How do I change the audio length within a video

[Gandalf]

I am using version 2.8.0 of Avidemux, and the problem that I am experiencing with a few of the videos that I have downloaded from the internet have a situation where the audio starts out correctly synchronized with the video, but the longer that the video plays, the more the video gets out of sync with the audio (in one example, the file information indicates that the video portion length is 22:05.073 minutes, and the length of the audio portion is 22:05.111 minutes)

[eumagga0x2a]

I am using version 2.8.0 of Avidemux

I would recommend to update to the latest 2.8.1 nightly due to all the bugs fixed since the last release.

the problem that I am experiencing with a few of the videos that I have downloaded from the internet have a situation where the audio starts out correctly synchronized with the video, but the longer that the video plays, the more the video gets out of sync with the audio

Does it happen only in Avidemux? In any case, the problem has nothing to do with the length of the audio track. If audio gets ahead of video, the most probable reason is video decoding and display being not 100% real time, else it may be Avidemux getting frame rate wrong. In this case, please provide admlog.txt (located in %localappdata%\avidemux\) resulting from starting Avidemux (the latest nightly, please) and loading such a video.

[Gandalf]

I first noticed it when I was playing them back in GNOME MPlayer (Slackware Linux, which is my operating system).

[eumagga0x2a]

Good. Due to shortage of coffee grounds, please provide at least admlog.txt or preferably a sample.