Display Modes

A video output device has one or more display modes. The characteristics of each mode determine how video is displayed. When any software displays video on a video output device, it must select which of the device's display modes to use.

The characteristics of a display mode include

the height of the displayed image, in pixels
the width of the displayed image, in pixels
the horizontal resolution of the display, in pixels per inch
the vertical resolution of the display, in pixels per inch
the refresh rate of the display, in Hertz
the pixel type of the display
a text description of the display mode

The characteristics can also include a list of decompressor components required for the mode that are provided specifically for the video output device. If a video output device cannot directly display any of the pixel formats supported by QuickTime, the vendor of the device must provide one or more special decompressors to convert supported pixel formats to a format the device can display. If a video output device can display one or more of the pixel formats supported by QuickTime, the Image Compression Manager can use standard decompressors that are included with QuickTime, and the list of special decompressor components can be empty.

These characteristics, returned by the QTVideoOutputGetDisplayModeList function, are stored in a QT atom container. For a description of this QT atom container, see "Display Mode QT Atom Container" . For information about QT atom containers and how to traverse their contents, see "Movie Toolbox: Fundamentals."

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