How to fix old footage that shows comb lines whenever anything moves
Ask Vizard Agent to check the footage in motion rather than on frames, because interlacing is invisible on a still and obvious the moment anything moves. Where it finds combing, the fix is to deinterlace the source and rebuild the cut from that — deinterlacing a finished render repairs the stripes and softens everything else along with them.
What is the short version?
Old tape, broadcast archive and some camera presets record two half-frames a fraction of a second apart and weave them together. Nothing is wrong with either half, so a still frame looks fine — and a walking figure comes out in horizontal stripes.
- Tell Vizard Agent the material is old or from broadcast.
- Ask it to check for combing in motion, not on frames.
- Ask for the cut rebuilt from deinterlaced sources.
What do you need before you start?
The original files rather than an export of them. Vizard Agent deinterlaces the source and cuts from that, so having the material as delivered — tape capture, archive file, camera original — is what makes a clean result possible.
- The source files. Not a re-encode.
- Where they came from. Tape, broadcast, an old camera.
- Which shots look wrong. If you have noticed any.
- The delivery format. It sets the frame rate.
- Whether any of it is fine. Mixed sources are common.
What do you type into Vizard Agent?
Describe the symptom to Vizard Agent in plain words. You do not need to know the word "interlaced" — horizontal stripes across anything that moves is already a precise enough description, and it rules out all the other faults that merely look like softness.
Prompt
Variants worth knowing:
- "Stripes whenever someone moves." The symptom, precisely.
- "Looks fine when I pause it." Rules out softness and compression.
- "At the source." Not on the finished render.
What does Vizard Agent actually do?
Here is the sequence on a real archive-based cut where the combing was found late. Notice that it is the motion analysis that catches it — everything before that had looked at frames, and frames are exactly where this fault hides.
- Inspects the source files and their formats.
- Builds contact sheets and reviews the material.
- Assembles the cut from the selected sections.
- Runs a motion and sync analysis on the rendered cut.
- Finds the combing that the frame reviews could not show.
- Deinterlaces the source footage rather than the render.
- Rebuilds the cut from the corrected material.
- Checks a corrected frame from a moving moment.
- Checks sharpness alongside the deinterlace on the same shots.
- Confirms the rest of the picture was not softened by the fix.
Step four is the one people skip because it feels redundant. A contact sheet answers whether the shots are right; only playback answers whether they move correctly, and combing lives entirely in the second question.
Step six is the difference between a fix and a compromise. Deinterlacing a finished render applies the repair to titles, graphics and any progressive footage in the cut as well, softening all of it; doing it at the source touches only the material that needs it.
Step nine matters because the two faults look similar at a glance. Deinterlacing costs a little detail, so it is checked against sharpness on the same shots rather than assumed to be free.
What does the result look like?
Motion that holds together on screen. People walk across the frame without tearing into stripes, the titles and any modern footage in the cut are left exactly as they were, and Vizard Agent tells you which shots it deinterlaced and what that treatment cost each of them in sharpness.
When does this not work well?
Some of the damage is already baked in before Vizard Agent ever sees the file. If the only copy you have is an export that was itself made from woven frames, the two half-images have already been merged into one, and there is correspondingly less left to separate.
- Already-flattened exports. The halves are merged.
- Heavily compressed copies. The stripes are now blocks.
- Mixed sources in one file. Some shots need it, some do not.
- Very fast motion. Deinterlacing costs the most detail there.
- Material that was fine. Do not deinterlace progressive footage.
How do you fix a result that came back wrong?
Say whether what you are seeing is stripes or softness. Those are the two opposite sides of this particular fix — too little deinterlacing leaves the stripes in place, too much of it softens the whole picture — and Vizard Agent measures the two things separately.
- "Still striped on the wide shot." That source is deinterlaced too.
- "Everything looks soft now." The fix was applied too broadly.
- "The titles look worse." They were caught by a render-level pass.
- "Only some shots are affected." The sources are treated individually.
How does Vizard Agent compare to doing it yourself?
By hand you review the edit on contact sheets, which is efficient and shows you nothing, then deliver. The client watches it on a television and asks why everyone has stripes through them, and by then the cut is built on the wrong sources.
| By hand | Vizard Agent | |
|---|---|---|
| Where it is caught | By the client, in playback | In the motion analysis |
| What gets deinterlaced | The finished render | The sources that need it |
| Titles and graphics | Softened with everything else | Untouched |
| Mixed material | Treated the same | Treated per source |
| The cost | Unmeasured | Checked against sharpness |
Common questions
Why does it look fine when I pause? Because a still shows one moment. The stripes are two moments woven together.
Do I need to say "interlaced"? No. Describe the stripes and Vizard Agent will identify it.
Can it fix a finished export? Partly, and it softens everything. Vizard Agent prefers the source.
Will it soften my footage? A little, on the shots it treats. Vizard Agent reports the cost.
What if only some clips are affected? Vizard Agent treats them individually rather than applying one pass.
Does this apply to phone footage? Rarely. It is old tape, broadcast archive and some older cameras.
Will my titles be affected? Not if the fix is at the source, which is why Vizard Agent works there.
Can it upscale at the same time? Yes, and the order matters. Vizard Agent deinterlaces first.
How does it check the result? In motion, on the moments that were striped, not on a contact sheet.
What about the frame rate? Deinterlacing can double it. Tell Vizard Agent your delivery target.
Is there a version that keeps more detail? Yes, several approaches. Vizard Agent can compare them on one shot.
What if I only have a compressed copy? Harder. Vizard Agent will tell you what is recoverable.
Can it flag this before I start editing? Yes. Ask for a motion check on the sources first.
Why did nobody notice earlier? Because every review before playback looks at frames, and frames hide it.