Using Gspy with Non 640x480 Cameras
The following info was received from Phillip Coombs Feb 23/2001...
Having recently bought and setup a USB webcam to use with
Linux as a traffic cam, I've now spent a couple of days playing with everything
to do with webcams that I can. I cam across GSpy and gave it a go but unfortunately
though it compiled, it crashed and burned on execution. I've traced the
problem and thought I'd let you know what it was. Basically it was is that
GSpy assumes 640x480, as you mention in the docs, and my camera is 352x288
(it's a cheap ZoomCam). In the end I've changed the code to handle this
and thought I'd let you know in case you want to integrate it in the main
stream. Basically what I've done was to change the DEF_HEIGHT and DEF_WIDTH
#defines in v41if.h to be the values I've got, but then also changed all
occurances of 640 and 480 in the code to use those defines. In addition
to that, all values dependant on those values such as 320, 319 and so on
I've also changed to be derived from the #defines. Thus simply changing
the DEF_WIDTH and DEF_HEIGHT defines in one header will do all the necessary
changes for cameras with different dimensions, rather than having to search
for 640 etc everywhere. I think 95% of the changes were in callback.c,
one or two were in interface.c and one was in gspy.glade (which I did have
to change to a hard value since I'm not really familiar with Glade but
you may be able to overcome that). I guess in an ideal world you would
read the dimensions from the camera itself and adjust it dynamically. However
just doing and documenting the above changes maybe will quickly help other
people who want to use your program (which is _extremely_ neat) but who
have cameras that aren't 640x480. Cheers, and keep up the excellent work.
I have a very cheap USB Dexxa 352*288 webcam.
It works with the driver from http://qce-ga.sourceforge.net/
Honestly, I'm not a C of C++ programmer (I once started it, I'm still
interested in it, but I don't know a lot about it).
But the nice thing is that I was able to update the source after I read
the comment of Phillip Coombs.
It now works very nice with my Dexxa webcam.
I don't know if this patch is 100% correct, I only tested is by
gunzipping the gspy archive in another dir and applying the patch to it,
and that worked.
These are a few comments you may publish on your site about the patch.
if there are spelling mistakes in them, it's because English is not my
If you have a 352*288 webcam you can gunzip the gspy-0.1.5-src.tar.gz
$ tar -zxf gspy-0.1.5-src.tar.gz and also gunzip the patch with $ gunzip gspy-352x288.patch.gz then apply the patch $ patch -p0 < gspy-352x288.patch now descend into the gspy dir with $ cd gspy and do the usual: $ ./configure $ make (you might need to change to root) $ su (password) # make install This should work fine! If you have another resolution, you can easily change it in 'src/v4lif.h' you should change then all these lines (which isn't very difficult): #define DEF_WIDTH 352 //width of webcam input #define DEF_HEIGHT 288 //height of webcam input #define DEF_SW 176 //half of the width of webcam input #define DEF_SH 144 //half of the height of webcam input #define DEF_SWM 175 //half of the width minus one #define DEF_SHM 143 //half of the height minus one #define DEF_WM 351 //width minus one #define DEF_HM 287 //height minus one Greetz, Tom (tomNO_SPAMMERS@startgids.be)gspy-352x288.patch.gz(4545 bytes).