I had installed youtube-dl :# youtube-dlUsage: youtube-dl [OPTIONS] URL [URL...]youtube-dl: error: You must provide at least one URL.Type youtube-dl --help to see a list of all options.But when I run it with --extract-audio --audio-format mp3 [URL], it ended withWARNING: 0g7KawdsVSQ: writing DASH m4a. Only some players support this container. Install ffmpeg or avconv to fix this automatically.ERROR: ffprobe or avprobe not found. Please install one.And when I want to upgrade youtube-dl package, to install additional files:Reading package lists... DoneBuilding dependency tree       Reading state information... DoneCalculating upgrade... E: Unable to locate package youtube-dlAnd when I want to install ffmpeg:# apt-get install ffmpegReading package lists... DoneBuilding dependency tree       Reading state information... DonePackage ffmpeg is not available, but is referred to by another package.This may mean that the package is missing, has been obsoleted, oris only available from another sourceSorry if this a newbie question, but I hadn't found anything on Google, with, upgrading unexisting but installed package?Sorry about few details:Using Kali GNU/Linux 2.0 (sana) 64-bit.I'm trying to upgrade, with command: apt-get upgrade youtube-dl>   > >  # apt-cache policy youtube-dl ffmpeg> >     > > > ffmpeg:> >       Installed: (none)> >       Candidate: (none)> >       Version table:> >     N: Unable to locate package youtube-dl# apt-cache policyPackage files: 100 /var/lib/dpkg/status     release a=now 500 http://security.kali.org/kali-security/ sana/updates/non-free amd64 Packages     release o=Kali,a=kali-current,n=sana,c=non-free     origin security.kali.org 500 http://security.kali.org/kali-security/ sana/updates/contrib amd64 Packages     release o=Kali,a=kali-current,n=sana,c=contrib     origin security.kali.org 500 http://security.kali.org/kali-security/ sana/updates/main amd64 Packages     release o=Kali,a=kali-current,n=sana,c=main     origin security.kali.orgPinned packages:EDID 2:  Sources.list# # deb cdrom:[Debian GNU/Linux 2.0 _Sana_ - Official Snapshot amd64 LIVE/INSTALL Binary 20150811-08:02]/ sana contrib main non-free#deb cdrom:[Debian GNU/Linux 2.0 _Sana_ - Official Snapshot amd64 LIVE/INSTALL Binary 20150811-08:02]/ sana contrib main non-freedeb http://security.kali.org/kali-security/ sana/updates main contrib non-freedeb-src http://security.kali.org/kali-security/ sana/updates main contrib non-free
I had installed program, but when I want to upgrade, it could not find him
apt;package management;kali linux;upgrade
You're missing sources in your sources.list.See Kali sources.list Repositories, which says:On a standard, clean install of Kali Linux, you should have the  following two entries present in /etc/apt/sources.list:deb http://http.kali.org/kali sana main non-free contribdeb http://security.kali.org/kali-security sana/updates main contrib non-freeYou appear to have the second line, but not the first. Check your sources.list.