running open cv on a Mac M1 machine with python 3.9 natively

[mv96]

pip command used to install - pip install opencv-python

----> 9 import cv2

/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/cv2/init.py in
----> 5 from .cv2 import *

ImportError: dlopen(/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/cv2/cv2.cpython-39-darwin.so, 2): Library not loaded: /opt/homebrew/opt/ffmpeg/lib/libavcodec.58.dylib
Referenced from: /Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/cv2/cv2.cpython-39-darwin.so
Reason: image not found

Any help would be appreciated ?

[asenyaev]

@mv96, I've tested the latest version of opencv-python on Mac Mini with M1 and did not have any issues. I've tried to reproduce it using following commands:

arch -arm64 python3.9 -m pip install --user --no-cache --force-reinstall opencv-python
git clone https://github.com/opencv/opencv.git
git clone https://github.com/opencv/opencv_extra.git
export OPENCV_TEST_DATA_PATH=$(pwd)/opencv_extra/testdata
cd opencv
arch -arm64 python3.9 modules/python/test/test.py -v --repo .

And one more short test getting the build information in a self-created test.py file:

import cv2 as cv
from cv2 import *

print(cv.getBuildInformation())

Running this command:

arch -arm64 python3.9 test.py

Could you share more details? I would try to reproduce and solve your issue.

[yongce]

@asenyaev I tried your steps and got the same error.

$ arch -arm64 python3.9 -m pip install --user --no-cache --force-reinstall opencv-python
Collecting opencv-python
Downloading opencv_python-4.5.3.56-cp39-cp39-macosx_11_0_arm64.whl (10.7 MB)
|████████████████████████████████| 10.7 MB 4.2 MB/s
Collecting numpy>=1.21.0
Downloading numpy-1.21.2-cp39-cp39-macosx_11_0_arm64.whl (12.4 MB)
|████████████████████████████████| 12.4 MB 3.5 MB/s
Installing collected packages: numpy, opencv-python
WARNING: The scripts f2py, f2py3 and f2py3.9 are installed in '/Users/tuyongce/Library/Python/3.9/bin' which is not on PATH.
Consider adding this directory to PATH or, if you prefer to suppress this warning, use --no-warn-script-location.
Successfully installed numpy-1.21.2 opencv-python-4.5.3.56

$ arch -arm64 python3.9 modules/python/test/test.py -v --repo .
Traceback (most recent call last):
File "/Users/tuyongce/work/ai/opencv/modules/python/test/test.py", line 22, in
from tests_common import NewOpenCVTests
File "/Users/tuyongce/work/ai/opencv/modules/python/test/tests_common.py", line 13, in
import cv2 as cv
File "/Users/tuyongce/Library/Python/3.9/lib/python/site-packages/cv2/init.py", line 5, in
from .cv2 import *
ImportError: dlopen(/Users/tuyongce/Library/Python/3.9/lib/python/site-packages/cv2/cv2.cpython-39-darwin.so, 2): Library not loaded: /opt/homebrew/opt/ffmpeg/lib/libavcodec.58.dylib
Referenced from: /Users/tuyongce/Library/Python/3.9/lib/python/site-packages/cv2/cv2.cpython-39-darwin.so
Reason: image not found

[asenyaev]

@yongce, yes, I've found the source of the problem - no libs inside a package. It was built using libs in a local environment and wasn't linked to a package.

I'm working on it, fix will be added as soon as possible.

[asenyaev]

@mv96 @yongce The issue was fixed and changes were merged into master. The next release of packages will upload fixed wheels.