Add support for ffmpeg's supplemental tools

README.md

@@ -234,6 +234,15 @@ See the [FFmpeg documentation](https://ffmpeg.org/general.html#External-librarie
 |  version3       | upgrade (L)GPL to version 3 |
 |  xmm-clobber-test | check XMM registers for clobbering |
 
+## Tools and utilities
+
+FFmpeg includes a handful of often-overlooked tools that are useful for troubleshooting and other advanced work. These tools are not installed by default, but you can enable them by setting `ASDF_FFMPEG_ENABLE_TOOLS`. For example, to enable `ffescape` and `graph2dot`, use the following:
+
+```sh
+export ASDF_FFMPEG_ENABLE_TOOLS="ffescape graph2dot"
+```
+
+A full list of tools can be found in the [FFmpeg source tree](https://github.com/FFmpeg/FFmpeg/tree/master/tools).
 
 # Contributing
 

lib/utils.bash

@@ -220,6 +220,12 @@ install_version() {
     test -x "$install_path/$tool_cmd" || fail "Expected $install_path/$tool_cmd to be executable."
 
     echo "$TOOL_NAME $version installation was successful!"
+
+    for tool in $(echo ${ASDF_FFMPEG_ENABLE_TOOLS:-}); do
+      MAKEFLAGS="-j$ASDF_CONCURRENCY" make tools/${tool} || exit 1
+      cp tools/${tool} $install_path || exit 1
+      echo "${tool} installation was successful!"
+    done
   ) || (
     rm -rf "$install_path"
     fail "An error occurred while installing $TOOL_NAME $version."