* GQView
* (C) 2005 John Ellis
*
+ * Authors:
+ * Raw NEF jpeg extraction based on nefextract.c by Joseph Heled,
+ * in addition nefextract.c is based on dcraw by Dave Coffin.
+ *
* This software is released under the GNU General Public License (GNU GPL).
* Please read the included file COPYING for more information.
* This software comes with no warranty of any kind, use at your own risk!
#include "exif.h"
+/*
+ *-----------------------------------------------------------------------------
+ * Raw NEF embedded jpeg extraction for Nikon
+ *-----------------------------------------------------------------------------
+ */
+
+static guint tiff_table(unsigned char *data, const guint len, guint offset, ExifByteOrder byte_order,
+ guint *image_offset, guint *jpeg_len);
+
+
+static void tiff_entry(unsigned char *data, const guint len, guint offset, ExifByteOrder byte_order,
+ guint *image_offset, guint *image_length, guint *jpeg_start, guint *jpeg_len)
+{
+ static gint size[] = { 1,1,1,2,4,8,1,1,2,4,8,4,8 };
+ guint tag;
+ guint type;
+ guint count;
+ guint segment;
+
+ tag = exif_byte_get_int16(data + offset, byte_order);
+ type = exif_byte_get_int16(data + offset + 2, byte_order);
+ count = exif_byte_get_int32(data + offset + 4, byte_order);
+
+ if (type > 12) return;
+ if (count * size[type] > 4)
+ {
+ segment = exif_byte_get_int32(data + offset + 8, byte_order);
+ if (len < segment + count * size[type]) return;
+ }
+ else
+ {
+ segment = offset + 8;
+ }
+
+ if (tag == 0x14a &&
+ type == EXIF_FORMAT_LONG_UNSIGNED)
+ {
+ /* sub IFD table */
+ gint i;
+
+ for (i = 0; i < count; i++)
+ {
+ guint subset;
+
+ subset = exif_byte_get_int32(data + segment + i * 4, byte_order);
+ tiff_table(data, len, subset, byte_order, image_offset, image_length);
+ }
+
+ }
+ else if (tag == 0x201)
+ {
+ /* jpeg data start offset */
+ *jpeg_start = exif_byte_get_int32(data + segment, byte_order);
+ }
+ else if (tag == 0x202)
+ {
+ /* jpeg data length */
+ *jpeg_len = exif_byte_get_int32(data + segment, byte_order);
+ }
+}
+
+static guint tiff_table(unsigned char *data, const guint len, guint offset, ExifByteOrder byte_order,
+ guint *image_offset, guint *image_length)
+{
+ guint count;
+ guint i;
+ guint jpeg_start = 0;
+ guint jpeg_len = 0;
+
+ if (len < offset + 2) return FALSE;
+
+ count = exif_byte_get_int16((unsigned char *)data + offset, byte_order);
+
+ if (len < offset + count * 12 + 4) return 0;
+ offset += 2;
+
+ for (i = 0; i < count; i++)
+ {
+ tiff_entry(data, len, offset + i * 12, byte_order,
+ image_offset, image_length, &jpeg_start, &jpeg_len);
+ }
+
+ if (jpeg_start > 0 &&
+ jpeg_len > *image_length)
+ {
+ *image_offset = jpeg_start;
+ *image_length = jpeg_len;
+ }
+
+ return exif_byte_get_int32((unsigned char *)data + offset + count * 12, byte_order);
+}
+
+/*
+ * Walk the first TIFF IFD table and check for existence of a "make" tag (0x10f) that
+ * identifies NIKON CORPORATION, so that we can abort quickly if it is not a raw NEF.
+ */
+static gint tiff_nikon_verify(unsigned char *data, const guint len, guint offset, ExifByteOrder byte_order)
+{
+ guint nb_entries;
+ guint i;
+
+ if (len < offset + 2) return FALSE;
+
+ nb_entries = exif_byte_get_int16(data + offset, byte_order);
+ offset += 2;
+ if (len < offset + nb_entries * 12 + 4) return FALSE;
+
+ for (i = 0; i < nb_entries; i++)
+ {
+ guint segment;
+
+ segment = offset + i * 12;
+ if (exif_byte_get_int16(data + segment, byte_order) == 0x10f &&
+ exif_byte_get_int16(data + segment + 2, byte_order) == EXIF_FORMAT_STRING)
+ {
+ guint count;
+ guint make_text;
+
+ count = exif_byte_get_int32(data + segment + 4, byte_order);
+ make_text = exif_byte_get_int32(data + segment + 8, byte_order);
+
+ if (count >= 17 &&
+ memcmp(data + make_text, "NIKON CORPORATION", 17) == 0)
+ {
+ return TRUE;
+ }
+
+ return FALSE;
+ }
+ }
+
+ return FALSE;
+}
+
+gint format_nikon_raw(const void *data, const guint len,
+ guint *image_offset, guint *exif_offset)
+{
+ guint i_off = 0;
+ guint i_len = 0;
+ ExifByteOrder byte_order;
+ guint offset;
+
+ if (len < 8) return FALSE;
+
+ if (memcmp(data, "II", 2) == 0)
+ {
+ byte_order = EXIF_BYTE_ORDER_INTEL;
+ }
+ else if (memcmp(data, "MM", 2) == 0)
+ {
+ byte_order = EXIF_BYTE_ORDER_MOTOROLA;
+ }
+ else
+ {
+ return FALSE;
+ }
+
+ if (exif_byte_get_int16((unsigned char *)data + 2, byte_order) != 0x002A)
+ {
+ return FALSE;
+ }
+
+ offset = exif_byte_get_int32((unsigned char *)data + 4, byte_order);
+ if (!tiff_nikon_verify((unsigned char *)data, len, offset, byte_order)) return FALSE;
+
+ while (offset != 0)
+ {
+ guint next_offset = 0;
+ tiff_table((unsigned char *)data, len, offset, byte_order, &i_off, &i_len);
+ offset = next_offset;
+ }
+
+ if (i_off != 0)
+ {
+ if (image_offset) *image_offset = i_off;
+ return TRUE;
+ }
+
+ return FALSE;
+}
+
+
/*
*-----------------------------------------------------------------------------
* EXIF Makernote for Nikon
projects / geeqie.git / blobdiff