I meet an error when running the demo.py to detect objects from video

python demo.py video -n yolox-s -c tools/latest_ckpt.pth.tar -f exps/default/yolox_tiny.py --path tools/test_imgs/192.mp4 --conf 0.25 --nms 0.45 --tsize 416 --save_result

the error messages are:
[ WARN:0] global ../opencv/modules/videoio/src/cap_gstreamer.cpp (919) open OpenCV | GStreamer warning: unable to query duration of stream
[ WARN:0] global ../opencv/modules/videoio/src/cap_gstreamer.cpp (956) open OpenCV | GStreamer warning: Cannot query video position: status=1, value=0, duration=-1
2021-08-12 17:27:38 | INFO | main:185 - video save_path is ./YOLOX_outputs/yolox_tiny/vis_res/2021_08_12_17_27_38/192.mp4

(python:3819): GStreamer-CRITICAL **: 17:27:38.792: gst_element_make_from_uri: assertion 'gst_uri_is_valid (uri)' failed
[ WARN:0] global ../opencv/modules/videoio/src/cap_gstreamer.cpp (1601) open OpenCV | GStreamer warning: cannot link elements
libva info: VA-API version 1.8.0
libva info: User environment variable requested driver 'iHD'
libva info: Trying to open /opt/intel/mediasdk/lib64/iHD_drv_video.so
libva info: Found init function __vaDriverInit_1_8
DRM_IOCTL_I915_GEM_APERTURE failed: Invalid argument
Assuming 131072kB available aperture size.
May lead to reduced performance or incorrect rendering.
get chip id failed: -1 [22]
param: 4, val: 0
libva error: /opt/intel/mediasdk/lib64/iHD_drv_video.so init failed
libva info: va_openDriver() returns 18
MFX: Can't initialize session
2021-08-12 17:27:39 | INFO | main:128 - Infer time: 0.2944s
2021-08-12 17:27:39 | INFO | main:128 - Infer time: 0.0084s
2021-08-12 17:27:39 | INFO | main:128 - Infer time: 0.0067s
2021-08-12 17:27:39 | INFO | main:128 - Infer time: 0.0067s
2021-08-12 17:27:39 | INFO | main:128 - Infer time: 0.0068s

Start with demo.py and the reported video command using tools/test_imgs/192.mp4, then inspect the video input and output handling around the logged save_path. Compare the OpenCV/GStreamer and VA-API messages with the point where inference continues. Done means the demo processes the video without the reported failure and saves the resulting video.