$ emerge --info
$ eix -e mpv
$ emerge -pv mpv # если eix не установлен

> mpv "https://www.youtube.com/watch?v=ThkpGloK6fU"
 (+) Video --vid=1 (*) (h264 1920x1080 25.000fps)
 (+) Audio --aid=1 --alang=eng (*) (aac 2ch 44100Hz)
AO: [oss] 44100Hz stereo 2ch s32
VO: [gpu] 1920x1080 yuv420p
AV: 00:09:21 / 00:09:21 (100%) A-V:  0.000 Dropped: 10 Cache: 0.0s

Exiting... (End of file)

> pkg info mpv
mpv-0.33.0_6,1
Name           : mpv
Version        : 0.33.0_6,1
Installed on   : Sat Mar 27 00:04:47 2021 MSK
Origin         : multimedia/mpv
Architecture   : FreeBSD:12:amd64
Prefix         : /usr/local
Categories     : audio multimedia
Licenses       : GPLv2+, LGPL21+
Maintainer     : multimedia@FreeBSD.org
WWW            : https://mpv.io
Comment        : Free and open-source general-purpose video player
Options        :
	ALSA           : off
	ARCHIVE        : on
	CACA           : off
	CDIO           : on
	DOCS           : off
	DVDNAV         : on
	EXAMPLES       : off
	JACK           : off
	LCMS2          : on
	LIBBLURAY      : off
	LUAJIT         : off
	MANPAGES       : off
	MUJS           : off
	OPENAL         : off
	OPENGL         : on
	PULSEAUDIO     : off
	SDL            : off
	SIXEL          : on
	TEST           : off
	UCHARDET       : on
	V4L            : off
	VAAPI          : on
	VDPAU          : on
	VULKAN         : off
	WAYLAND        : off
	X11            : on
	YTDL           : on
	ZIMG           : on
Shared Libs required:
	libzimg.so.2
	libavutil.so.56
	libcdio_paranoia.so.2
	libXinerama.so.1
	libXext.so.6
	libjpeg.so.8
	libswresample.so.3
	libXv.so.1
	libva-drm.so.2
	libdrm.so.2
	libavdevice.so.58
	libcdio.so.19
	libXss.so.1
	libvdpau.so.1
	libva.so.2
	libX11.so.6
	libgbm.so.1
	libavfilter.so.7
	libavcodec.so.58
	libarchive.so.13
	libEGL.so.1
	libsixel.so.1
	liblua-5.2.so
	libswscale.so.5
	libdvdread.so.7
	libva-x11.so.2
	libXrandr.so.2
	libavformat.so.58
	libass.so.9
	libdvdnav.so.4
	libcdio_cdda.so.2
	liblcms2.so.2
	libuchardet.so.0
Shared Libs provided:
	libmpv.so.1
Annotations    :
	FreeBSD_version: 1202505
Flat size      : 4.14MiB
Description    :
Mpv is based on the MPlayer and mplayer2 projects which it greatly improves.
It supports a wide variety of video file formats, audio and video codecs, and
subtitle types. Special input URL types are available to read input from
a variety of sources other than disk files. Depending on platform, a variety of
different video and audio output methods are supported.

WWW: https://mpv.io

> pkg info youtube_dl
youtube_dl-2021.03.31
Name           : youtube_dl
Version        : 2021.03.31
Installed on   : Mon Apr  5 21:04:25 2021 MSK
Origin         : www/youtube_dl
Architecture   : FreeBSD:12:*
Prefix         : /usr/local
Categories     : www
Licenses       : UNLICENSE
Maintainer     : multimedia@FreeBSD.org
WWW            : https://yt-dl.org/
Comment        : Program for downloading videos from various services
Options        :
	FFMPEG         : on
	RTMPDUMP       : on
Annotations    :
	repo_type      : binary
	repository     : comp
Flat size      : 1.83MiB
Description    :
youtube-dl is a small command-line program for downloading videos
from YouTube.com, metacafe.com, google video, photobucket videos,
yahoo videos, dailymotion and others

WWW: https://yt-dl.org/