objc2_video_toolbox

Function VTSessionCopyProperty

Source 
pub unsafe extern "C-unwind" fn VTSessionCopyProperty(
    session: &VTSession,
    property_key: &CFString,
    allocator: Option<&CFAllocator>,
    property_value_out: *mut c_void,
) -> i32
Available on crate feature VTSession only.
Expand description

Retrieves a property on a video toolbox session.

The caller must release the retrieved property value. <BR

Note: for most types of property, the returned values should be considered immutable. In particular, for CFPropertyList types, sharing of mutable property value objects between the client, session and codec should be avoided. However, some properties will be used for exchanging service objects that are inherently mutable (eg, CVPixelBufferPool).

Parameter propertyKey: The key for the property to retrieve.

Parameter allocator: An allocator suitable for use when copying property values.

Parameter propertyValueOut: Points to a variable to receive the property value, which must be a CF-registered type – the caller may call CFGetTypeID() on it to identify which specific type. The caller must release the this property value.

Returns: noErr if successful; kVTPropertyNotSupportedErr for unrecognized or unsupported properties.