+@section Alliance for Open Media (AOM)
+
+FFmpeg can make use of the AOM library for AV1 decoding and encoding.
+
+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 AMD AMF/VCE
+
+FFmpeg can use the AMD Advanced Media Framework library under Windows
+for accelerated H.264 and HEVC encoding on hardware with Video Coding Engine (VCE).
+
+To enable support you must obtain the AMF framework header files from
+@url{https://github.com/GPUOpen-LibrariesAndSDKs/AMF.git}.
+
+Create an @code{AMF/} directory in the system include path.
+Copy the contents of @code{AMF/amf/public/include/} into that directory.
+Then configure FFmpeg with @code{--enable-amf}.
+
+@section AviSynth
+
+FFmpeg can read AviSynth scripts as input. To enable support, pass
+@code{--enable-avisynth} to configure. The correct headers are
+included in compat/avisynth/, which allows the user to enable support
+without needing to search for these headers themselves.
+
+For Windows, supported AviSynth variants are
+@url{http://avisynth.nl, AviSynth 2.6 RC1 or higher} for 32-bit builds and
+@url{http://avs-plus.net, AviSynth+ r1718 or higher} for 32-bit and 64-bit builds.
+
+For Linux and OS X, the supported AviSynth variant is
+@url{https://github.com/avxsynth/avxsynth, AvxSynth}.
+
+@float NOTE
+There is currently a regression in AviSynth+'s @code{capi.h} header as of
+October 2016, which interferes with the ability for builds of FFmpeg to use
+MSVC-built binaries of AviSynth. Until this is resolved, you can make sure
+a known good version is installed by checking out a version from before
+the regression occurred:
+
+@code{git clone -b MT git://github.com/AviSynth/AviSynthPlus.git @*
+cd AviSynthPlus @*
+git checkout -b oldheader b4f292b4dbfad149697fb65c6a037bb3810813f9 @*
+make install PREFIX=/install/prefix}
+@end float
+
+@float NOTE
+AviSynth and AvxSynth are loaded dynamically. Distributors can build FFmpeg
+with @code{--enable-avisynth}, and the binaries will work regardless of the
+end user having AviSynth or AvxSynth installed - they'll only need to be
+installed to use AviSynth scripts (obviously).
+@end float
+
+@section Chromaprint
+
+FFmpeg can make use of the Chromaprint library for generating audio fingerprints.
+Pass @code{--enable-chromaprint} to configure to
+enable it. See @url{https://acoustid.org/chromaprint}.
+
+@section codec2
+
+FFmpeg can make use of the codec2 library for codec2 decoding and encoding.
+There is currently no native decoder, so libcodec2 must be used for decoding.
+
+Go to @url{http://freedv.org/}, download "Codec 2 source archive".
+Build and install using CMake. Debian users can install the libcodec2-dev package instead.
+Once libcodec2 is installed you can pass @code{--enable-libcodec2} to configure to enable it.
+
+The easiest way to use codec2 is with .c2 files, since they contain the mode information required for decoding.
+To encode such a file, use a .c2 file extension and give the libcodec2 encoder the -mode option:
+@code{ffmpeg -i input.wav -mode 700C output.c2}.
+Playback is as simple as @code{ffplay output.c2}.
+For a list of supported modes, run @code{ffmpeg -h encoder=libcodec2}.
+Raw codec2 files are also supported.
+To make sense of them the mode in use needs to be specified as a format option:
+@code{ffmpeg -f codec2raw -mode 1300 -i input.raw output.wav}.
+
+@section davs2