3399proD解码速度缓慢问题

3399proD上，使用如下py代码，接入网络摄像头，并尝试转成rtsp流推送出去，发现解码过程耗时较高，想请问下，原因出在哪里？

1. import cv2
   
2. import time
   
3. import gi
   
4. gi.require_version('Gst', '1.0')
   
5. gi.require_version('GstRtspServer', '1.0')
   
6. from gi.repository import GObject, Gst, GstRtspServer
   
7. 
   
8. uri = "rtsp://admin:a1234567@192.168.49.94/h264/ch1/main/av_stream"
   
9. t0 =  time.time()
   
10. gst_str = ('rtspsrc location={} latency=0 ! '
    
11.            'rtph264depay ! h264parse ! mppvideodec ! '
    
12.            'videoconvert ! video/x-raw,format=BGR,formaterate=25/1 ! appsink sync=false').format(uri)
    
13. cap = cv2.VideoCapture(gst_str, cv2.CAP_GSTREAMER)
    
14. 
    
15. t = time.time()
    
16. print('VideoCapture cost', t - t0)
    
17. print('cap isOpened', cap.isOpened())
    
18. width = 1920
    
19. height = 1080
    
20. out_send = cv2.VideoWriter('appsrc ! video/x-raw, format=BGR ! queue ! videoconvert ! video/x-raw,width={},height={} ! queue ! mpph264enc ! queue ! video/x-h264, stream-format=byte-stream ! h264parse ! rtph264pay pt=96 config-interval=1 ! udpsink host=127.0.0.1 port=5400'.format(width, height), cv2.CAP_GSTREAMER, 0, 25, (width, height), True)
    
21. print('out_send', out_send.isOpened())
    
22. rtsp_port_num = 8554
    
23. server = GstRtspServer.RTSPServer.new()
    
24. server.props.service = "%d" % rtsp_port_num
    
25. 
    
26. server.attach(None)
    
27. factory = GstRtspServer.RTSPMediaFactory.new()
    
28. factory.set_launch("(udpsrc name=pay0 port=5400 \
    
29.                                         caps="application/x-rtp, media=video, clock-rate=90000, \
    
30.                                         encoding-name=(string)H264, payload=96 ")")
    
31. factory.set_shared(True)
    
32. server.get_mount_points().add_factory("/test", factory)
    
33. 
    
34. num = 0
    
35. start = time.perf_counter()
    
36. while True:       
    
37.         t1 = time.time()
    
38.         ret, frame = cap.read()
    
39.         t2 = time.time()
    
40.         print('time cost', round(t2 - t1, 4))
    
41.         if not ret:
    
42.                 break
    
43.         t3 = time.time()#
    
44.         out_send.write(frame)
    
45.         t4 = time.time()
    
46.         if cv2.waitKey(1) & 0xFF == ord("q"):
    
47.                 cap.release()
    
48.                 out_send.release()
    
49.                 break
    
50.         num +=1

复制代码测试发现，在cap.read()出的耗时，达到170ms+，这个是什么原因呢？？

然后我也用dmesg命令查看后台日志，发现如下问题：

1. [  600.365372] rk_vcodec: vpu_service_ioctl:2140: error: unknown vpu service ioctl cmd 40086c01
   
2. [  605.194149] Core dump to |/usr/lib/systemd/systemd-coredump 3732 1000 1000 11 1681456866 18446744073709551615 debian10.toybrick mpp_dec_parser pipe failed
   
3. [ 3189.955584] rk_vcodec: vpu_service_ioctl:2140: error: unknown vpu service ioctl cmd 40086c01
   
4. [ 3189.960992] Core dump to |/usr/lib/systemd/systemd-coredump 21788 1000 1000 11 1681459451 18446744073709551615 debian10.toybrick mpp_dec_parser pipe failed
   

复制代码

mppvideodec 这个库转码安装的