How to check recordings with MP4Fix?¶

The mp4fix check command inspects your ClonerAlliance UHD Halo recordings and reports which ones can benefit from optimization. It only reads your files - nothing is ever written, so it is always safe to run.

Basic Usage¶

Point check at a recording. On Windows:

.\mp4fix-windows-x64.exe check "D:\Videos\VID_20260728175011.mp4"

On macOS:

./mp4fix-macos check ~/Movies/VID_20260728175011.mp4

A recording that can be optimized shows a report like this:

VID_20260728175011.mp4
  3840x2160  59.94 fps  HEVC  5 m 21 s  4.5 Mbps
  CAN BE OPTIMIZED - 1 improvement available:
    - Timeline precision - ...
  To apply:  mp4fix optimize "VID_20260728175011.mp4"

The full report describes each improvement in plain language - for example, timeline precision adds richer timing detail so desktop players and editors show smooth motion and import the file reliably. Your video and audio data are never touched.

A recording that needs nothing shows:

VID_20260731090447.mp4
  3840x2160  59.94 fps  HEVC  11 m 32 s  8.0 Mbps
  ALREADY OPTIMAL - no changes needed

Understanding the Results¶

Result	Meaning
CAN BE OPTIMIZED	The recording will benefit from optimization. Run `mp4fix optimize` to apply the improvements.
ALREADY OPTIMAL	The recording needs nothing and is left unchanged.
SKIPPED	The file is not a ClonerAlliance recording and is always left untouched.

Checking a Whole Folder¶

You can pass a folder instead of a single file. Add -r to include all sub-folders:

.\mp4fix-windows-x64.exe check -r "D:\Videos"

After checking several files, MP4Fix prints a short summary of how many can be optimized.

Note

You can point check directly at the memory card or USB drive while it is connected to your computer - no need to copy the recordings first.

Next Steps¶

When you are ready to apply the improvements, see How to optimize recordings with MP4Fix?.

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