Enhance Canon MakerNote parsing; add Nikon ISO2

Bump version to 0.4.25 and update CHANGES.md. Add a missing Nikon ShotInfo D300A ISO2 tag mapping (0x0265) and regenerate makernote tag names. Improve Canon MakerNote handling: include EOS 7D in the PSInfo cohort and add EOS Kiss X7i / EOS-1D X to the PSInfo2 cohort selection logic. Change logic for Canon main tag 0x0038 so short byte blobs are treated as the placeholder (ContextualName) while long byte blobs are left named as BatteryType (wire_count <= 8 is considered short). Update TIFF decode and Canon makernote code accordingly and add/adjust tests to cover the new behaviors (including helpers for long Canon tag 0x0038 blobs and cohort selection tests).

Author: ssh4net

CHANGES.md

@@ -1,5 +1,27 @@
 # OpenMeta Changes
 
+## 0.4.25 - 2026-05-21
+
+Changes compared with `0.4.24`.
+
+### Changed
+
+- Improved Canon CameraInfo PictureStyle interpretation for EOS 7D,
+  EOS Kiss X7i, and EOS-1D X model cohorts by selecting the matching
+  PSInfo/PSInfo2 table.
+- Split Canon MakerNote main tag `0x0038` byte-blob naming by observed
+  payload size, preserving the placeholder for short blobs while reporting
+  long battery-type payloads as `BatteryType`.
+
+## 0.4.24 - 2026-05-21
+
+Changes compared with `0.4.23`.
+
+### Added
+
+- Added the missing Nikon ShotInfo D300A `ISO2` MakerNote name used by the
+  ExifTool-compatible interpretation path.
+
 ## 0.4.23 - 2026-05-21
 
 Changes compared with `0.4.22`.

VERSION

@@ -1 +1 @@
-0.4.23
+0.4.25

registry/exif/makernotes/nikon.jsonl

@@ -1196,6 +1196,7 @@
 {"kind":"exif.tag","ifd":"makernote:nikon:shotinfo","tag":"0x024d","name":"ShutterCount"}
 {"kind":"exif.tag","ifd":"makernote:nikon:shotinfod300a","tag":"0x0000","name":"ShotInfoVersion"}
 {"kind":"exif.tag","ifd":"makernote:nikon:shotinfod300a","tag":"0x025c","name":"ISO2"}
+{"kind":"exif.tag","ifd":"makernote:nikon:shotinfod300a","tag":"0x0265","name":"ISO2"}
 {"kind":"exif.tag","ifd":"makernote:nikon:shotinfod300a","tag":"0x0279","name":"ShutterCount"}
 {"kind":"exif.tag","ifd":"makernote:nikon:shotinfod300a","tag":"0x02d1","name":"AFFineTuneAdj"}
 {"kind":"exif.tag","ifd":"makernote:nikon:shotinfod300b","tag":"0x0000","name":"ShotInfoVersion"}

src/openmeta/exif_makernote_canon.cc

@@ -328,7 +328,7 @@ canon_camerainfo_prefers_psinfo(std::string_view model) noexcept
         "EOS 50D",          "EOS 5D Mark II",
         "EOS 1000D",        "EOS DIGITAL REBEL XS",
         "EOS Kiss F",       "EOS-1D Mark III",
-        "EOS-1Ds Mark III",
+        "EOS-1Ds Mark III", "EOS 7D",
     };
     return canon_model_matches_any(model, kCanonModels);
 }
@@ -337,9 +337,7 @@ static bool
 canon_camerainfo_prefers_psinfo2(std::string_view model) noexcept
 {
     static constexpr std::string_view kCanonModels[] = {
-        "EOS 60D",
-        "EOS 6D",
-        "EOS 5D Mark III",
+        "EOS 60D", "EOS 6D", "EOS 5D Mark III", "EOS Kiss X7i", "EOS-1D X",
     };
     return canon_model_matches_any(model, kCanonModels);
 }
@@ -3824,7 +3822,7 @@ decode_canon_makernote(const TiffConfig& cfg,
                                         abs_value_off, value_bytes,
                                         store.arena(), options.limits,
                                         status_out);
-        if (tag == 0x0038u && type == 7
+        if (tag == 0x0038u && type == 7 && count <= 8U
             && entry.value.kind == MetaValueKind::Bytes) {
             entry.flags |= EntryFlags::ContextualName;
             entry.origin.name_context_kind = EntryNameContextKind::CanonMain0038;

src/openmeta/exif_makernote_tag_names_generated.inc

@@ -5876,6 +5876,7 @@ static constexpr MakerNoteTagNameEntry kMakernoteNikonShotinfo[] = {
 static constexpr MakerNoteTagNameEntry kMakernoteNikonShotinfod300a[] = {
     { 0x0000u, "ShotInfoVersion" },
     { 0x025Cu, "ISO2" },
+    { 0x0265u, "ISO2" },
     { 0x0279u, "ShutterCount" },
     { 0x02D1u, "AFFineTuneAdj" },
 };

src/openmeta/exif_tiff_decode.cc

@@ -999,7 +999,8 @@ namespace {
             }
         }
         if (ifd_name == "mk_canon0" && tag == 0x0038u
-            && entry->value.kind == MetaValueKind::Bytes) {
+            && entry->value.kind == MetaValueKind::Bytes
+            && entry->origin.wire_count <= 8U) {
             entry->flags |= EntryFlags::ContextualName;
             entry->origin.name_context_kind
                 = EntryNameContextKind::CanonMain0038;

tests/exif_tag_names_test.cc

@@ -31,6 +31,8 @@ TEST(ExifTagNames, MapsCommonTags)
               std::string_view("NumberOfImages"));
 
     EXPECT_EQ(exif_tag_name("mk_nikon0", 0x0002), std::string_view("ISO"));
+    EXPECT_EQ(exif_tag_name("mk_nikon_shotinfod300a_0", 0x0265),
+              std::string_view("ISO2"));
     EXPECT_EQ(exif_tag_name("mk_canon0", 0x0003),
               std::string_view("CanonFlashInfo"));
     EXPECT_EQ(exif_tag_name("mk_fuji0", 0x1000), std::string_view("Quality"));

tests/makernote_decode_test.cc

@@ -903,6 +903,24 @@ namespace {
         return mn;
     }
 
+    static std::vector<std::byte> make_canon_makernote_main_tag0038_long_bytes()
+    {
+        std::vector<std::byte> mn;
+        append_u16le(&mn, 1);
+        append_u16le(&mn, 0x0038);
+        append_u16le(&mn, 7);
+        append_u32le(&mn, 76);
+        append_u32le(&mn, 18U);
+        append_u32le(&mn, 0);
+        EXPECT_EQ(mn.size(), 18U);
+        append_u32le(&mn, 76U);
+        append_bytes(&mn, "LP-E6NH");
+        while (mn.size() < 18U + 76U) {
+            mn.push_back(std::byte { 0 });
+        }
+        return mn;
+    }
+
     static std::vector<std::byte> make_canon_custom_functions1d_makernote()
     {
         // Canon MakerNote with:
@@ -7755,6 +7773,32 @@ TEST(MakerNoteDecode, MarksCanonMainTag0038PlaceholderForByteBlob)
               std::string_view("Canon_0x0038"));
 }
 
+TEST(MakerNoteDecode, KeepsCanonMainTag0038BatteryTypeForLongByteBlob)
+{
+    const std::vector<std::byte> mn
+        = make_canon_makernote_main_tag0038_long_bytes();
+    const std::vector<std::byte> tiff = make_test_tiff_with_makernote("Canon",
+                                                                      mn);
+
+    MetaStore store;
+    std::array<ExifIfdRef, 8> ifds {};
+    ExifDecodeOptions options;
+    options.decode_makernote   = true;
+    const ExifDecodeResult res = decode_exif_tiff(tiff, store, ifds, options);
+    EXPECT_EQ(res.status, ExifDecodeStatus::Ok);
+
+    store.finalize();
+    const std::span<const EntryId> ids = store.find_all(
+        exif_key("mk_canon0", 0x0038));
+    ASSERT_EQ(ids.size(), 1U);
+    const Entry& e = store.entry(ids[0]);
+    EXPECT_FALSE(any(e.flags, EntryFlags::ContextualName));
+    EXPECT_EQ(exif_entry_name(store, e, ExifTagNamePolicy::Canonical),
+              std::string_view("BatteryType"));
+    EXPECT_EQ(exif_entry_name(store, e, ExifTagNamePolicy::ExifToolCompat),
+              std::string_view("BatteryType"));
+}
+
 TEST(MakerNoteDecode, SelectsCanonCustom350dTableFromCountFallback)
 {
     const std::vector<std::byte> mn
@@ -8574,6 +8618,24 @@ TEST(MakerNoteDecode, PrefersCanonCameraInfoPsinfoFor1000dCohort)
     ASSERT_EQ(store.find_all(exif_key("mk_canon_psinfo_0", 0x0090)).size(), 1U);
 }
 
+TEST(MakerNoteDecode, PrefersCanonCameraInfoPsinfoFor7dCohort)
+{
+    std::vector<std::byte> mn = make_canon_camera_info_psinfo2_makernote();
+    const std::vector<std::byte> tiff
+        = make_test_tiff_with_makernote_and_model("Canon", "Canon EOS 7D", mn);
+
+    MetaStore store;
+    std::array<ExifIfdRef, 8> ifds {};
+    ExifDecodeOptions options;
+    options.decode_makernote   = true;
+    const ExifDecodeResult res = decode_exif_tiff(tiff, store, ifds, options);
+    EXPECT_EQ(res.status, ExifDecodeStatus::Ok);
+
+    store.finalize();
+    EXPECT_TRUE(store.find_all(exif_key("mk_canon_psinfo2_0", 0x0090)).empty());
+    ASSERT_EQ(store.find_all(exif_key("mk_canon_psinfo_0", 0x0090)).size(), 1U);
+}
+
 TEST(MakerNoteDecode, PrefersCanonCameraInfoPsinfo2For5dMarkIiiCohort)
 {
     std::vector<std::byte> mn = make_canon_camera_info_psinfo2_makernote();
@@ -8594,6 +8656,46 @@ TEST(MakerNoteDecode, PrefersCanonCameraInfoPsinfo2For5dMarkIiiCohort)
               1U);
 }
 
+TEST(MakerNoteDecode, PrefersCanonCameraInfoPsinfo2ForKissX7iCohort)
+{
+    std::vector<std::byte> mn = make_canon_camera_info_psinfo2_makernote();
+    const std::vector<std::byte> tiff
+        = make_test_tiff_with_makernote_and_model("Canon", "Canon EOS Kiss X7i",
+                                                  mn);
+
+    MetaStore store;
+    std::array<ExifIfdRef, 8> ifds {};
+    ExifDecodeOptions options;
+    options.decode_makernote   = true;
+    const ExifDecodeResult res = decode_exif_tiff(tiff, store, ifds, options);
+    EXPECT_EQ(res.status, ExifDecodeStatus::Ok);
+
+    store.finalize();
+    EXPECT_TRUE(store.find_all(exif_key("mk_canon_psinfo_0", 0x0090)).empty());
+    ASSERT_EQ(store.find_all(exif_key("mk_canon_psinfo2_0", 0x0090)).size(),
+              1U);
+}
+
+TEST(MakerNoteDecode, PrefersCanonCameraInfoPsinfo2For1dXCohort)
+{
+    std::vector<std::byte> mn = make_canon_camera_info_psinfo2_makernote();
+    const std::vector<std::byte> tiff
+        = make_test_tiff_with_makernote_and_model("Canon", "Canon EOS-1D X",
+                                                  mn);
+
+    MetaStore store;
+    std::array<ExifIfdRef, 8> ifds {};
+    ExifDecodeOptions options;
+    options.decode_makernote   = true;
+    const ExifDecodeResult res = decode_exif_tiff(tiff, store, ifds, options);
+    EXPECT_EQ(res.status, ExifDecodeStatus::Ok);
+
+    store.finalize();
+    EXPECT_TRUE(store.find_all(exif_key("mk_canon_psinfo_0", 0x0090)).empty());
+    ASSERT_EQ(store.find_all(exif_key("mk_canon_psinfo2_0", 0x0090)).size(),
+              1U);
+}
+
 TEST(MakerNoteDecode,
      FallsBackToCanonCameraInfoPictureStyleWhenPsinfo2TailIsInvalid)
 {