fix: clamp default audio bitrate to 160 kbps for iPod Nano 7 compatibility

src/audio_converter.py

@@ -43,7 +43,7 @@ class AudioConverter:
                               track_info: TrackInfo, 
                               input_file: str,
                               format: str = "m4a", 
-                              audio_bitrate: int = 256,
+                              audio_bitrate: int = 160,
                               overwrite: bool = False) -> str:
         """
         Convert audio file to iPod-compatible format
@@ -90,10 +90,13 @@ class AudioConverter:
                 logger.warning(f"Existing file is too small ({file_size} bytes), re-converting")
                 os.remove(output_file)
         
-        # Build ffmpeg command — iPod Nano 7 is strict about AAC parameters:
+        # iPod Nano 7 is strict about AAC parameters:
         #   - AAC-LC profile only (HE-AAC causes playback issues/crashes)
         #   - 44100 Hz sample rate (firmware expects this exactly)
-        #   - Max 160 kbps for stereo (higher bitrates may truncate playback)
+        #   - Max 160 kbps for stereo (higher bitrates cause clicks/truncation)
+        if audio_bitrate > 160:
+            logger.warning("Bitrate %d kbps exceeds iPod Nano 7 max (160 kbps), clamping to 160", audio_bitrate)
+            audio_bitrate = 160
         codec = "aac" if format == "m4a" else "libmp3lame"
         cmd = [
             "ffmpeg", "-y", "-i", input_file,
@@ -190,7 +193,7 @@ class AudioConverter:
                               output_file: Optional[str] = None,
                               resolution: str = "640x480",
                               video_bitrate: int = 1500,
-                              audio_bitrate: int = 256,
+                              audio_bitrate: int = 160,
                               overwrite: bool = False) -> str:
         """
         Convert video file to iPod-compatible format

src/cli.py

@@ -74,8 +74,8 @@ class YouTubeToIPodCLI:
             "--quality", "-q",
             help="Audio quality in kbps",
             type=int,
-            choices=[128, 192, 256, 320],
-            default=256
+            choices=[96, 112, 128, 160],
+            default=160
         )
         
         # Video support
@@ -128,7 +128,7 @@ class YouTubeToIPodCLI:
         
         return parser.parse_args()
     
-    def download(self, url: str, format: str = "m4a", quality: int = 256, video: bool = False) -> List[TrackInfo]:
+    def download(self, url: str, format: str = "m4a", quality: int = 160, video: bool = False) -> List[TrackInfo]:
         """
         Download audio/video from YouTube
         
@@ -156,9 +156,9 @@ class YouTubeToIPodCLI:
                tracks: List[TrackInfo], 
                output_dir: str, 
                format: str = "m4a", 
-               quality: int = 256,
-               video: bool = False,
-               resolution: str = "640x480") -> List[Tuple[TrackInfo, str]]:
+                quality: int = 160,
+                video: bool = False,
+                resolution: str = "640x480") -> List[Tuple[TrackInfo, str]]:
         """
         Convert downloaded tracks to iPod-compatible format
         

src/config_loader.py

@@ -97,7 +97,7 @@ class ConfigLoader:
             
         self.config.set('General', 'output_dir', os.path.join(os.path.expanduser("~"), "Music", "iPod"))
         self.config.set('General', 'format', 'm4a')
-        self.config.set('General', 'quality', '256')
+        self.config.set('General', 'quality', '160')
         self.config.set('General', 'clean_temp', 'true')
         
         # Video section

src/main.py

@@ -69,7 +69,7 @@ class WorkerThread(QThread):
         url = self.kwargs.get("url")
         output_dir = self.kwargs.get("output_dir", "downloads")
         fmt = self.kwargs.get("format", "m4a")
-        quality = self.kwargs.get("quality", 256)
+        quality = self.kwargs.get("quality", 160)
 
         self.progress_signal.emit(0, f"Initializing download from {url}")
 
@@ -93,7 +93,7 @@ class WorkerThread(QThread):
         local_files = self.kwargs.get("local_files", [])
         output_dir = self.kwargs.get("output_dir", "converted")
         fmt = self.kwargs.get("format", "m4a")
-        quality = self.kwargs.get("quality", 256)
+        quality = self.kwargs.get("quality", 160)
 
         valid_tracks = [
             t for t in tracks
@@ -314,9 +314,9 @@ class MainWindow(QMainWindow):
         self.format_combo.addItems(["m4a", "mp3"])
         quality_label = QLabel("Quality (kbps):")
         self.quality_spin = QSpinBox()
-        self.quality_spin.setRange(128, 320)
-        self.quality_spin.setValue(256)
-        self.quality_spin.setSingleStep(32)
+        self.quality_spin.setRange(96, 160)
+        self.quality_spin.setValue(160)
+        self.quality_spin.setSingleStep(16)
         format_layout.addWidget(format_label)
         format_layout.addWidget(self.format_combo)
         format_layout.addWidget(quality_label)

src/youtube_downloader.py

@@ -215,7 +215,7 @@ class YouTubeDownloader:
             logger.error(f"Error extracting playlist info: {e}")
             return []
     
-    def download_audio(self, track_info: TrackInfo, format: str = "m4a", quality: int = 256) -> Optional[str]:
+    def download_audio(self, track_info: TrackInfo, format: str = "m4a", quality: int = 160) -> Optional[str]:
         """
         Download audio from YouTube video
         
@@ -341,7 +341,7 @@ class YouTubeDownloader:
             if self.progress_callback:
                 self.progress_callback(95, f"Download error: {self.current_track.title}")
     
-    def process_url(self, url: str, format: str = "m4a", quality: int = 256) -> List[TrackInfo]:
+    def process_url(self, url: str, format: str = "m4a", quality: int = 160) -> List[TrackInfo]:
         """
         Process a YouTube URL (video or playlist)