Fix: Safe camera detection for macOS (M1/M2) to prevent OpenCV AVX/th… #1236

brynwhyman · 2025-05-08T08:45:47Z

This PR addresses a crash I had to work around when launching on Apple Silicon (M1/M2/M3). The issue stemmed from OpenCV's threaded camera enumeration causing a fatal error due to AVX instruction mismatches or GIL violations.

Replaces the original get_available_cameras() logic with a safe fallback for macOS that avoids multithreaded access and AVX instruction usage.
Adds platform-specific logging to help users understand what's detected.
Retains the original Windows-specific logic (via pygrabber) for full cross-platform compatibility.

Tested on:

macOS 14.4.1 (Apple M2)
Python 3.10
Camera detection succeeded and GUI preview works without crash

Let me know if you'd like help extending this further. Thanks!

Summary by Sourcery

Implement a safe camera detection mechanism for macOS and Unix-like systems to prevent crashes related to OpenCV threading and AVX instructions

New Features:

Implemented a safe fallback camera detection method for macOS and Unix systems

Bug Fixes:

Fixed camera detection crash on Apple Silicon (M1/M2/M3) platforms
Resolved OpenCV threading and AVX instruction compatibility issues on macOS

Enhancements:

Simplified camera detection logic for non-Windows platforms
Added platform-specific logging for camera detection

…read crashes

sourcery-ai · 2025-05-08T08:45:51Z

Reviewer's Guide

This pull request modifies the get_available_cameras() function in modules/ui.py to prevent crashes on Apple Silicon (macOS) by introducing a simplified camera detection strategy. For macOS and other Unix-like systems, it now exclusively attempts to access the default camera (index 0) via cv2.VideoCapture(0), thereby avoiding multithreaded operations and potential AVX instruction issues inherent in the previous, more exhaustive camera probing. The Windows-specific camera detection using pygrabber is largely retained, but its OpenCV fallback for cases where no cameras are found by pygrabber has been removed. Logging for camera detection has also been updated to be more platform-specific.

File-Level Changes

Change	Details	Files
Implemented a safer, simplified camera detection method for macOS and Linux systems.	Replaced iterative multi-camera probing with a direct check for the default camera (index 0) to prevent crashes related to multithreading/AVX instructions on Apple Silicon. Updated the docstring of `get_available_cameras` to describe the new approach.	`modules/ui.py`
Streamlined the camera detection process for Windows.	Removed the OpenCV-based fallback from the Windows camera detection logic.	`modules/ui.py`
Enhanced diagnostic logging during camera detection.	Added new informational logs for the Unix camera detection path. Revised error log messages to be more specific for both Windows and Unix platforms.	`modules/ui.py`
Refactored import statements within `get_available_cameras`.	Moved `cv2` and `platform` imports to be local to the function scope.	`modules/ui.py`

Possibly linked issues

#-1: PR changes camera detection on macOS to fix OpenCV initialization failure reported in the issue.
#0: The PR fixes the webcam detection problem on Apple Silicon described in the issue by changing the camera detection logic.

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sourcery-ai

Hey @brynwhyman - I've reviewed your changes - here's some feedback:

Camera detection on Linux is now limited to index 0; consider retaining multi-index probing for Linux if the original crash was macOS-specific.
The OpenCV fallback for Windows camera detection (when pygrabber finds no devices) appears to have been removed; please clarify if this was intentional.

Here's what I looked at during the review

🟡 General issues: 2 issues found
🟢 Security: all looks good
🟢 Testing: all looks good
🟢 Documentation: all looks good

Sourcery is free for open source - if you like our reviews please consider sharing them ✨

_{Help me be more useful! Please click 👍 or 👎 on each comment and I'll use the feedback to improve your reviews.}

sourcery-ai · 2025-05-08T08:47:50Z

modules/ui.py

 def get_available_cameras():
-    """Returns a list of available camera names and indices."""
+    """
+    Safe camera detection for macOS and Unix-like systems that avoids threading and AVX crashes.
+    Returns a tuple of (camera_indices, camera_names).
+    """


suggestion: Clarify behavior differences across platforms in the docstring.

Also note that on Windows the function enumerates devices via DirectShow; add this to the docstring to distinguish platform strategies.

Suggested change

def get_available_cameras():

"""Returns a list of available camera names and indices."""

"""

Safe camera detection for macOS and Unix-like systems that avoids threading and AVX crashes.

Returns a tuple of (camera_indices, camera_names).

"""

def get_available_cameras():

"""

Safe camera detection that avoids threading and AVX crashes.

On macOS and Unix-like systems, it utilizes a safe detection mechanism to list available cameras.

On Windows, devices are enumerated via DirectShow.

Returns a tuple of (camera_indices, camera_names).

"""

sourcery-ai · 2025-05-08T08:47:50Z

modules/ui.py

-        return camera_indices, camera_names
+    # macOS or Linux
+    try:
+        print("[Info] Safely checking for available cameras...")


suggestion: Use a logging framework instead of print statements.

A logging framework provides configurable levels and outputs, improving maintainability and configurability of debug and error messages in production.

Suggested implementation:

import logging # (other imports below)

logging.error(f"[Camera Detection Error - Windows]: {e}")

logging.info("Safely checking for available cameras...")

logging.warning("Default camera (index 0) not available.")

logging.error(f"[Camera Detection Error - Unix]: {e}")

Please ensure that the logging configuration (level, formatting, etc.) is set up in your application so that these logging calls behave as expected. If there is an existing logging setup in your code base, this configuration might already be in place.

brynwhyman · 2025-05-08T10:09:35Z

Likely solves this issue too: #1166

brynwhyman · 2025-05-16T04:32:58Z

Should I make the changes suggested by the bot?

arturo-lr-dev · 2025-05-20T16:07:33Z

tryed on M4 and seem that didn't work.

Seems the camera is loading but the UI doesn't show anything

Log:
DEPRECATION WARNING: The system version of Tk is deprecated and may be removed in a future release. Please don't rely on it. Set TK_SILENCE_DEPRECATION=1 to suppress this warning.
[Info] Safely checking for available cameras...

Version apple: 15.5
Python 3.10.13

Solved: Just use python 3.10.16

Now I have the fps problems

brynwhyman · 2025-05-23T03:35:52Z

@arturo-lr-dev thanks for testing.

Now I have the fps problems

Is this something that exists when trying to install from the main branch too? Wondering if it's an issue with this PR or not

arturo-lr-dev · 2025-06-03T04:42:27Z

@brynwhyman it happens with both branches, i think is not a problem of this branch

ridhoperdana · 2025-06-10T09:52:52Z

tryed on M4 and seem that didn't work.

Seems the camera is loading but the UI doesn't show anything

Log: DEPRECATION WARNING: The system version of Tk is deprecated and may be removed in a future release. Please don't rely on it. Set TK_SILENCE_DEPRECATION=1 to suppress this warning. [Info] Safely checking for available cameras...

Version apple: 15.5 Python 3.10.13

Solved: Just use python 3.10.16

Now I have the fps problems

Hi, i am using the same python version and the same mac version. I got blank view of the UI

the log doesnt show any error (except the SSL)

(venv) ➜  Deep-Live-Cam git:(main) ✗ python3.10 run.py --execution-provider coreml
/Users/ridhoperdana/workspace/Deep-Live-Cam/venv/lib/python3.10/site-packages/albumentations/check_version.py:147: UserWarning: Error fetching version info <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1007)>
  data = fetch_version_info()
DEPRECATION WARNING: The system version of Tk is deprecated and may be removed in a future release. Please don't rely on it. Set TK_SILENCE_DEPRECATION=1 to suppress this warning.
[Info] Safely checking for available cameras...

do you ever got the same issue?

@arturo-lr-dev

Fix: Safe camera detection for macOS (M1/M2) to prevent OpenCV AVX/th…

c1a6dc6

…read crashes

sourcery-ai bot reviewed May 8, 2025

View reviewed changes

brynwhyman mentioned this pull request May 8, 2025

mac M4 Max, The error is as follows #1166

Open

brynwhyman mentioned this pull request May 16, 2025

MacOS Camera initialized Error(15.4.1) #1238

Open

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