Lots of EXIF mode fixes and improvements by Dennis Real (closes #87)

Squashed commit of the following:

commit 58dd2e303c5ee380527d92a3fa3d6baeeacb50a1
Merge: cf6f032 82a976e
Author: Dennis Real <github@tildepipe.org>
Date:   Sat Mar 31 18:43:47 2012 +0200

    Merge branch 'master' of git://github.com/derf/feh

commit cf6f0320c15abd753951990a963d5c94b180bbde
Merge: 10b7b1e 877e634
Author: Dennis Real <github@tildepipe.org>
Date:   Sun Mar 25 19:07:30 2012 +0200

    Merge branch 'master' of git://github.com/derf/feh

commit 10b7b1e3e10ba650b240a742947cb6850bbadd23
Author: Dennis Real <github@tildepipe.org>
Date:   Sat Mar 24 14:41:15 2012 +0100

    Support for Canon Exif makernote tags

commit 3c284dc81dcb26249114b7ecf32ed0000f492b8b
Author: Dennis Real <github@tildepipe.org>
Date:   Thu Mar 22 19:44:32 2012 +0100

    Support for Active D-Lightning

commit ad5aea8cb853cc9d1b322c69f4812ad0bcb08ef3
Merge: cc6de20 9c43b64
Author: Dennis Real <github@tildepipe.org>
Date:   Thu Mar 22 19:01:38 2012 +0100

    Merge remote branch 'upstream/master'

commit cc6de20061eaa7172aa0184e03df947da14d713e
Author: Dennis Real <github@tildepipe.org>
Date:   Thu Mar 22 19:00:30 2012 +0100

    Nikon makernote parts changed

commit e401bd9c78a82b8290ec524e56b7c832631725e6
Author: Dennis Real <github@tildepipe.org>
Date:   Wed Mar 21 19:47:15 2012 +0100

    1. Own module for nikon maker notes
    2. Support for AFInfo2

commit 39cbd1ed2b6693beea5e974a6ae83207c6e9a826
Merge: 9e1bbf8 a100123
Author: Dennis Real <github@tildepipe.org>
Date:   Fri Mar 16 22:22:28 2012 +0100

    Merge remote branch 'upstream/master'

commit 9e1bbf874500e99506baffec3c6b54ed04e60a2f
Author: Dennis Real <github@tildepipe.org>
Date:   Fri Mar 16 22:20:58 2012 +0100

    - exif handling changed
    - gps info added if available

commit 8e96382805eb77a82209df9d71dbf9c0dd1c4cdb
Merge: 77fa5ac 29cd868
Author: Dennis Real <github@tildepipe.org>
Date:   Fri Mar 16 19:13:47 2012 +0100

    Merge branch 'master' of git://github.com/derf/feh

commit 77fa5aca182435f2771511832ea198d027393ceb
Merge: 93a90e6 3b2756b
Author: Dennis Real <github@tildepipe.org>
Date:   Wed Mar 7 17:18:07 2012 +0100

    Merge branch 'master' of git://github.com/derf/feh

commit 93a90e60d0cf093ca71c34f4f5dbfde974f433f0
Merge: a81465d 52d5da9
Author: Dennis Real <github@tildepipe.org>
Date:   Tue Mar 6 21:42:40 2012 +0100

    Merge branch 'master' of git://github.com/derf/feh

commit a81465d019593cfd1e506eb66f20f6b5e10488f3
Merge: a19e50d 31afac4
Author: Dennis Real <github@tildepipe.org>
Date:   Mon Mar 5 17:23:40 2012 +0100

    Merge branch 'master' of git://github.com/derf/feh

commit a19e50deb749c5188bdbc75a5c1cd6ab1f3f3a3a
Merge: 1c89da1 fe9a16b
Author: Dennis Real <github@tildepipe.org>
Date:   Sun Mar 4 15:35:45 2012 +0100

    Merge branch 'master' of ssh://github.com/reald/feh

commit 1c89da1269089d98529a6635c36d014da1b08eb4
Author: Dennis Real <github@tildepipe.org>
Date:   Tue Feb 28 22:37:22 2012 +0100

    test case adapted to new testfile

commit bb3c9d3571e43f913c6f659fefd9cd34971fd004
Author: Dennis Real <github@tildepipe.org>
Date:   Tue Feb 28 22:34:51 2012 +0100

    test file with some exif data added

commit fe9a16bce3f06d45acf103fc4439c1af2dc4ac6c
Author: Dennis Real <github@tildepipe.org>
Date:   Tue Feb 28 22:37:22 2012 +0100

    test case adapted to new testfile

commit e0bedc0438cf4ab4eafe43afca0886ad63591560
Merge: 46801fe 69ecc5c
Author: Dennis Real <github@tildepipe.org>
Date:   Tue Feb 28 22:36:08 2012 +0100

    Merge remote branch 'upstream/master'

commit 46801fee8de26f4e0af2ed294c3a4f7fc1c45ca3
Author: Dennis Real <github@tildepipe.org>
Date:   Tue Feb 28 22:34:51 2012 +0100

    test file with some exif data added

1 files changed, 370 insertions, 0 deletions

diff --git a/src/exif_nikon.c b/src/exif_nikon.c
new file mode 100644
index 0000000..f4a8eea
--- /dev/null
+++ b/src/exif_nikon.c
@@ -0,0 +1,370 @@
+/* exif_nikon.c
+
+Copyright (C) 2012      Dennis Real.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to
+deal in the Software without restriction, including without limitation the
+rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+sell copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies of the Software and its documentation and acknowledgment shall be
+given in the documentation and software packages that this Software was
+used.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+*/
+
+#ifdef HAVE_LIBEXIF
+
+#include <stdio.h>
+#include <libexif/exif-data.h>
+
+#include "feh.h"
+#include "debug.h"
+#include "exif.h"
+#include "exif_nikon.h"
+
+
+/* Flash control mode */
+/* http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/Nikon.html#FlashControlMode */
+#define EXN_FLASH_CONTROL_MODES_MAX 9
+char *EXN_NikonFlashControlModeValues[EXN_FLASH_CONTROL_MODES_MAX] = {"Off", 
+                                       "iTTL-BL", "iTTL", "Auto Aperture", 
+                                       "Automatic", "GN (distance priority)", 
+                                       "Manual", "Repeating Flash", 
+                                       "N/A" /* "N/A" is not a nikon setting */
+                                       };
+
+#define EXN_FLASH_CONTROL_MODE_MASK 0x7F
+
+
+/* AFInfo2 */
+/* http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/Nikon.html#AFInfo2 */
+#define EXN_CONTRAST_DETECT_AF_MAX 2
+char *EXN_NikonContrastDetectAF[EXN_CONTRAST_DETECT_AF_MAX] = {"Off", "On"};
+
+/* AFArea Mode for ContrastDetectAF Off */
+#define EXN_AF_AREA_MODE_P_MAX 13
+char *EXN_NikonAFAreaModePhase[EXN_AF_AREA_MODE_P_MAX] = {
+  "Single Area", "Dynamic Area", "Dynamic Area (closest subject)",
+  "Group Dynamic ", "Dynamic Area (9 points) ", "Dynamic Area (21 points)",
+  "Dynamic Area (51 points) ", "Dynamic Area (51 points, 3D-tracking)",
+  "Auto-area", "Dynamic Area (3D-tracking)", "Single Area (wide)",
+  "Dynamic Area (wide)", "Dynamic Area (wide, 3D-tracking)"};
+
+/* AFArea Mode for ContrastDetectAF On */
+#define EXN_AF_AREA_MODE_C_MAX 5
+char *EXN_NikonAFAreaModeContr[EXN_AF_AREA_MODE_C_MAX] = {
+  "Contrast-detect", 
+  "Contrast-detect (normal area)", 
+  "Contrast-detect (wide area)", 
+  "Contrast-detect (face priority)", 
+  "Contrast-detect (subject tracking)"};
+
+#define EXN_PHASE_DETECT_AF_MAX 4
+char *EXN_NikonPhaseDetectAF[EXN_PHASE_DETECT_AF_MAX] = {"Off", "On (51-point)", 
+                                                         "On (11-point)", "On (39-point)"};
+
+/* PrimaryAFPoint and AFPointsUsed only valid with PhaseDetectAF == On */
+
+#define EXN_PRIM_AF_PT_51_MAX 52
+char * EXN_Prim_AF_Pt_51[EXN_PRIM_AF_PT_51_MAX] = {"(none)", "C6 (Center)", "B6", "A5",
+  "D6", "E5", "C7", "B7", "A6", "D7", "E6", "C5", "B5", "A4", "D5", "E4", "C8", "B8",
+  "A7", "D8", "E7", "C9", "B9", "A8", "D9", "E8", "C10", "B10", "A9", "D10", "E9",
+  "C11", "B11", "D11", "C4", "B4", "A3", "D4", "E3", "C3", "B3", "A2", "D3", "E2",
+  "C2", "B2", "A1", "D2", "E1", "C1", "B1", "D1"};
+  
+#define EXN_PRIM_AF_PT_11_MAX 12
+char * EXN_Prim_AF_Pt_11[EXN_PRIM_AF_PT_11_MAX] = {"(none)", "Center", "Top", "Bottom",
+  "Mid-left", "Upper-left", "Lower-left", "Far Left", "Mid-right", "Upper-right",
+  "Lower-right",  "Far Right"};
+
+#define EXN_PRIM_AF_PT_39_MAX 40
+char * EXN_Prim_AF_Pt_39[EXN_PRIM_AF_PT_39_MAX] = {"(none)", "C6 (Center)", "B6", "A2",
+  "D6", "E2", "C7", "B7", "A3", "D7", "E3", "C5", "B5", "A1", "D5", "E1", "C8", "B8",
+  "D8", "C9", "B9", "D9", "C10", "B10", "D10", "C11", "B11", "D11", "C4", "B4", "D4",
+  "C3", "B3", "D3", "C2", "B2", "D2", "C1", "B1", "D1"};
+
+
+static void exn_get_prim_af_pt(unsigned int phasedetectaf,
+                               unsigned int primafpt,
+                               char * buffer,
+                               unsigned int maxsize);
+static void exn_get_mnote_nikon_34(ExifData *ed, char * buffer, unsigned int maxsize);
+static void exn_get_mnote_nikon_168(ExifData *ed, char * buffer, unsigned int maxsize);
+static void exn_get_mnote_nikon_183(ExifData *ed, char * buffer, unsigned int maxsize);
+
+
+
+/* get primary AF point */
+static void exn_get_prim_af_pt(unsigned int phasedetectaf,
+                               unsigned int primafpt,
+                               char * buffer,
+                               unsigned int maxsize)
+{
+  
+  switch(phasedetectaf)
+  {
+    case 0:
+    {
+      /* phasedetect not used. should not happen */
+      snprintf(buffer, maxsize, "FAIL");
+      return;
+    }
+    break;
+    case 1:
+    {
+      /* 51 pt */
+      if ( primafpt < EXN_PRIM_AF_PT_51_MAX )
+      {
+        snprintf(buffer, maxsize, "%s", EXN_Prim_AF_Pt_51[primafpt]);
+      }
+      return;
+    }
+    break;
+    case 2:
+    {
+      /* 11 pt */
+      if ( primafpt < EXN_PRIM_AF_PT_11_MAX )
+      {
+        snprintf(buffer, maxsize, "%s", EXN_Prim_AF_Pt_11[primafpt]);
+      }
+      return;
+    }
+    break;
+    case 3:
+    {
+      /* 39 pt */
+      if ( primafpt < EXN_PRIM_AF_PT_39_MAX )
+      {
+        snprintf(buffer, maxsize, "%s", EXN_Prim_AF_Pt_39[primafpt]);
+      }
+      return;
+    }
+    break;
+    default:
+    {
+      snprintf(buffer, maxsize, "?");
+      return;    
+    }
+    break;
+  
+  }
+   
+}
+
+
+
+/* get ActiveD-Lighting (34) info */
+static void exn_get_mnote_nikon_34(ExifData *ed, char * buffer, unsigned int maxsize)
+{
+  char buf[EXIF_STD_BUF_LEN];
+  unsigned int data = 0;
+  char *answer;
+
+  buf[0] = '\0';
+  exif_get_mnote_tag(ed, 34, buf, sizeof(buf));
+  sscanf(buf, "(null): %u", &data); 	/* not directly supported by libexif yet */
+  
+  switch(data)
+  {
+    case 0:
+    {
+      answer = "Off";
+    }
+    break;
+    case 1:
+    {
+      answer = "Low";
+    }
+    break;
+    case 3:
+    {
+      answer = "Normal";
+    }
+    break;
+    case 5:
+    {
+      answer = "High";
+    }
+    break;
+    case 7:
+    {
+      answer = "Extra High";
+    }
+    break;
+    case 65535:
+    {
+      answer = "Auto";
+    }
+    break;
+    default:
+    {
+      answer = "N/A"; /* this is not a nikon value */
+    }
+
+  }
+
+  snprintf(buffer, maxsize, "Active D-Lightning: %s\n", answer);
+  
+}
+
+
+
+/* get nikon Flash info: control mode (168) info */
+static void exn_get_mnote_nikon_168(ExifData *ed, char * buffer, unsigned int maxsize)
+{
+  char buf[EXIF_STD_BUF_LEN];
+  unsigned int version = 0;
+  unsigned int length = 0;
+  unsigned int exn_fcm = (EXN_FLASH_CONTROL_MODES_MAX-1); /* default to N/A */
+
+  /* libexif does not support flash info 168 yet. so we have to parse the debug data :-( */
+  buf[0] = '\0';
+  exif_get_mnote_tag(ed, 168, buf, sizeof(buf));
+  sscanf(buf, "(null): %u bytes unknown data: 303130%02X%*10s%02X", &length, &version, &exn_fcm);
+  exn_fcm = exn_fcm & EXN_FLASH_CONTROL_MODE_MASK;
+
+  if ( (exn_fcm < EXN_FLASH_CONTROL_MODES_MAX)
+       && ( ((length == 22) && (version == '3'))      /* Nikon FlashInfo0103 */
+            || ((length == 22) && (version == '4'))   /* Nikon FlashInfo0104 */
+            || ((length == 21) && (version == '2'))   /* Nikon FlashInfo0102 */
+            || ((length == 19) && (version == '0'))   /* Nikon FlashInfo0100 */
+          )
+     )
+  {
+    snprintf(buffer, maxsize, "NikonFlashControlMode: %s\n", EXN_NikonFlashControlModeValues[exn_fcm]);
+  }
+
+}
+
+
+
+/* get nikon AFInfo2 (183) info */
+static void exn_get_mnote_nikon_183(ExifData *ed, char * buffer, unsigned int maxsize)
+{
+  char buf[EXIF_STD_BUF_LEN];
+  unsigned int contrastdetectaf = 0;
+  unsigned int afareamode = 0;
+  unsigned int phasedetectaf = 0;
+  unsigned int primaryafpoint = 0;
+  unsigned int version = 0;
+  unsigned int length = 0;
+
+  /* AFInfo2 */
+  /* libexif does not support AFInfo2 183 yet. so we have to parse the debug data :-( */
+  buf[0] = '\0';
+  exif_get_mnote_tag(ed, 183, buf, sizeof(buf));
+  sscanf(buf, "(null): %u bytes unknown data: 303130%02X%02X%02X%02X%02X", &length, &version, 
+    &contrastdetectaf,
+    &afareamode,
+    &phasedetectaf,
+    &primaryafpoint
+    );
+
+
+  if ( ((length == 30) && (version == '0'))
+       && (contrastdetectaf < EXN_CONTRAST_DETECT_AF_MAX)
+       && (phasedetectaf < EXN_PHASE_DETECT_AF_MAX)
+       )
+  {
+    if ( (contrastdetectaf != 0) && (afareamode < EXN_AF_AREA_MODE_C_MAX) )
+    {
+      /* Contrast AF (live view) */
+      snprintf(buffer, maxsize, 
+               "ContrastDetectAF: %s; AFAreaMode: %s\n", 
+               EXN_NikonContrastDetectAF[contrastdetectaf],
+               EXN_NikonAFAreaModeContr[afareamode]);
+
+    }
+    else if ( (phasedetectaf != 0) && (afareamode < EXN_AF_AREA_MODE_P_MAX) )
+    {
+      /* Phase AF */
+      buf[0] = '\0';
+      exn_get_prim_af_pt(phasedetectaf, primaryafpoint, buf, EXIF_STD_BUF_LEN);
+    
+      snprintf(buffer, maxsize, 
+               "PhaseDetectAF: %s; AreaMode: %s; PrimaryAFPoint: %s\n", 
+               EXN_NikonPhaseDetectAF[phasedetectaf],
+               EXN_NikonAFAreaModePhase[afareamode],
+               buf
+               );
+    }
+
+  }
+}
+
+
+
+/* get interesting nikon maker note tags in readable form */
+void exn_get_mnote_nikon_tags(ExifData *ed, unsigned int tag, char * buffer, unsigned int maxsize)
+{
+  char buf[EXIF_STD_BUF_LEN];
+
+  buf[0] = '\0';
+  exif_get_tag(ed, EXIF_IFD_EXIF, EXIF_TAG_FLASH, buf, sizeof(buf));
+  exif_trim_spaces(buf);
+
+  switch(tag)
+  {
+    /* show only if flash was used */
+    case 8:   /* Flash Setting */
+    case 9:   /* Flash Mode */
+    case 24:  /* Flash exposure bracket value */
+    case 135: /* Flash used */
+    {
+      if ( !(strcmp("Flash: Flash did not fire\n", buf) == 0) )
+      {
+        /* show extended flash info only if flash was fired */
+        exif_get_mnote_tag(ed, tag, buffer, maxsize);
+      }
+    }
+    break;
+
+    case 34:
+    {
+      /* ActiveD-Lighting */
+      exn_get_mnote_nikon_34(ed, buffer, maxsize);
+    }
+    break;
+    
+    case 168:
+    {
+      /* Flash info: control mode */
+      if ( !(strcmp("Flash: Flash did not fire\n", buf) == 0) )
+      {
+        /* show extended flash info only if flash was fired */
+        exn_get_mnote_nikon_168(ed, buffer, maxsize);
+      }
+    }
+    break;
+
+    case 183:
+    {
+      /* AFInfo 2 */
+      exn_get_mnote_nikon_183(ed, buffer, maxsize);
+    }
+    break;
+    
+    default:
+    {
+      /* normal makernote tags without special treatment */
+      exif_get_mnote_tag(ed, tag, buffer, maxsize);
+    }
+    break;
+  }
+
+
+  return;
+}
+
+#endif