The entropy encoding mode for H.264 compression.
- iOS 7.0+
- macOS 10.10+
- Mac Catalyst 13.0+
- tvOS 9.0+
If supported by an H.264 encoder, this property controls whether the encoder should use Context-based Adaptive Variable Length Coding (CAVLC) or Context-based Adaptive Binary Arithmetic Coding (CABAC). CABAC generally gives better compression at the expense of higher computational overhead.
The default value is encoder-specific and may change depending on other encoder settings. Care should be taken when using this property as changes may result in a configuration which is not compatible with a requested Profile and Level. Results in this case are undefined, and could include encode errors or a non-compliant output stream.