[FFmpeg-devel] [PATCH v4 1/4] doc: Explain what "context" means

[Andrew Sayers]

On Wed, May 29, 2024 at 01:06:30PM +0200, Paul B Mahol wrote:
> On Wed, May 29, 2024 at 12:50 PM Andrew Sayers <ffmpeg-devel at pileofstuff.org>
> wrote:
> 
[...]
> > *Are AVOptions just command-line options?*
> >
> > I have trouble with statements like "AVOptions is a framework for options",
> > both because it's circular and because the term "option" is too broad to be
> > meaningful.
> >
> > I've previously pushed the word "reflection" on the assumption that options
> > can be used anywhere variables are used.  For example, imagine a decoder
> > that
> > could be reconfigured on-the-fly to reduce CPU usage at the cost of
> > displaying
> > blurier images.  That can't be part of the public interface because it's
> > codec-specific, but I could imagine updating some kind of "output_quality"
> > AVOption as a user slides a slider up and down.
> >
> > But the CLI tools are largely non-interactive, so have I just
> > misunderstood?
> >
> > How about saying "AVOptions is a framework for command-line options"?
> >
> 
> ffmpeg is cli tool
> 
> libavfilter is library
> 
> AVOptions is certainly and primarily not framework for command-line options.

"Command-line option" might be the wrong word, but I've just checked
write_number() in libavutil/opt.c, and it seems to do non-atomic updates
without locking anything.  That suggests I was indeed wrong to think it could
be used on-the-fly - maybe "initial configuration options" would be a better
term?  Possibly with a warning somewhere about how AVOptions is not reentrant?