Re: New Version Notification for draft-vkrasnov-h2-compression-dictionaries-01.txt

[Patrick McManus <[e-mail]>]

On Thu, Nov 3, 2016 at 6:32 AM, Jyrki Alakuijala <[e-mail]> wrote:

> Yes, this is consistent with our experiments. Brotli + custom dictionary
> is more efficient than SDCH + custom dictionary with further gzip or brotli
> compression.
>
> With small (~150 kB) dictionaries brotli wins SDCH by 10-20 % (20 % at
> brotli quality 11, 10 % at quality 6), with larger (1 MB) dictionaries
> more, 20-30 % (30 % at brotli quality 11, 20 % at quality 6). The larger
> the custom dictionary, the more powerful brotli comes in comparison to
> SDCH. All our experiments indicate that SDCH is fully redundant and can be
> abandoned if we add custom dictionary support to brotli content encoding.
>


this is a good discussion.

We should also be congnizant of the recent movement towards
"content-encodings should be self describing" that came out of the
encrypted object draft discussion - which sdch doesn't quite match (yet?).
Perhaps a brotli with a uri for its custom dictionary combined with push of
the dict gets us there (handwave).