Re: Suggestion / feature request

[Carlos Aguilar]

Le 19/04/2012 16:17, Tassilo Horn a écrit :

Carlos Aguilar <address@hidden> writes:

Hi Carlos,

I often use doc-view mode with medium to large pdf/ps/dvi files, when
writing/modifying latex documents.

Yes, frequently changing documents are clearly not the prime use-case
for doc-view, exactly because of the reasons you mention.  Do you use
AUCTeX for writing your documents?  If yes, then preview-latex might be
exactly what you need.

,----[ (info "(preview-latex)Top") ]
|    preview-latex is a package embedding preview fragments into Emacs
| source buffers under the AUCTeX editing environment for LaTeX.  It uses
| `preview.sty' for the extraction of certain environments (most notably
| displayed formulas).  Other applications of this style file are
| possible and exist.
`----

Ummm I suppose I am a bit of a maniac I really feel unconfortable if I don't have the real pdf in front of me and can go back and forward to check the global aspect of the document  ...

I wondered if it would be possible to keep a set of signatures of the
pdf/ps/dvi pages processed so that those that are unchanged are not
reconverted to (already existing) bitmap images.

Um, I have no idea how to do that.  Doc-view only knows the PNG images
generated from the original document, and you can't compare those with
pages in the document.

Well, it also has the old document's contents in the current buffer and
the updated document is on the file system, so in theory it could also
compare the documents.  But I have no clue how to do that.  Googling
around, I've found http://www.qtrac.eu/comparepdf.html, but I'm not sure
if it does the trick.  (Oh, and of course if the comparison of the docs
is not significantly cheaper than a reconversion, there's no sense in
doing so. ;-))

Of course it must be MUCH cheaper.

I have tried to use pdftk burst (which splits almost instantaneously a pdf file in a set of files with one page each) with two closely different versions of a large pdf. The idea was : if the pdf for each file is exactly the same when pages are unchanged just a checksum will do the test (and be very significantly cheaper than a reconversion).

The resulting pdf files are close for each page but different. Maybe there is a workaround with pdftk or directly with gs ... but before doing that the question is :
Would you change doc-view if it is possible to find a (simple enough) way to obtain the functionality I am talking about ? Or do you believe this is uninteresting/dangerous/outofscope ?

cheers,

Carlos

Bye,
Tassilo