AVI
Also known as: .avi, Audio Video Interleave
A container format from the 1990s, still occasionally produced by inexpensive cameras and best converted before it reaches an edit.
Updated
What it means
AVI is a container rather than a codec. It holds video and audio streams the way an MP4 does, with a much older design and far less of the information a modern tool expects to find.
Its limitations are structural. No clean support for variable frame rate, awkward handling of files beyond a few gigabytes, and no standard place for the Video metadata a camera would normally write.
It survives in two places. Old archives, and inexpensive cameras and dash units that ship an AVI writer because it is simple to implement. Neither is a reason to keep it.
How it works in practice
The first step is conversion. Transcoding an AVI to a modern container before editing avoids a long list of small and unrelated problems, and nothing is lost by doing it early.
What is inside matters more than the wrapper. An AVI can carry a modern codec or something from twenty years ago, and the codec rather than the extension decides whether anything will play it.
Audio sync is the thing to check. AVI handles variable rates badly, so a clip from a cheap camera frequently drifts, and the drift shows up late if nobody looks for it.
What to watch out for
Editors accept it inconsistently. Some open it, some refuse, and some open it and then fail at export, which is a Transcode failure waiting at the end of the work.
Large files break in unexpected ways. The original format had a size limit that newer variants work around differently, so a long recording can be unreadable in one tool and perfectly fine in another.
Converting late wastes the work. An edit built on AVI clips and then converted loses the trims, so Codec support is a question to settle before a timeline exists.
How RawClip handles it
Older containers are converted before analysis, so an AVI from a dash camera or an archive is handled like any other clip. What matters is the codec inside, since a very old one is read less reliably than a current one would be.