* `callback` Function
Begin subscribing for presentation events and captured frames, the `callback`
-will be called with `callback(frameBuffer, dirtyRect)` when there is a
+will be called with `callback(image, dirtyRect)` when there is a
presentation event.
-The `frameBuffer` is a `Buffer` that contains raw pixel data. On most machines,
-the pixel data is effectively stored in 32bit BGRA format, but the actual
-representation depends on the endianness of the processor (most modern
-processors are little-endian, on machines with big-endian processors the data
-is in 32bit ARGB format).
+The `image` is a [NativeImage](native-image.md) that contains the image data of
+the frame.
The `dirtyRect` is an object with `x, y, width, height` properties that
describes which part of the page was repainted. If `onlyDirty` is set to
-`true`, `frameBuffer` will only contain the repainted area. `onlyDirty`
+`true`, `image` will only contain the repainted area. `onlyDirty`
defaults to `false`.
#### `contents.endFrameSubscription()`