Distorted Video Aspect: Why It Happens and How to Fix It
Faces in the video look squashed or stretched — aspect distortion is the most commonly mishandled picture problem. The instinct is to stretch it back, and the correct fix is precisely not to.
Where distortion comes from: three causes
Source files whose resolution and aspect tag disagree: legacy DV and capture-card output like 720×576 uses non-square pixels, with the ratio stored in a tag rather than the pixel count. When the tag is lost or ignored, the picture distorts. Second: a player or platform stretching the frame to the wrong ratio — platform transcoders, projectors and old TVs all do this.
Third, you did it yourself: the editing canvas was set to the wrong ratio and a 4:3 picture was exported into a 16:9 frame. The quick test is reference shapes: faces, a round clock, a square window. If circles turn into ellipses, the ratio is wrong; if circles stay circles, it is a composition issue, not distortion.
The fix: crop back to ratio, never stretch
Stretching the picture back does not work in most tools: tools take pixel dimensions, and changing dimensions necessarily stretches pixels — you just rotate the distortion. The correct path is two steps: crop a correctly-proportioned region out of the distorted frame using the four-edge frame, then scale the cropped picture to the target resolution.
Which edges to crop depends on composition: for 4:3 legacy footage going to 16:9, crop the sides and keep the centered subject; if the subject sits off-center, crop more from the empty side. Sacrificing picture area to preserve the ratio is always the right trade — viewers tolerate reframing far more than they tolerate distortion.
Distortion you should not fix: the tag is right
One kind of distortion must be left alone: non-square-pixel material like 720×576 displays correctly in players that honor aspect tags, and only distorts in players or platforms that assume square pixels. Fixing it makes things worse — cropped footage never comes back, and the tag was correct all along.
The test: check two or three different players and devices. Distorted everywhere — true distortion, fix by cropping. Distorted in only one environment — that environment’s problem; deliver the source untouched and note the aspect tag in the parameter sheet so the recipient checks their playback side.
Self-check after fixing
Three checks after the fix: face proportions (the eye is most sensitive there), round objects, and on-screen text. If text is still squashed, the crop ratio is off — go back and adjust the edges. Also remember that crop plus scale are two lossy operations, so give the final encode enough quality; do not waste the repair on a starved last step.