How can i modify the Encoding Time of a mp4 file?

[Haslick]

I just need to copy the Create Date to Encoding Time. I already try with this command:

-encodingtime<createdate

And this too:

-microsoft:encodingtime<createdate

But both threw this message:

======== ./CAM00007.mp4
Nothing changed in ./CAM00007.mp4
    0 image files updated
    1 image files unchanged
Warning: Sorry, encodingtime is not writable - ./CAM00007.mp4
Warning: No writable tags set from ./CAM00007.mp4
<-END-

How can i modify the Encoding Time of a mp4 file?

[Hayo Baan]

The short answer is, you can't. At least not with ExifTool (see the tag documentation). You might be able to alter it with e.g. a video editing program, but I don't think any of these allow you to alter individual metadata tags. And even if they allow this, you might not be able to edit this specific tag as it is Microsoft (only).

If the tag is already is present a possible solution would be to use e.g. a hex editor and change it in-place. This is basically the approach I took for another specific (M2TS video) question that was asked on this forum, and for which I wrote a special script. While the script itself is not applicable to your situation, a similar approach might be feasible. If you point me to a downloadable sample mp4, I will have a look.