2 bugs (?)

monstermax

My setup: Debian Jessie, SDK v. 0.3.0324, ASI120MM USB2.0 (I dont know the firmware version), i5 2.4 GHz, Qt version 5.7

I am working on an autoguider application for my self-made telescope control and ran into following problems:

(1) The new versions (0.4.xx) of the SDK simply do not work. Video frame grabbing results in a timeout, but the camera seems to connect normally; I have not investigated further because 0.3 works more or less fine.

(2) This bug occurs in conjunction with Qt and concerns the oacapture software (and my own software). Setting the exposure time to about 50-100 ms results in a frame-rate drop and corrupted frames - or sometimes the whole system crashes. This only occurs when the ASI_BANDWIDTH_OVERLOAD is enabled and set so something like 80. Setting it to 0 and non-automatic solves the problem. OaCapture offers the option to disable the overload - one might consider to set this as default for this camera, as I personally prefer stable frames over a high rate.

Of course I can only speak for my specific hardware setup - but perhaps this has already happened to other people.

wuu

When you use the new sdk, did you add ASIInitCamera after the opening?

This function was not in the old one.

monstermax

(1)

Thanks for the hint! Adding ASIInitCamera solved the first issue. Reading more closely would have helped...

(2)

In the meantime I discovered that the SDK has nothing to do with the corrupted frames bug. ASI_BANDWIDTHOVERLOAD can be set more or less freely, but: A good implementation of QOpenGLWidget is needed in order to make the problem disappear. Simply posting a QImage to a QLabel does not work properly (at least for me). Anyway, implementing OpenGL under C++/Qt gives higher frame rates (same as Windows) than using the QLabel approach. A good example is provided here (thanks to Kuba Ober / SO):

https://github.com/KubaO/stackoverflown/tree/master/questions/asi-astro-cam-39968889

I think oacapture does not use OpenGL; one might consider implementing it.

Sam@ZWO

the broken frame happen with USB2.0 cameras on linux or Mac

that's why we suggest linux and Mac user choose to use our USB3.0 cameras

gulinux

Hi,

I'm writing an autoguder module for my Linux application too: PlanetaryImager (http://blog.gulinux.net/en/planetary-imager).

It probably won't suit your needs, as mine will not be an autoguider application itself, but just a simple autoguider module for planetary imaging, but if you want to share some code and/or knowledge, please feel free to contact me.

Also, you might want to just test your camera for problem, right now I'm using SDK 0.4 too.

gulinux

MonsterMax wrote:
(1)

Thanks for the hint! Adding ASIInitCamera solved the first issue. Reading more closely would have helped...

(2)

In the meantime I discovered that the SDK has nothing to do with the corrupted frames bug. ASI_BANDWIDTHOVERLOAD can be set more or less freely, but: A good implementation of QOpenGLWidget is needed in order to make the problem disappear. Simply posting a QImage to a QLabel does not work properly (at least for me). Anyway, implementing OpenGL under C++/Qt gives higher frame rates (same as Windows) than using the QLabel approach. A good example is provided here (thanks to Kuba Ober / SO):

https://github.com/KubaO/stackoverflown/tree/master/questions/asi-astro-cam-39968889

I think oacapture does not use OpenGL; one might consider implementing it.

Oh I did just read this part, I didn't notice it before.

In my own code, I'm using a highly customized version of QGraphicsView.

You might want to check if this works fine for you, since switching to OpenGL seems a bit overkill to me, and might not be always faster (it's really dependant on your VGA card).