The application relates to Audio & Video Tools. We recommend checking the downloaded files with any free antivirus.
From the developer:
The 3ivx team is dedicated to providing video compression solutions. MacMPEG2Decoder is probably the most affordable MPEG2 to QuickTime application for MacOS since it is totally free. The original application was written by VLich who brought it to version 1.0b5. We are taking over VLich's excellent work to bring MacMPEG2Decoder even further. MM2D is now released under LGPL and MPL licenses.