feat: add extended animation encoding options

.gitignore

@@ -5,4 +5,9 @@ node_modules
 *.o
 wasm
 *.tmp
-.npmrc
+.npmrc
+.idea
+
+# build artifacts (generated by npm run build-wasm:dev)
+src/webp-wasm.js
+src/webp-wasm.wasm

.gitmodules

@@ -1,10 +1,6 @@
 [submodule "libwebp"]
 	path = libwebp
-	branch = "v1.3.2"
-	url = https://github.com/webmproject/libwebp.git
-	ignore = all
+	url = https://chromium.googlesource.com/webm/libwebp
 [submodule "emsdk"]
 	path = emsdk
-	branch = "3.1.56"
-	url = https://github.com/juj/emsdk.git
-	ignore = all
+	url = https://github.com/emscripten-core/emsdk.git

CLAUDE.md

@@ -0,0 +1,80 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+webp-wasm is a pure WebAssembly/JavaScript port of libwebp that enables WebP encoding/decoding (including animated WebP) in browsers and Node.js without native dependencies.
+
+## Build Commands
+
+```bash
+# Full build (ESM with TypeScript)
+npm run build
+
+# Development build (outputs to src/ for hot reload)
+npm run build-wasm:dev
+
+# Build variants
+npm run build:esm      # ESM module build
+npm run build:cjs      # CommonJS build
+
+# Run tests
+npm test
+
+# Development server (Vite)
+npm run dev
+```
+
+## Architecture
+
+### Build Pipeline
+
+```
+libwebp (C) → Emscripten → webp-wasm.wasm + webp-wasm.js → TypeScript wrapper → dist/
+```
+
+1. **libwebp/** - Vendored libwebp v1.3.2 source (git submodule)
+2. **webp/** - C++ wrapper using Emscripten bindings (`emscripten/bind.h`)
+3. **src/index.ts** - TypeScript API that loads and wraps the WASM module
+4. **Makefile** - Orchestrates WASM compilation using emcc/em++
+
+### Key Files
+
+| File | Purpose |
+|------|---------|
+| `webp/webp.cpp` | Emscripten bindings (EMSCRIPTEN_BINDINGS macro) |
+| `webp/encode.cpp` | WebP encoding including animation |
+| `webp/decode.cpp` | WebP decoding including animation |
+| `src/index.ts` | Public TypeScript API |
+| `src/types.d.ts` | TypeScript type definitions |
+| `build.sh` | Build script with emsdk auto-setup |
+
+### Dependencies (Git Submodules)
+
+| Submodule | Version | Source |
+|-----------|---------|--------|
+| libwebp | v1.3.2 | chromium.googlesource.com/webm/libwebp |
+| emsdk | 3.1.74 | github.com/emscripten-core/emsdk |
+
+The build script automatically installs emsdk if `EMSDK` environment variable is not set.
+
+## API Structure
+
+The library exports async functions that load the WASM module on first call:
+
+- **Encoding**: `encodeRGB`, `encodeRGBA`, `encode`, `encodeAnimation`
+- **Decoding**: `decodeRGB`, `decodeRGBA`, `decodeAnimation`
+- **Utilities**: `encoderVersion`, `decoderVersion`
+
+Animation encoding supports per-frame quality settings via `WebPAnimationFrame.config`.
+
+## Testing
+
+Tests use Jest with experimental WASM module support:
+```bash
+npm test                           # Run all tests
+npm test -- tests/encode.test.js   # Run single test file
+```
+
+Test fixtures are PNG images in `tests/fixtures/`.

Makefile

@@ -1,11 +1,17 @@
 SRC = webp
 CODEC_DIR = libwebp
-EMSDK_INCLUDE_DIR = emsdk/upstream/emscripten/cache/sysroot/include
+
+# Use EMSDK env var if set, otherwise use local submodule
+EMSDK_PATH ?= $(if $(EMSDK),$(EMSDK),./emsdk)
+EMSDK_INCLUDE_DIR = $(EMSDK_PATH)/upstream/emscripten/cache/sysroot/include
+EMCC = $(EMSDK_PATH)/upstream/emscripten/emcc
+EMPP = $(EMSDK_PATH)/upstream/emscripten/em++
+EMCMAKE = $(EMSDK_PATH)/upstream/emscripten/emcmake
 
 .PHONY: clean
 
 webp-wasm.js: webp.o decode.o encode.o version.o ${CODEC_DIR}/libwebp.a ${CODEC_DIR}/libsharpyuv.a ${CODEC_DIR}/libwebpmux.a ${CODEC_DIR}/libwebpdemux.a
-	emsdk/upstream/emscripten/emcc \
+	$(EMCC) \
 		-lembind \
 		-s EXPORT_ES6=$(EXPORT_ES6) \
 		-s MODULARIZE \
@@ -15,7 +21,7 @@ webp-wasm.js: webp.o decode.o encode.o version.o ${CODEC_DIR}/libwebp.a ${CODEC_
 		-v
 
 %.o: ${SRC}/%.cpp
-	emsdk/upstream/emscripten/em++ -c \
+	$(EMPP) -c \
 	-std=c++17 \
 	-I ${CODEC_DIR} \
 	-I ${EMSDK_INCLUDE_DIR} \
@@ -27,7 +33,7 @@ webp-wasm.js: webp.o decode.o encode.o version.o ${CODEC_DIR}/libwebp.a ${CODEC_
 	$(MAKE) -C $(@D)
 
 $(CODEC_DIR)/Makefile: ${CODEC_DIR}/CMakeLists.txt
-	emsdk/upstream/emscripten/emcmake cmake \
+	$(EMCMAKE) cmake \
 		-DCMAKE_DISABLE_FIND_PACKAGE_Threads=1 \
 		-DWEBP_BUILD_CWEBP=ON \
 		-DWEBP_BUILD_DWEBP=ON \

README.md

@@ -285,6 +285,103 @@ npm run build-wasm:dev && npm run dev
 
 ## Building
 
+### Prerequisites
+
+- **Node.js 18+**
+- **CMake 3.16+**
+
+### Build Steps
+
+```shell
+# Clone with submodules
+git clone --recursive <repository-url>
+cd webp-wasm
+
+# Install dependencies
+npm install
+
+# Build (automatically installs emsdk if needed)
+npm run build
+```
+
+If you have a system-wide emsdk installation, you can use it instead:
 ```shell
+source /path/to/emsdk_env.sh
 npm run build
+```
+
+### Dependencies
+
+This project uses git submodules:
+
+| Submodule | Version | Source |
+|-----------|---------|--------|
+| libwebp | v1.3.2 | https://chromium.googlesource.com/webm/libwebp |
+| emsdk | 3.1.74 | https://github.com/emscripten-core/emsdk |
+
+```shell
+# Initialize submodules after clone
+git submodule update --init --recursive
+```
+
+To upgrade dependencies:
+```shell
+# Upgrade libwebp
+cd libwebp && git fetch --tags && git checkout v1.4.0 && cd ..
+git add libwebp && git commit -m "chore: upgrade libwebp to v1.4.0"
+
+# Upgrade emsdk
+cd emsdk && git fetch --tags && git checkout 3.1.75 && cd ..
+git add emsdk && git commit -m "chore: upgrade emsdk to 3.1.75"
+# Note: Update EMSDK_VERSION in build.sh accordingly
+```
+
+## Integration Guide
+
+### Local Development (npm link)
+
+For local development, you can link this library to your project:
+
+```shell
+# In webp-wasm directory
+npm link
+
+# In your project directory
+npm link wasm-webp
+```
+
+### Vite Configuration
+
+When using with Vite, add the following configuration:
+
+```typescript
+// vite.config.ts
+import wasm from 'vite-plugin-wasm'
+import topLevelAwait from 'vite-plugin-top-level-await'
+
+export default defineConfig({
+  plugins: [
+    wasm(),
+    topLevelAwait(),
+  ],
+  worker: {
+    format: 'es',
+    plugins: () => [
+      wasm(),
+      topLevelAwait(),
+    ],
+  },
+  optimizeDeps: {
+    exclude: ['wasm-webp'],
+  },
+  // For npm link support
+  server: {
+    fs: {
+      allow: [
+        // Add the path to linked wasm-webp
+        '/path/to/webp-wasm',
+      ],
+    },
+  },
+})
 ```

build.sh

@@ -1,3 +1,30 @@
+#!/bin/bash
+
+EMSDK_VERSION="3.1.74"
+
+# Setup emsdk: use env var or local submodule
+if [ -z "$EMSDK" ]; then
+    echo "EMSDK not set, using local submodule..."
+
+    # Initialize submodule if needed
+    if [ ! -f "./emsdk/emsdk.py" ]; then
+        echo "Initializing emsdk submodule..."
+        git submodule update --init emsdk
+    fi
+
+    # Install and activate if not already done
+    if [ ! -d "./emsdk/upstream" ]; then
+        echo "Installing emsdk ${EMSDK_VERSION}..."
+        ./emsdk/emsdk install ${EMSDK_VERSION}
+        ./emsdk/emsdk activate ${EMSDK_VERSION}
+    fi
+
+    # Source emsdk environment
+    source ./emsdk/emsdk_env.sh
+fi
+
+echo "Using EMSDK: $EMSDK"
+
 DIST_DIR="./dist"
 WASM_OUT_DIR="./dist/cjs"
 EXPORT_ES6=0
@@ -8,11 +35,11 @@ if [ ! -d $DIST_DIR ]; then
 fi
 
 
-if [ $1 == "-dev" ]; then
+if [ "$1" == "-dev" ]; then
 	WASM_OUT_DIR="./src"
 	CLEAN_WASM_DIR="${WASM_OUT_DIR}/webp-wasm.*"
 	EXPORT_ES6=1
-elif [ $1 == "-es6" ]; then
+elif [ "$1" == "-es6" ]; then
 	WASM_OUT_DIR="./dist/esm"
 	EXPORT_ES6=1
 fi
@@ -25,4 +52,4 @@ mkdir $WASM_OUT_DIR
 make -C \
 	./ WASM_OUT_DIR=$WASM_OUT_DIR \
 	EXPORT_ES6=$EXPORT_ES6 \
-	CLEAN_WASM_DIR=$CLEAN_WASM_DIR
+	CLEAN_WASM_DIR=$CLEAN_WASM_DIR