Hi, there is something I can't figure out and i need some help.

I am using handbrake to convert iphone videos to H264, MP4 format, but I don't know how to rotate the videos 90degree.

So my question is
a) Is there a program that allows you to rotate H264 format videos?
b) is there a program that allows you to convert videos into H264 format while simultaniously rotating them 90 degree?

If you just want to play it back on your computer VLC player can do what you mention.

"Choose tools from the menu bar and select effects and filters, on the video effects tab, click on the transform checkbox and choose your degrees of rotation. The video is rotated counter-clockwise, so to rotate clockwise 90 degrees you’ll want to choose rotate by 270 degrees."

If you want to export the video through hand brake i believe its possible through some command line stuff as it doesn't have a GUI option. Aside from that im sure Vegas can do what you want.