Adding transcoader / recoverable errors

croaker/server.py

@@ -29,7 +29,8 @@ class RequestHandler(socketserver.StreamRequestHandler):
         "FFWD": "            - Skip to the next track in the playlist.",
         "HELP": "            - Display command help.",
         "KTHX": "            - Close the current connection.",
-        "STOP": "            - Stop Croaker.",
+        "STOP": "            - Stop the current track and stream silence.",
+        "STFU": "            - Terminate the Croaker server."
     }
 
     def handle(self):
@@ -45,6 +46,7 @@ class RequestHandler(socketserver.StreamRequestHandler):
         """
         while True:
             self.data = self.rfile.readline().strip().decode()
+            logger.debug(f"Received: {self.data}")
             try:
                 cmd = self.data[0:4].strip().upper()
                 args = self.data[5:]
@@ -86,6 +88,9 @@ class RequestHandler(socketserver.StreamRequestHandler):
         return self.send("\n".join(f"{cmd} {txt}" for cmd, txt in self.supported_commands.items()))
 
     def handle_STOP(self, args):
+        return(self.server.stop_event.set())
+
+    def handle_STFU(self, args):
         self.send("Shutting down.")
         self.server.stop()
 

croaker/streamer.py

@@ -1,4 +1,6 @@
+import queue
 import logging
+import io
 import os
 import threading
 from functools import cached_property
@@ -6,6 +8,8 @@ from pathlib import Path
 
 import shout
 
+from croaker import transcoder
+
 logger = logging.getLogger('streamer')
 
 
@@ -22,6 +26,11 @@ class AudioStreamer(threading.Thread):
         self.load_requested = load_event
         self.chunk_size = chunk_size
 
+    @cached_property
+    def silence(self):
+        with (Path(__file__).parent / 'silence.mp3').open('rb') as stream:
+            return io.BytesIO(stream.read())
+
     @cached_property
     def _shout(self):
         s = shout.Shout()
@@ -37,19 +46,38 @@ class AudioStreamer(threading.Thread):
         return s
 
     def run(self):
-        logger.debug("Initialized")
         self._shout.open()
-        while not self.stop_requested.is_set():
-            self._shout.get_connected()
-            track = self.queue.get(block=True)
-            logger.debug(f"Received: {track = }")
-            if track:
+        logger.debug(f"Connnected to shoutcast server at {self._shout.host}:{self._shout.port}")
+        while True:
+
+            # If the user said STOP, clear the queue.
+            if self.stop_requested.is_set():
+                logger.debug("Stop requested; clearing queue.")
+                self.clear_queue()
+                self.stop_requested.clear()
+
+            # Check to see if there is a queued request. If there is, play it.
+            # If there isn't, or if there's a problem playing the request,
+            # fallback to silence.
+            not_playing = False
             try:
-                    self.play(Path(track.decode()))
-                except shout.ShoutException as e:
-                    logger.error("An error occurred while streaming a track.", exc_info=e)
-                    self._shout.close()
-                    self._shout.open()
+                request = self.queue.get(block=False)
+                logger.debug(f"Received: {request = }")
+                self.play_file(Path(request.decode()))
+            except queue.Empty:
+                logger.debug("Nothing queued; looping silence.")
+                not_playing = True
+            except Exception as exc:
+                logger.error("Caught exception; falling back to silence.", exc_info=exc)
+                not_playing = True
+
+            if not_playing:
+                try:
+                    self.silence.seek(0, 0)
+                    self._shout.set_metadata({"song": '[NOTHING PLAYING]'})
+                    self.play_from_stream(self.silence)
+                except Exception as exc:
+                    logger.error("Caught exception trying to loop silence!", exc_info=exc)
         self._shout.close()
 
     def clear_queue(self):
@@ -60,12 +88,19 @@ class AudioStreamer(threading.Thread):
         self.load_requested.clear()
         logger.debug("Load event cleared.")
 
-    def play(self, track: Path):
-        with track.open("rb") as fh:
-            self._shout.get_connected()
+    def _read_chunk(self, filehandle):
+        chunk = filehandle.read(self.chunk_size)
+        return chunk
+
+    def play_file(self, track: Path):
         logger.debug(f"Streaming {track.stem = }")
         self._shout.set_metadata({"song": track.stem})
-            input_buffer = fh.read(self.chunk_size)
+        with transcoder.open(track) as fh:
+            return self.play_from_stream(fh)
+
+    def play_from_stream(self, stream):
+        self._shout.get_connected()
+        input_buffer = self._read_chunk(stream)
         while True:
 
             # To load a playlist, stop streaming the current track and clear the queue
@@ -77,8 +112,7 @@ class AudioStreamer(threading.Thread):
 
             # Stop streaming and clear the queue
             if self.stop_requested.is_set():
-                    logger.debug("Stop was requested.")
-                    self.stop_requested.clear()
+                logger.debug("Stop was requested; aborting current stream.")
                 return
 
             # Stop streaming and clear the queue
@@ -89,7 +123,7 @@ class AudioStreamer(threading.Thread):
 
             # continue streaming the current track to icecast, until complete
             buf = input_buffer
-                input_buffer = fh.read(self.chunk_size)
+            input_buffer = self._read_chunk(stream)
             if len(buf) == 0:
                 break
             self._shout.send(buf)

croaker/transcoder.py

@@ -0,0 +1,35 @@
+from pathlib import Path
+import subprocess
+import logging
+
+import ffmpeg
+
+logger = logging.getLogger('transcoder')
+
+
+def open(infile: Path):
+    """
+    Return a stream of mp3 data for the given path on disk.
+
+    If the requested path is an mp3, return a filehandle on the file. Otherwise,
+    invoke ffmpeg to tranascode whatever was requested to mp3 format and return
+    a pipe to ffmpeg's STDOUT.
+    """
+    suffix = infile.suffix.lower()
+    if suffix == '.mp3':
+        logger.debug(f"Not transcoding mp3 {infile = }")
+        return infile.open('rb')
+
+    ffmpeg_args = (
+        ffmpeg
+        .input(str(infile))
+        .output('-', format='mp3', q=2)
+        .global_args('-hide_banner', '-loglevel', 'quiet')
+        .compile()
+    )
+
+    # Force close STDIN to prevent ffmpeg from trying to read from it. silly ffmpeg.
+    proc = subprocess.Popen(ffmpeg_args, stdout=subprocess.PIPE, stdin=subprocess.PIPE)
+    proc.stdin.close()
+    logger.debug(f"Spawned ffmpeg (PID {proc.pid}) with args {ffmpeg_args = }")
+    return proc.stdout

pyproject.toml

@@ -9,7 +9,7 @@ packages = [
 ]
 
 [tool.poetry.dependencies]
-python = "^3.8"
+python = ">=3.10,<4.0"
 prompt-toolkit = "^3.0.38"
 typer = "^0.9.0"
 python-dotenv = "^0.21.0"
@@ -21,6 +21,7 @@ requests = "^2.31.0"
 psutil = "^5.9.8"
 exscript = "^2.6.28"
 python-shout = "^0.2.8"
+ffmpeg-python = "^0.2.0"
 
 [tool.poetry.scripts]
 croaker = "croaker.cli:app"