Re: DJVU files and ImageMagick

[Roland Winkler <winkler@gnu.org>]

On Sat, Feb 02 2019, Stephen Berman wrote:
> I build Emacs from master with ImageMagick support, but if I try to
> visit a DJVU file (e.g. a ca. 200 page book of about 1.5 MB),
> immediately almost all my system's RAM is consumed, bringing Emacs to a
> halt, so it doesn't display the file, and I can recover the memory only
> by killing Emacs.

I am just curious: why are all pages converted immediately to emacs'
internal format upon loading a multipage document (be it a djvu document
or any other format)?  This sounds like a misfeature to me.  I am not
surprised this quickly consums all available memory, say, if you wanted
to work with multiple djvu documents simultaneously.

The djvu package from GNU Elpa uses the command line tool ddjvu from
djvulibre to convert only the one page that is currently displayed.
This approach is very fast in my experience, and it is obviously by far
less demanding when working with many "many-pages" documents.

> (I normally view DJVU files in Emacs using the djvu package from ELPA

Really?  Hooray, someone else is using this package, too.  I thought I
was the very only one.

Roland