5b 100644
--- a/src/jpeg.c
+++ b/src/jpeg.c
@@ -1,14 +1,20 @@
 #define SOI_MK	0xFFD8		/* start of image	*/
+#define APP_MK	0xFFE0		/* custom, up to FFEF */
+#define COM_MK	0xFFFE		/* commment segment	*/
 #define SOF_MK	0xFFC0		/* start of frame	*/
-#define EOI_MK	0xFFD9		/* end of image		*/
+#define SOS_MK	0xFFDA		/* start of scan	*/
+#define DHT_MK	0xFFC4		/* Huffman table	*/
+#define DQT_MK	0xFFDB		/* Quant. table		*/
 #define DRI_MK	0xFFDD		/* restart interval	*/
+#define EOI_MK	0xFFD9		/* end of image		*/
+#define MK_MSK	0xFFF0
 
 #define get_size(fi) (((unsigned int)Image[fi]) << 8) + (unsigned int)Image[fi+1]
 
 unsigned char GetJPEGHeaderInfo (unsigned char *Image,unsigned int *offset,unsigned int *x_size,unsigned int *y_size, unsigned char *depth)
 {
 	unsigned int aux;
-	int hCounter = 0;
+	int hCounter = 0, hAantal;
   	/* First find the SOI marker: */
   		aux = get_size(hCounter); hCounter+=2;
   		if (aux != SOI_MK)
@@ -17,13 +23,30 @@ unsigned char GetJPEGHeaderInfo (unsigned char *Image,unsigned int *offset,unsig
     	printf("%ld:\tINFO:\tFound the SOI marker!\n", hCounter);
 
 		/* Read first marker */
-		while( aux != SOF_MK)
+		while( (aux != EOI_MK) && (aux != 0))
 		{
 			aux = get_size(hCounter); hCounter+=2;
-			if(aux == SOF_MK)
+			switch(aux)
 			{
-			  get_size(hCounter); hCounter+=2;	/* header size, don't care */
+			case APP_MK:
+				hAantal = get_size(hCounter);
+				printf("\tJFIF marker - APP0 Marker size: %i Count: %i\n", hAantal,hCounter);
+				printf("\tversion: %02x%02x units %x Xdensity %i Ydensity %i Xthumbnail %i Ythumbnail %i",
+				Image[hCounter+7],Image[hCounter+8],Image[hCounter+9],get_size(hCounter+10),get_size(hCounter+12)
+				,Image[hCounter+14],Image[hCounter+15]);
+				hCounter = hCounter + hAantal;
+			break;
+			case COM_MK:
+				hAantal = get_size(hCounter);
+				printf("\tcommment segment Marker size: %i Count: %i\n", hAantal,hCounter);
+				hCounter = hCounter + hAantal;
+			break;
+			case SOF_MK:
 
+			  hAantal= get_size(hCounter); 	/* header size */
+				printf("\tSOF: %i Count: %i\n", hAantal,hCounter);
+				hAantal= hCounter + get_size(hCounter);
+				hCounter+=2;
 	    	  /* load basic image parameters */
 	    	  hCounter++;	/* precision, 8bit, don't care */
 	    	  *y_size = get_size(hCounter); hCounter+=2;
@@ -36,27 +59,41 @@ unsigned char GetJPEGHeaderInfo (unsigned char *Image,unsigned int *offset,unsig
 			  printf("\tINFO:\t");
 			  switch (*depth)
 			  {
-			  	  case 1:
-			      printf("Monochrome");
-			      break;
-			  	  case 3:
-			      printf("Color");
-			      break;
-			  	  default:
-			  	    printf("Not a");
-			      break;
+			  	  case 1: printf("Monochrome"); break;
+			  	  case 3: printf("Color"); break;
+			  	  default: printf("Not a"); break;
 			    }
 			  printf(" JPEG image!\n");
+			  hCounter = hAantal;
 
-	    	  return 0;
-			}
-			else
+			break;
+			case DHT_MK:
+				hAantal = get_size(hCounter);
+				printf("\tHuffman table size: %i Count: %i\n", hAantal,hCounter);
+				hCounter = hCounter + hAantal;
+			break;
+			case DQT_MK:
+				hAantal = get_size(hCounter);
+				printf("\tQuant. table size: %i Count: %i\n", hAantal,hCounter);
+				hCounter = hCounter + hAantal;
+			break;
+			default:
+				hAantal = get_size(hCounter);
+				printf("\tOverig nl: %04X Count: %i, aantal: %i\n", aux,hCounter, hAantal);
 				hCounter = hCounter + get_size(hCounter);
+			}
 		}
+	printf("\tEinde op: aux: %04X Count: %i \n", aux, hCounter);
 	return 1;
 }
 
 unsigned char WriteJPEGHeaderInfo (unsigned char *Image,unsigned int offset,unsigned int x_size,unsigned int y_size, unsigned char depth)
 {
+	// SOI marker + JFIF marker - APP0 Marker size: 16 Count: 4
+
+	// version: 0102 units 1 Xdensity 300 Ydensity 300 Xthumbnail 0 Ythumbnail 0
+	// FF,D8,FF,E0,00,10,4A,46,49,46,00,01,02,01,01,2C,01,2C,00,00
+
+
 	return 0;
 }
-- 
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