Thin horizontal teeth along the edge of a moving person or object can be a sign of interlaced fields being combined poorly. The effect is often called combing because alternating lines appear to show different positions.
It is a different pattern from large compression blocks, so a useful report describes the shape and movement rather than calling every defect pixelation.
Look for alternating-line displacement
Imagine an arm moving between two successive fields. One set of lines can contain the earlier position and the next set the later position. A simple weave can place both into a single displayed frame. Along the moving boundary, the two positions form a fine serrated pattern.
A static part of the image may remain sharp because it has not changed between fields. That contrast is a clue: the defect can follow movement while a stationary background looks normal. It is not sufficient evidence by itself, but it gives you a much better starting description.
Compression artifacts tend to have other structures, such as blocks, smeared texture or ringing around edges. Several problems can coexist, so avoid forcing the whole picture into one diagnosis after noticing a single pattern.
Capture an example responsibly
If a screenshot is permitted and contains no private information, it may illustrate the visible edge. Keep the program timestamp and whether playback or pause produced it. A player can process paused frames differently, so a screenshot should accompany a description of the moving result.
Do not resize the image aggressively before examining it. Scaling and compression of the screenshot can hide fine alternating lines or introduce new patterns. For a support report, keep an original local copy and share only the relevant non-private crop if appropriate.
Compare another moving edge in the same program. If the teeth appear only on one graphic or one inserted shot, the issue may belong to that production element rather than the entire player output.
Follow the defect through the available evidence
Read the source scan type if the player exposes it. Then note the player's deinterlacing setting, if there is one, and the output mode. Do not assume a television marked progressive can never display a badly converted interlaced source; the damage may already be baked into the incoming picture.
A reversible change to a documented deinterlacing option can help test the theory. If it changes the moving edge while everything else stays constant, keep that observation. If it does nothing, restore the original setting and report the limit instead of stacking unrelated adjustments.
- Choose a repeatable moment with a clearly moving edge.
- Describe the fine line pattern and whether static areas remain clean.
- Record source scan information and the current player option.
- Test one supported deinterlacing alternative if available.
- Report the exact scene and result without claiming an unobserved upstream cause.
Useful answers
Is combing the same as blocky compression?
No. Combing is an alternating-line motion pattern; compression damage may appear as blocks, smearing or edge noise. They can occur together.
Why does it appear on moving objects but not the background?
Successive interlaced fields can capture movement at different positions, while an unchanged background remains aligned between fields.