file.cs

		[DllImport(Constants.CoreMediaLibrary)]
		extern static /* OSStatus */ CMBlockBufferError CMBlockBufferCreateWithMemoryBlock (
			/* CFAllocatorRef */ IntPtr structureAllocator,
			/* void * */ IntPtr memoryBlock,
			/* size_t */ nuint blockLength,
			/* CFAllocatorRef */ IntPtr blockAllocator,
			/* CMBlockBufferCustomBlockSource* */ IntPtr customBlockSource, // Can be null
			/* size_t */ nuint offsetToData,
			/* size_t */ nuint dataLength,
			CMBlockBufferFlags flags,
			/* CMBlockBufferRef* */ out IntPtr newBlockBuffer);

		public static CMBlockBuffer FromMemoryBlock (IntPtr memoryBlock, nuint blockLength, CMCustomBlockAllocator customBlockSource, nuint offsetToData, nuint dataLength, CMBlockBufferFlags flags, out CMBlockBufferError error)
		{
			var blockAllocator = memoryBlock == IntPtr.Zero ? IntPtr.Zero : CFAllocator.Null.Handle;
			IntPtr buffer;
			error = CMBlockBufferCreateWithMemoryBlock (IntPtr.Zero, memoryBlock, blockLength, blockAllocator, IntPtr.Zero, offsetToData, dataLength, flags, out buffer);
			if (error != CMBlockBufferError.None)
				return null;

			return ObjCRuntime.Runtime.GetINativeObject<CMBlockBuffer> (buffer, true);
		}