cpudetection - Enables runtime CPU detection (useful for bindist, compatibility on other CPUs)
cuda - Enables CUDA-based acceleration. Mostly used for specific filters.
dav1d - Enables AV1 decoding via media-libs/dav1d.
debug - Enable extra debug codepaths, like asserts and extra output. If you want to get meaningful backtraces see https://wiki.gentoo.org/wiki/Project:Quality_Assurance/Backtraces
doc - Add extra documentation (API, Javadoc, etc). It is recommended to enable per package instead of globally
encode - Add support for encoding of audio or video files
fdk - Use external fdk-aac library for AAC encoding
fftools_aviocat - cat's a URL to another one, useful for dumping streams.
fribidi - Enables fribidi support in the drawtext filter.
gcrypt - Enables gcrypt support: Needed for rtmp(t)e support if openssl, librtmp or gmp is not used.
gme - Enables support for media-libs/game-music-emu for playing various video game music formats.
gmp - Add support for dev-libs/gmp (GNU MP library)
gnutls - Prefer net-libs/gnutls as SSL/TLS provider (ineffective with USE=-ssl)
gpl - Build GPL code. Should be enabled unless you require LGPL binaries.
gsm - Add support for the gsm lossy speech compression codec
hardcoded-tables - Use pre-calculated tables rather than calculating them on the fly. It results in an increase of approximately 15% in the size of libavcodec, the main library impacted by this change. It enables savings in table generation time, done once at codec initialization, since by hardcoding the tables, they do not need to be computed at runtime. However, the savings are often negligible (~100k cycles is a typical number) especially when amortized over the entire encoding/decoding operation. Improvements are being made to the runtime initialization, and so over time, this option will have an impact on fewer and fewer codecs.
iconv - Enable support for the iconv character set conversion library
iec61883 - Support for FireWire DV/HDV input device using media-libs/libiec61883.
ieee1394 - Enable FireWire/iLink IEEE1394 support (dv, camera, ...)
jack - Add support for the JACK Audio Connection Kit
jpeg2k - Support for JPEG 2000, a wavelet-based image compression format
jpegxl - Enable JPEG XL de/encoding via media-libs/libjxl.
kvazaar - Enables media-libs/kvazaar based HEVC encoder.
ladspa - Enable the ability to support ladspa plugins
lcms - Enable ICC profile support via media-libs/lcms.
libaom - Enables media-libs/libaom based AV1 codec support.
libaribb24 - Enables ARIB text and caption decoding via media-libs/aribb24.
libass - SRT/SSA/ASS (SubRip / SubStation Alpha) subtitle support
libcaca - Add support for colored ASCII-art graphics
libdrm - Enables x11-libs/libdrm support for better screen grabbing and hardware accelerated codecs.
libilbc - Enables iLBC de/encoding via media-libs/libilbc.
libplacebo - Adds flexible GPU-accelerated processing filter based on media-libs/libplacebo.
librtmp - Enables Real Time Messaging Protocol using librtmp (media-video/rtmpdump) in addition to FFmpeg's native implementation.
libsoxr - Enables audio resampling through media-libs/soxr.
libtesseract - Enables the OCR filter via app-text/tesseract.
libv4l - Uses media-libs/libv4l for video4linux instead of direct calls. Adds support for more devices via the userspace library.
libxml2 - Uses dev-libs/libxml2 to enable dash demuxing support.
nvenc - Add support for NVIDIA Encoder/Decoder (NVENC/NVDEC) API for hardware accelerated encoding and decoding on NVIDIA cards (requires x11-drivers/nvidia-drivers)
pulseaudio - Add sound server support via media-libs/libpulse (may be PulseAudio or PipeWire)
qsv - Enable Intel Quick Sync Video via media-libs/intel-mediasdk (ffmpeg versions older than, and including, 5.1) or media-libs/oneVPL (ffmpeg version newer than 5.1).
rav1e - Enables AV1 encoding support via media-video/rav1e.
rubberband - Adds time-stretching and pitch-shifting audio filter based on media-libs/rubberband.
samba - Add support for SAMBA (Windows File and Printer sharing)
sdl - Add support for Simple Direct Layer (media library)
snappy - Enable app-arch/snappy support. Required for e.g. Vidvox Hap encoder.
sndio - Enable support for the media-sound/sndio backend
speex - Add support for the speex audio codec (used for speech)
srt - Enable support for Secure Reliable Transport (SRT) via net-libs/srt
ssh - Enable SSH/sftp support via net-libs/libssh.
static-libs - Build static versions of dynamic libraries as well
svg - Add support for SVG (Scalable Vector Graphics)
svt-av1 - Enables AV1 encoding support via media-libs/svt-av1.
test - Enable dependencies and/or preparations necessary to run tests (usually controlled by FEATURES=test but can be toggled independently)
theora - Add support for the Theora Video Compression Codec
threads - Add threads support for various packages. Usually pthreads
truetype - Add support for FreeType and/or FreeType2 fonts
twolame - Enables MP2 encoding via media-sound/twolame as an alternative to the internal encoder.
v4l - Enable support for video4linux (using linux-headers or userspace libv4l libraries)
vaapi - Enable Video Acceleration API for hardware decoding
vdpau - Enable the Video Decode and Presentation API for Unix acceleration interface
verify-sig - Verify upstream signatures on distfiles
vidstab - Enables video stabilization filter using vid.stab library (media-libs/vidstab).
vmaf - Enables Netflix's perceptual video quality assessment filter using the library (media-libs/libvmaf).
vorbis - Add support for the OggVorbis audio codec
vpx - Enables VP8 and VP9 codec support using libvpx: Decoding does not require this to be enabled but libvpx can also be used for decoding; encoding requires this useflag to be enabled though.
vulkan - Add support for 3D graphics and computing via the Vulkan cross-platform API
wavpack - Add support for wavpack audio compression tools
