[FFmpeg-devel] [PATCH] doc/developer: origin of tables should be documented.

Nicolas George george at nsup.org
Fri Jul 31 12:50:02 EEST 2020


Lynne (12020-07-31):
> I disagree. We don't have any proprietary blobs in our codebase.
> Everything that you think is binary is in fact a well defined VLC
> table that simply describes bit positions and lengths.

Please read my message more carefully (and possibly with less
hostility): I never said that the tables we have right now are
proprietary blobs.

What I am saying is that accepting them in new code creates a loophole
that somebody with bad intentions could exploit in the future. One of my
reasons for insisting on this is to close that loophole.

> Neither are quantization tables. They're again, well defined series of
> lookup tables that always follow a simple pattern, be it linear or
> some exponent.

Then all I am asking is:

/* Geometric progression with ratio 42. */

Or, if you used a one-liner in whatever language of your choice, just
copy-paste it into the comment:

/* Zsh: for i in {0..11}; printf "%8x\\n" $[440*2**(22+i/12.)] */

That is all I am asking. Is it really too much to ask? One line of
comment!

> Forcing developers to meticulously describe standard bitstream readers
> or copying entire chunks of specifications as comments just because
> you don't understand them,

If they are standard, just name them or put a Wikipedia link.

> or want to justify your own personal war, or are paranoid of binary
> blobs is not acceptable.

Please refrain from personal attacks. The only thing I am at "war"
against is bad code by Libre Software standards.

Libre Software is not just about churning out code that does the work;
that's for proprietary software and its poor cousin Open Source. Libre
Software is also about building collective knowledge. Libre Software is
almost as much teaching as it is coding, so that other developers can
extend it rather than just using it.

> In the first place no one would commit actual binary blobs (read:
> CPU-specific bytecode or a series of bytes needed to initialize a
> device) to the codebase.

I hope so. I am not convinced some company would not try to.

> And if developers were forced to copy chunks of spec as comments into
> the codebase you'll end up with licensed content just sitting in the
> codebase, making us liable for lawsuits.

As I said, if the explanations already exist elsewhere, just a link or a
bibliography reference is enough. No need to copy chunks, I never talked
about is and do not know why you think I did.

Regards,

-- 
  Nicolas George
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