Checking for JPEG XL support via libavcodec : no ('libavcodec >= 59.27.100' not found)
Checking for new engine support for librubberband : no ('rubberband >= 3.0.0' not found)
Checking for FFmpeg library : no ('libavutil >= 56.70.100 libavcodec >= 58.134.100 libavformat >= 58.76.100 libswscale >= 5.9.100 libavfilter >= 7.110.100 libswresample >= 3.9.100' not found)
Unable to find development files for some of the required FFmpeg libraries. Git master is recommended.

• ERROR: media-video/mpv-0.35.0.20221230::media-kit failed (configure phase):
• configure failed
  *
• Call stack:
• ebuild.sh, line 93: Called src_configure
• environment, line 4491: Called waf-utils_src_configure '-confdir=/etc/mpv' 'disable-libmpv-shared' 'disable-debug-build' 'disable-html-build' 'disable-pdf-build' 'enable-manpage-build' 'disable-cplugins' 'disable-test' 'enable-iconv' 'enable-lua' 'disable-javascript' 'enable-zlib' 'enable-libbluray' 'enable-dvdnav' 'enable-cdda' 'enable-uchardet' 'disable-rubberband' 'disable-lcms2' 'disable-libarchive' 'enable-libavdevice' 'enable-sdl2' 'disable-pipewire' 'disable-pulse' 'disable-jack' 'disable-openal' '-disable-opensles'
  '-enable-alsa' 'disable-coreaudio' 'disable-cocoa' 'disable-drm' 'disable-cuda-hwaccel' 'disable-gbm' 'disable-wayland' 'enable-x11' 'enable-xv' 'disable-gl-cocoa' 'enable-gl-x11' 'enable-egl-x11' 'disable-egl-drm' 'disable-gl-wayland' 'enable-vdpau' 'enable-vdpau-gl-x11' 'enable-vaapi' 'enable-vaapi-x11' 'disable-vaapi-wayland' 'disable-vaapi-drm' 'disable-caca' 'enable-jpeg' 'enable-shaderc' 'enable-libplacebo' 'disable-rpi' 'disable-plain-gl' 'enable-vulkan' 'disable-sdl2-gamepad' 'disable-cuda-hwaccel' 'disable-cuda-interop' 'disable-dvbin' 'disable-zimg' 'enable-vaapi-x-egl' 'disable-android' 'disable-egl-android' 'disable-uwp' 'disable-audiounit' 'disable-macos-media-player' 'disable-wasapi' 'disable-ios-gl' 'disable-macos-touchbar' 'disable-macos-cocoa-cb' 'disable-tvos' 'disable-egl-angle-win32' 'disable-swift' 'bashdir=/usr/share/bash-completion/completions' 'zshdir=/usr/share/zsh/site-functions' '-disable-build-date'
• environment, line 5498: Called die
• The specific snippet of code:
• env "${CMD[@]}" || die "configure failed"