doc: Add muxers/demuxers list option

Signed-off-by: Mulvya <mulvya@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

doc/demuxers.texi

@@ -13,8 +13,9 @@ You can disable all the demuxers using the configure option
 the option @code{--enable-demuxer=@var{DEMUXER}}, or disable it
 with the option @code{--disable-demuxer=@var{DEMUXER}}.
 
-The option @code{-formats} of the ff* tools will display the list of
-enabled demuxers.
+The option @code{-demuxers} of the ff* tools will display the list of
+enabled demuxers. Use @code{-formats} to view a combined list of
+enabled demuxers and muxers.
 
 The description of some of the currently available demuxers follows.
 

doc/ffmpeg.texi

@@ -1547,7 +1547,7 @@ to enable LAME support by passing @code{--enable-libmp3lame} to configure.
 The mapping is particularly useful for DVD transcoding
 to get the desired audio language.
 
-NOTE: To see the supported input formats, use @code{ffmpeg -formats}.
+NOTE: To see the supported input formats, use @code{ffmpeg -demuxers}.
 
 @item
 You can extract images from a video, or create a video from many images:

doc/fftools-common-opts.texi

@@ -110,6 +110,12 @@ Show version.
 @item -formats
 Show available formats (including devices).
 
+@item -demuxers
+Show available demuxers.
+
+@item -muxers
+Show available muxers.
+
 @item -devices
 Show available devices.
 

doc/muxers.texi

@@ -13,8 +13,9 @@ You can disable all the muxers with the configure option
 with the options @code{--enable-muxer=@var{MUXER}} /
 @code{--disable-muxer=@var{MUXER}}.
 
-The option @code{-formats} of the ff* tools will display the list of
-enabled muxers.
+The option @code{-muxers} of the ff* tools will display the list of
+enabled muxers. Use @code{-formats} to view a combined list of
+enabled demuxers and muxers.
 
 A description of some of the currently available muxers follows.