Hi Thorsten, ----- Original Message ----- From: "Thorsten Behrens" <[EMAIL PROTECTED]> Newsgroups: openoffice.dev To: <dev@openoffice.org> Sent: Tuesday, May 17, 2005 5:38 PM Subject: Re: [dev] question about improving the speed of openning .ppt file
> "jiangdongjin" <[EMAIL PROTECTED]> writes: > > > To my opinion, OOo impress opens .ppt file slower because of: > > 1. It imports all contents before displays, but MS Powerpoint only > > imports those needed; > > 2. It create too many temp files for those pictures embeded in > > slide pages, but MS Powerpoint do nothing about this. > > > Hi jiangdongjin, > > as you've found out by yourself, not streaming out the images to temp > files hogs huge amounts of memory (and is therefore not an > option). > > Your first item is actually the crucial point here: as our PPT import > is just that, an import, we really have to fully read the file > content. This is because our own, internal representation of the > document content (the 'model') must be complete before anything can be > displayed. There are currently no mechanisms to lazy-load only the > first slide, and the remainder only on demand. > As I mentioned : OOo impress imports all contents before displays, but MS Powerpoint only imports those needed; I have tried to change the synchronous load mechanism but I failed :) So many things I need to know and change. I found when open my test .ppt file(contains many jpg or bmp pictures), the most time-wasted points are those functions to load picture. i.e. ImportGIF(...) ImportPNG(...) ImportJPEG(...) ImportXBM(...) ...... If I omit these functions, My test .ppt file opened as fast as MS Powerpoint(maybe 1-2 seconds slower), but all my pictures are missing. So my plan is, in the load phase, I only load some basic infomation like width and height of the picture(I think only these are necessary for formatting), then display.After that if I really need some pictures(display or operation), I import it from input stream. Is my method feasible? Thanks! best regards, jiangdongjin