PyObjC VideoToolbox Framework

Warnings

• breaking PyObjC 12.0 and later dropped support for Python 3.9.
  Fix: Upgrade to Python 3.10 or newer. If you must use Python 3.9, pin pyobjc-framework-videotoolbox to `<12.0`.
• breaking PyObjC 11.0 and later dropped support for Python 3.8.
  Fix: Upgrade to Python 3.9 or newer. If you must use Python 3.8, pin pyobjc-framework-videotoolbox to `<11.0`.
• breaking PyObjC 11.1 changed how `init` methods in Python subclasses interact with Objective-C's Automatic Reference Counting (ARC). PyObjC now correctly models that methods in the 'init' family steal a reference to self and return a new reference.
  Fix: Review Python subclasses that implement `init` methods to ensure they correctly handle object ownership and ARC semantics, as incorrect handling can lead to memory leaks or premature deallocation.
• gotcha Interaction between `__new__` and `__init__` in Python subclasses changed in PyObjC 10.3 and 10.3.1. While 10.3 removed support for calling `__init__` in some cases, 10.3.1 re-enabled it for classes with user-implemented `__new__`. However, if relying on PyObjC's default `__new__`, `__init__` might not be called.
  Fix: If implementing custom `__new__` in an `objc.lookUpClass` or `objc.subclass` derived class, ensure `__init__` is explicitly called if needed. If using PyObjC's default `__new__`, be aware that `__init__` might be bypassed, requiring initialization logic to be handled elsewhere (e.g., in `__new__` or a class method).
• gotcha PyObjC's experimental support for free-threading (PEP 703) introduced in Python 3.13 is still evolving. Earlier PyObjC versions (e.g., 10.3) explicitly stated no support.
  Fix: Exercise caution when using PyObjC with free-threading in Python 3.13 or newer. Thoroughly test thread-safe operations, as the feature is experimental and may have unexpected interactions or stability issues.
• gotcha As of PyObjC 10.1, `os.fspath(someURL)` will raise a `TypeError` for Cocoa `NSURL` (or `CFURLRef`) instances that do not refer to local filesystem paths.
  Fix: Before using `os.fspath` with an `NSURL` instance, ensure it represents a local filesystem path. For other types of URLs, explicitly convert to a string representation if needed (e.g., `url.absoluteString()`) or access `url.path` for local paths.

Install

• pip install pyobjc-framework-videotoolbox Install latest version

Imports

• VideoToolbox

  from VideoToolbox import VTCopyVideoEncoderList

Quickstart

This quickstart demonstrates how to import and use a basic function from the VideoToolbox framework to list available video encoders on the system.

import objc
from VideoToolbox import VTCopyVideoEncoderList

# Get a list of available video encoders
# VTCopyVideoEncoderList takes a CFDictionaryRef as an argument, or None for default
encoder_list = VTCopyVideoEncoderList(None)

if encoder_list:
    print(f"Found {len(encoder_list)} video encoders:")
    for encoder in encoder_list:
        # encoder is an NSDictionary (bridged to Python dict)
        print(f"  - {encoder.get('kVTVideoEncoderComponentDisplayName', 'Unknown Encoder')}")
        print(f"    Type: {encoder.get('kVTVideoEncoderComponentType', 'Unknown')}")
else:
    print("No video encoders found.")