mConvert allows movie editing in an arbitrary (trim,change bitrate,remove or keep sound , change movie size, file size,rotation) and can upload to facebook, youtube easily
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Tutorial
1. Select the movie from the camera roll and maybe trim it right at the screen now
2. In the screen Movie Info you can select the properties for the movie output as off off sound, choose the resolution, adjust the bit/pixel (this is the property that allows setting the ratio of bits per pixels when this small gear up aspect ratio movie size to as small and vice versa)
3. To create the movie hit the Convert button after you've created the movie is standing moves to screen preview to preivew, export to camera roll, upload facebook, youtube