diff --git a/README.md b/README.md
index 0c03b32..75b2c84 100644
--- a/README.md
+++ b/README.md
@@ -154,7 +154,8 @@ Settings are stored in `~/.config/sendspin/`:
 | `use_mpris` | boolean | TUI/daemon | Enable MPRIS integration (default: true) |
 | `hook_start` | string | TUI/daemon | Command to run when audio stream starts |
 | `hook_stop` | string | TUI/daemon | Command to run when audio stream stops |
-| `source` | string | serve | Default audio source (file path or URL) |
+| `source` | string | serve | Default audio source (file path or URL, ffmpeg input) |
+| `source_format` | string | serve | ffmpeg container format for audio source |
 | `clients` | array | serve | Client URLs to connect to (`--client`) |
 
 Settings are automatically saved when changed through the TUI. You can also edit the JSON file directly while the client is not running.
diff --git a/sendspin/cli.py b/sendspin/cli.py
index 883785d..1b2d069 100644
--- a/sendspin/cli.py
+++ b/sendspin/cli.py
@@ -75,6 +75,11 @@ def parse_args(argv: Sequence[str] | None = None) -> argparse.Namespace:
         default=None,
         help="Audio source: local file path or URL (http/https)",
     )
+    serve_parser.add_argument(
+        "--source-format",
+        default=None,
+        help="ffmpeg container format for source audio",
+    )
     serve_parser.add_argument(
         "--demo",
         action="store_true",
@@ -392,6 +397,7 @@ async def _run_serve_mode(args: argparse.Namespace) -> int:
 
     serve_config = ServeConfig(
         source=source,
+        source_format=args.source_format or settings.source_format,
         port=args.port,
         name=args.name,
         clients=args.clients or settings.clients,
diff --git a/sendspin/serve/__init__.py b/sendspin/serve/__init__.py
index be9d36f..e1c076d 100644
--- a/sendspin/serve/__init__.py
+++ b/sendspin/serve/__init__.py
@@ -63,6 +63,7 @@ class ServeConfig:
     """Configuration for the serve command."""
 
     source: str
+    source_format: str | None = None
     port: int = 8928
     name: str = "Sendspin Server"
     clients: list[str] | None = None
@@ -220,7 +221,7 @@ def on_server_event(server: SendspinServer, event: SendspinEvent) -> None:
 
             # Decode and stream audio
             try:
-                audio_source = await decode_audio(config.source)
+                audio_source = await decode_audio(config.source, source_format=config.source_format)
                 media_stream = MediaStream(
                     main_channel_source=audio_source.generator,
                     main_channel_format=audio_source.format,
diff --git a/sendspin/serve/source.py b/sendspin/serve/source.py
index 1d46866..1a5c9e4 100644
--- a/sendspin/serve/source.py
+++ b/sendspin/serve/source.py
@@ -50,6 +50,7 @@ async def decode_audio(
     *,
     target_sample_rate: int = 48000,
     target_channels: int = 2,
+    source_format: str | None = None,
 ) -> AudioSource:
     """
     Decode an audio source (file path or URL) to PCM.
@@ -78,7 +79,7 @@ async def pcm_generator() -> AsyncGenerator[bytes, None]:
                 if container is not None:
                     container.close()
 
-                container = av.open(source)
+                container = av.open(format=source_format, file=source)
                 resampler = av.AudioResampler(format="s16", layout=layout, rate=target_sample_rate)
                 for frame in container.decode(container.streams.audio[0]):
                     for resampled in resampler.resample(frame):
diff --git a/sendspin/settings.py b/sendspin/settings.py
index fd739e6..3bd7643 100644
--- a/sendspin/settings.py
+++ b/sendspin/settings.py
@@ -201,6 +201,7 @@ class ServeSettings(BaseSettings):
     """Settings for serve mode."""
 
     source: str | None = None
+    source_format: str | None = None
     clients: list[str] | None = None
 
     def update(
@@ -210,6 +211,7 @@ def update(
         log_level: str | None = None,
         listen_port: int | None = None,
         source: str | None = None,
+        source_format: str | None = None,
         clients: list[str] | None = None,
     ) -> None:
         """Update settings fields. Only changed fields trigger a save."""
@@ -219,6 +221,7 @@ def update(
                 "log_level": log_level,
                 "listen_port": listen_port,
                 "source": source,
+                "source_format": source_format,
                 "clients": clients,
             }
         )
@@ -238,6 +241,7 @@ def _load(self) -> None:
             self.log_level = data.get("log_level")
             self.listen_port = data.get("listen_port")
             self.source = data.get("source")
+            self.source_format = data.get("source_format")
             self.clients = data.get("clients")
             logger.info("Loaded settings from %s", self._settings_file)
         except (json.JSONDecodeError, OSError) as e: