From 7c9c181a043e8ab6c09e6a0a1af563f96511cf24 Mon Sep 17 00:00:00 2001 From: Christian Thaeter Date: Wed, 27 Jun 2007 03:54:02 +0200 Subject: [PATCH] add FrameDescriptor to the wiki --- wiki/backend.html | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/wiki/backend.html b/wiki/backend.html index 815e032c9..d573be65e 100644 --- a/wiki/backend.html +++ b/wiki/backend.html @@ -816,10 +816,12 @@ FileMap objects are transparent to the application, it will only requests [[Fram Whenever a FileMap is in use, it is checked out into a in-use list where it is not subject of aging. -
+
'Frames' are the smallest datablocks handled by the Backend. The application tells the Backend to make [[File]]s availabe and then only requests Frames from the Backend, all other datastructures of the backend are private.
 
-Actually Frames are blocks of continous memory, they can be anything depending on the usage of the [[File]] (Video frames, encoder frames, blocks of sound samples).
+Actually Frames are (references to) blocks of continous memory, they can be anything depending on the usage of the [[File]] (Video frames, encoder frames, blocks of sound samples).
+
+Each [[Frame]] points to a [[FrameDescriptor]] which describes the shared properties of [[Frame]]s of the same kind. For video frames this [[FrameDescriptor]] will define the policies of the used color modell, resolution, aspect ratio and so on, for example.
 
 Frames are referenced by a smart-pointer like object which manages the lifetime and caching behaviour. There are 3 states such a frame reference can be:
 # readonly: the backing FileMap is checked out from the aging list, frames can be read