Re: [pdf-devel] Predictor filter

[Ed]

On 22 January 2011 21:07, Jose E. Marchesi <address@hidden> wrote:
> You can find several unit tests for the currently implemented filters in
> both torture/unit/base/stm/pdf-stm-read.c and
> torture/unit/base/stm/pdf-stm-write.c. I guess that a similar approach
> could be used to test the predictor filters.

The ones I looked at mostly encode a simple string, which can't be
done for the predictor stuff because it's explicitly binary scanlines.
(I knew nothing about the predictor filter before this afternoon - I
surmise so far it's at the heart of embedding PNG in PDF?) Is the
library advanced to the state that I can try to construct PDFs with
authoring tools which stress this in various ways? I really just
picked this up and ran with it since it didn't seem like a big task: I
reworked the interface using some similar modules as guidelines and
maintaining the same operational behaviour. It compiles, it
successfully passes parameters to the module from the pdf-filter
program. But I don't have any test data or anything of that nature, I
was just working on a flyspray task. I'm reluctant to offer code I
haven't even run though. I did port the decoder as well when I was
bored this afternoon, but similar provisos apply. I guess if I had a
test PDF I could round-trip it and demonstrate some functionality in
both decoder and encoder modules.

Ed