运行 OpenCV 在 Ubuntu 上时出现 GStreamer 警告

Question

我正在尝试在我的 raspberry pi（Ubuntu 系统）上获取脚本运行ning。现在，我只是在复习 opencv 的基础知识，因为我已经有一段时间没有使用它了。所以我直接从 OpenCV 网站复制粘贴了这段代码，然后运行它。

import numpy as np
import cv2 as cv

cap = cv.VideoCapture(0)

if not cap.isOpened():
    print("Cannot open camera")
    exit()

while True:
    # Capture frame-by-frame
    ret, frame = cap.read()
    
    # if frame is read correctly ret is True
    if not ret:
        print("Can't receive frame (stream end?). Exiting ...")
        break
        
    # Our operations on the frame come here
    gray = cv.cvtColor(frame, cv.COLOR_BGR2GRAY)
    
    # Display the resulting frame
    cv.imshow('frame', gray)
    
    if cv.waitKey(1) == ord('q'):
        break
        
# When everything done, release the capture
cap.release()
cv.destroyAllWindows()

只是，运行它给了我一个纯灰色 window 作为弹出窗口并抛出这些错误：

[ WARN:0] global /usr/local/src/opencv-4.4.0/modules/videoio/src/cap_gstreamer.cpp (1761) handleMessage OpenCV | GStreamer warning: Embedded video playback halted; module v4l2src0 reported: Internal data stream error.
[ WARN:0] global /usr/local/src/opencv-4.4.0/modules/videoio/src/cap_gstreamer.cpp (888) open OpenCV | GStreamer warning: unable to start pipeline
[ WARN:0] global /usr/local/src/opencv-4.4.0/modules/videoio/src/cap_gstreamer.cpp (480) isPipelinePlaying OpenCV | GStreamer warning: GStreamer: pipeline have not been created

代码仍然运行，因为我可以通过按 'q' 关闭 window。但是视频流部分出现了严重错误。我什至不知道什么是 GStreamer，更不知道什么是 GStreamer 管道。我不知道如何解决这个问题，也没有在网上找到任何有效的方法。

Answer 1

我的代码在 jetson nano

上运行运行

def __gstreamer_pipeline(
        camera_id,
        capture_width=1920,
        capture_height=1080,
        display_width=1920,
        display_height=1080,
        framerate=30,
        flip_method=0,
    ):
    return (
            "nvarguscamerasrc sensor-id=%d ! "
            "video/x-raw(memory:NVMM), "
            "width=(int)%d, height=(int)%d, "
            "format=(string)NV12, framerate=(fraction)%d/1 ! "
            "nvvidconv flip-method=%d ! "
            "video/x-raw, width=(int)%d, height=(int)%d, format=(string)BGRx ! "
            "videoconvert ! "
            "video/x-raw, format=(string)BGR ! appsink max-buffers=1 drop=True"
            % (
                    camera_id,
                    capture_width,
                    capture_height,
                    framerate,
                    flip_method,
                    display_width,
                    display_height,
            )
    )
   
stream = cv2.VideoCapture(__gstreamer_pipeline(camera_id=0, flip_method=2), cv2.CAP_GSTREAMER)

运行 OpenCV 在 Ubuntu 上时出现 GStreamer 警告

GStreamer warning when running OpenCV on Ubuntu

python

ubuntu

opencv

gstreamer

raspberry-pi