From 510de539bd8df525755a92ea4c20ec0bf1de88db Mon Sep 17 00:00:00 2001
From: Peter Stensson <petest@axis.com>
Date: Mon, 8 Mar 2021 13:44:04 +0100
Subject: [PATCH] Add support for SensitivityType tag

As per EXIF specification, SensitivityType tag should
be recorded when PhotographicSensitivity(AKA ISOSpeedRatings)
is recorded.
---
 libexif/exif-entry.c | 12 ++++++++++++
 libexif/exif-tag.c   |  7 +++++++
 libexif/exif-tag.h   |  1 +
 3 files changed, 20 insertions(+)

diff --git a/libexif/exif-entry.c b/libexif/exif-entry.c
index 822a6416..d08b2dbb 100644
--- a/libexif/exif-entry.c
+++ b/libexif/exif-entry.c
@@ -778,6 +778,16 @@ static const struct {
       {8, {N_("Landscape mode (for landscape photos with the background "
 	      "in focus)"), N_("Landscape"), NULL}},
       {0, {NULL}}}},
+  { EXIF_TAG_SENSITIVITY_TYPE,
+    { {0, {N_("Unknown"), NULL}},
+      {1, {N_("Standard output sensitivity (SOS)"), NULL}},
+      {2, {N_("Recommended exposure index (REI)"), NULL}},
+      {3, {N_("ISO speed"), NULL}},
+      {4, {N_("Standard output sensitivity (SOS) and recommended exposure index (REI)"), NULL}},
+      {5, {N_("Standard output sensitivity (SOS) and ISO speed"), NULL}},
+      {6, {N_("Recommended exposure index (REI) and ISO speed"), NULL}},
+      {7, {N_("Standard output sensitivity (SOS) and recommended exposure index (REI) and ISO speed"), NULL}},
+      {0, {NULL}}}},
   { EXIF_TAG_FLASH,
     { {0x0000, {N_("Flash did not fire"), N_("No flash"), NULL}},
       {0x0001, {N_("Flash fired"), N_("Flash"), N_("Yes"), NULL}},
@@ -1295,6 +1305,7 @@ exif_entry_get_value (ExifEntry *e, char *val, unsigned int maxlen)
 	case EXIF_TAG_FOCAL_PLANE_RESOLUTION_UNIT:
 	case EXIF_TAG_RESOLUTION_UNIT:
 	case EXIF_TAG_EXPOSURE_PROGRAM:
+	case EXIF_TAG_SENSITIVITY_TYPE:
 	case EXIF_TAG_FLASH:
 	case EXIF_TAG_SUBJECT_DISTANCE_RANGE:
 	case EXIF_TAG_COLOR_SPACE:
@@ -1450,6 +1461,7 @@ exif_entry_initialize (ExifEntry *e, ExifTag tag)
 	case EXIF_TAG_SUBJECT_DISTANCE_RANGE:
 	case EXIF_TAG_FLASH:
 	case EXIF_TAG_ISO_SPEED_RATINGS:
+	case EXIF_TAG_SENSITIVITY_TYPE:
 
 	/* SHORT, 1 component, default 0 */
 	case EXIF_TAG_IMAGE_WIDTH:
diff --git a/libexif/exif-tag.c b/libexif/exif-tag.c
index 30e09179..d4bb2b3d 100644
--- a/libexif/exif-tag.c
+++ b/libexif/exif-tag.c
@@ -524,6 +524,13 @@ static const struct TagEntry {
 	{EXIF_TAG_TIME_ZONE_OFFSET, "TimeZoneOffset", N_("Time Zone Offset"),
 	 N_("Encodes time zone of camera clock relative to GMT."),
 	 ESL_UNKNOWN},
+	{EXIF_TAG_SENSITIVITY_TYPE, "SensitivityType", N_("Sensitivity Type"),
+	 N_("The SensitivityType tag indicates which one of the parameters of "
+	 	"ISO12232 is the PhotographicSensitivity tag. Although it is an optional "
+		"tag, it should be recorded when a PhotographicSensitivity tag is recorded. "
+		"Value = 4, 5, 6, or 7 may be used in case that the values of plural parameters "
+		"are the same."),
+	 { ESL_NNNN, ESL_NNNN, ESL_OOOO, ESL_NNNN, ESL_NNNN } },
 	{EXIF_TAG_EXIF_VERSION, "ExifVersion", N_("Exif Version"),
 	 N_("The version of this standard supported. Nonexistence of this "
 	    "field is taken to mean nonconformance to the standard."),
diff --git a/libexif/exif-tag.h b/libexif/exif-tag.h
index c5518027..225f2a21 100644
--- a/libexif/exif-tag.h
+++ b/libexif/exif-tag.h
@@ -90,6 +90,7 @@ typedef enum {
 	EXIF_TAG_ISO_SPEED_RATINGS		= 0x8827,
 	EXIF_TAG_OECF				= 0x8828,
 	EXIF_TAG_TIME_ZONE_OFFSET		= 0x882a,
+	EXIF_TAG_SENSITIVITY_TYPE		= 0x8830,
 	EXIF_TAG_EXIF_VERSION			= 0x9000,
 	EXIF_TAG_DATE_TIME_ORIGINAL		= 0x9003,
 	EXIF_TAG_DATE_TIME_DIGITIZED		= 0x9004,