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diff --git a/doc/filters.texi b/doc/filters.texi index 21a5bf5d5f..6e01df9fb5 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -13192,6 +13192,63 @@ PAL output (25i): 16p: 33333334 @end example +@section threshold + +Apply threshold effect to video stream. + +This filter needs four video streams to perform thresholding. +First stream is stream we are filtering. +Second stream is holding threshold values, third stream is holding min values, +and last, fourth stream is holding max values. + +The filter accepts the following option: + +@table @option +@item planes +Set which planes will be processed, unprocessed planes will be copied. +By default value 0xf, all planes will be processed. +@end table + +For example if first stream pixel's component value is less then threshold value +of pixel component from 2nd threshold stream, third stream value will picked, +otherwise fourth stream pixel component value will be picked. + +Using color source filter one can perform various types of thresholding: + +@subsection Examples + +@itemize +@item +Binary threshold, using gray color as threshold: +@example +ffmpeg -i 320x240.avi -f lavfi -i color=gray -f lavfi -i color=black -f lavfi -i color=white -lavfi threshold output.avi +@end example + +@item +Inverted binary threshold, using gray color as threshold: +@example +ffmpeg -i 320x240.avi -f lavfi -i color=gray -f lavfi -i color=white -f lavfi -i color=black -lavfi threshold output.avi +@end example + +@item +Truncate binary threshold, using gray color as threshold: +@example +ffmpeg -i 320x240.avi -f lavfi -i color=gray -i 320x240.avi -f lavfi -i color=gray -lavfi threshold output.avi +@end example + +@item +Threshold to zero, using gray color as threshold: +@example +ffmpeg -i 320x240.avi -f lavfi -i color=gray -f lavfi -i color=white -i 320x240.avi -lavfi threshold output.avi +@end example + +@item +Inverted threshold to zero, using gray color as threshold: +@example +ffmpeg -i 320x240.avi -f lavfi -i color=gray -i 320x240.avi -f lavfi -i color=white -lavfi threshold output.avi +@end example +@end itemize + @section thumbnail Select the most representative frame in a given sequence of consecutive frames. |