warn user on startup if ffmpeg is not available

Closes #41

.gitignore

@@ -9,3 +9,5 @@ build/
 *.egg-info
 .install-cache/
 .vim/
+venv/
+.venv/

fc2_live_dl/FC2LiveDL.py

@@ -87,6 +87,18 @@ async def __aexit__(self, *err):
         self._session = None
 
     async def download(self, channel_id):
+        # Check ffmpeg
+        if not await FFMpeg.is_available():
+            if self.params["remux"]:
+                self._logger.error(
+                    "ffmpeg not found in PATH, remuxing is not available"
+                )
+                self._logger.error(
+                    "please install ffmpeg or disable remuxing with --no-remux"
+                )
+                raise FileNotFoundError(FFMpeg.FFMPEG_BIN)
+
+        # Initialize
         self._logger = Logger("fc2 " + channel_id)
         tasks = []
         fname_stream = None

fc2_live_dl/ffmpeg.py

@@ -12,6 +12,24 @@ def __init__(self, flags):
         self._ffmpeg = None
         self._flags = flags
 
+    @classmethod
+    async def is_available(cls):
+        """
+        Check if ffmpeg binary exists and is executable.
+        """
+
+        try:
+            proc = await asyncio.create_subprocess_exec(
+                cls.FFMPEG_BIN,
+                "-version",
+                stdout=asyncio.subprocess.DEVNULL,
+                stderr=asyncio.subprocess.DEVNULL,
+            )
+            ret = await proc.wait()
+            return ret == 0
+        except FileNotFoundError:
+            return False
+
     async def __aenter__(self):
         self._loop = asyncio.get_running_loop()
         self._ffmpeg = await asyncio.create_subprocess_exec(

setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = fc2-live-dl
-version = 2.1.2
+version = 2.1.3
 author = Hizkia Felix
 author_email = [email protected]
 description = Download live streams from FC2