Need a Video Resizer?

Sometimes, you may need to resize your video or change its aspect ratio – for example, if you have a wide-screen (16:9 aspect ratio) HD video that you want to watch on the 4:3 aspect ratio screen of your iPod Classic. If you try to upload a video with an incorrect aspect ratio to your device, the video will either not play at all or will be displayed incorrectly (probably with stretched-out images).

You can correct the problem easily by resizing video with Movavi Video Converter. The program supports all popular video formats, including AVI, MOV, MP4, MPEG, and WMV, so you can use it to resize movies in almost any format as well as reduce video file size if necessary. Movavi Video Converter offers plenty of ready-made presets for popular websites and social networks, enabling you to resize video for YouTube, Facebook, and other sites.

To start working with Movavi’s video resizer app, download and install the Windows or Mac version of the software on your computer.

All these four methods preserve the original frame proportions with no distortion in the output clip.

2. Now let’s imagine that we have two rectangles: the size of the first matches the width and height of the original video, and the dimensions of the second match the width and height of the chosen preset. The program overlays one rectangle with the other and changes the width and height of the 640 × 480 frame, placing it inside the second one.

If you need to change the frame proportions in your video, you can easily set a new size manually. Select Custom from the Frame size list and enter the required values in pixels into the Width and Height fields. You can also pick one of the standard video resolutions from the same list.

Changing the proportions of an image can result in problems like unwanted stretching of the video, a pixelation effect, or unwanted black bars around the frame (the so-called “postage stamp effect”). To avoid these issues, set the correct resize method and resize quality parameters in the Settings window.

• Stretch – the original video frame is stretched (or condensed) to the specified frame size (width and height).

• Letter box – the original video frame is placed within the output frame. The aspect ratio stays the same, and the free space between the input and the output frames appears as black bars. This method is set by default in Movavi Video Converter.

• Crop – the original video frame is placed within the output frame. The aspect ratio stays the same, and the parts of the input frame that go beyond the output frame size are cut off.

• Auto – a compromise between Stretch and Crop. The program will simultaneously crop and stretch your video to meet the required size.

Resize quality

Four options are available for resize quality: Low (Draft), Good (Fast), High (Medium), and Best (Slow). The picture below shows the differences between the first and last of these options.

• Low (Draft) – this mode uses the nearest-neighbor interpolation method. It works fairly quickly, but the quality of the output video is reflected in the speed. When you increase the frame size, there will likely be visible pixelation effects.

• Good (Fast) and High (Medium) – both of these modes use bilinear interpolation. They work a little more slowly but provide a better video quality than the draft mode. The pixelation is still visible at larger frame sizes, but, in general, the image looks smoother. Good will work a bit faster than High and provide a somewhat lower image quality (as it is evident from their names), but in reality the difference is almost unnoticeable. You will likely only see a difference if you change the resolution considerably. The default mode in Movavi Video Converter is Good since it provides good balance between speed and quality.

• Best (Slow) – uses bicubic interpolation. This process works much more slowly, but the quality of the output video is higher. When you increase the frame size, the image is smoothed and there is no pixelation. Additionally, when you reduce the frame size using this method, moiré patterns and other unwanted effects are much less likely to appear than for the other three methods, which can cause thin lines on your video to look broken and have an irregular thickness; Best quality will maintain the integrity of the thin lines.