diff --git a/CLAUDE.md b/CLAUDE.md
index a82ae12..3fa9940 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -99,61 +99,32 @@ Common Lispでは同じパッケージ内で同名関数を再定義すると警
 
 ### 高優先度
 
-#### 出力ファイル名生成関数の引数統一 ✅ **完了**
-出力ファイル名生成関数の引数を統一し、APIの一貫性を向上：
+#### FFmpeg実行エラーハンドリング強化
+`ffmpeg.lisp`の`run-cmd`関数を例外ベース方式に改善し、堅牢性を向上させる。
 
-**実施内容:**
-- `generate-gif-output-filename`の引数を`(input &optional opts)`から`(opts)`に変更
-- `main.lisp`のGIFモードでの呼び出し方法を修正
-- 関連するテストケースを更新
-- パッケージエクスポートの追加（`visp-options-output`, `safe-parse-float`）
-
-**結果:**
-すべての出力ファイル名生成関数が`opts`を第一引数として受け取るAPIに統一され、
-テストスイートでの検証とバイナリビルドでの動作確認も完了。
-
-#### GIFモードのオプション制限強化 ✅ **完了**
-GIFモードで`--input`オプションとの組み合わせエラーが適切に処理されていない問題を修正：
-
-**問題:**
-- `visp --input test.mp4 --gif --dry-run`でオプション解析が競合し、入力ファイルが空文字列になる
-- GIFモードは`visp --gif <file>`の構文のみを受け付けるべきだが、`--input`オプションが禁止リストに含まれていない
-
-**解決策:**
-1. `validate-gif-mode`関数の禁止オプションリストに`visp-options-input`を追加
-2. GIFモードでは`--gif <file> [--output <filename>] [--dry-run]`の構文のみを許可
-3. 不正な構文でのエラーメッセージを改善
-
-**影響範囲:**
-- `src/validate.lisp`: GIFモードバリデーションの強化
-- `t/test-validate.lisp`: 関連テストケースの追加
-
-#### 関数名重複問題の解決
-`util.lisp`と`validate.lisp`で類似のパース関数が重複している問題を統合する：
-
-**問題:**
-- `util.lisp:3-10`: `parse-float`関数
-- `util.lisp:12-18`: `safe-parse-float`関数（parse-floatのラッパー）
-- `validate.lisp:284-288`: `parse-speed-float`関数（独自実装）
-- `video.lisp:28`: `safe-parse-float`を参照しているが定義場所が曖昧
-
-**解決策:**
-1. 共通のパース関数を`util.lisp`に統合
-2. エラーハンドリングを統一
-3. 全ての呼び出し箇所を統一された関数に修正
-
-#### ffmpeg実行エラーハンドリング強化
-`ffmpeg.lisp:14`の`run-cmd`関数でエラーハンドリングが不十分：
-
-**現在の問題:**
-- ffmpeg実行失敗時のエラー情報が不十分
+**現在の課題:**
+- FFmpeg実行失敗時のエラー情報が不十分
 - 出力ディレクトリの書き込み権限チェックなし
-- 処理中断時の一時ファイル削除なし
-
-**改善策:**
-1. ffmpegの詳細エラーメッセージ取得
-2. 事前の書き込み権限チェック
-3. 処理中断時のクリーンアップ処理
+- 処理中断時の一時ファイル削除機能なし
+
+**改善内容:**
+- `visp-ffmpeg-error`を使用した構造化エラーハンドリング
+- FFmpegの詳細なエラーメッセージとコマンド情報の取得
+- 事前の書き込み権限チェック
+- 処理中断時のクリーンアップ処理
+
+#### 残りのvalidate関数の例外ベース化
+まだ`(uiop:quit 1)`を使用している関数を例外ベースに移行する。
+
+**対象関数:**
+- `validate-codec`: エンコーダー可用性チェック
+- `validate-gif-mode`: GIFモード特有のバリデーション
+- `validate-merge-files`: マージファイルの検証
+- `validate-output`: 出力パス検証
+
+**作業内容:**
+- 各関数を例外ベースに変更
+- 対応するエラーケーステストの追加
 
 ### 中優先度
 
diff --git a/src/exceptions.lisp b/src/exceptions.lisp
new file mode 100644
index 0000000..01eff2a
--- /dev/null
+++ b/src/exceptions.lisp
@@ -0,0 +1,95 @@
+(in-package :visp)
+
+;; ベースとなる例外クラス
+(define-condition visp-error (error)
+  ((message :initarg :message 
+            :reader visp-error-message
+            :documentation "エラーメッセージ")
+   (context :initarg :context 
+            :reader visp-error-context
+            :initform nil
+            :documentation "エラーが発生したコンテキスト（入力値など）"))
+  (:documentation "VISPアプリケーションのベースエラークラス")
+  (:report (lambda (condition stream)
+             (format stream "VISP Error: ~A" 
+                     (visp-error-message condition)))))
+
+;; バリデーション関連のエラー
+(define-condition visp-validation-error (visp-error)
+  ()
+  (:documentation "入力値やオプションのバリデーションエラー")
+  (:report (lambda (condition stream)
+             (format stream "Validation Error: ~A~@[ (context: ~A)~]"
+                     (visp-error-message condition)
+                     (visp-error-context condition)))))
+
+;; オプション関連のエラー
+(define-condition visp-option-error (visp-validation-error)
+  ((option-name :initarg :option-name
+                :reader visp-option-error-option-name
+                :initform nil
+                :documentation "エラーが発生したオプション名"))
+  (:documentation "コマンドラインオプションのエラー")
+  (:report (lambda (condition stream)
+             (format stream "Option Error~@[ in --~A~]: ~A~@[ (value: ~A)~]"
+                     (visp-option-error-option-name condition)
+                     (visp-error-message condition)
+                     (visp-error-context condition)))))
+
+;; ファイル関連のエラー
+(define-condition visp-file-error (visp-validation-error)
+  ((file-path :initarg :file-path
+              :reader visp-file-error-file-path
+              :initform nil
+              :documentation "エラーが発生したファイルパス"))
+  (:documentation "ファイル操作のエラー")
+  (:report (lambda (condition stream)
+             (format stream "File Error~@[ (~A)~]: ~A"
+                     (visp-file-error-file-path condition)
+                     (visp-error-message condition)))))
+
+;; ffmpeg実行関連のエラー
+(define-condition visp-ffmpeg-error (visp-error)
+  ((command :initarg :command
+            :reader visp-ffmpeg-error-command
+            :initform nil
+            :documentation "実行に失敗したffmpegコマンド")
+   (exit-code :initarg :exit-code
+              :reader visp-ffmpeg-error-exit-code
+              :initform nil
+              :documentation "ffmpegの終了コード"))
+  (:documentation "ffmpeg実行時のエラー")
+  (:report (lambda (condition stream)
+             (format stream "FFmpeg Error~@[ (exit code: ~A)~]: ~A"
+                     (visp-ffmpeg-error-exit-code condition)
+                     (visp-error-message condition)))))
+
+;; ヘルパー関数: 簡単に例外を発生させるためのユーティリティ
+
+(defun error-option (message &key option-name context)
+  "オプションエラーを発生させる"
+  (error 'visp-option-error
+         :message message
+         :option-name option-name
+         :context context))
+
+(defun error-file (message &key file-path context)
+  "ファイルエラーを発生させる"
+  (error 'visp-file-error
+         :message message
+         :file-path file-path
+         :context context))
+
+(defun error-validation (message &key context)
+  "バリデーションエラーを発生させる"
+  (error 'visp-validation-error
+         :message message
+         :context context))
+
+(defun error-ffmpeg (message &key command exit-code context)
+  "ffmpegエラーを発生させる"
+  (error 'visp-ffmpeg-error
+         :message message
+         :command command
+         :exit-code exit-code
+         :context context))
\ No newline at end of file
diff --git a/src/main.lisp b/src/main.lisp
index 97bd135..390b674 100644
--- a/src/main.lisp
+++ b/src/main.lisp
@@ -1,51 +1,74 @@
 (in-package :visp)
 
 (defun main (&optional args)
-  (unless (ffmpeg-available-p)
-    (format t "~a ffmpeg not found in your system. Please install ffmpeg first.~%" (log-tag "error"))
-    (uiop:quit 1))
-
-  ;; 引数がなければコマンドラインから取得
-  (unless args (setf args (uiop:command-line-arguments)))
-  (setf args (clean-args args))
-
-  (when (member "--help" args :test #'string=)
-    (print-help)
-    (uiop:quit 0))
-
-  (let ((opts (parse-args-to-options args)))
-    (dispatch-validation opts)
-
-    (cond
-      ;; 1. GIF モード
-      ((visp-options-gif opts)
-       (let* ((input (visp-options-input opts))
-              (fps (get-video-fps input)) 
-              (output (generate-gif-output-filename opts))
-              (cmd (build-gif-cmd opts output fps)))
-         (run-cmd cmd output (visp-options-dry-run opts))))
-
-      ;; 2. 結合モード
-      ((visp-options-merge-files opts)
-       (let* ((output (generate-merge-output-filename opts))
-              (cmd (build-merge-cmd opts output)))
-         (run-cmd cmd output (visp-options-dry-run opts))))
-
-      ;; 3. バッチモード
-      ((visp-options-batch-files opts)
-       (dolist (file (visp-options-batch-files opts))
-        ;; 出力ファイル名やコマンド生成を通常モードと共通化するため、input を一時的に設定
-        (setf (visp-options-input opts) file)
-        ;; 出力ファイル名生成
-        (let* ((ext (getf (visp-options-codec-info opts) :ext))
-               (filename (generate-output-filename opts ext))         ;; ファイル名だけ
-               (output (output-path-in-same-directory file filename)) ;; ディレクトリと結合してフルパス化
-               (cmd (build-cmd opts output)))
-          (run-cmd cmd output (visp-options-dry-run opts)))))
-
-      ;; 4. 通常処理
-      (t
-       (let* ((ext (getf (visp-options-codec-info opts) :ext))
-              (output (generate-output-filename opts ext))
-              (cmd (build-cmd opts output)))
-         (run-cmd cmd output (visp-options-dry-run opts)))))))
+  (handler-case
+    (progn
+      (unless (ffmpeg-available-p)
+        (format t "~a ffmpeg not found in your system. Please install ffmpeg first.~%" (log-tag "error"))
+        (uiop:quit 1))
+
+      ;; 引数がなければコマンドラインから取得
+      (unless args (setf args (uiop:command-line-arguments)))
+      (setf args (clean-args args))
+
+      (when (member "--help" args :test #'string=)
+        (print-help)
+        (uiop:quit 0))
+
+      (let ((opts (parse-args-to-options args)))
+        (dispatch-validation opts)
+
+        (cond
+          ;; 1. GIF モード
+          ((visp-options-gif opts)
+           (let* ((input (visp-options-input opts))
+                  (fps (get-video-fps input)) 
+                  (output (generate-gif-output-filename opts))
+                  (cmd (build-gif-cmd opts output fps)))
+             (run-cmd cmd output (visp-options-dry-run opts))))
+
+          ;; 2. 結合モード
+          ((visp-options-merge-files opts)
+           (let* ((output (generate-merge-output-filename opts))
+                  (cmd (build-merge-cmd opts output)))
+             (run-cmd cmd output (visp-options-dry-run opts))))
+
+          ;; 3. バッチモード
+          ((visp-options-batch-files opts)
+           (dolist (file (visp-options-batch-files opts))
+            ;; 出力ファイル名やコマンド生成を通常モードと共通化するため、input を一時的に設定
+            (setf (visp-options-input opts) file)
+            ;; 出力ファイル名生成
+            (let* ((ext (getf (visp-options-codec-info opts) :ext))
+                   (filename (generate-output-filename opts ext))         ;; ファイル名だけ
+                   (output (output-path-in-same-directory file filename)) ;; ディレクトリと結合してフルパス化
+                   (cmd (build-cmd opts output)))
+              (run-cmd cmd output (visp-options-dry-run opts)))))
+
+          ;; 4. 通常処理
+          (t
+           (let* ((ext (getf (visp-options-codec-info opts) :ext))
+                  (output (generate-output-filename opts ext))
+                  (cmd (build-cmd opts output)))
+             (run-cmd cmd output (visp-options-dry-run opts)))))))
+
+    ;; 例外ハンドリング: VISP固有のエラー
+    (visp-validation-error (e)
+      (format t "~a ~a~%" (log-tag "error") (visp-error-message e))
+      (uiop:quit 1))
+    
+    (visp-ffmpeg-error (e)
+      (format t "~a ~a~%" (log-tag "error") (visp-error-message e))
+      (when (visp-ffmpeg-error-command e)
+        (format t "~a Failed command: ~{~a~^ ~}~%" (log-tag "info") (visp-ffmpeg-error-command e)))
+      (uiop:quit 1))
+    
+    (visp-error (e)
+      (format t "~a ~a~%" (log-tag "error") (visp-error-message e))
+      (uiop:quit 1))
+    
+    ;; 予期しないエラー
+    (error (e)
+      (format t "~a Unexpected error: ~a~%" (log-tag "error") e)
+      (format t "~a Please report this issue with the command you ran.~%" (log-tag "info"))
+      (uiop:quit 1))))
\ No newline at end of file
diff --git a/src/package.lisp b/src/package.lisp
index 39364dc..7d6618f 100644
--- a/src/package.lisp
+++ b/src/package.lisp
@@ -16,6 +16,23 @@
    ;; help.lisp
    :print-help
 
+  ;; exceptions.lisp
+  :visp-error
+  :visp-error-message
+  :visp-error-context
+  :visp-validation-error
+  :visp-option-error
+  :visp-option-error-option-name
+  :visp-file-error
+  :visp-file-error-file-path
+  :visp-ffmpeg-error
+  :visp-ffmpeg-error-command
+  :visp-ffmpeg-error-exit-code
+  :error-option
+  :error-file
+  :error-validation
+  :error-ffmpeg
+
   ;; validate.lisp
   :validate-merge-files
   :validate-gif-mode
diff --git a/src/validate.lisp b/src/validate.lisp
index e2a0891..2d9739b 100644
--- a/src/validate.lisp
+++ b/src/validate.lisp
@@ -5,17 +5,15 @@
   (let ((input (visp-options-input opts)))
     ;; 入力ファイルの存在チェック
     (unless (and input (not (string= input "")))
-      (format t "~a --gif mode requires a video file. Use: visp --gif <video-file>~%"
-              (log-tag "error"))
-      (uiop:quit 1))
-
+      (error-option "--gif mode requires a video file. Use: visp --gif <video-file>"
+                    :option-name "gif"))
 
     ;; GIFモード対応拡張子チェック（全動画形式対応）
     (let ((ext (input-extension input)))
       (unless (member ext +allowed-input-extensions+ :test #'string-equal)
-        (format t "~a --gif mode supports video files (.mp4, .mov, .flv, .avi, .webm), but got '~a'.~%"
-                (log-tag "error") ext)
-        (uiop:quit 1)))
+        (error-file "--gif mode supports video files (.mp4, .mov, .flv, .avi, .webm)"
+                    :file-path input
+                    :context ext)))
 
     ;; すべての他オプションを禁止（--dry-runのみ特別に許可）
     (let ((disallowed-options (list
@@ -34,9 +32,8 @@
                                 (visp-options-speed opts)
                                 (visp-options-merge-files opts))))
       (when (some #'identity disallowed-options)
-        (format t "~a --gif mode does not accept any other options. Use: visp --gif <video-file> [--dry-run]~%" 
-                (log-tag "error"))
-        (uiop:quit 1)))))
+        (error-option "--gif mode does not accept any other options. Use: visp --gif <video-file> [--dry-run]"
+                      :option-name "gif")))))
 
 (defun validate-merge-files (opts)
   "Validate options specific to --merge mode."
@@ -55,25 +52,27 @@
               (visp-options-hflip opts)
               (visp-options-vflip opts)
               (visp-options-speed opts))
-      (format t "~a --merge cannot be combined with other options.~%" (log-tag "error"))
-      (uiop:quit 1))
+      (error-option "--merge cannot be combined with other options"
+                    :option-name "merge"))
 
     ;; ファイル数チェック
     (unless (and files (>= (length files) 2))
-      (format t "~a At least two .mp4 files must be specified for --merge.~%" (log-tag "error"))
-      (uiop:quit 1))
+      (error-option "At least two .mp4 files must be specified for --merge"
+                    :option-name "merge"
+                    :context (if files (format nil "~a file(s) provided" (length files)) "no files")))
 
     ;; 拡張子チェック
     (dolist (file files)
       (unless (string-equal (input-extension file) ".mp4")
-        (format t "~a Only .mp4 files are supported for --merge (got: ~a).~%" (log-tag "error") file)
-        (uiop:quit 1)))
+        (error-file "Only .mp4 files are supported for --merge"
+                    :file-path file
+                    :context (input-extension file))))
 
     ;; ファイル存在確認
     (dolist (file files)
       (unless (probe-file file)
-        (format t "~a Input file '~a' does not exist.~%" (log-tag "error") file)
-        (uiop:quit 1)))
+        (error-file "Input file does not exist"
+                    :file-path file)))
 
     ;; 動画情報取得
     (let* ((infos (mapcar #'get-video-info files)))
@@ -83,16 +82,15 @@
         (let ((file (car pair))
               (info (cdr pair)))
           (unless (and (getf info :fps) (getf info :width) (getf info :height))
-            (format t "~a Failed to extract fps/width/height from file: ~a~%" (log-tag "error") file)
-            (format t "~a This file may be corrupted or not a valid video.~%" (log-tag "error"))
-            (uiop:quit 1))))
+            (error-file "Failed to extract fps/width/height from file. This file may be corrupted or not a valid video"
+                        :file-path file))))
 
       ;; 音声混在チェック
       (let ((has-audio-list (mapcar (lambda (info) (getf info :has-audio)) infos)))
         (unless (or (every #'identity has-audio-list)
                     (every #'not has-audio-list))
-          (format t "~a --merge does not support mixing audio and non-audio files.~%" (log-tag "error"))
-          (uiop:quit 1)))
+          (error-option "--merge does not support mixing audio and non-audio files"
+                        :option-name "merge")))
 
       ;; fps混在チェック（warn）
       (let ((fps-list (remove-duplicates (mapcar (lambda (info) (getf info :fps)) infos)
@@ -119,16 +117,17 @@
   (let ((input (visp-options-input opts)))
     ;; 入力の有無は必須
     (unless input
-      (format t "Usage: visp --input <filename or directory> [--res 4k] [--mute] ...~%")
-      (uiop:quit 1))
+      (error-option "Input file or directory is required"
+                    :option-name "input"
+                    :context "Usage: visp --input <filename or directory> [--res 4k] [--mute] ..."))
 
     ;; ディレクトリ指定っぽい場合
     (if (uiop:directory-pathname-p input)
         (progn
           ;; ディレクトリが存在するか
           (unless (uiop:directory-exists-p input)
-            (format t "~a Directory '~a' does not exist.~%" (log-tag "error") input)
-            (uiop:quit 1))
+            (error-file "Directory does not exist"
+                        :file-path input))
 
           ;; 対象ファイルの取得
           (let ((files (remove-if-not
@@ -136,8 +135,8 @@
                              (member (input-extension p) +allowed-input-extensions+ :test #'string-equal))
                          (uiop:directory-files input))))
             (when (null files)
-              (format t "~a No valid video files found in directory '~a'.~%" (log-tag "error") input)
-              (uiop:quit 1))
+              (error-file "No valid video files found in directory"
+                          :file-path input))
 
             ;; batch-files にファイル名 (string 型) を格納
             (setf (visp-options-batch-files opts) (mapcar #'namestring files))
@@ -148,15 +147,15 @@
         (progn
           ;; ファイル存在チェック
           (unless (probe-file input)
-            (format t "~a Input file '~a' does not exist.~%" (log-tag "error") input)
-            (uiop:quit 1))
+            (error-file "Input file does not exist"
+                        :file-path input))
 
           ;; 拡張子チェック
           (let ((ext (input-extension input)))
             (unless (member ext +allowed-input-extensions+ :test #'string-equal)
-              (format t "~a visp does not support the input file extension '~a'.~%"
-                      (log-tag "error") ext)
-              (uiop:quit 1)))
+              (error-file "Unsupported input file extension"
+                          :file-path input
+                          :context ext)))
 
             ;; 動画情報の表示
             (print-video-info (get-video-info input))))))
@@ -170,16 +169,15 @@
 
     ;; --reverse と --loop は併用不可
     (when (and rev repeat)
-      (format t "~a --loop and --reverse options cannot be used together.~%"
-              (log-tag "error"))
-      (uiop:quit 1))
+      (error-option "--loop and --reverse options cannot be used together"
+                    :option-name "reverse"))
 
     ;; --reverse がサポートする拡張子は限定
     (when rev
       (unless (member ext '(".mp4" ".mov") :test #'string-equal)
-        (format t "~a --reverse option only supports .mov or .mp4 extensions.~%"
-                (log-tag "error"))
-        (uiop:quit 1))
+        (error-option "--reverse option only supports .mov or .mp4 extensions"
+                      :option-name "reverse"
+                      :context ext))
 
       ;; メモリ使用に関する警告
       (format t "~a --reverse may consume a large amount of memory. Consider using small input files.~%"
@@ -198,9 +196,9 @@
       (let ((repeati (parse-integer repeat :junk-allowed t)))
         ;; stream_loopの仕様上(repeat >= 1)がマスト
         (unless (and (integerp repeati) (>= repeati 1))
-          (format t "~a --loop must be an integer >= 1, but got '~a'.~%"
-                  (log-tag "error") repeat)
-          (uiop:quit 1))
+          (error-option "--loop must be an integer >= 1"
+                        :option-name "loop"
+                        :context repeat))
         ;; repeat は数値に変換して保存
         (setf (visp-options-repeat opts) repeati)))))
 
@@ -212,8 +210,8 @@
 
     ;; --res と --half の併用は禁止
     (when (and res half)
-      (format t "~a --res and --half cannot be used together.~%" (log-tag "error"))
-      (uiop:quit 1))
+      (error-option "--res and --half cannot be used together"
+                    :option-name "res"))
 
     ;; --res が指定されていれば有効な解像度か確認
     (when res
@@ -222,10 +220,9 @@
                        (parse-dimensions res))))
         (if dims
             (setf (visp-options-scale opts) dims)
-            (progn
-              (format t "~a visp does not support the resolution '~a'.~%"
-                      (log-tag "error") res)
-              (uiop:quit 1)))))))
+            (error-option "Unsupported resolution"
+                          :option-name "res"
+                          :context res))))))
 
 (defun validate-half (opts)
   "If --half is specified, get original resolution using ffprobe and set scaled dimensions."
@@ -235,8 +232,9 @@
           (destructuring-bind (w . h) dims
             (setf (visp-options-scale opts)
                   (cons (floor w 2) (floor h 2))))
-          (format t "~a Could not determine resolution for --half. Original size will be used.~%"
-                  (log-tag "warn"))))))
+          (error-option "Could not determine resolution for --half"
+                        :option-name "half"
+                        :context (visp-options-input opts))))))
 
 (defun validate-fps (opts)
   "Validate that --fps is a positive integer if specified."
@@ -245,9 +243,9 @@
       (let ((fpsi (parse-integer fps :junk-allowed t)))
         ;; fpsは必ず0より大きい整数
         (unless (and (integerp fpsi) (> fpsi 0))
-          (format t "~a --fps must be a positive integer, but got '~a'.~%" 
-                  (log-tag "error") fps)
-          (uiop:quit 1))
+          (error-option "--fps must be a positive integer"
+                        :option-name "fps"
+                        :context fps))
         ;; 明示的に整数に変換して再セット
         (setf (visp-options-fps opts) fpsi)))))
 
@@ -258,16 +256,15 @@
 
     ;; 指定された codec が visp の対応リストにない場合
     (when (and key (not codec-info))
-      (format t "~a visp does not support the codec '~a'.~%" 
-              (log-tag "error") key)
-      (uiop:quit 1))
+      (error-option "visp does not support this codec"
+                    :option-name "codec"
+                    :context key))
 
     ;; codec はあるが、システムに encoder が存在しない場合
     (when (and codec-info
                (not (encoder-available-p (getf codec-info :encoder))))
-      (format t "~a ffmpeg on this system does not support the encoder '~a'.~%"
-              (log-tag "error") (getf codec-info :encoder))
-      (uiop:quit 1))
+      (error-ffmpeg "ffmpeg on this system does not support this encoder"
+                    :context (getf codec-info :encoder)))
 
     ;; hapとproresはpix_fmtを指定しないといけない（そしてそれは固定値）
     (when (getf codec-info :pix_fmt)
@@ -283,7 +280,9 @@
   (when (visp-options-mono opts)
     (let ((codec (visp-options-codec opts)))
       (when (member codec '("prores" "hap") :test #'string=)
-        (error "The --mono option is not supported with codec ~A." codec)))))
+        (error-option "The --mono option is not supported with this codec"
+                      :option-name "mono"
+                      :context codec)))))
 
 
 (defun validate-speed (opts)
@@ -293,9 +292,9 @@
       (let ((speedf (parse-number speed)))
         ;; speedは必ず0より大きい数値
         (unless (and (numberp speedf) (> speedf 0))
-          (format t "~a --speed must be a positive number, but got '~a'.~%" 
-                  (log-tag "error") speed)
-          (uiop:quit 1))
+          (error-option "--speed must be a positive number"
+                        :option-name "speed"
+                        :context speed))
         ;; 明示的に数値に変換して再セット
         (setf (visp-options-speed opts) speedf)))))
 
@@ -306,9 +305,9 @@
       ;; 出力ファイルのディレクトリが存在するかチェック
       (let ((parent-dir (uiop:pathname-directory-pathname (pathname output))))
         (unless (uiop:directory-exists-p parent-dir)
-          (format t "~a Output directory '~a' does not exist.~%" 
-                  (log-tag "error") (namestring parent-dir))
-          (uiop:quit 1))))))
+          (error-file "Output directory does not exist"
+                      :file-path (namestring parent-dir)
+                      :context output))))))
 
 (defun validate-options (opts)
   (validate-input opts)
diff --git a/t/test-exceptions.lisp b/t/test-exceptions.lisp
new file mode 100644
index 0000000..ca6bae9
--- /dev/null
+++ b/t/test-exceptions.lisp
@@ -0,0 +1,97 @@
+(defpackage :visp.test.exceptions
+  (:use :cl :rove)
+  (:import-from :visp
+                ;; 例外クラス
+                :visp-error
+                :visp-error-message
+                :visp-error-context
+                :visp-validation-error
+                :visp-option-error
+                :visp-option-error-option-name
+                :visp-file-error
+                :visp-file-error-file-path
+                :visp-ffmpeg-error
+                :visp-ffmpeg-error-command
+                :visp-ffmpeg-error-exit-code
+                ;; ヘルパー関数
+                :error-option
+                :error-file
+                :error-validation
+                :error-ffmpeg))
+
+(in-package :visp.test.exceptions)
+
+(deftest visp-error-basic-tests
+  (testing "visp-error basic functionality"
+    (let ((err (make-condition 'visp-error 
+                               :message "Test error"
+                               :context "test-context")))
+      (ok (string= (visp-error-message err) "Test error"))
+      (ok (string= (visp-error-context err) "test-context")))
+    
+    (let ((err (make-condition 'visp-error :message "Simple error")))
+      (ok (string= (visp-error-message err) "Simple error"))
+      (ok (null (visp-error-context err))))))
+
+(deftest visp-option-error-tests
+  (testing "visp-option-error functionality"
+    (let ((err (make-condition 'visp-option-error
+                               :message "Invalid value"
+                               :option-name "speed"
+                               :context "abc")))
+      (ok (string= (visp-error-message err) "Invalid value"))
+      (ok (string= (visp-option-error-option-name err) "speed"))
+      (ok (string= (visp-error-context err) "abc")))))
+
+(deftest visp-file-error-tests
+  (testing "visp-file-error functionality"
+    (let ((err (make-condition 'visp-file-error
+                               :message "File not found"
+                               :file-path "/path/to/file.mp4")))
+      (ok (string= (visp-error-message err) "File not found"))
+      (ok (string= (visp-file-error-file-path err) "/path/to/file.mp4")))))
+
+(deftest visp-ffmpeg-error-tests
+  (testing "visp-ffmpeg-error functionality"
+    (let ((err (make-condition 'visp-ffmpeg-error
+                               :message "Command failed"
+                               :command '("ffmpeg" "-i" "input.mp4")
+                               :exit-code 1)))
+      (ok (string= (visp-error-message err) "Command failed"))
+      (ok (equal (visp-ffmpeg-error-command err) '("ffmpeg" "-i" "input.mp4")))
+      (ok (= (visp-ffmpeg-error-exit-code err) 1)))))
+
+(deftest error-helper-functions-tests
+  (testing "error-option helper"
+    (ok (signals visp-option-error
+                 (error-option "Invalid speed" :option-name "speed" :context "abc"))))
+  
+  (testing "error-file helper"
+    (ok (signals visp-file-error
+                 (error-file "File not found" :file-path "/nonexistent.mp4"))))
+  
+  (testing "error-validation helper"
+    (ok (signals visp-validation-error
+                 (error-validation "Invalid input" :context "test"))))
+  
+  (testing "error-ffmpeg helper"
+    (ok (signals visp-ffmpeg-error
+                 (error-ffmpeg "Command failed" :command '("ffmpeg") :exit-code 1)))))
+
+(deftest exception-hierarchy-tests
+  (testing "Exception inheritance hierarchy"
+    ;; visp-validation-error is a subtype of visp-error
+    (ok (signals visp-error
+                 (error-validation "test")))
+    
+    ;; visp-option-error is a subtype of visp-validation-error
+    (ok (signals visp-validation-error
+                 (error-option "test")))
+    
+    ;; visp-file-error is a subtype of visp-validation-error
+    (ok (signals visp-validation-error
+                 (error-file "test")))
+    
+    ;; visp-ffmpeg-error is a subtype of visp-error
+    (ok (signals visp-error
+                 (error-ffmpeg "test")))))
\ No newline at end of file
diff --git a/t/test-validate.lisp b/t/test-validate.lisp
index 6da6bb7..e2e8517 100644
--- a/t/test-validate.lisp
+++ b/t/test-validate.lisp
@@ -4,7 +4,15 @@
                 :make-visp-options
                 :parse-number
                 :validate-speed
-                :validate-gif-mode))
+                :validate-input
+                :validate-reverse
+                :validate-repeat
+                :validate-resolution
+                :validate-half
+                :validate-fps
+                :validate-gif-mode
+                :visp-option-error
+                :visp-file-error))
 
 (in-package :visp.test.validate)
 
@@ -41,7 +49,24 @@
     (let ((opts (make-visp-options)))
       (setf (visp:visp-options-speed opts) nil)
       (visp:validate-speed opts)
-      (ok (null (visp:visp-options-speed opts))))))
+      (ok (null (visp:visp-options-speed opts)))))
+
+  (testing "Throws visp-option-error for invalid speed values"
+    (let ((opts (make-visp-options)))
+      (setf (visp:visp-options-speed opts) "invalid")
+      (ok (signals visp-option-error (validate-speed opts))))
+    
+    (let ((opts (make-visp-options)))
+      (setf (visp:visp-options-speed opts) "-1.5")
+      (ok (signals visp-option-error (validate-speed opts))))
+    
+    (let ((opts (make-visp-options)))
+      (setf (visp:visp-options-speed opts) "0")
+      (ok (signals visp-option-error (validate-speed opts))))
+    
+    (let ((opts (make-visp-options)))
+      (setf (visp:visp-options-speed opts) "abc")
+      (ok (signals visp-option-error (validate-speed opts)))))))
 
 (deftest validate-output-tests
   (testing "Validates output option with existing directory"
@@ -91,10 +116,35 @@
       (visp:validate-gif-mode opts)
       (ok t)))
 
-  ;; NOTE: Error case tests have been temporarily removed due to (uiop:quit 1) 
-  ;; incompatibility with test framework. These will be added back when 
-  ;; validation functions are refactored to use exceptions instead of process exit.
-  ;; See CLAUDE.md "テストコード全体の改修とエラーケーステストの追加" for details.
+  (testing "Error when no input provided in GIF mode"
+    (let ((opts (make-visp-options)))
+      (setf (visp:visp-options-gif opts) t)
+      ;; input is nil by default
+      (ok (signals visp-option-error (validate-gif-mode opts))))
+    
+    (let ((opts (make-visp-options)))
+      (setf (visp:visp-options-gif opts) t)
+      (setf (visp:visp-options-input opts) "")
+      (ok (signals visp-option-error (validate-gif-mode opts)))))
+  
+  (testing "Error when unsupported file format in GIF mode"
+    (let ((opts (make-visp-options)))
+      (setf (visp:visp-options-gif opts) t)
+      (setf (visp:visp-options-input opts) "test.txt")
+      (ok (signals visp-file-error (validate-gif-mode opts)))))
+  
+  (testing "Error when --gif used with other options"
+    (let ((opts (make-visp-options)))
+      (setf (visp:visp-options-gif opts) t)
+      (setf (visp:visp-options-input opts) "test.mp4")
+      (setf (visp:visp-options-res opts) "hd")
+      (ok (signals visp-option-error (validate-gif-mode opts))))
+    
+    (let ((opts (make-visp-options)))
+      (setf (visp:visp-options-gif opts) t)
+      (setf (visp:visp-options-input opts) "test.mp4")
+      (setf (visp:visp-options-codec opts) "h264")
+      (ok (signals visp-option-error (validate-gif-mode opts)))))
 
   (testing "Allows --dry-run with --gif"
     (let ((opts (make-visp-options)))
@@ -103,4 +153,98 @@
       (setf (visp:visp-options-dry-run opts) t)
       ;; エラーが発生しないことをテスト
       (visp:validate-gif-mode opts)
-      (ok t))))
\ No newline at end of file
+      (ok t))))
+
+(deftest validate-input-error-tests
+  (testing "Error when no input provided"
+    (let ((opts (make-visp-options)))
+      ;; input is nil by default
+      (ok (signals visp-option-error (validate-input opts)))))
+  
+  (testing "Error when input file does not exist"
+    (let ((opts (make-visp-options)))
+      (setf (visp:visp-options-input opts) "/nonexistent/file.mp4")
+      (ok (signals visp-file-error (validate-input opts)))))
+  
+  (testing "Error when input directory does not exist"
+    (let ((opts (make-visp-options)))
+      (setf (visp:visp-options-input opts) "/nonexistent/directory/")
+      (ok (signals visp-file-error (validate-input opts))))))
+
+(deftest validate-reverse-error-tests
+  (testing "Error when --reverse and --loop used together"
+    (let ((opts (make-visp-options)))
+      (setf (visp:visp-options-rev opts) t)
+      (setf (visp:visp-options-repeat opts) 2)
+      (setf (visp:visp-options-input opts) "test.mp4")
+      (ok (signals visp-option-error (validate-reverse opts)))))
+  
+  (testing "Error when --reverse used with unsupported extension"
+    (let ((opts (make-visp-options)))
+      (setf (visp:visp-options-rev opts) t)
+      (setf (visp:visp-options-input opts) "test.avi")
+      (ok (signals visp-option-error (validate-reverse opts))))))
+
+(deftest validate-repeat-error-tests
+  (testing "Error when --loop is not a positive integer"
+    (let ((opts (make-visp-options)))
+      (setf (visp:visp-options-repeat opts) "invalid")
+      (ok (signals visp-option-error (validate-repeat opts))))
+    
+    (let ((opts (make-visp-options)))
+      (setf (visp:visp-options-repeat opts) "0")
+      (ok (signals visp-option-error (validate-repeat opts))))
+    
+    (let ((opts (make-visp-options)))
+      (setf (visp:visp-options-repeat opts) "-1")
+      (ok (signals visp-option-error (validate-repeat opts))))))
+
+(deftest validate-resolution-error-tests
+  (testing "Error when --res and --half used together"
+    (let ((opts (make-visp-options)))
+      (setf (visp:visp-options-res opts) "fhd")
+      (setf (visp:visp-options-half opts) t)
+      (ok (signals visp-option-error (validate-resolution opts)))))
+  
+  (testing "Error when --res has unsupported value"
+    (let ((opts (make-visp-options)))
+      (setf (visp:visp-options-res opts) "unsupported-resolution")
+      (ok (signals visp-option-error (validate-resolution opts))))))
+
+(deftest validate-fps-error-tests
+  (testing "Error when --fps is not a positive integer"
+    (let ((opts (make-visp-options)))
+      (setf (visp:visp-options-fps opts) "invalid")
+      (ok (signals visp-option-error (validate-fps opts))))
+    
+    (let ((opts (make-visp-options)))
+      (setf (visp:visp-options-fps opts) "0")
+      (ok (signals visp-option-error (validate-fps opts))))
+    
+    (let ((opts (make-visp-options)))
+      (setf (visp:visp-options-fps opts) "-30")
+      (ok (signals visp-option-error (validate-fps opts))))))
+
+(deftest validate-output-error-tests
+  (testing "Error when output directory does not exist"
+    (let ((opts (make-visp-options)))
+      (setf (visp:visp-options-output opts) "/nonexistent/directory/output.mp4")
+      (ok (signals visp-file-error (validate-output opts))))))
+
+(deftest validate-codec-error-tests
+  (testing "Error when unsupported codec specified"
+    (let ((opts (make-visp-options)))
+      (setf (visp:visp-options-codec opts) "unsupported-codec")
+      (ok (signals visp-option-error (validate-codec opts))))))
+
+(deftest validate-mono-error-tests
+  (testing "Error when --mono used with unsupported codecs"
+    (let ((opts (make-visp-options)))
+      (setf (visp:visp-options-mono opts) t)
+      (setf (visp:visp-options-codec opts) "prores")
+      (ok (signals visp-option-error (validate-mono opts))))
+    
+    (let ((opts (make-visp-options)))
+      (setf (visp:visp-options-mono opts) t)
+      (setf (visp:visp-options-codec opts) "hap")
+      (ok (signals visp-option-error (validate-mono opts))))))
\ No newline at end of file
diff --git a/visp.asd b/visp.asd
index fbbfaeb..201b739 100644
--- a/visp.asd
+++ b/visp.asd
@@ -7,21 +7,23 @@
   :components ((:module "src"
                  :components
                  ((:file "package")
-                  (:file "const")
-                  (:file "log")
-                  (:file "help")
-                  (:file "options")
-                  (:file "util")
-                  (:file "video")
-                  (:file "ffmpeg")
-                  (:file "validate")
-                  (:file "main")))))
+                  (:file "const" :depends-on ("package"))
+                  (:file "log" :depends-on ("package"))
+                  (:file "help" :depends-on ("package"))
+                  (:file "exceptions" :depends-on ("package"))
+                  (:file "options" :depends-on ("package"))
+                  (:file "util" :depends-on ("package"))
+                  (:file "video" :depends-on ("package" "util"))
+                  (:file "ffmpeg" :depends-on ("package" "util" "video"))
+                  (:file "validate" :depends-on ("package" "exceptions" "util" "video"))
+                  (:file "main" :depends-on ("package" "exceptions" "options" "util" "video" "ffmpeg" "validate" "help" "log"))))))
 
 (defsystem "visp/test"
   :depends-on (:visp :rove)
   :components ((:module "t"
                 :components
-                ((:file "test-ffmpeg")
+                ((:file "test-exceptions")
+                 (:file "test-ffmpeg")
                  (:file "test-util")
                  (:file "test-util-output")
                  (:file "test-validate"))))