[FFmpeg-cvslog] doc/filters: update aiir filter documentation

[Paul B Mahol]

ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Tue Jan  9 18:01:44 2018 +0100| [d38a223943d12c603c87ce806023ab4f4c0769c9] | committer: Paul B Mahol

doc/filters: update aiir filter documentation

Signed-off-by: Paul B Mahol <onemda at gmail.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=d38a223943d12c603c87ce806023ab4f4c0769c9
---

 doc/filters.texi | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/doc/filters.texi b/doc/filters.texi
index 217a2af42b..d29c40080f 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -1085,6 +1085,26 @@ Set output gain.
 @item f
 Set coefficients format.
 Can be @code{tf} - transfer function or @code{zp} - Z-plane zeros/poles.
+Default is @code{zp}.
+
+ at item r
+Set kind of processing.
+Can be @code{d} - direct or @code{s} - serial cascading. Defauls is @code{s}.
+
+ at item e
+Set filtering precision.
+
+ at table @option
+ at item dbl
+double-precision floating-point (default)
+ at item flt
+single-precision floating-point
+ at item i32
+32-bit integers
+ at item i16
+16-bit integers
+ at end table
+
 @end table
 
 Coefficients in @code{tf} format are separated by spaces and are in ascending