treetips · Aug 31, 2026 · Aug 31, 2026
diff --git a/.gitattributes b/.gitattributes
@@ -11,4 +11,7 @@ tools/upscal/bin/upscayl-bin filter=lfs diff=lfs merge=lfs -text
 tools/libjxl/bin/macos/cjxl filter=lfs diff=lfs merge=lfs -text
 tools/libjxl/bin/macos/*.dylib filter=lfs diff=lfs merge=lfs -text
 tools/libavif/bin/macos/avifenc filter=lfs diff=lfs merge=lfs -text
+tools/libwebp/bin/macos/cwebp filter=lfs diff=lfs merge=lfs -text
+tools/libwebp/bin/linux/cwebp filter=lfs diff=lfs merge=lfs -text
+tools/libwebp/bin/windows/cwebp.exe filter=lfs diff=lfs merge=lfs -text
 tools/**/.version filter=lfs diff=lfs merge=lfs -text
diff --git a/.opencode/skills/setup-webp/SKILL.md b/.opencode/skills/setup-webp/SKILL.md
@@ -0,0 +1,78 @@
+---
+name: setup-webp
+description: WebP (libwebp) ツールを Google Storage から取得して tools/libwebp に配置するスキル
+---
+
+# setup-webp
+
+`libwebp` は GitHub Releases で配布されていないため、Google Storage (`https://storage.googleapis.com/downloads.webmproject.org/releases/webp/index.html`) から取得する。
+
+## バージョン
+
+- `lib/core/constants/app_constants.dart:webpVersion` で管理（現在 `1.6.0`）
+
+## 配布アーカイブ
+
+| OS | Arch | アーカイブ |
+|---|---|---|
+| macOS | arm64 | `libwebp-1.6.0-mac-arm64.tar.gz` |
+| macOS | x86-64 | `libwebp-1.6.0-mac-x86-64.tar.gz` |
+| Linux | x86-64 | `libwebp-1.6.0-linux-x86-64.tar.gz` |
+| Linux | aarch64 | `libwebp-1.6.0-linux-aarch64.tar.gz` |
+| Windows | x64 | `libwebp-1.6.0-windows-x64.zip` |
+
+ベースURL: `https://storage.googleapis.com/downloads.webmproject.org/releases/webp/`
+
+## 配置先
+
+```
+tools/libwebp/bin/macos/cwebp        # mac-arm64 または mac-x86-64 の bin/cwebp
+tools/libwebp/bin/macos/cwebp (x86_64版は別途 tools/libwebp/bin/macos-x64 などを用意せず、現行 PathService は macos 単一を想定)
+tools/libwebp/bin/linux/cwebp
+tools/libwebp/bin/windows/cwebp.exe
+```
+
+> ローカル開発では実行ホストのアーキテクチャに合わせたアーカイブのみを `tools/libwebp/bin/<os>` に配置すれば動作する。リリース配布時は全OS分を格納する。
+
+## Workflow
+
+1. **バージョン確認**
+   - `AppConstants.webpVersion` を読む
+
+2. **ダウンロード**
+   - `tool/setup_webp.dart` または `scripts/setup-webp.sh` を実行
+   ```bash
+   dart run tool/setup_webp.dart
+   # または
+   bash .opencode/skills/setup-webp/scripts/setup.sh
+   ```
+
+3. **展開**
+   - `tar.gz` は `GZipDecoder` + `TarDecoder`（`package:archive`）で展開
+   - `zip` は `ZipDecoder` で展開
+   - アーカイブ内の `*/bin/cwebp`（または `cwebp.exe`）を `tools/libwebp/bin/<os>/` へコピー
+
+4. **権限付与**
+   ```bash
+   chmod +x tools/libwebp/bin/macos/cwebp
+   chmod +x tools/libwebp/bin/linux/cwebp
+   ```
+
+5. **検証**
+   ```bash
+   tools/libwebp/bin/macos/cwebp -version
+   tools/libwebp/bin/macos/cwebp -help | head -n 20
+   ```
+
+6. **アプリ側連携**
+   - `PathService.libwebpBinDirectory()` / `cwebpBinPath()` が `tools/libwebp/bin/<os>` を解決
+   - `ToolInstaller` が `libwebp/bin/<os>/cwebp` の存在を `isInstalled()` / `repairMissingTools()` で検証し、欠損時は Google Storage から自動取得（`_downloadAndExtractLibwebp()`）
+   - `CompressionService._compressWebp()` が `cwebp -preset <preset> -q <quality> -m <method> -mt input -o output` を実行
+
+## 関連ドキュメント
+
+- `docs/design/feature/convert-flow/compression.md` - WebP 圧縮パラメータ（`WEBP_PRESET` / `WEBP_METHOD`）
+- `docs/design/feature/convert.md` - フォーマットプルダウンに `WebP` を追加
+- `lib/data/services/tool_installer.dart` - Google Storage からの取得ロジック
+- `lib/data/services/path_service.dart` - `libwebpBinDirectory()` / `cwebpBinPath()`
+- `lib/data/services/compression_service.dart` - WebP 圧縮実装
diff --git a/.opencode/skills/setup-webp/scripts/setup.sh b/.opencode/skills/setup-webp/scripts/setup.sh
@@ -0,0 +1,125 @@
+#!/bin/bash
+set -euo pipefail
+
+# WebP セットアップスクリプト（shell 版）
+# Google Storage から libwebp を取得して tools/libwebp に配置する
+# 使用: bash .opencode/skills/setup-webp/scripts/setup.sh [--current-only]
+
+VERSION="1.6.0"
+BASE_URL="https://storage.googleapis.com/downloads.webmproject.org/releases/webp"
+
+CURRENT_ONLY=false
+if [[ "${1:-}" == "--current-only" ]]; then
+  CURRENT_ONLY=true
+fi
+
+# OS/Arch 判定
+OS="$(uname -s)"
+ARCH="$(uname -m)"
+echo "VERSION=$VERSION OS=$OS ARCH=$ARCH CURRENT_ONLY=$CURRENT_ONLY"
+
+download_and_extract() {
+  local archive_name="$1"
+  local dest_dir="$2"
+  local url="$BASE_URL/$archive_name"
+  local tmp_file="/tmp/$archive_name"
+
+  echo "=== $archive_name -> $dest_dir ==="
+  echo "url=$url"
+
+  if [[ -f "$tmp_file" ]]; then
+    rm -f "$tmp_file"
+  fi
+
+  echo "downloading..."
+  curl -L -o "$tmp_file" "$url"
+  echo "downloaded $tmp_file ($(du -h "$tmp_file" | cut -f1))"
+
+  mkdir -p "$dest_dir"
+  local exe_name="cwebp"
+  if [[ "$dest_dir" == *"windows"* ]]; then
+    exe_name="cwebp.exe"
+  fi
+
+  if [[ "$archive_name" == *.zip ]]; then
+    unzip -o -j "$tmp_file" "*/bin/$exe_name" -d "$dest_dir" 2>/dev/null || {
+      echo "Trying alternative unzip pattern..."
+      unzip -l "$tmp_file" | grep cwebp
+      unzip -o "$tmp_file" -d "/tmp/webp_extract"
+      find /tmp/webp_extract -name "$exe_name" -type f -exec cp {} "$dest_dir/$exe_name" \;
+      rm -rf /tmp/webp_extract
+    }
+    # unzip -j は bin パスを除去して直接配置する
+    if [[ -f "$dest_dir/$exe_name" ]]; then
+      echo "extracted $dest_dir/$exe_name"
+    else
+      # fallback: find
+      find /tmp -name "$exe_name" 2>/dev/null | head -5
+      echo "failed to extract $exe_name from $archive_name"
+      unzip -l "$tmp_file" | head -20
+      exit 1
+    fi
+  else
+    local tmp_extract="/tmp/webp_extract_$$"
+    mkdir -p "$tmp_extract"
+    tar -xzf "$tmp_file" -C "$tmp_extract"
+    local found
+    found="$(find "$tmp_extract" -name "$exe_name" -type f | head -n1)"
+    if [[ -z "$found" ]]; then
+      echo "cwebp not found in $archive_name"
+      find "$tmp_extract" -type f | head -20
+      rm -rf "$tmp_extract"
+      exit 1
+    fi
+    cp "$found" "$dest_dir/$exe_name"
+    echo "extracted $dest_dir/$exe_name from $found"
+    rm -rf "$tmp_extract"
+  fi
+
+  if [[ "$dest_dir" != *"windows"* ]]; then
+    chmod +x "$dest_dir/$exe_name"
+    echo "chmod +x $dest_dir/$exe_name"
+  fi
+
+  if [[ -f "$dest_dir/$exe_name" ]]; then
+    echo "verify: $dest_dir/$exe_name -version"
+    "$dest_dir/$exe_name" -version || "$dest_dir/$exe_name" -help | head -n 5 || true
+  fi
+
+  rm -f "$tmp_file"
+}
+
+if [[ "$CURRENT_ONLY" == true ]]; then
+  if [[ "$OS" == "Darwin" ]]; then
+    if [[ "$ARCH" == "arm64" ]]; then
+      download_and_extract "libwebp-${VERSION}-mac-arm64.tar.gz" "tools/libwebp/bin/macos"
+    else
+      download_and_extract "libwebp-${VERSION}-mac-x86-64.tar.gz" "tools/libwebp/bin/macos"
+    fi
+  elif [[ "$OS" == "Linux" ]]; then
+    if [[ "$ARCH" == "aarch64" ]]; then
+      download_and_extract "libwebp-${VERSION}-linux-aarch64.tar.gz" "tools/libwebp/bin/linux"
+    else
+      download_and_extract "libwebp-${VERSION}-linux-x86-64.tar.gz" "tools/libwebp/bin/linux"
+    fi
+  elif [[ "$OS" == *"MINGW"* || "$OS" == *"MSYS"* || "$OS" == *"CYGWIN"* ]]; then
+    download_and_extract "libwebp-${VERSION}-windows-x64.zip" "tools/libwebp/bin/windows"
+  else
+    echo "Unknown OS: $OS, trying macos arm64 as fallback"
+    download_and_extract "libwebp-${VERSION}-mac-arm64.tar.gz" "tools/libwebp/bin/macos"
+  fi
+else
+  # 全OS分をダウンロード（配布用）
+  download_and_extract "libwebp-${VERSION}-mac-arm64.tar.gz" "tools/libwebp/bin/macos"
+  # x86_64 は同じ dest なので別途保存しない（必要なら macos-x64 として分離可能）
+  # download_and_extract "libwebp-${VERSION}-mac-x86-64.tar.gz" "tools/libwebp/bin/macos-x64"
+  download_and_extract "libwebp-${VERSION}-linux-x86-64.tar.gz" "tools/libwebp/bin/linux"
+  # aarch64 は同様にスキップ
+  download_and_extract "libwebp-${VERSION}-windows-x64.zip" "tools/libwebp/bin/windows"
+fi
+
+echo ""
+echo "Done. Installed:"
+ls -lh tools/libwebp/bin/macos/cwebp 2>/dev/null || echo "  macos: not found"
+ls -lh tools/libwebp/bin/linux/cwebp 2>/dev/null || echo "  linux: not found"
+ls -lh tools/libwebp/bin/windows/cwebp.exe 2>/dev/null || echo "  windows: not found"
diff --git a/docs/design/feature/about.md b/docs/design/feature/about.md
@@ -146,3 +146,14 @@
 - 現在のバージョンを表示します。
 - バージョン番号はGitHub Releasesの `タグ名` です。
 - バージョン番号はFlutterの定数クラスで管理するので、そこから取得します。
+
+### ✏️ WebP
+
+#### 静的ラベル
+
+- `WebP (libwebp)` という静的ラベルを表示します。
+
+#### 動的ラベル
+
+- 現在のバージョンを表示します。
+- バージョン番号はFlutterの定数クラスで管理するので、そこから取得します。
diff --git a/docs/design/feature/convert-flow/compression.md b/docs/design/feature/convert-flow/compression.md
@@ -370,3 +370,116 @@ aom-specific advanced options:
 Version: 1.4.2 (dav1d [dec]:1.5.4, aom [enc/dec]:3.14.1)
 libyuv : unavailable
 ```
+
+## ✳️ WebP
+
+### ✏️ コマンド
+
+```shell
+cwebp \
+  -preset "${WEBP_PRESET}" \
+  -q "${QUALITY}" \
+  -m "${WEBP_METHOD}" \
+  -mt \
+  "$input" \
+  -o "$output"
+```
+
+拡張子は固定で `.webp` とします。
+`最適化種別` 毎のパラメータは以下で固定します。
+
+| 最適化種別    | WEBP_PRESET | WEBP_METHOD (`-m` 0=fast..6=slowest) | 補足                                                               |
+|----------|-------------|--------------------------------------|------------------------------------------------------------------|
+| アニメ・イラスト | drawing     | 4                                    | エッジ・ベタ塗り保持に強い `drawing`。デフォルトの `-m 4` で品質と速度のバランス                |
+| 実写・写真    | photo       | 4                                    | 実写向けチューニングの `photo`。`-m 4`（デフォルト）でバランス重視                         |
+| 速度優先     | default     | 0                                    | プリセット補正なしの `default` + `-m 0`（最速）でエンコード時間最優先。`-sns`/`-f` 等はデフォルト |
+| 画質最優先    | photo       | 6                                    | 実写/イラスト両用で高圧縮な `photo` + `-m 6`（最遅・最高圧縮効率）。速度を犠牲にサイズと歪みを最優先      |
+
+> 参考: `-m` は圧縮効率（探索量）であり、`0` が最速・低圧縮、`6` が最遅・高圧縮。`-preset` は `drawing` / `photo` / `default` などが内部の `-sns` / `-f` / `-sharpness` / セグメント等のデフォルトを上書きするため、`-preset` を先頭に置いた上で `-m` を上書きする運用とします。
+
+### ✏️ help
+
+```shell
+❯ cwebp --help                                          
+
+Usage:
+ cwebp [-preset <...>] [options] in_file [-o out_file]
+
+If input size (-s) for an image is not specified, it is
+assumed to be a PNG, JPEG, TIFF or WebP file.
+Note: Animated PNG and WebP files are not supported.
+
+Options:
+  -h / -help ............. short help
+  -H / -longhelp ......... long help
+  -q <float> ............. quality factor (0:small..100:big), default=75
+  -alpha_q <int> ......... transparency-compression quality (0..100),
+                           default=100
+  -preset <string> ....... preset setting, one of:
+                            default, photo, picture,
+                            drawing, icon, text
+     -preset must come first, as it overwrites other parameters
+  -z <int> ............... activates lossless preset with given
+                           level in [0:fast, ..., 9:slowest]
+
+  -m <int> ............... compression method (0=fast, 6=slowest), default=4
+  -segments <int> ........ number of segments to use (1..4), default=4
+  -size <int> ............ target size (in bytes)
+  -psnr <float> .......... target PSNR (in dB. typically: 42)
+
+  -s <int> <int> ......... input size (width x height) for YUV
+  -sns <int> ............. spatial noise shaping (0:off, 100:max), default=50
+  -f <int> ............... filter strength (0=off..100), default=60
+  -sharpness <int> ....... filter sharpness (0:most .. 7:least sharp), default=0
+  -strong ................ use strong filter instead of simple (default)
+  -nostrong .............. use simple filter instead of strong
+  -sharp_yuv ............. use sharper (and slower) RGB->YUV conversion
+  -partition_limit <int> . limit quality to fit the 512k limit on
+                           the first partition (0=no degradation ... 100=full)
+  -pass <int> ............ analysis pass number (1..10)
+  -qrange <min> <max> .... specifies the permissible quality range
+                           (default: 0 100)
+  -crop <x> <y> <w> <h> .. crop picture with the given rectangle
+  -resize <w> <h> ........ resize picture (*after* any cropping)
+  -resize_mode <string> .. one of: up_only, down_only, always (default)
+  -mt .................... use multi-threading if available
+  -low_memory ............ reduce memory usage (slower encoding)
+  -map <int> ............. print map of extra info
+  -print_psnr ............ prints averaged PSNR distortion
+  -print_ssim ............ prints averaged SSIM distortion
+  -print_lsim ............ prints local-similarity distortion
+  -d <file.pgm> .......... dump the compressed output (PGM file)
+  -alpha_method <int> .... transparency-compression method (0..1), default=1
+  -alpha_filter <string> . predictive filtering for alpha plane,
+                           one of: none, fast (default) or best
+  -exact ................. preserve RGB values in transparent area, default=off
+  -blend_alpha <hex> ..... blend colors against background color
+                           expressed as RGB values written in
+                           hexadecimal, e.g. 0xc0e0d0 for red=0xc0
+                           green=0xe0 and blue=0xd0
+  -noalpha ............... discard any transparency information
+  -lossless .............. encode image losslessly, default=off
+  -near_lossless <int> ... use near-lossless image preprocessing
+                           (0..100=off), default=100
+  -hint <string> ......... specify image characteristics hint,
+                           one of: photo, picture or graph
+
+  -metadata <string> ..... comma separated list of metadata to
+                           copy from the input to the output if present.
+                           Valid values: all, none (default), exif, icc, xmp
+
+  -short ................. condense printed message
+  -quiet ................. don't print anything
+  -version ............... print version number and exit
+  -noasm ................. disable all assembly optimizations
+  -v ..................... verbose, e.g. print encoding/decoding times
+  -progress .............. report encoding progress
+
+Experimental Options:
+  -jpeg_like ............. roughly match expected JPEG size
+  -af .................... auto-adjust filter strength
+  -pre <int> ............. pre-processing filter
+
+Supported input formats:
+  WebP, JPEG, PNG, PNM (PGM, PPM, PAM), TIFF
+```
diff --git a/docs/design/feature/convert.md b/docs/design/feature/convert.md
@@ -113,6 +113,7 @@
   - PNG
   - JPEG XL
   - AV1
+  - WebP
 - 初期値は `JPEG XL` です。
 
 #### ℹ️

diff --git a/lib/core/constants/app_constants.dart b/lib/core/constants/app_constants.dart
@@ -17,6 +17,9 @@ class AppConstants {
   /// AV1 (libavif) のバージョン。
   static const String av1Version = 'v1.4.2';
 
+  /// WebP (libwebp) のバージョン。
+  static const String webpVersion = '1.6.0';
+
   /// GitHub のリポジトリオーナー。
   static const String githubOwner = 'treetips';
 
@@ -34,7 +37,8 @@ class AppConstants {
   /// 値は GitHub Releases の `tools-v{version}.zip` の実ハッシュと一致させること。
   /// リリースワークフロー（release.yml）で build 前に自動差し替えられるため、
   /// 通常は手動で変更する必要はない。
-  static const String toolsSha256 = '9d00d1268aefcdf2bedd0a63da3cc8c9e0bf81059d3ed072b5512810aab63d6b';
+  static const String toolsSha256 =
+      '9d00d1268aefcdf2bedd0a63da3cc8c9e0bf81059d3ed072b5512810aab63d6b';
 
   /// アップデート情報 JSON の URL。
   ///

diff --git a/lib/core/models/output_format.dart b/lib/core/models/output_format.dart
@@ -5,7 +5,8 @@ enum OutputFormat {
   jpeg,
   png,
   jpegXl,
-  av1;
+  av1,
+  webp;
 
   const OutputFormat();
 
@@ -15,6 +16,7 @@ enum OutputFormat {
     OutputFormat.png => l10n.formatPng,
     OutputFormat.jpegXl => l10n.formatJpegXl,
     OutputFormat.av1 => l10n.formatAv1,
+    OutputFormat.webp => l10n.formatWebp,
   };
 
   /// 出力ファイルの拡張子。
@@ -23,5 +25,6 @@ enum OutputFormat {
     OutputFormat.png => '.png',
     OutputFormat.jpegXl => '.jxl',
     OutputFormat.av1 => '.avif',
+    OutputFormat.webp => '.webp',
   };
 }
-Original file line number
+Diff line change
@@ Expand Up / @@ -113,6 +113,7 @@ @@
       - PNG
       - JPEG XL
       - AV1
+      - WebP
     - 初期値は `JPEG XL` です。
     #### ℹ️
@@ Expand Down @@