From 2d9385aebc2f7f19ac6b4637ff8bd72a17c91be5 Mon Sep 17 00:00:00 2001 From: gpoirier Date: Sun, 24 Jul 2005 21:58:34 +0000 Subject: [PATCH] General note about filtering from Rich's encoding guide git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@16088 b3059339-0415-0410-9bf9-f77b7e298cf2 --- DOCS/xml/en/encoding-guide.xml | 43 ++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) diff --git a/DOCS/xml/en/encoding-guide.xml b/DOCS/xml/en/encoding-guide.xml index 67ff6bf637..1aa21d8182 100644 --- a/DOCS/xml/en/encoding-guide.xml +++ b/DOCS/xml/en/encoding-guide.xml @@ -1085,6 +1085,49 @@ Filtering + + Learning how to use MEncoder's video filters + is essential to producing good encodes. + All video processing is performed through the filters -- cropping, + scaling, color adjustment, noise removal, sharpening, deinterlacing, + telecine, inverse telecine, and deblocking, just to name a few. + Along with the vast number of supported input formats, the variety of + filters available in MEncoder is one of its + main advantages over other similar programs. + + + + Filters are loaded in a chain using the -vf option: + + -vf filter1=options,filter2=options,... + + Most filters take several numeric options separated by colons, but + the syntax for options varies from filter to filter, so read the man + page for details on the filters you wish to use. + + + + Filters operate on the video in the order they are loaded. + For example, the following chain: + + -vf crop=688:464:12:4,scale=640:464 + + will first crop the 688x464 region of the picture with upper-left + corner at (12,4), and then scale the result down to 640x464. + + + + Certain filters need to be loaded at or near the beginning of the + filter chain, in order to take advantage of information from the + video decoder that will be lost or invalidated by other filters. + The principal examples are (postprocessing, only + when it is performing deblock or dering operations), + (another postprocessor to remove MPEG artifacts), + (inverse telecine), and + (for converting soft telecine to hard + telecine). + + In general, you want to do as little filtering as possible to the movie in order to remain close to the original DVD source. Cropping is often