-215 opencv config_error ai_generated true

cv2.error: OpenCV(4.5.5) /modules/videoio/src/cap_gstreamer.cpp:1156: error: (-215:Assertion failed) !pipeline.empty() in function 'open'

ID: opencv/gstreamer-pipeline-string-error

Also available as: JSON · Markdown · 中文
88%Fix Rate
82%Confidence
1Evidence
2023-03-10First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
4.5.5 active — — —
4.6.0 active — — —
4.7.0 active — — —

Root Cause

GStreamer pipeline string passed to VideoCapture is empty or malformed, causing the pipeline to fail to initialize.

generic

中文

传递给VideoCapture的GStreamer管道字符串为空或格式错误，导致管道初始化失败。

Official Documentation

https://docs.opencv.org/4.5.5/d4/d15/group__videoio__flags__gstreamer.html

Workarounds

  1. 90% success Ensure the pipeline string is non-empty and correctly formatted, e.g., `cap = cv2.VideoCapture('videotestsrc ! appsink')` 
    Ensure the pipeline string is non-empty and correctly formatted, e.g., `cap = cv2.VideoCapture('videotestsrc ! appsink')`
  2. 85% success Test the pipeline with `gst-launch-1.0` command line before using it in OpenCV to verify syntax. 
    Test the pipeline with `gst-launch-1.0` command line before using it in OpenCV to verify syntax.
  3. 70% success If using a camera, use `cap = cv2.VideoCapture(0)` instead of a pipeline string to avoid this error. 
    If using a camera, use `cap = cv2.VideoCapture(0)` instead of a pipeline string to avoid this error.

中文步骤

  1. Ensure the pipeline string is non-empty and correctly formatted, e.g., `cap = cv2.VideoCapture('videotestsrc ! appsink')`
  2. Test the pipeline with `gst-launch-1.0` command line before using it in OpenCV to verify syntax.
  3. If using a camera, use `cap = cv2.VideoCapture(0)` instead of a pipeline string to avoid this error.

Dead Ends

Common approaches that don't work:

  1. Adding quotation marks around the pipeline string in Python. 50% fail

    Adding extra spaces or quotes around the pipeline string does not fix the underlying syntax; GStreamer expects exact format.

  2. Passing a video file path without the 'filesrc location=' prefix. 80% fail

    Using a file path instead of a pipeline string still triggers the assertion because the pipeline is empty.

  3. Reinstalling GStreamer from source without checking pipeline syntax. 40% fail

    Installing a different GStreamer version may break syntax compatibility.