How to Change Pixel Aspect Ratio in Kdenlive

When importing video footage into Kdenlive, you may sometimes encounter stretched or distorted clips due to mismatched pixel aspect ratios. This guide provides a straightforward, step-by-step walkthrough on how to access and modify the pixel aspect ratio directly within a clip’s properties in Kdenlive, allowing you to quickly restore your footage to its correct visual proportions.

Step 1: Locate the Clip in the Project Bin

To change a clip’s aspect ratio, you must modify the source file settings before or after placing it on the timeline. Go to the Project Bin tab (usually located in the top-left interface panel) and find the stretched clip you want to fix.

Step 2: Open Clip Properties

Right-click on the target clip in the Project Bin and select Clip Properties from the context menu. This will open the properties panel, which displays detailed information about the video’s resolution, frame rate, and codecs.

Step 3: Navigate to the Properties Tab

Within the Clip Properties window, make sure you are on the primary Properties tab. If you do not see the aspect ratio settings immediately, look for the Advanced tab or click on the file details icon at the top of the properties pane.

Step 4: Force the Pixel Aspect Ratio

  1. Locate the setting labeled Aspect ratio or Force pixel aspect ratio.
  2. Check the box next to Force pixel aspect ratio to unlock the manual override.
  3. Input the correct ratio values into the box (for example, 1:1 for standard square pixels, 4:3, or 16:9 depending on the original formatting of the camera sensor).
  4. Alternatively, you can select a preset ratio from the dropdown menu if your version of Kdenlive provides one.

Step 5: Save and Apply

Click the OK or Apply button at the bottom of the Clip Properties panel to save your changes. The clip in both the Project Bin and on your timeline will instantly update to reflect the new, corrected aspect ratio without any stretching.