After Effects announced on their official website long time ago that it could support AVI videos without problem. But the fact is that some AVI videos are rejected by it. As far as we know, AVI is a 'container' which can incorporate most any sort of video and audio format. That is to say, AVI videos can be encoded by different codecs like DivX/Xvid, which makes After Effects refuse them. Then how can we make all AVI files compatible with After Effects? The best workaround is to encode AVI to MPEG/MOV(AVC)