My son bought me an Apple TV as a gift. Before I can use it I have to convert all of my video to M4V. I can't find a program to do that. I would prefer a freeware but will consider something else if that's all there is. I was told handbrake would do it but all I could get it to offer is MP4 and MKV. Ideally I'd prefer a windows product rather than the proprietary Apple TV. I can take it back but I'd rather make it work if possible. I think Itunes will do it in the cloud but I doubt I have any control of file size such as video/audio bit rate, frame rate etc and I do not like Apple at all. So I'd rather a non-Apple converter. I had a DVD player once that supported DIVX but the only program that could encode DIVX was DIVX software. Other converters were able to convert to DIVX, but even though they could do it, it didn't work because the finished product would not run on a DIVX player.
I do not own apple tv, but to the best of my knowledge it supports h.264 video formats including .mov and .mp4. You do not need to convert anything to M4V because that is a format developed by Apple that includes DRM (copy protection), so the only video you would have in that format anyway is stuff purchased from apple (itunes, etc).
Handbrake should be able to handle these conversions.