The Ubuntu repo contains Avidemux version 2.5:
# apt-cache showpkg avidemux
Package: avidemux
Versions: 1:2.5.4-0ubuntu13 (/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_raring_multiverse_binary-amd64_Packages)
Description Language: File: /var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_raring_multiverse_binary-amd64_Packages
Description Language: File: /var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_raring_multiverse_i18n_Translation-en
Reverse Depends:
libavidemux0:i386,avidemux 1:2.5.0-0.0ubuntu3
avidemux:i386,avidemux
libavidemux0,avidemux 1:2.5.0-0.0ubuntu3
avidemux-common,avidemux 1:2.4.0-0.0
Dependencies: 1:2.5.4-0ubuntu13 - libatk1.0-0 (2 1.12.4) libavidemux0 (2 1:2.5.4) libc6 (2 2.14) libcairo2 (2 1.2.4) libgcc1 (2 1:4.1.1) libgdk-pixbuf2.0-0 (2 2.22.0) libglib2.0-0 (2 2.14.0) libgtk2.0-0 (2 2.24.0) libsdl1.2debian (2 1.2.11) libstdc++6 (2 4.6) libvpx1 (2 1.0.0) libx11-6 (0) libxext6 (0)) libxml2 (2 2.7.4) libxv1 (0) avidemux-common (0) avidemux-plugins-gtk (0) avidemux:i386 (0)
Provides: 1:2.5.4-0ubuntu13 -
Reverse Provides: avidemux-qt 1:2.5.4-0ubuntu13 avidemux-cli 1:2.5.4-0ubuntu13
How to install Avidemux 2.6 on latest Ubuntu / Linux Mint?..