VideoWriter fails silently for multiple codecs on macOS Intel

[pauladkisson]

Summary

cv2.VideoWriter fails silently for multiple codecs (HFYU, XVID, mp4v) on macOS Intel (x86_64) in opencv-python-headless 4.13.0.90. No exception is raised, but isOpened() returns False and no video file is created.

This is a regression from 4.12.0.88, where all codecs work correctly.

Environment

• OpenCV version: opencv-python-headless 4.13.0.90
• Python version: 3.10.18
• OS: macOS 15.7.2 (x86_64 / Intel)

Note: This bug only affects macOS Intel (x86_64), not macOS ARM (Apple Silicon).

Steps to reproduce

import os
import tempfile

import cv2
import numpy as np

print(f"OpenCV version: {cv2.__version__}")

test_dir = tempfile.mkdtemp()

codecs = ["MJPG", "HFYU", "XVID", "mp4v"]

print("\nTesting VideoWriter codecs:")
print("-" * 40)

for codec in codecs:
    video_path = os.path.join(test_dir, f"test_{codec}.avi")

    writer = cv2.VideoWriter(
        filename=video_path,
        fourcc=cv2.VideoWriter_fourcc(*codec),
        fps=25,
        frameSize=(200, 100),
    )

    opened = writer.isOpened()
    status = "OK" if opened else "FAILED"

    if opened:
        frame = np.random.randint(0, 255, size=(100, 200, 3), dtype="uint8")
        writer.write(frame)
        writer.release()
        os.remove(video_path)
    else:
        writer.release()

    print(f"{codec:6} : {status}")

os.rmdir(test_dir)

Expected behavior

All standard codecs should work:

OpenCV version: 4.12.0

Testing VideoWriter codecs:
----------------------------------------
MJPG   : OK
HFYU   : OK
XVID   : OK
mp4v   : OK

Actual behavior

Only MJPG works; other codecs fail silently:

OpenCV version: 4.13.0

Testing VideoWriter codecs:
----------------------------------------
[ WARN:0@0.056] global cap.cpp:781 open VIDEOIO(CV_IMAGES): raised OpenCV exception:

OpenCV(4.13.0) /Users/macmini_16g/GHA-Actions-Opencv-Python/_work/opencv-python/opencv-python/opencv/modules/videoio/src/cap_images.cpp:411: error: (-215:Assertion failed) !filename_pattern.empty() in function 'CvVideoWriter_Images'


MJPG   : OK
[ WARN:0@0.104] global cap.cpp:781 open VIDEOIO(CV_IMAGES): raised OpenCV exception:

OpenCV(4.13.0) /Users/macmini_16g/GHA-Actions-Opencv-Python/_work/opencv-python/opencv-python/opencv/modules/videoio/src/cap_images.cpp:411: error: (-215:Assertion failed) !filename_pattern.empty() in function 'CvVideoWriter_Images'


HFYU   : FAILED
[ WARN:0@0.104] global cap.cpp:781 open VIDEOIO(CV_IMAGES): raised OpenCV exception:

OpenCV(4.13.0) /Users/macmini_16g/GHA-Actions-Opencv-Python/_work/opencv-python/opencv-python/opencv/modules/videoio/src/cap_images.cpp:411: error: (-215:Assertion failed) !filename_pattern.empty() in function 'CvVideoWriter_Images'


XVID   : FAILED
mp4v   : FAILED