Re: Help with QimgCvtImg -- RPG400-L


Thanks, Al.

I've tried your code, and it works just fine here. I made some reallyminor changes to it:

a) I removed the 2nd parameter (out_path) because it wasn't used, andthat's just one more place for something to go wrong.

b) I changed the size of the 1st parameter (in_path) to 32, since 33leaves a chance for garbage to appear in the parameter.

c) I changed the "MainStgOS" parameter to use a field called QMAINO01,which is defined identically to QMAINI01 (other than the name). You werepassing QIMGO0300 to it, and I didn't understand why. That parameterisn't in IMGO0300 format...

d) I changed the BytesProvided field of Ext_APIError to 0. This isn'twhat's causing your error, it just makes it easier (IMHO) to debug whenyou get a meaningful error in your job log. If you have additional codethat uses the results of the DS, it's easy enough to change it back whenyou're done debugging the API call.

I also had a create an output queue called NOPRINT, which was a trivialtask. For testing purposes, I downloaded the G4.TIF file from thefollowing link:

http://www.fileformat.info/format/tiff/sample/

As long as I remembered to pass the pathname in the first parm to yourprogram, it ran without any problems and generated a spooled file. Ihaven't checked to see that the spooled file is valid, though.

I do get a pointer error when I forget to pass the first parameter to yourprogram. The problem can't be that simple, can it?

I do have a few suggestions that will make this program a lot easier todeal with:

a) Use more meaningful names for the fields in the data structures. Thebiggest headache with this program is trying to figure out what QIMCT00stands for and what makes it different from QIMCQ00, QIMBS00, etc. I hadto look them up in the manual, and that's not nice to do to other poeple.Instead, I suggest using names like "CprType" "CprQual" so that peoplehave a clue what the field are for.

b) Instead of hardcoding numbers, use constants to give the number ameaningful name. Instead of setting QIMDSF03 to 22, I'd rather setStreamFmt to PCL (where PCL is a named constant for the number 22)

c) Instead of using from/to notation for the data structures, considerusing length notation. I shudder to think of the amount of work it'd taketo fix one of these structures if it were defined wrong.

d) Instead of using the "B" data type, use the "I" data type. Your programwill then be able to work with a larger range of values and will runfaster. There's no advantage to the "B" data type -- "I" is always abetter choice -- the only change you'd have to make to the program is tosearch for B in column 40 and replace it with an I... simple change and amuch better result.

e) Dont' hard-code the lengths of the data structures in the INZstataements. Instead, use %SIZE. Right now you have:


 D  BytesProvided                 9B 0 Inz( 0 )

Instead, I suggest coding:

 D  BytesProvided                10I 0 Inz( %size(Ext_APIError) )

(not just for that one data structure, but all of them). That way, if youdo want to make it bigger (to get more message info, provide a longer pathname, or whatever) all you have to do is change the field sizes, thecompiler will automatically calculate proper lengths for you.

This is also a safety measure, since if you get that length wrong, thecompiler


But, anyway, the code worked okay for me.

---
Scott Klement  http://www.scottklement.com

On Thu, 26 Jan 2006, Al Pineda wrote:

Scott,
 Here is the prototype for the API call:

 D Image           PR                  extproc('QimgCvtImg')
D   ControlS                          LIKE(QIMC0100)
D   InputImageS                       LIKE(QIMI0100)
D   MainStgS                          LIKE(QMAINI01)
D   OutputStGS                        LIKE(QIMO0200)
D   MainStgOS                         LIKE(QIMO0300)
D   Feedback                          LIKE(QIMF0100)
D   APIError                   272