我正在尝试安装特定版本的 FFMPEG (4.1.4)，但是，当我尝试执行时：
sudo add-apt-repository ppa:mc3man/trusty-media
我收到以下错误信息：
Hit:1 http://rs.archive.ubuntu.com/ubuntu bionic InRelease
Hit:2 http://rs.archive.ubuntu.com/ubuntu bionic-updates InRelease
Hit:3 http://security.ubuntu.com/ubuntu bionic-security InRelease
Hit:4 http://ppa.launchpad.net/jonathonf/ffmpeg-4/ubuntu bionic InRelease
Hit:5 http://rs.archive.ubuntu.com/ubuntu bionic-backports InRelease
Hit:6 https://repo.skype.com/deb stable InRelease
Hit:7 https://download.docker.com/linux/ubuntu bionic InRelease
Ign:8 http://ppa.launchpad.net/mc3man/trusty-media/ubuntu bionic InRelease
Hit:9 https://packages.microsoft.com/repos/vscode stable InRelease
Hit:10 http://ppa.launchpad.net/webupd8team/java/ubuntu bionic InRelease
Err:11 http://ppa.launchpad.net/mc3man/trusty-media/ubuntu bionic Release
404 Not Found [IP: 91.189.95.83 80]
Reading package lists... Done
E: The repository 'http://ppa.launchpad.net/mc3man/trusty-media/ubuntu bionic Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: Target Packages (stable/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list:54 and /etc/apt/sources.list:56
W: Target Packages (stable/binary-all/Packages) is configured multiple times in /etc/apt/sources.list:54 and /etc/apt/sources.list:56
W: Target Translations (stable/i18n/Translation-en_US) is configured multiple times in /etc/apt/sources.list:54 and /etc/apt/sources.list:56
W: Target Translations (stable/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list:54 and /etc/apt/sources.list:56
W: Target DEP-11 (stable/dep11/Components-amd64.yml) is configured multiple times in /etc/apt/sources.list:54 and /etc/apt/sources.list:56
W: Target DEP-11 (stable/dep11/Components-all.yml) is configured multiple times in /etc/apt/sources.list:54 and /etc/apt/sources.list:56
W: Target DEP-11-icons-small (stable/dep11/icons-48x48.tar) is configured multiple times in /etc/apt/sources.list:54 and /etc/apt/sources.list:56
W: Target DEP-11-icons (stable/dep11/icons-64x64.tar) is configured multiple times in /etc/apt/sources.list:54 and /etc/apt/sources.list:56
W: Target CNF (stable/cnf/Commands-amd64) is configured multiple times in /etc/apt/sources.list:54 and /etc/apt/sources.list:56
W: Target CNF (stable/cnf/Commands-all) is configured multiple times in /etc/apt/sources.list:54 and /etc/apt/sources.list:56
W: Target Packages (main/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list:52 and /etc/apt/sources.list.d/vscode.list:3
W: Target Packages (main/binary-all/Packages) is configured multiple times in /etc/apt/sources.list:52 and /etc/apt/sources.list.d/vscode.list:3
W: Target Translations (main/i18n/Translation-en_US) is configured multiple times in /etc/apt/sources.list:52 and /etc/apt/sources.list.d/vscode.list:3
W: Target Translations (main/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list:52 and /etc/apt/sources.list.d/vscode.list:3
W: Target DEP-11 (main/dep11/Components-amd64.yml) is configured multiple times in /etc/apt/sources.list:52 and /etc/apt/sources.list.d/vscode.list:3
W: Target DEP-11 (main/dep11/Components-all.yml) is configured multiple times in /etc/apt/sources.list:52 and /etc/apt/sources.list.d/vscode.list:3
W: Target DEP-11-icons-small (main/dep11/icons-48x48.tar) is configured multiple times in /etc/apt/sources.list:52 and /etc/apt/sources.list.d/vscode.list:3
W: Target DEP-11-icons (main/dep11/icons-64x64.tar) is configured multiple times in /etc/apt/sources.list:52 and /etc/apt/sources.list.d/vscode.list:3
W: Target CNF (main/cnf/Commands-amd64) is configured multiple times in /etc/apt/sources.list:52 and /etc/apt/sources.list.d/vscode.list:3
W: Target CNF (main/cnf/Commands-all) is configured multiple times in /etc/apt/sources.list:52 and /etc/apt/sources.list.d/vscode.list:3
W: Target Packages (main/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list:52 and /etc/apt/sources.list.d/vscode.list:3
W: Target Packages (main/binary-all/Packages) is configured multiple times in /etc/apt/sources.list:52 and /etc/apt/sources.list.d/vscode.list:3
W: Target Translations (main/i18n/Translation-en_US) is configured multiple times in /etc/apt/sources.list:52 and /etc/apt/sources.list.d/vscode.list:3
W: Target Translations (main/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list:52 and /etc/apt/sources.list.d/vscode.list:3
W: Target DEP-11 (main/dep11/Components-amd64.yml) is configured multiple times in /etc/apt/sources.list:52 and /etc/apt/sources.list.d/vscode.list:3
W: Target DEP-11 (main/dep11/Components-all.yml) is configured multiple times in /etc/apt/sources.list:52 and /etc/apt/sources.list.d/vscode.list:3
W: Target DEP-11-icons-small (main/dep11/icons-48x48.tar) is configured multiple times in /etc/apt/sources.list:52 and /etc/apt/sources.list.d/vscode.list:3
W: Target DEP-11-icons (main/dep11/icons-64x64.tar) is configured multiple times in /etc/apt/sources.list:52 and /etc/apt/sources.list.d/vscode.list:3
W: Target CNF (main/cnf/Commands-amd64) is configured multiple times in /etc/apt/sources.list:52 and /etc/apt/sources.list.d/vscode.list:3
W: Target CNF (main/cnf/Commands-all) is configured multiple times in /etc/apt/sources.list:52 and /etc/apt/sources.list.d/vscode.list:3
W: Target Packages (stable/binary-amd64/Packages) is configured multiple times in /etc/apt/sources.list:54 and /etc/apt/sources.list:56
W: Target Packages (stable/binary-all/Packages) is configured multiple times in /etc/apt/sources.list:54 and /etc/apt/sources.list:56
W: Target Translations (stable/i18n/Translation-en_US) is configured multiple times in /etc/apt/sources.list:54 and /etc/apt/sources.list:56
W: Target Translations (stable/i18n/Translation-en) is configured multiple times in /etc/apt/sources.list:54 and /etc/apt/sources.list:56
W: Target DEP-11 (stable/dep11/Components-amd64.yml) is configured multiple times in /etc/apt/sources.list:54 and /etc/apt/sources.list:56
W: Target DEP-11 (stable/dep11/Components-all.yml) is configured multiple times in /etc/apt/sources.list:54 and /etc/apt/sources.list:56
W: Target DEP-11-icons-small (stable/dep11/icons-48x48.tar) is configured multiple times in /etc/apt/sources.list:54 and /etc/apt/sources.list:56
W: Target DEP-11-icons (stable/dep11/icons-64x64.tar) is configured multiple times in /etc/apt/sources.list:54 and /etc/apt/sources.list:56
W: Target CNF (stable/cnf/Commands-amd64) is configured multiple times in /etc/apt/sources.list:54 and /etc/apt/sources.list:56
W: Target CNF (stable/cnf/Commands-all) is configured multiple times in /etc/apt/sources.list:54 and /etc/apt/sources.list:56
当我尝试执行时，也会发生同样的事情sudo apt-get update。老实说，我对 Linux 并没有太多经验，我看到有人尝试编辑 /etc/apt/sources.list，但我真的不确定我应该注释掉哪一行，甚至不知道这是否是正确的方法。有什么想法吗？