Kdenlive Audio Sync: How to Drop Frames on Slow PCs

When editing video on older or lower-spec computers, Kdenlive’s playback can lag, causing the audio and video to fall out of synchronization. This article provides a quick, step-by-step guide on how to configure Kdenlive to drop video frames during playback, ensuring your audio remains perfectly synced in real-time.

Enabling Real-Time Preview (Frame Dropping)

Kdenlive includes a built-in feature designed to drop video frames when your CPU or GPU cannot keep up with the playback speed. Enabling this option prioritizes audio playback over visual smoothness.

1. Open your Kdenlive project.
2. Locate the Project Monitor (the video player window showing your timeline preview).
3. Right-click anywhere inside the video playback screen of the Project Monitor.
4. In the context menu that appears, click on Real-Time Preview to enable it (a checkmark should appear next to it).

Once activated, Kdenlive will automatically skip rendering resource-heavy video frames during playback to keep the playhead aligned with the audio track.

Additional Adjustments for Slower Machines

If enabling Real-Time Preview is not enough to prevent audio lag, you can combine it with these two performance-boosting settings:

• Lower the Preview Resolution: At the bottom right of the Project Monitor, click the resolution scaling dropdown (it may show 1:1 by default). Change this to 1/2, 1/4, or even 1/8 resolution. This reduces the rendering load significantly without affecting the final export quality.
• Enable Proxy Clips: Go to Settings > Configure Kdenlive > Project Defaults and check the box for Proxy Clips. This creates low-resolution copies of your footage for editing purposes, which require far less processing power to play back in sync.