tornadoAsyncTranscode.py

class FlvFormater(tornado.web.RequestHandler):
    @tornado.web.asynchronous
    def get(self, video_name):
        self.set_header("Content-Type", "video/x-flv")
        cmd = "/usr/local/bin/ffmpeg -i %s -f flv -acodec aac -s vga -"%video_name
        self.ioloop = tornado.ioloop.IOLoop.instance()
        self.pipe = cmdfd = os.popen(cmd)
        #self.pipe = cmdfd = open("a.avi", "r")
        self.ioloop.add_handler( cmdfd.fileno(), self.async_callback(self.on_read), self.ioloop.READ )


    def on_read(self, fd, events):
        buffer = self.pipe.read(1024)
        try:
            assert buffer
            self.write(buffer)
            self.flush()
        except:
            self.pipe.close()
            self.ioloop.remove_handler(fd)
            self.finish()