All of the names in the selector are short and easy to read, there's just a lot of them. I don't even know what the method does or what any of the parameter typ

All of the names in the selector are short and easy to read, there's just a lot of them. I don't even know what the method does or what any of the parameter types, but I can make what I'd assume is a fairly accurate guess: outputImageProviderFromBufferWithPixelFormat: Some kind of pixel format enumeration, probably along the lines of "[Class name of the receiver]PixelFormat". Also, the function probably returns an "OutputImageProvider", or something like that (could be a id with a protocol associated, due to "provider"). This one is longer than the others, but that's just because it contains information about what the message will return. pixelsWide: The width of the output image in pixels, hopefully an NSUInteger (but sadly, probably an NSInteger, and Swift is only making this discrepancy worse). pixelsHigh: Same as above. baseAddress: A pointer to the buffer referenced. bytesPerRow: The number of bytes per row, probably size_t? releaseCallback: Something to call when the provider is released, probably a block? Actually, judging by the next parameter, probably a function pointer. Wow, this must be an old API! releaseContext: An argument to pass to releaseCallback. colorSpace: A color space value. Possibly an enumeration of RGB, HSV, etc., or a more complex type. shouldColorMatch: While I'm not sure what color matching actually is, I do know that this parameter enables or disables it, and is of type BOOL.