How to Deinterlace Video in Avidemux (and When NOT To)

Deinterlacing converts interlaced video — where each frame is two half-resolution fields captured at different moments — into clean progressive frames. In Avidemux you do this with a Deinterlace video filter (Video > Filters), which requires re-encoding. But here is the part every generic tutorial skips: you should not deinterlace everything that looks interlaced. Movie content from DVDs is often segmented progressive — Avidemux weaves those fields back together correctly with no filter at all, and deinterlacing it anyway throws away half your vertical resolution for nothing. Diagnose first, filter second.

Step 1: diagnose — true interlaced or segmented progressive?

How to tell: step through the video frame by frame. If moving objects show “combing” (horizontal teeth) and the two fields clearly show different moments, it is true interlaced. If the picture looks clean when Avidemux displays it and only shows combing in a naive player, it is probably segmented progressive — leave it alone. This “don’t deinterlace blindly” insight comes straight from the Avidemux forum moderators, and it is the single biggest quality mistake beginners make.

Step 2: apply the deinterlace filter

1. Open the video in Avidemux.
2. Set Video Output to a real encoder (e.g. Mpeg4 AVC (x264)) — filters are disabled in Copy mode.
3. Go to Video > Filters and add a Deinterlace filter from the Interlacing category.
4. Pick the filter variant and field order that matches your source (top-field-first vs bottom-field-first — wrong order makes motion stutter; preview to verify).
5. Set Audio Output as needed, Output Format to Mp4 Muxer, and Save.

Bitrate advice for the re-encode

Deinterlacing forces a re-encode, and re-encoding interlaced-origin material needs more bits than you might expect — the deinterlacer invents detail that the encoder must then preserve. Practical starting points:

• Use x264 with a quality-based mode (CRF) rather than a fixed low bitrate, so complex motion gets the bits it needs.
• Do not downscale in the same pass unless you must — judge the deinterlace quality at full resolution first.
• Keep the frame rate as-is. Doubling the frame rate (“bob” deinterlacing to 50/60p) is smoother but doubles file size and is a separate creative choice.

See our compress video guide and filters guide for the encoder settings in depth.

Alternative: let the player do it

If you are only watching the video yourself (not uploading or archiving it), consider not deinterlacing at all: players like VLC and mpv deinterlace on the fly during playback, in real time, with zero quality commitment. Permanent deinterlacing is for files you share, upload, or archive — where you cannot control the player.