topic report an APEX kernel bug in MBDT for VISION

report an APEX kernel bug

1054072686 — Mon, 23 Jul 2018 04:35:42 GMT

report an APEX bug, it doesn't happen in EMU environment.
Create a very simple project with one input and one output
matNumberInlet0(512, 512, VSDK_CV_8UC1);
matNumberOutlet0(512, 512, VSDK_CV_8UC1)
write only one code in kernel like-->
static int staticint = 0;
vec32u* pDst = (vec32u*)dst0;
pDst[staticint] = staticint++;
return;
//expect result, every iteration, only one line's value is set.
//wrong result, at the first iteration, not only 0, but also 64, 128, ... lines's value is set.
// then you can see different values(1,3,5,7....) is set is the last rows, although i just expect to see one line is set at the bottom.

Re: report an APEX kernel bug

Daniel_Popa — Wed, 25 Jul 2018 08:24:34 GMT

Hi christinaxu,

In case of bug reports for the Vision SDK via NXP Community, what is the preferred way to handle these subjects?

Do you know is there is a dedicated person for support VSDK issues on the community?

In general, this community space was created to handle MATLAB Vision Toolbox related issues but if we can help users in generic Vision SDK topics we will be happy to do it.

Thank you!

Daniel

Re: report an APEX kernel bug

1054072686 — Wed, 25 Jul 2018 10:21:42 GMT

I think I already got the answer for this issue.
It's due to APEX will copy CMEM buffer to output matrix repeatedly by default even if you did nothing during some of the iterations.
that means if you change a value in the first iteration, but you did nothing in all other following iterations.
because the CMEM buffer may include several iteration contents, so the first iteration result will be copied to some other iterations.
thus you will get a wrong impression, you assign value once, but many lines are assinged.

you can say it is an apex bug, also you can say it's not.

--Smith Ou