gentoo-overlay/media-video/avidemux/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
  <herd>video</herd>
  <use>
    <flag name="aften">Enable A/52 (AC-3) audio encoder support.</flag>
    <flag name="amr">Enable Adaptive Multi-Rate format support via <pkg>media-libs/opencore-amr</pkg>.</flag>
    <flag name="vpx">Enable VP8 codec support via <pkg>media-libs/libvpx</pkg>.</flag>
  </use>
</pkgmetadata>