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        VDI Viewer for PDA >> VDIV Discussion >>  suggestions for handheld implementation
        
(Message started by: dlmohn on Sep 14th, 2004, 12:47pm)
Title: suggestions for handheld implementation
Post by dlmohn on Sep 14th, 2004, 12:47pm
Ah!  A good beginning.

However, if possible, you might take a look at Sony's ClieViewer app.  It takes about as long to load/decode an image (jpg) as your first level compression.  It then displays the whole image scaled to fit in available screen space.  But it only decodes once.  tapping on provided +/- icons results in quite rapid +/- zooming up to and beyond 100%.  Scrolling is also rapid and perfomed on a stylus-drag basis.

I am guessing that the algorithm only processis that part of the image showing on the screen plus whatever fraction would be added/subtracted during zooms or scrolling.  If so, that would imply a possible decoding into a pixel array (bmp?).   This could be done in main mem if enough space or on card mem if not.  Don't know where it sticks the buffer for large images or what limits may exist on image size.

Possibly, if you did your "compression" processing at the time the user requested a +/- zoom, instead of all at the beginning, it would at least  seem faster.  

One bug(?) that needs addressing is that when an image is being "compressed", tapping on the "cancel" message drops you out of VDI rather than leaving you at an image selection menu.  

And of course, as has already been suggested by Greg O., being able to call VDI from another app, sending it a location name to be matched to an xy list for a given map would be great!   ;D  [If the provided name location was not found for the last map loaded, the user could be delivered to the map selection menu .]

regards,
Title: Re: suggestions for handheld implementation
Post by Denis Bakin on Sep 18th, 2004, 12:57pm
Hi David,
Are you writing about a Sony Clie that has an ARM processor? The only reason the decompression is slow there is that the decompression code is not compiled for ARM. I decided not to do it for this release to save some of my time and about 40K of useless code for old handheld owners (by the way I myself is one of those :-)).  As for the points of interest on a map, it would cirtainly be a nice feature. The most likely it will end up on the top of the to do list.
Title: Re: suggestions for handheld implementation
Post by dlmohn on Sep 20th, 2004, 1:54am
I'm using a Clie TG50/H.  Don't know if it has an ARM cpu or not.  It is OS5.

What cpu's do the T3's have?
Title: Re: suggestions for handheld implementation
Post by Denis Bakin on Sep 22nd, 2004, 6:44pm
It is said here
http://www.pdabuyersguide.com/palm_Tungsten_T3.htm
that T3 has 400MHz XScale.
I saw a number 200MHz for your Sony  here:
http://www.sony.com.hk/Electronics/pr_t/pr/06032003b_e.htm
If the information is correct you might expect some slowdown comparing to T3.


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