Fix various if parenthesis misplacements.

[ffmpeg] / doc / filters.texi

diff --git a/doc/filters.texi b/doc/filters.texi
index 6c98dc0fdcc78fd42884c79deb9d4443398a9930..cefb8ad0c3235a48166d72fac2cfb00d1afb557b 100644 (file)
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -110,7 +110,7 @@ The filter accepts a string of the form:
 the corresponding numeric value defined in @file{libavutil/samplefmt.h}.
 
 @var{channel_layout} specifies the channel layout, and can be a string
-or the corresponding number value defined in @file{libavutil/chlayout.h}.
+or the corresponding number value defined in @file{libavutil/audioconvert.h}.
 
 @var{packing_format} specifies the type of packing in output, can be one
 of "planar" or "packed", or the corresponding numeric values "0" or "1".
@@ -235,6 +235,54 @@ the listener (standard for speakers).
 
 Ported from SoX.
 
+@section pan
+
+Mix channels with specific gain levels. The filter accepts the output
+channel layout followed by a set of channels definitions.
+
+The filter accepts parameters of the form:
+"@var{l}:@var{outdef}:@var{outdef}:..."
+
+@table @option
+@item l
+output channel layout or number of channels
+
+@item outdef
+output channel specification, of the form:
+"@var{out_name}=[@var{gain}*]@var{in_name}[+[@var{gain}*]@var{in_name}...]"
+
+@item out_name
+output channel to define, either a channel name (FL, FR, etc.) or a channel
+number (c0, c1, etc.)
+
+@item gain
+multiplicative coefficient for the channel, 1 leaving the volume unchanged
+
+@item in_name
+input channel to use, see out_name for details; it is not possible to mix
+named and numbered input channels
+@end table
+
+If the `=' in a channel specification is replaced by `<', then the gains for
+that specification will be renormalized so that the total is 1, thus
+avoiding clipping noise.
+
+For example, if you want to down-mix from stereo to mono, but with a bigger
+factor for the left channel:
+@example
+pan=1:c0=0.9*c0+0.1*c1
+@end example
+
+A customized down-mix to stereo that works automatically for 3-, 4-, 5- and
+7-channels surround:
+@example
+pan=stereo: FL < FL + 0.5*FC + 0.6*BL + 0.6*SL : FR < FR + 0.5*FC + 0.6*BR + 0.6*SR
+@end example
+
+Note that @file{ffmpeg} integrates a default down-mix (and up-mix) system
+that should be preferred (see "-ac" option) unless you have very specific
+needs.
+
 @section volume
 
 Adjust the input audio volume.
@@ -1139,7 +1187,7 @@ For more information about libfreetype, check:
 Apply fade-in/out effect to input video.
 
 It accepts the parameters:
-@var{type}:@var{start_frame}:@var{nb_frames}
+@var{type}:@var{start_frame}:@var{nb_frames}[:@var{options}]
 
 @var{type} specifies if the effect type, can be either "in" for
 fade-in, or "out" for a fade-out effect.
@@ -1152,6 +1200,25 @@ effect has to last. At the end of the fade-in effect the output video
 will have the same intensity as the input video, at the end of the
 fade-out transition the output video will be completely black.
 
+@var{options} is an optional sequence of @var{key}=@var{value} pairs,
+separated by ":". The description of the accepted options follows.
+
+@table @option
+
+@item type, t
+See @var{type}.
+
+@item start_frame, s
+See @var{start_frame}.
+
+@item nb_frames, n
+See @var{nb_frames}.
+
+@item alpha
+If set to 1, fade only alpha channel, if one exists on the input.
+Default value is 0.
+@end table
+
 A few usage examples follow, usable too as test scenarios.
 @example
 # fade in first 30 frames of video
@@ -1165,6 +1232,9 @@ fade=in:0:25, fade=out:975:25
 
 # make first 5 frames black, then fade in from frame 5-24
 fade=in:5:20
+
+# fade in alpha over first 25 frames of video
+fade=in:0:25:alpha=1
 @end example
 
 @section fieldorder
@@ -1197,7 +1267,7 @@ which is bottom field first.
 
 For example:
 @example
-./ffmpeg -i in.vob -vf "fieldorder=bff" out.dv
+ffmpeg -i in.vob -vf "fieldorder=bff" out.dv
 @end example
 
 @section fifo
@@ -2273,7 +2343,7 @@ Pass the images of input video on to next video filter as multiple
 slices.
 
 @example
-./ffmpeg -i in.avi -vf "slicify=32" out.avi
+ffmpeg -i in.avi -vf "slicify=32" out.avi
 @end example
 
 The filter accepts the slice height as parameter. If the parameter is
@@ -2385,7 +2455,7 @@ unsharp=7:7:2.5
 unsharp=7:7:-2:7:7:-2
 
 # Use the default values with @command{ffmpeg}
-./ffmpeg -i in.avi -vf "unsharp" out.mp4
+ffmpeg -i in.avi -vf "unsharp" out.mp4
 @end example
 
 @section vflip
@@ -2393,7 +2463,7 @@ unsharp=7:7:-2:7:7:-2
 Flip the input video vertically.
 
 @example
-./ffmpeg -i in.avi -vf "vflip" out.avi
+ffmpeg -i in.avi -vf "vflip" out.avi
 @end example
 
 @section yadif