使用opencv-python和Gstreamer进行rstp流转发时出现问题

程序正常运行，但是当使用VLC打开视频流时，显示不出来，当在终端中使用gst-launch-1.0运行时，出现错误如下，好像是无法加载管道信息，对于Gstreamer我是个新手，请各位大佬不吝赐教，拜谢！！

python程序

import cv2
import gi

gi.require_version('Gst', '1.0')
gi.require_version('GstRtspServer', '1.0')
from gi.repository import Gst, GstRtspServer, GObject, GLib


class SensorFactory(GstRtspServer.RTSPMediaFactory):
    def __init__(self, **properties):
        super(SensorFactory, self).__init__(**properties)
        # self.cap = cv2.VideoCapture(0)
        self.cap = cv2.VideoCapture('rtsp://******')
        self.weight = self.cap.get(cv2.CAP_PROP_FRAME_WIDTH)
        self.height = self.cap.get(cv2.CAP_PROP_FRAME_HEIGHT)
        self.fps = self.cap.get(cv2.CAP_PROP_FPS)
        self.number_frames = 0
        # self.fps = 25
        self.duration = 1 / self.fps * Gst.SECOND * 10  # duration of a frame in nanoseconds
        self.launch_string = 'appsrc name=source is-live=true block=true format=GST_FORMAT_TIME ' \
                             'caps=video/x-raw,format=BGR,width={},height={},framerate={}/1 ' \
                             '! videoconvert ! video/x-raw,format=I420 ' \
                             '! x264enc speed-preset=fast tune=zerolatency ' \
                             '! rtph264pay config-interval=1 name=pay0 pt=96'.format(self.weight, self.height, self.fps)

    def on_need_data(self, src, lenght):

        while self.cap.isOpened():
            ret, frame = self.cap.read()
            data = frame.tostring()
            buf = Gst.Buffer.new_allocate(None, len(data), None)
            buf.fill(0, data)
            buf.duration = self.duration
            timestamp = self.number_frames * self.duration
            buf.pts = buf.dts = int(timestamp)
            buf.offset = timestamp
            self.number_frames += 1
            retval = src.emit('push-buffer', buf)

            print('pushed buffer, frame {}, duration {} ns, durations {} s'.format(self.number_frames, self.duration,
                self.duration / Gst.SECOND))

            if retval != Gst.FlowReturn.OK:
                print(retval)

    def do_create_element(self, url):
        return Gst.parse_launch(self.launch_string)

    def do_configure(self, rtsp_media):
        self.number_frames = 0
        appsrc = rtsp_media.get_element().get_child_by_name('source')
        appsrc.connect('need-data', self.on_need_data)


class GstServer(GstRtspServer.RTSPServer):
    def __init__(self, **properties):
        super(GstServer, self).__init__(**properties)
        self.factory = SensorFactory()
        self.factory.set_shared(True)
        # self.port = 8080
        self.get_mount_points().add_factory("/test", self.factory)
        self.attach(None)


GObject.threads_init()
Gst.init(None)

server = GstServer()

loop = GObject.MainLoop()
loop.run()

错误代码

scy@scy-ai:~$ gst-launch-1.0 rtspsrc latency=20 location="rtsp://*******:8554/test" ! rtph264depay ! h264parse ! avdec_h264 ! autovideosink

Setting pipeline to PAUSED ...
Pipeline is live and does not need PREROLL ...
Progress: (open) Opening Stream
Progress: (connect) Connecting to rtsp://***********:8554/test
Progress: (open) Retrieving server options
ERROR: from element /GstPipeline:pipeline0/GstRTSPSrc:rtspsrc0: Could not read from resource.
Additional debug info:
gstrtspsrc.c(5917): gst_rtsp_src_receive_response (): /GstPipeline:pipeline0/GstRTSPSrc:rtspsrc0:
Could not receive message. (Timeout while waiting for server response)
ERROR: pipeline doesn't want to preroll.
Setting pipeline to PAUSED ...
Setting pipeline to READY ...
Setting pipeline to NULL ...
Freeing pipeline ...