Support prepared EXR batches and TIFF/IFD1

Bump VERSION and add docs/workflow for GitHub Pages; update README and docs to describe EXR and TIFF progress. Add CI yamllint rule and .github workflow to build and publish Sphinx docs.

Introduce EXR host-integration helpers in src/include/openmeta/exr_adapter.h and src/openmeta/exr_adapter.cc: new types and functions to materialize ExrAdapterBatch from a prepared transfer bundle (build_prepared_exr_attribute_batch) and a file-helper wrapper (build_exr_attribute_batch_from_file). Add parsing/encoding helpers for the prepared EXR string-attribute payload format and error handling.

Significant enhancements to TIFF/EXIF handling in src/openmeta/metadata_transfer.cc: add IFD1 support and explicit subIFD indexing, new TransferExifIfdRef classification, support for preserving downstream page/aux tails, and plumbing to emit the IFD1 pointer when present. Introduce big/64-bit TIFF (BigTIFF) support via a TiffLayout abstraction: widen count/offset fields, add read/write helpers for 64-bit values, adjust parsing/serialization for classic and BigTIFF variants, handle endian conversion for new types, and extend parsed/serialized structures to track next-ifd offsets and subIFDs. Tests and Python bindings were updated accordingly.

Author: ssh4net

.github/workflows/docs-pages.yml

@@ -0,0 +1,90 @@
+---
+name: docs-pages
+
+on:
+  pull_request:
+    paths:
+      - ".github/workflows/docs-pages.yml"
+      - "CMakeLists.txt"
+      - "README.md"
+      - "SECURITY.md"
+      - "NOTICE.md"
+      - "cmake/Doxyfile.in"
+      - "docs/**"
+      - "src/include/**"
+  push:
+    branches:
+      - main
+    tags:
+      - "*"
+    paths:
+      - ".github/workflows/docs-pages.yml"
+      - "CMakeLists.txt"
+      - "README.md"
+      - "SECURITY.md"
+      - "NOTICE.md"
+      - "cmake/Doxyfile.in"
+      - "docs/**"
+      - "src/include/**"
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+concurrency:
+  group: docs-pages-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Setup Pages
+        uses: actions/configure-pages@v5
+
+      - name: Setup Python
+        uses: actions/setup-python@v6
+        with:
+          python-version: "3.12"
+          cache: "pip"
+          cache-dependency-path: docs/requirements.txt
+
+      - name: Install docs dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y doxygen graphviz ninja-build
+          python -m pip install --upgrade pip
+          python -m pip install -r docs/requirements.txt
+
+      - name: Configure docs build
+        run: >
+          cmake -S . -B build -G Ninja
+          -DOPENMETA_BUILD_SPHINX_DOCS=ON
+          -DOPENMETA_BUILD_SHARED=OFF
+          -DOPENMETA_BUILD_TOOLS=OFF
+
+      - name: Build docs
+        run: cmake --build build --target openmeta_docs_sphinx --parallel
+
+      - name: Upload Pages artifact
+        uses: actions/upload-pages-artifact@v4
+        with:
+          path: build/docs/html
+
+  deploy:
+    if: github.ref == 'refs/heads/main' || startsWith(github.ref, 'refs/tags/')
+    needs: build
+    runs-on: ubuntu-latest
+    permissions:
+      pages: write
+      id-token: write
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4

.yamllint

@@ -0,0 +1,7 @@
+---
+extends: default
+
+rules:
+  truthy:
+    # GitHub Actions uses the unquoted top-level key `on`.
+    check-keys: false

README.md

@@ -12,6 +12,14 @@ Read-path coverage is broad and regression-gated. Write/edit support is real
 for the main transfer targets, but parts of that API surface are still draft
 and may change as the transfer contract stabilizes.
 
+Current planning estimate:
+
+| Milestone | Status |
+| --- | --- |
+| Read parity on tracked still-image corpora | About `99-100%` |
+| Transfer / export milestone | About `80-85%` |
+| Overall product milestone | About `97-98%` |
+
 Current baseline-gated snapshot on tracked corpora:
 - HEIC/HEIF, CR3, and mixed RAW EXIF tag-id compare gates are passing.
 - EXR header metadata compare is passing for name/type/value-class checks.
@@ -84,11 +92,22 @@ Current target status:
 
 In practice:
 - JPEG and TIFF are the strongest transfer targets today.
+- TIFF edit support now covers classic TIFF, BigTIFF, bounded `ifd1`
+  chain rewrite with preserved downstream page tails, and bounded
+  TIFF/DNG-style SubIFD rewrite with preserved downstream auxiliary tails
+  and preserved trailing existing children when only the front subset is
+  replaced.
+- For DNG-like TIFF sources, the current bounded merge policy is:
+  replace the source-supplied front preview/aux structures, preserve
+  existing target page tails and trailing auxiliary children.
 - PNG, WebP, JP2, JXL, bounded BMFF, and EXR all have real first-class
   transfer entry points.
 - EXR is still narrower than the container-edit targets: it emits safe string
-  header attributes through the transfer core, but it does not rewrite full
-  EXR files yet.
+  header attributes through the transfer core, can materialize a prepared
+  `ExrAdapterBatch` for host exporters, and Python can inspect that prepared
+  EXR attribute batch through the direct `build_exr_attribute_batch_from_file`
+  binding or the helper-layer `openmeta.python.get_exr_attribute_batch(...)`,
+  but OpenMeta does not rewrite full EXR files yet.
 - Writer-side sync behavior is now partially explicit instead of implicit:
   generated XMP can independently keep or suppress EXIF-derived and
   IPTC-derived projection during transfer preparation.

VERSION

@@ -1 +1 @@
-0.4.5
+0.4.6

docs/doxygen.md

@@ -37,6 +37,23 @@ cmake --build build --target openmeta_docs_sphinx
 Output goes to `build/docs/html/index.html`. Doxygen XML goes to
 `build/docs/doxygen/xml/index.xml`.
 
+## Publish on GitHub Pages
+
+The repository includes a GitHub Actions workflow at
+`.github/workflows/docs-pages.yml` that builds the Sphinx site and publishes it
+to GitHub Pages.
+
+Recommended setup:
+
+- In the repository settings, set **Pages** to **GitHub Actions** as the
+  source.
+- Pull requests build the docs but do not deploy.
+- Pushes to `main` and tag pushes build and deploy the site.
+
+The workflow only runs when docs inputs change: `docs/**`, `src/include/**`,
+`README.md`, `SECURITY.md`, `NOTICE.md`, `CMakeLists.txt`, or the workflow
+itself.
+
 ## Generate API docs (manual)
 
 From the `OpenMeta/` repo root:

docs/metadata_transfer_plan.md

@@ -26,6 +26,8 @@ The core rule is:
 
 ## Current Status
 
+Current planning estimate for this lane: about `80-85%`.
+
 Source-side readiness is already strong:
 - tracked EXIF read gates are green on `HEIC/HEIF`, `CR3`, and mixed RAW corpora
 - tracked MakerNote gates are green
@@ -45,13 +47,13 @@ The first public write-side sync controls are also in place:
 | Target | Status | Current shape | Main limits |
 | --- | --- | --- | --- |
 | JPEG | First-class | Prepared bundle, compiled emit, byte-writer emit, edit planning/apply, file helper, bounded JUMBF/C2PA staging | Not a full arbitrary metadata editor yet |
-| TIFF | First-class | Prepared bundle, compiled emit, edit planning/apply, file helper, streaming edit path | Broader TIFF/DNG rewrite coverage is still narrower than JPEG |
+| TIFF | First-class | Prepared bundle, compiled emit, classic-TIFF and BigTIFF edit planning/apply, bounded `ifd1` chain rewrite with preserved downstream page tails, bounded TIFF/DNG-style SubIFD rewrite with preserved downstream auxiliary tails and preserved trailing existing children when only the front subset is replaced, file helper, streaming edit path | Broader TIFF/DNG rewrite coverage is still narrower than JPEG |
 | PNG | Bounded but real | Prepared bundle, compiled emit, bounded chunk rewrite/edit, file-helper roundtrip | Not a general PNG chunk editor |
 | WebP | Bounded but real | Prepared bundle, compiled emit, bounded chunk rewrite/edit, file-helper roundtrip | Not a general WebP chunk editor |
 | JP2 | Bounded but real | Prepared bundle, compiled emit, bounded box rewrite/edit, file-helper roundtrip | `jp2h` synthesis is still out of scope |
 | JXL | Bounded but real | Prepared bundle, compiled emit, bounded box rewrite/edit, file-helper roundtrip | Still narrower than JPEG/TIFF |
 | HEIF / AVIF / CR3 | Bounded but real | Prepared bundle, compiled emit, bounded BMFF item/property edit, file-helper roundtrip | Not broad BMFF writer parity |
-| EXR | Bounded but real | Prepared bundle, compiled emit, direct backend attribute emit, CLI/Python transfer surface | No file rewrite/edit path yet; current transfer payload is safe string attributes only |
+| EXR | Bounded but real | Prepared bundle, compiled emit, direct backend attribute emit, prepared-bundle to `ExrAdapterBatch` bridge, CLI/Python transfer surface | No file rewrite/edit path yet; current transfer payload is safe string attributes only |
 
 ## What Is Already Implemented
 
@@ -85,6 +87,13 @@ These support the public transfer flow:
 OpenMeta now has explicit end-to-end read-backed transfer tests for:
 - source JPEG -> JPEG edit/apply -> read-back
 - source JPEG -> TIFF edit/apply -> read-back
+- source JPEG -> TIFF edit/apply with `ifd1` -> read-back
+- source TIFF/BigTIFF with existing multi-page `ifd1 -> next` chain ->
+  replace `ifd1` -> preserve downstream tail
+- source DNG-like TIFF with `subifd0` + `ifd1` -> TIFF edit/apply -> read-back
+- source DNG-like TIFF with `subifd0` + `ifd1` -> BigTIFF edit/apply -> read-back
+- source TIFF/BigTIFF with existing `subifd0 -> next` auxiliary chain ->
+  replace `subifd0` -> preserve downstream auxiliary tail
 - source JPEG -> PNG edit/apply -> read-back
 - source JPEG -> WebP edit/apply -> read-back
 - source JPEG -> JP2 edit/apply -> read-back
@@ -119,6 +128,17 @@ Also a first-class target.
 Implemented:
 - EXIF, XMP, ICC, and IPTC transfer
 - edit planning and apply
+- classic-TIFF and BigTIFF rewrite support
+- bounded `ifd1` chain rewrite support, including preserving an existing
+  downstream page tail when `ifd1` is replaced
+- bounded TIFF/DNG-style SubIFD rewrite support, including preserving an
+  existing downstream auxiliary tail when `subifdN` is replaced
+- bounded front-subset `SubIFD` replacement that preserves trailing existing
+  children from the target file
+- bounded DNG-style merge policy in the file-helper path:
+  source-supplied preview/aux front structures replace the target front
+  structures, while existing target page tails and trailing auxiliary
+  children are preserved
 - file-based helper flow
 - streaming edit output
 
@@ -184,6 +204,19 @@ It still keeps the older integration bridge:
 - `build_exr_attribute_part_views(...)`
 - `replay_exr_attribute_batch(...)`
 
+The transfer lane now also exposes:
+- `build_prepared_exr_attribute_batch(...)`
+- `build_exr_attribute_batch_from_file(...)`
+- Python `build_exr_attribute_batch_from_file(...)` for direct file-to-batch
+  host-side inspection without going through the generic transfer probe
+- Python helper wrappers:
+  `openmeta.python.probe_exr_attribute_batch(...)` and
+  `openmeta.python.get_exr_attribute_batch(...)`
+
+That keeps EXR host integrations on the transfer path: callers can prepare one
+`TransferTargetFormat::Exr` bundle, then materialize a native
+`ExrAdapterBatch` without re-projecting from the source `MetaStore`.
+
 Current EXR transfer scope is intentionally conservative:
 - safe flattened `string` header attributes
 - backend emission through `ExrTransferEmitter`

src/include/openmeta/exr_adapter.h

@@ -2,6 +2,7 @@
 
 #include "openmeta/exr_decode.h"
 #include "openmeta/meta_store.h"
+#include "openmeta/metadata_transfer.h"
 
 #include <cstddef>
 #include <cstdint>
@@ -94,6 +95,18 @@ struct ExrAdapterReplayResult final {
     std::string message;
 };
 
+/// File-helper options for \ref build_exr_attribute_batch_from_file.
+struct BuildExrAttributeBatchFileOptions final {
+    PrepareTransferFileOptions prepare;
+    ExrAdapterOptions adapter;
+};
+
+/// File-helper result for \ref build_exr_attribute_batch_from_file.
+struct BuildExrAttributeBatchFileResult final {
+    PrepareTransferFileResult prepared;
+    ExrAdapterResult adapter;
+};
+
 /**
  * \brief Builds one owned EXR-native attribute batch from a \ref MetaStore.
  *
@@ -107,6 +120,39 @@ build_exr_attribute_batch(const MetaStore& store, ExrAdapterBatch* out,
                           const ExrAdapterOptions& options
                           = ExrAdapterOptions {}) noexcept;
 
+/**
+ * \brief Builds one EXR-native attribute batch from a prepared EXR transfer
+ * bundle.
+ *
+ * This bridges the transfer pipeline with EXR host integrations: callers can
+ * prepare metadata once with \ref prepare_metadata_for_target using
+ * \ref TransferTargetFormat::Exr, then materialize a host-facing
+ * \ref ExrAdapterBatch without re-projecting from the source \ref MetaStore.
+ *
+ * Current EXR prepared transfer blocks serialize one logical `string`
+ * attribute per block and target part `0`.
+ */
+ExrAdapterResult
+build_prepared_exr_attribute_batch(const PreparedTransferBundle& bundle,
+                                   ExrAdapterBatch* out,
+                                   const ExrAdapterOptions& options
+                                   = ExrAdapterOptions {}) noexcept;
+
+/**
+ * \brief Reads one file, prepares EXR transfer metadata, then materializes a
+ * host-facing \ref ExrAdapterBatch.
+ *
+ * This is the direct public file-helper for thin bindings and host tools.
+ * Internally it wraps \ref prepare_metadata_for_target_file, forces the
+ * prepared target format to \ref TransferTargetFormat::Exr, then calls
+ * \ref build_prepared_exr_attribute_batch.
+ */
+BuildExrAttributeBatchFileResult
+build_exr_attribute_batch_from_file(
+    const char* path, ExrAdapterBatch* out,
+    const BuildExrAttributeBatchFileOptions& options
+    = BuildExrAttributeBatchFileOptions {}) noexcept;
+
 /**
  * \brief Builds contiguous per-part spans over one \ref ExrAdapterBatch.
  *