Re: CFF table processing for WOFF2?

On 23/4/15 02:03, Behdad Esfahbod wrote:
> Hi,
>
> Is the working group open to adding processed CFF table to WOFF2 or is
> it too late?  Maybe we can do that in a compatible way?
>
> There's already rumour on the net (which we have anecdotically
> confirmed) that CFF fonts compress better in WOFF2 if desubroutinized.
> It's unintuitive but makes some sense, if Brotli is great at capturing
> redundancy, it should perform at least as well as the subroutinization.

This is an interesting possibility, but I do have a concern... unless 
the decoder can "re-subroutinize" the font (which seems like it would 
add substantial complexity to the decoder) this has the potential to 
significantly increase the in-memory footprint of the decoded font. For 
memory-constrained devices, that might be a poor tradeoff.

(I have no actual statistics to support or deny this. Both the potential 
savings of compressed size and the resulting change to the uncompressed 
size would be interesting to know...)

>
> I have only one transform on top of that in mind right now: drop the
> offsets to charstrings.  At reconstruction time, split charstring array
> on endchar.
>
> If there is interest I can prototype it and report savings.
>
> Cheers,
>
> behdad

Received on Thursday, 23 April 2015 06:16:09 UTC