In69mp4

It is possible that the term refers to one of the following:

It may be a specific filename, directory, or unique hash used within a private server, gaming community, or niche media repository. in69mp4

You might be looking for a standard MP4-related technology or a specific codec (like H.264/H.265). It is possible that the term refers to

Based on the available information, does not appear to be a widely recognized commercial product, standard file format, or documented software feature. standard file format