Rotate a MP4 file, while preserving codec and quality attributes

Solution 1:

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.

Solution 2:

1. Open Avidemux (free video editing software)
2. Open your mp4 file.
3. Choose a "Video Output" other than "Copy" [I chose "Mpeg4 ASP (ff)"]
4. Choose Video > Filters (or in Windows, press Ctrl+Alt+F)
5. Double-click "Rotate" to add that filter
6. Choose 90 degrees
7. Press "Close" to exit "Video Filter Manager"
8. Save

(Thanks to @secret for getting me started, but his/her list of steps weren't complete.)

Solution 3:

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!

Solution 4:

1. Open Avidemux
2. Press Ctrl+Alt+F (for Windows)
3. Select Rotate
4. Save