Error: 'Unable to determine the codec required.'

[Alfonso Pérez Escudero]

This error message means that the format of video you are trying to track is incompatible with idTracker (because it is not compatible with Matlab). While in theory the problem can be solved by installing the missing codec, in practice I have never been able so solve it that way. Therefore, the only workaround is to transform the video into a different format. For example, mp4 usually works well with idTracker. You can transform your video using Handbrake or any other software for video manipulation.