If you have a video with odd dimensions, you can change the video's resolution to conform with standard display formats. And if you aren't too concerned about the quality of a video, you can lower a video's resolution to produce a smaller file. Whatever your reason, Avidemux can help you set new video resolutions without having to completely re-encode your videos.
Download and install a free copy of Avidemux (see Resources). Launch Avidemux after the installation process has completed.
Click on the program's "Open" button. Load your video file into the program using the file explorer window that appears.
Click on the "Video" menu box. Select your video's codec from the menu box, if you don't wish to re-encode your video with a new codec. You can choose a new codec, if desired (see Tips).
Click on the "Filter" button under the "Video" heading. Click on the "Transform" heading in the "Video Filter Manager" menu. Double-click on the "Resize" filter.
Enter the desired pixel height and width into the corresponding fields inside of the "Resize" menu box. You can use the "Percent" slider to increase or decrease the resolution of your video -- the height and width are adjusted proportionally.
Click on the "Resize" menu's "OK" button, then click on the "Close" button in the "Video Filter Manager."
Click on the "Save Video" button in Avidemux's toolbar. Select a folder to store the output video file, using the "Select File to Save" explorer window. Type a name for your video into the window's "File name" field and click "Save."
If you don't know your video's codec type, press the "Alt" and "Enter" keys on your keyboard. You'll find your video's codec next to the "Codec 4CC" heading when the "Properties" menu appears.