Re: Remove metadata from MP4 on Windows

This line looks interesting. The "-c copy" is an attempt to not modify the
video and audio stream, then the "map" options are attempts to edit the
4CC in the movie containing metadata. Anything the CODEC does not recognize,
is ignored, and that's how you store metadata, is make a 4CC that won't
cause grief to the CODEC.
 ffmpeg -y -i "test.mkv" -c copy -map_metadata -1
    -metadata title="My Title" -metadata creation_time=2016-09-20T21:30:00 -map_chapters -1 "test.mkv"
 And obviously, some amount of metadata is needed for the movie to function,
and these would be fields that are "in-band" and not "out-of-band". That
is likely why the command is attempting to edit the Title. And the Title
might show up in a Windows Properties dialog. Microsoft is only interested
in certain fields, for the purposes of Search Indexer and other fields are
ignored. I think they know what most all of the metadata is, but they
won't write tools for it. Only a certain amount works in search.
 Generally, 4CC packets are length sensitive, and if you want to use a
hex editor to expunge something, make sure you don't change the length.
If the word was "Hello", you would replace it with "XXXXX".
 As for ownership of content, steganography or watermarking, there are
some effective methods out there that are hard to remove. with the right
tool, it might print on the screen "Property of Paramount Pictures".
Metadata is the more "obvious" marking, but is not the only means.
With a good watermark, even conversion from one CODEC to another, will
not remove the marking.