Rotate a MP4 file, while preserving codec and quality attributes

"There's no way to rotate a video without re-encoding it. So you can only appoximate the size and quality.

I recommend VirtualDub to do the rotation. It's free and fast."

"I used Avidemux, a free video editor.
This software allows you to rotate any movie.
In a drop-down list you can select the desired output format (e.g. MP4, AVI, FLV, etc.).
If using the MPEG-4 ASP setting in the video drop-down list, you will have to fiddle around with Quantizer setting (A higher number means reduced file size and less quality).
This tool is great when you capture a movie on your cell phone and want to send the movie to friends!"

"You can rotate an MP4 video using VLC and some awesome nice guy wrote a detailed set of instructions with screenshots here: http://www.wintipsdotorg/how-to-rotate-and-save-a-video-using-vlc-media-player/
(Disclaimer: This post isn't spam, I have no connection at all to the site or the dude who wrote the instructions. I merely used the instructions to rotate a video of my baby daughter and so I'm just really grateful for it.)"

The easiest method I've seen is with QuickTime (Pro), open Movie Properties, click Video Track, then go to Visual Settings and use the arrows to rotate as needed. Then close the Movie Properties, then do a File Save As.

I had many .mov files that needed rotation. I used Square 5 Streamclip and did not loose any quality. Super easy to save as in many file formats: http://www.squared5.com/svideo/mpeg-streamclip-win.html