How do I install it?


Linux

Package subtitlecomposer is latest stable version.
Package subtitlecomposer-git is latest git build.

Bionic (18.04): Repository (i386 / amd64) Binary Packages Focal (20.04): Repository (amd64) Binary Packages Groovy (20.10): Repository (amd64) Binary Packages Hirsute (21.04): Repository (amd64) Binary Packages Hirsute (21.10): Repository (amd64) Binary Packages
Run following in terminal as root:

                  echo 'deb http://download.opensuse.org/repositories/home:/maxrd2/xUbuntu_18.04/ /' | sudo tee /etc/apt/sources.list.d/home:maxrd2.list
curl -fsSL https://download.opensuse.org/repositories/home:maxrd2/xUbuntu_18.04/Release.key | gpg --dearmor | sudo tee /etc/apt/trusted.gpg.d/home_maxrd2.gpg > /dev/null
sudo apt update
sudo apt install subtitlecomposer
Run following in terminal as root:

                  echo 'deb http://download.opensuse.org/repositories/home:/maxrd2/xUbuntu_20.04/ /' | sudo tee /etc/apt/sources.list.d/home:maxrd2.list
curl -fsSL https://download.opensuse.org/repositories/home:maxrd2/xUbuntu_20.04/Release.key | gpg --dearmor | sudo tee /etc/apt/trusted.gpg.d/home_maxrd2.gpg > /dev/null
sudo apt update
sudo apt install subtitlecomposer
Run following in terminal as root:

                  echo 'deb http://download.opensuse.org/repositories/home:/maxrd2/xUbuntu_20.10/ /' | sudo tee /etc/apt/sources.list.d/home:maxrd2.list
curl -fsSL https://download.opensuse.org/repositories/home:maxrd2/xUbuntu_20.10/Release.key | gpg --dearmor | sudo tee /etc/apt/trusted.gpg.d/home_maxrd2.gpg > /dev/null
sudo apt update
sudo apt install subtitlecomposer
Run following in terminal as root:

                  echo 'deb http://download.opensuse.org/repositories/home:/maxrd2/xUbuntu_21.04/ /' | sudo tee /etc/apt/sources.list.d/home:maxrd2.list
curl -fsSL https://download.opensuse.org/repositories/home:maxrd2/xUbuntu_21.04/Release.key | gpg --dearmor | sudo tee /etc/apt/trusted.gpg.d/home_maxrd2.gpg > /dev/null
sudo apt update
sudo apt install subtitlecomposer
Run following in terminal as root:

                  echo 'deb http://download.opensuse.org/repositories/home:/maxrd2/xUbuntu_21.10/ /' | sudo tee /etc/apt/sources.list.d/home:maxrd2.list
curl -fsSL https://download.opensuse.org/repositories/home:maxrd2/xUbuntu_21.10/Release.key | gpg --dearmor | sudo tee /etc/apt/trusted.gpg.d/home_maxrd2.gpg > /dev/null
sudo apt update
sudo apt install subtitlecomposer

Package subtitlecomposer is latest stable version.
Package subtitlecomposer-git is latest git build.

Debian 10: Repository (i586 / amd64) Binary Packages Debian 11: Repository (i586 / amd64) Binary Packages Unstable: Repository (amd64) Binary Packages Testing: Repository (i586 / amd64) Binary Packages
Run following in terminal as root:

                  echo 'deb http://download.opensuse.org/repositories/home:/maxrd2/Debian_10/ /' | sudo tee /etc/apt/sources.list.d/home:maxrd2.list
curl -fsSL https://download.opensuse.org/repositories/home:maxrd2/Debian_10/Release.key | gpg --dearmor | sudo tee /etc/apt/trusted.gpg.d/home_maxrd2.gpg > /dev/null
sudo apt update
sudo apt install subtitlecomposer
Run following in terminal as root:

                  echo 'deb http://download.opensuse.org/repositories/home:/maxrd2/Debian_11/ /' | sudo tee /etc/apt/sources.list.d/home:maxrd2.list
curl -fsSL https://download.opensuse.org/repositories/home:maxrd2/Debian_11/Release.key | gpg --dearmor | sudo tee /etc/apt/trusted.gpg.d/home_maxrd2.gpg > /dev/null
sudo apt update
sudo apt install subtitlecomposer
Run following in terminal as root:

                  echo 'deb http://download.opensuse.org/repositories/home:/maxrd2/Debian_Unstable/ /' | sudo tee /etc/apt/sources.list.d/home:maxrd2.list
curl -fsSL https://download.opensuse.org/repositories/home:maxrd2/Debian_Unstable/Release.key | gpg --dearmor | sudo tee /etc/apt/trusted.gpg.d/home_maxrd2.gpg > /dev/null
sudo apt update
sudo apt install subtitlecomposer
Run following in terminal as root:

                  echo 'deb http://download.opensuse.org/repositories/home:/maxrd2/Debian_Testing/ /' | sudo tee /etc/apt/sources.list.d/home:maxrd2.list
curl -fsSL https://download.opensuse.org/repositories/home:maxrd2/Debian_Testing/Release.key | gpg --dearmor | sudo tee /etc/apt/trusted.gpg.d/home_maxrd2.gpg > /dev/null
sudo apt update
sudo apt install subtitlecomposer
Add the following to /etc/pacman.conf (need to edit as root):

                [home_maxrd2_Arch]
# Subtitle Composer
SigLevel = Optional TrustAll
Server = https://downloadcontent.opensuse.org/repositories/home:/maxrd2/Arch/x86_64/
Repository and packages are signed with GPG key DE85E73C17AF00C8E865B04F0073ABF073738FA0.
Update/install key as root:

                wget -O - https://build.opensuse.org/projects/home:maxrd2/public_key | pacman-key --add -
pacman-key --lsign-key DE85E73C17AF00C8E865B04F0073ABF073738FA0
Finally install the package as root:
pacman -Sy subtitlecomposer
Or if you prefer latest git build:
pacman -Sy subtitlecomposer-git

Package subtitlecomposer is latest stable version.
Package subtitlecomposer-git is latest git build.

Fedora 33: Repository (x86_64 / armv7l / aarch64 / ppc64le) Binary Packages Fedora 34: Repository (x86_64 / armv7l / aarch64 / ppc64le) Binary Packages Fedora 35: Repository (x86_64 / armv7l / aarch64 / ppc64le) Binary Packages
Run following in terminal as root:

                  dnf config-manager --add-repo https://download.opensuse.org/repositories/home:maxrd2/Fedora_33/home:maxrd2.repo
dnf install subtitlecomposer
Run following in terminal as root:

                  dnf config-manager --add-repo https://download.opensuse.org/repositories/home:maxrd2/Fedora_34/home:maxrd2.repo
dnf install subtitlecomposer
Run following in terminal as root:

                  dnf config-manager --add-repo https://download.opensuse.org/repositories/home:maxrd2/Fedora_35/home:maxrd2.repo
dnf install subtitlecomposer

Package subtitlecomposer is latest stable version.
Package subtitlecomposer-git is latest git build.

Tumbleweed: Repository (i586 / x86_64 / aarch64 / armv7hl) Binary Packages Leap 15.1: Repository (x86_64 / ppc64le) Binary Packages Leap 15.2: Repository (x86_64 / ppc64le / aarch64 / armv7hl) Binary Packages Leap 15.3: Repository (i586 / x86_64 / ppc64le / aarch64) Repository (armv7hl) Binary Packages Leap 15.4: Repository (i586 / x86_64 / ppc64le / aarch64) Repository (armv7hl) Binary Packages
Run following in terminal as root:

                  zypper addrepo https://download.opensuse.org/repositories/home:maxrd2/openSUSE_Tumbleweed/home:maxrd2.repo
zypper refresh
zypper install subtitlecomposer
Run following in terminal as root:

                  zypper addrepo https://download.opensuse.org/repositories/home:maxrd2/openSUSE_Leap_15.1/home:maxrd2.repo
zypper refresh
zypper install subtitlecomposer
Run following in terminal as root:

                  zypper addrepo https://download.opensuse.org/repositories/home:maxrd2/openSUSE_Leap_15.2/home:maxrd2.repo
zypper refresh
zypper install subtitlecomposer
Run following in terminal as root:

                  zypper addrepo https://download.opensuse.org/repositories/home:maxrd2/openSUSE_Leap_15.3/home:maxrd2.repo
zypper refresh
zypper install subtitlecomposer
Run following in terminal as root:

                  zypper addrepo https://download.opensuse.org/repositories/home:maxrd2/openSUSE_Leap_15.3_ARM/home:maxrd2.repo
zypper refresh
zypper install subtitlecomposer
Run following in terminal as root:

                  zypper addrepo https://download.opensuse.org/repositories/home:maxrd2/openSUSE_Leap_15.4/home:maxrd2.repo
zypper refresh
zypper install subtitlecomposer
Run following in terminal as root:

                  zypper addrepo https://download.opensuse.org/repositories/home:maxrd2/openSUSE_Leap_15.4_ARM/home:maxrd2.repo
zypper refresh
zypper install subtitlecomposer

AppImage is a self-contained executable with all dependencies included that runs on any Linux system.

It’s quite simple to run AppImages. All you have to do is download them, make them executable and run them.
Here's more details on how to run AppImage.

Download stable version: i686 x86_64 aarch64 armv7l
Download latest git development version: i686 x86_64 aarch64 armv7l
Add the Flathub and KDE Apps nightly repositories:

                flatpak remote-add --user --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo
flatpak remote-add --user --if-not-exists kdeapps --from https://distribute.kde.org/kdeapps.flatpakrepo
Then install the flatpak:
flatpak install org.kde.subtitlecomposer
Subtitle Composer is already available on most Linux distributions.
You can install it from the KDE Software Center.
Windows Download: Stable 0.7.1 Version (x86) Git Development Version (x86) Sources Clone the git repository:

          git clone https://invent.kde.org/multimedia/subtitlecomposer.git
        
Instructions for building from sources can be found on the wiki page.