Yes and no

It depends on what your AVI is made up from.
AVI is a container. AVI means Audio Video Interleave. AVI contains only information that describes how to store the data in file and how to decompress the video and the audio (which codecs to use for these purposes).
DivX (XviD) is a codec, a video compressor and decompressor. Video data can be compressed with DivX (XviD) codec and stored inside AVI files.
Also, CinePak, Indeo, Huffyuv and other video codecs can be used to create AVI files.
Typical AVI: the Video compressed with DivX, and the Audio compressed with MP3.
AVI may contain the video data compressed with Cinepak, and uncompressed WAV PCM audio.
In other words, the universal AVI container allows to use many combinations of codecs (encoders/decoders) for storing the video/audio data.
MPEG-4 is not a codec, and it is not a container.
MPEG-4 is a name of collection of methods defining compression of audio and visual (AV) digital data. Related technology agreed upon by the ISO/IEC Moving Picture Experts Group (MPEG) under the formal standard ISO/IEC 14496.
So, if your AVIs have been coded using DivX, then yes you should be able to play them. If not, then, no.