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Re: Getting progress data update from Ghostscript

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In article <403fa89e-af00-4fc0-ad71-a1de09dffafc@googlegroups.com>, 
kkchan7440@gmail.com says...

> > 1) PostScript is delivered as a stream of bytes, the interpreter 
cannot 
> > tell how far through a strema it is, because it doens't know how big the 
> > input is.
> 
> Initially I am thinking of getting progress data from driver side, for example a TIFF or PNG driver. Using image height as an percentage measurement but that does not include interpretation time. 

That's only going to work if the device is using a clist (display list). 
Normally the entire canvas is held in memory and rendered to by the 
marking operations, then the entire canvas is written to the output.

So you will need to enforce clist mode, which may impact performance. 
Its also not a really good measure, since as you note, it doesn't 
include any interpretation time at all.

Additionally you will need to reproduce any changes you make in the 
devices each time we make a new release, so its going to be awkward to 
maintain.


> Yes, postscript will be rather tricky to get page count. PDF should be 
> doable.

There is already code for retrieving the page count in a PDF file. In 
the general case, in a PostScript file, its not possible at all.

 
> BTW is there any discussion group about ghostscript code modification or enhancement.

There is the gs-devel mailing list, and that's about it.


			Ken

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Getting progress data update from Ghostscript Peter C <kkchan7440@gmail.com> - 2015-05-22 02:04 -0700
  Re: Getting progress data update from Ghostscript ken <ken@spamcop.net> - 2015-05-22 12:35 +0100
    Re: Getting progress data update from Ghostscript Peter C <kkchan7440@gmail.com> - 2015-05-22 05:11 -0700
      Re: Getting progress data update from Ghostscript ken <ken@spamcop.net> - 2015-05-22 15:15 +0100

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