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Diffstat (limited to 'doc/filters.texi')
| -rw-r--r-- | doc/filters.texi | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/doc/filters.texi b/doc/filters.texi index 5cb29235ba..037d6ad492 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -1742,9 +1742,16 @@ scale=w='min(500\, iw*3/2):h=-1' @section select Select frames to pass in output. -It accepts in input an expression, which is evaluated for each input -frame. If the expression is evaluated to a non-zero value, the frame -is selected and passed to the output, otherwise it is discarded. +This filter accepts the following options: + +@table @option + +@item expr +An expression, which is evaluated for each input frame. If the expression is +evaluated to a non-zero value, the frame is selected and passed to the output, +otherwise it is discarded. + +@end table The expression can contain the following constants: @@ -1831,13 +1838,13 @@ Some examples follow: select # the above is the same as: -select=1 +select=expr=1 # skip all frames: -select=0 +select=expr=0 # select only I-frames -select='eq(pict_type\,I)' +select='expr=eq(pict_type\,I)' # select one frame every 100 select='not(mod(n\,100))' |