配置：(ROV水下机器人

python代码

UDP视频流

控制软件是QGroundCtrol

系统Ubuntu 18)

代码是从github上搬运的，放在CSDN也是方便大家检索，并且给出一些自己在使用代码遇到的问题。

原网址：https://gist.github.com/patrickelectric/443645bb0fd6e71b34c504d20d475d5a

搬运代码如下：

#!/usr/bin/env python
"""
BlueRov video capture class
"""import cv2
import gi
import numpy as npgi.require_version('Gst', '1.0')
from gi.repository import Gstclass Video():"""BlueRov video capture class constructorAttributes:port (int): Video UDP portvideo_codec (string): Source h264 parservideo_decode (string): Transform YUV (12bits) to BGR (24bits)video_pipe (object): GStreamer top-level pipelinevideo_sink (object): Gstreamer sink elementvideo_sink_conf (string): Sink configurationvideo_source (string): Udp source ip and port"""def __init__(self, port=5600):"""SummaryArgs:port (int, optional): UDP port"""Gst.init(None)self.port = portself._frame = None# [Software component diagram](https://www.ardusub.com/software/components.html)# UDP video stream (:5600)self.video_source = 'udpsrc port={}'.format(self.port)# [Rasp raw image](http://picamera.readthedocs.io/en/release-0.7/recipes2.html#raw-image-capture-yuv-format)# Cam -> CSI-2 -> H264 Raw (YUV 4-4-4 (12bits) I420)self.video_codec = '! application/x-rtp, payload=96 ! rtph264depay ! h264parse ! avdec_h264'# Python don't have nibble, convert YUV nibbles (4-4-4) to OpenCV standard BGR bytes (8-8-8)self.video_decode = \'! decodebin ! videoconvert ! video/x-raw,format=(string)BGR ! videoconvert'# Create a sink to get dataself.video_sink_conf = \'! appsink emit-signals=true sync=false max-buffers=2 drop=true'self.video_pipe = Noneself.video_sink = Noneself.run()def start_gst(self, config=None):""" Start gstreamer pipeline and sinkPipeline description list e.g:['videotestsrc ! decodebin', \'! videoconvert ! video/x-raw,format=(string)BGR ! videoconvert','! appsink']Args:config (list, optional): Gstreamer pileline description list"""if not config:config = \['videotestsrc ! decodebin','! videoconvert ! video/x-raw,format=(string)BGR ! videoconvert','! appsink']command = ' '.join(config)self.video_pipe = Gst.parse_launch(command)self.video_pipe.set_state(Gst.State.PLAYING)self.video_sink = self.video_pipe.get_by_name('appsink0')@staticmethoddef gst_to_opencv(sample):"""Transform byte array into np arrayArgs:sample (TYPE): DescriptionReturns:TYPE: Description"""buf = sample.get_buffer()caps = sample.get_caps()array = np.ndarray((caps.get_structure(0).get_value('height'),caps.get_structure(0).get_value('width'),3),buffer=buf.extract_dup(0, buf.get_size()), dtype=np.uint8)return arraydef frame(self):""" Get FrameReturns:iterable: bool and image frame, cap.read() output"""return self._framedef frame_available(self):"""Check if frame is availableReturns:bool: true if frame is available"""return type(self._frame) != type(None)def run(self):""" Get frame to update _frame"""self.start_gst([self.video_source,self.video_codec,self.video_decode,self.video_sink_conf])self.video_sink.connect('new-sample', self.callback)def callback(self, sink):sample = sink.emit('pull-sample')new_frame = self.gst_to_opencv(sample)self._frame = new_framereturn Gst.FlowReturn.OKif __name__ == '__main__':# Create the video object# Add port= if is necessary to use a different onevideo = Video()while True:# Wait for the next frameif not video.frame_available():continueframe = video.frame()cv2.imshow('frame', frame)if cv2.waitKey(30)&0xff==27:break

遇到的问题：

1. 我用的是Anaconda的虚拟环境，所以用apt-install下载gi后仍然无法在虚拟环境中使用gi(即代码报错，“NO module named gi”)，而虚拟环境中的python版本已经不支持gi。通过以下指令强行下载gi:

（解决方法搬运至下方链接23楼）

https://stackoverflow.com/questions/59838238/importerror-cannot-import-name-gi-from-partially-initialized-module-gi-mo

pip install --ignore-installed PyGObject

1. 打开QGC软件后，代码无法正常运行获取视频流。

解决办法：在QGC的视频流设置中将Enable 关闭，即关闭QGC的视频获取。这样代码和软件就不会对视频流进行“占线”，实现操作机器人的同时可以对图像进行处理。