I agree with icarolongo: you cannot honestly write that "proprietary
(non-free) formats *require* counsel and accused people to install
proprietary software".
It is true that, in theory, it is harder to get free software codecs to read
a format whose specifications are not freely available. However, in practice,
the best MPEG4 decoder is in VLC, a free software program.
The risk is that, at some point, using their patents, MPEG LA sues the
VideoLAN project and other free software projects to force them to stop
distributing codecs for their formats. If that happens, people who value
their freedoms will stop reading those formats (including videos stored on
their system in those dangerous formats). Other people would feel the need
for proprietary a video player...
I did not understand in what way "confidentially" is related to
patent-unencumbered formats.
Something that I believe is missing in your letter is a quick explanation of
what is a "free format". Your sentence "By “free” here, I mean certain
freedoms, and not price" is too vague. I would rather write: "Free, in 'free
format', means the freedoms for anyone to read the technical specifications
of the format, to implement it and to use it. Free formats guarantee the
interoperability today and for the foreseeable future. On the contrary,
non-free formats are like trade secrets and impose a particular software
solution to be properly used. To hide the specifications of the format, that
solution necessarily denies the freedom for the user to access the source
code of the program, a fundamental freedom:
https://www.gnu.org/philosophy/free-sw.html";
I would explain as well what is a software patent: "In addition, non-free
formats usually are protected by software patents. That means a company
(sometimes doing only that) can sue any software developer who implemented
the format or even any mere user of the format. Those risks further hinder
interoperability. In the case of video formats, this risk is not merely
theoretical: MPEG LA is known to aggressively use its patents on the MPEG
formats: https://en.wikipedia.org/wiki/MPEG_LA";
