Merge commit 'c438899a706422b8362a13714580e988be4d638b'

* commit 'c438899a706422b8362a13714580e988be4d638b':
  Add AV1 video decoding support through libaom

This contains some extra changes taken from the libvpx decoder
wrapper, most of them contained in the set_pix_fmt() function.

Merged-by: James Almer <jamrial@gmail.com>

doc/general.texi

@@ -17,6 +17,14 @@ for more formats. None of them are used by default, their use has to be
 explicitly requested by passing the appropriate flags to
 @command{./configure}.
 
++@section Alliance for Open Media libaom
+
+FFmpeg can make use of the libaom library for AV1 decoding.
+
+Go to @url{http://aomedia.org/} and follow the instructions for
+installing the library. Then pass @code{--enable-libaom} to configure to
+enable it.
+
 @section OpenJPEG
 
 FFmpeg can use the OpenJPEG libraries for encoding/decoding J2K videos.  Go to
@@ -719,6 +727,8 @@ following image formats are supported:
 @item Autodesk Animator Flic video  @tab     @tab  X
 @item Autodesk RLE           @tab     @tab  X
     @tab fourcc: AASC
+@item AV1                    @tab     @tab  E
+    @tab Supported through external library libaom
 @item Avid 1:1 10-bit RGB Packer  @tab  X  @tab  X
     @tab fourcc: AVrp
 @item AVS (Audio Video Standard) video  @tab     @tab  X