Added some comments about DNG file endianess

Makefile

@@ -7,7 +7,7 @@ APP = simpleskycam
 OBJECTS := $(OBJECTS) gui.oo main.oo \
 		   video.oo videoframe.oo \
 		   videodev.oo videodev-v4l2.oo videodev-dumpfile.oo \
-		   convert.oo filter.oo detect.oo json.oo configuration.oo ser.oo
+		   convert.oo filter.oo detect.oo json.oo configuration.oo ser.oo dng.oo
 DISTNAME=simpleskycam-$(VERSION)
 DEPENDFILE=.depend
 

dng.cc

@@ -26,11 +26,25 @@ DNG::~DNG() {
   }
 }
 
+/*
+  Run-time detection if we are little- or big-endian.
+ */
+int DNG::IsBigEndian(void) {
+  int i = 1;
+  return ! *((char *)&i);
+}
+
 /*
   Sets the file name of the DNG file to be written.  Returns -1 on
   failure, 0 on success.
  */
 int DNG::setFile(char * file) {
+  /*
+    w = write
+    l = little endian
+    b = big endian
+    -> if neither l or b is given, data is written in native CPU format
+   */
   if (!(tif = TIFFOpen(file, "w"))) {
     return -1;
   }
@@ -139,7 +153,7 @@ int DNG::writeFile(void * data) {
     TIFFSetField(tif, TIFFTAG_PHOTOMETRIC, PHOTOMETRIC_CFA);
     TIFFSetField(tif, TIFFTAG_CFAREPEATPATTERNDIM, CFARepeatPattern);
     // 0 = Red, 1 = Green, 2 = Blue
-    TIFFSetField(tif, TIFFTAG_CFAPATTERN, "\001\000\002\001"); // GRGB
+    TIFFSetField(tif, TIFFTAG_CFAPATTERN, "\001\000\002\001"); // GRBG
   }
   else if(ColorID == DNG_COLORID_RGB) {
     TIFFSetField(tif, TIFFTAG_PHOTOMETRIC, PHOTOMETRIC_RGB);

dng.h

@@ -48,6 +48,7 @@ class DNG {
   int BitsPerSample;
   int SamplesPerPixel;
   int ColorID;
+  int IsBigEndian(void);
   
  public:
   DNG();