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QTMTB 08 - MediaGetOffscreenBufferSize (1-May-95)

MediaGetOffscreenBufferSize determines the dimensions of the offscreen buffer. Before the Base Media Handler allocates an offscreen buffer for your Derived Media Handler, it calls your MediaGetOffscreenBufferSize routine. The depth and color table used for the buffer are also passed. When this routine is called the bounds parameter specifies the size that the Base Media Handler intends to use for your offscreen by default. You can modify this as appropriate before returning. This capability is useful if your media handler can draw only at particular sizes. It is also useful for implementing anti-aliased drawing as you can request a buffer that is larger than your destination area and have the Base Media Handler scale the image down for you.

pascal ComponentResult MediaGetOffscreenBufferSize (ComponentInstance ci, Rect *bounds, short depth, CTabHandle ctab)

ci Component instance of a Base Media Handler.

bounds The boundaries of your offscreen buffer.

depth Depth of the offscreen.

ctab Color table associated with offscreen. You can set it to nil.

Errors:

badComponentInstance 0x80008001 Get a new component instance.
See also: QuickTime Tech Note QT4.

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