use fifo file to fool ffmpeg

transcoder.py

@@ -2,28 +2,38 @@ import ffmpeg
 from logger import logger
 from stream_listener import StreamListener
 from stream import StreamSource
+import os
+
+fifoFile = 'transcode-fifo'
 
 # converts the stream to mp3 before sending to the long-lasting mp3 connection
+# write to a fifo file instead of directly via stdin to fool ffmpeg into thinking it has seekable input
+# https://lists.libav.org/pipermail/ffmpeg-user/2007-May/008917.html
 class Transcoder(StreamSource):
 
   def __init__(self, upstream):
+    if os.path.exists(fifoFile):
+      os.remove(fifoFile)
+    os.mkfifo(fifoFile)
+    self.file = open(fifoFile, 'a')
     self.process = ( ffmpeg
-      .input('pipe:')
+      .input(fifoFile)
       .output('pipe:', format='mp3')
-      .run_async(pipe_stdin=True, pipe_stdout=True, pipe_stderr=True)
+      .run_async(pipe_stdout=True, pipe_stderr=True)
     )
     logger.add(self.process.stderr, "transcoder.log")
     self.listener = StreamListener(upstream, self)
     self.listener.start()
 
   def stop(self):
+    self.file.close()
     self.listener.stop()
-    self.process.stdin.close()
     self.process.stdout.close()
     self.process.stderr.close()
+    os.remove(fifoFile)
 
   def getStream(self):
     return self.process.stdout
 
   def write(self, chunk):
-    self.process.stdin.write(chunk)
+    self.file.write(chunk)