diff --git a/youtube_video_downloader.py b/youtube_video_downloader.py
index cd7c43a..af7d19e 100644
--- a/youtube_video_downloader.py
+++ b/youtube_video_downloader.py
@@ -1,5 +1,6 @@
 import os
 import yt_dlp
+import subprocess
 
 class YouTubeVideoDownloader:
     def __init__(self):
@@ -10,63 +11,117 @@ class YouTubeVideoDownloader:
         return {
             "required": {
                 "youtube_url": ("STRING", {"default": ""}),
-                "download_path": ("STRING", {"default": "D:\ComfyUI_windows_portable\ComfyUI\downloads"}),
+                "download_path": ("STRING", {"default": "D:/ComfyUI_downloads"}),
                 "resolution": (["360p", "480p", "720p", "1080p"], {"default": "720p"}),
+                "save_as_mp4": ("BOOLEAN", {"default": False}),
+                "audio_only": ("BOOLEAN", {"default": False})
             }
         }
     
-    RETURN_TYPES = ("STRING",)
-    RETURN_NAMES = ("video_path",)
+    RETURN_TYPES = ("STRING", "STRING")
+    RETURN_NAMES = ("video_path", "audio_path")
     FUNCTION = "download_youtube_video"
     CATEGORY = "Doctor-Tools"
     
-    def download_youtube_video(self, youtube_url, download_path, resolution):
+    def convert_mkv_to_mp4(self, mkv_path):
+        """Convert MKV to MP4 using FFmpeg"""
+        mp4_path = mkv_path.replace('.mkv', '.mp4')
+        try:
+            cmd = ['ffmpeg', '-i', mkv_path, '-codec', 'copy', mp4_path, '-y']
+            subprocess.run(cmd, check=True, capture_output=True)
+            # Remove original MKV if MP4 conversion successful
+            if os.path.exists(mp4_path) and os.path.getsize(mp4_path) > 0:
+                os.remove(mkv_path)
+                return mp4_path
+        except subprocess.CalledProcessError as e:
+            print(f"[ERROR] FFmpeg conversion failed: {e}")
+            return mkv_path
+        return mkv_path
+    
+    def download_youtube_video(self, youtube_url, download_path, resolution, save_as_mp4, audio_only):
         try:
             # Ensure the download directory exists
             os.makedirs(download_path, exist_ok=True)
             print(f"[INFO] Download path verified or created at: {download_path}")
             
-            # Create unique filename
+            # Create unique filenames
             import time
             timestamp = int(time.time())
-            video_path = os.path.join(download_path, f'video_{timestamp}.mkv')  # Using MKV as container
+            video_path = os.path.join(download_path, f'video_{timestamp}.mkv')
+            audio_path = os.path.join(download_path, f'audio_{timestamp}.wav')
+            final_video_path = video_path  # Will be updated if converted to MP4
             
-            # More explicit format selection
+            # First download audio as WAV
+            print("[INFO] Downloading and extracting audio...")
+            ydl_opts_audio = {
+                'format': 'bestaudio',
+                'outtmpl': audio_path[:-4],  # Remove .wav as it will be added by postprocessor
+                'postprocessors': [{
+                    'key': 'FFmpegExtractAudio',
+                    'preferredcodec': 'wav',
+                    'preferredquality': '192',
+                }],
+                'quiet': False,
+                'no_warnings': False,
+            }
+            
+            with yt_dlp.YoutubeDL(ydl_opts_audio) as ydl:
+                ydl.extract_info(youtube_url, download=True)
+            
+            # Verify audio file
+            if not os.path.exists(audio_path):
+                raise FileNotFoundError(f"Audio file not found at {audio_path}")
+            if os.path.getsize(audio_path) == 0:
+                raise ValueError(f"Downloaded audio file is empty: {audio_path}")
+            
+            # If audio_only is True, skip video download
+            if audio_only:
+                print("[INFO] Audio-only mode: Skipping video download")
+                return ("", audio_path)  # Return empty string for video path
+            
+            # Download video
+            print("[INFO] Downloading video...")
             height = resolution[:-1]  # Remove 'p' from resolution
             
-            ydl_opts = {
+            ydl_opts_video = {
                 'format': f'bestvideo[height<={height}][ext=mp4]+bestaudio[ext=m4a]/best[ext=mp4]/best',
                 'outtmpl': video_path,
-                'merge_output_format': 'mkv',  # Using MKV as it's more flexible with codecs
+                'merge_output_format': 'mkv',
                 'postprocessors': [{
                     'key': 'FFmpegVideoConvertor',
                     'preferedformat': 'mkv',
                 }],
                 'quiet': False,
                 'no_warnings': False,
-                'verbose': True,  # Add verbose output for debugging
             }
             
-            # Download video
-            with yt_dlp.YoutubeDL(ydl_opts) as ydl:
+            with yt_dlp.YoutubeDL(ydl_opts_video) as ydl:
                 info = ydl.extract_info(youtube_url, download=True)
-                print(f"[INFO] Download completed with format: {info.get('format', 'unknown')}")
+                print(f"[INFO] Video download completed with format: {info.get('format', 'unknown')}")
             
-            print(f"[INFO] Video downloaded to: {video_path}")
+            # Convert to MP4 if requested
+            if save_as_mp4:
+                print("[INFO] Converting to MP4...")
+                final_video_path = self.convert_mkv_to_mp4(video_path)
+                if final_video_path.endswith('.mp4'):
+                    print("[INFO] Successfully converted to MP4")
+                else:
+                    print("[WARNING] MP4 conversion failed, keeping MKV format")
             
-            # Verify file exists and has size > 0
-            if not os.path.exists(video_path):
-                raise FileNotFoundError(f"Video file not found at {video_path}")
+            # Verify video file
+            if not os.path.exists(final_video_path):
+                raise FileNotFoundError(f"Video file not found at {final_video_path}")
+            if os.path.getsize(final_video_path) == 0:
+                raise ValueError(f"Downloaded video file is empty: {final_video_path}")
             
-            if os.path.getsize(video_path) == 0:
-                raise ValueError(f"Downloaded file is empty: {video_path}")
-                
-            return (video_path,)
+            print(f"[INFO] Files saved to:\nVideo: {final_video_path}\nAudio: {audio_path}")
+            
+            return (final_video_path, audio_path)
             
         except Exception as e:
             error_message = f"[ERROR] Error during download: {str(e)}"
             print(error_message)
-            return (error_message,)
+            return (error_message, error_message)
 
 # Register node class mappings for ComfyUI
 NODE_CLASS_MAPPINGS = {