How to Fix Interlaced Video in Kdenlive

This article provides a straightforward guide on how to eliminate unsightly interlacing artifacts—often seen as horizontal, comb-like lines during motion—from your footage using Kdenlive. You will learn how to configure your project settings, apply Kdenlive’s built-in deinterlace effect, and export your final video as a clean, progressive file suitable for modern screens.

Understanding Interlaced Video Artifacts

Interlaced video (often labeled as 1080i or 576i) displays alternating odd and even horizontal lines to save bandwidth. While this worked well for old CRT televisions, modern digital screens display images progressively (all lines at once). When interlaced footage is played on progressive screens, fast-moving objects exhibit a jagged “combing” effect. Fixing this requires converting the interlaced fields into progressive frames, a process known as deinterlacing.

Method 1: Apply the Deinterlace Effect

The most direct way to fix a specific clip on your timeline is by using Kdenlive’s dedicated deinterlacing filter.

  1. Drag your interlaced clip onto the Timeline.
  2. Open the Effects tab (usually located in the bottom-left or top-left pane). If you cannot see it, go to the top menu and select View > Effects.
  3. In the search bar of the Effects tab, type Deinterlace.
  4. Drag and drop the Deinterlace effect directly onto the clip on your timeline.
  5. Select the clip to open the Effect/Composition Stack panel.
  6. In the effect properties, choose your preferred deinterlacing method. Yadif (Yet Another Deinterlacing Filter) or Bwdif are highly recommended as they offer the best balance between sharpness and motion smoothness.

Method 2: Force Deinterlacing in Clip Properties

If you want Kdenlive to handle the deinterlacing automatically before you even put the clip on the timeline, you can adjust the source clip settings.

  1. Go to the Project Bin and right-click on your interlaced video clip.
  2. Select Clip Properties from the context menu.
  3. Navigate to the Advanced tab.
  4. Locate the Scan Type or Deinterlace option.
  5. Change the setting from “Interlaced” (or “Automatic”) to Force Progressive or enable the deinterlacing checkbox (depending on your Kdenlive version). This forces the software to interpret the video as a progressive source, applying an internal deinterlacing algorithm.

Method 3: Export to a Progressive Format

Even if you apply effects, you must ensure your final project settings and render profile do not output an interlaced file.

  1. Ensure your project profile is progressive. Go to Project > Project Settings and select a progressive profile (e.g., 1080p 29.97fps or 1080p 50fps instead of 1080i).
  2. Click the Render button in the top toolbar (or press Ctrl + Enter).
  3. Select a progressive output format, such as MP4 (H.264/AAC) or WebM.
  4. In the render options, make sure the scanning mode is set to Progressive. Kdenlive will automatically deinterlace any remaining interlaced assets during the final rendering process.