Find frozen sections and thin frames with FFmpeg freezedetect, mpdecimate and framestep

Guide ID: art_01M6V5FHGEDS4GN22K8GCZJ0J5

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Guide title

Find frozen sections and thin frames with FFmpeg freezedetect, mpdecimate and framestep

Coverage

For editors and quality checkers who need to find where a clip holds still and reduce repeated frames. You end with a log of freezes and three ways to thin frames, so you can decide what to cut or drop. Based on the FFmpeg manual and not run; the command lines are assembled from the option descriptions.

Example

A hypothetical 30 fps clip with a title card held for 5 seconds: the documented defaults imply a freeze notice during the hold, and thinning by 3 would keep 10 frames per second. No run was made.

Useful starting points

• Because mpdecimate targets very low bitrate encoding, it may remove real frames; confirm slow-motion passages still play correctly.
• No freezes reported usually means the noise tolerance is too low or the minimum duration too long; false freezes mean the tolerance is too high.
• After thinning, compare frame counts and durations before and after, and check timestamps, since dropped frames change timing.