Filter (video)

{{Short description|Software component for decoding video or audio}}

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A video filter is a software component that performs some operation on a multimedia stream.{{cite web|url=https://msdn.microsoft.com/en-us/library/windows/desktop/dd390352(v=vs.85).aspx|title=Introduction to DirectShow Application Programming |accessdate=September 14, 2017}} Multiple filters can be used in a chain, known as a filter graph, in which each filter receives input from its upstream filter, processes the input and outputs the processed video to its downstream filter.

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With regards to video encoding three categories of filters can be distinguished:

• prefilters: used before encoding
• intrafilters: used while encoding (and are thus an integral part of a video codec)
• postfilters: used after decoding