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Alm865
July 9, 2015, 05:38:30
Hi,

We are using a standard USB3 Webcam that has a few video resolutions greater than 1080p. When we view the camera selecting the YUV format, everything is fine up to the 13MPx limit of the camera. When we view the camera selecting the MJPG, we can only view up to 1080p. When we view the camera in MJPG using a resolution much greater than 1080p (such as 4k) then we get a warning as shown in the attachment below when running in Debug mode, when running in Release the software crashes. The same behaviour is experienced in the pre-compiled demo app supplied with the library.

Also another issue we have found is that when selecting the MJPG format, the first couple of frames are completely black which we have to manually block out, YUV format does not seem to have that sort of behaviour.

Is this something you've seen before?

1789

Stefan Geissler
July 9, 2015, 14:37:38
I am very sorry, but we do not provide support for third party camera manufacturers.

Alm865
July 13, 2015, 02:39:53
Are you saying your C++ library does not work with MJPG webcams?

We do have one of your USB3 cameras and it only has YUV format so obviously we don't get the same issues.

The issue occurs on multiple Webcams with MJPG format video. I can also create a 'virtual' webcam with an MJPG stream and replicate the same issue so it is not isolated to a particular webcam, rather I believe it appears to be a problem with the library handling MJPG format videos greater than Full HD resolution.

Is it possible to tell me what the Assert means? It's obviously an assert at line 568 of 'FrameHandlerSinkCB.cpp'. I'm guessing 'size' in the expression '((long)pBuf->getBufferSize()) >= size)' is an internal buffer which is not big enough to handle the incoming frame?

Stefan Geissler
July 13, 2015, 08:09:08
Please let me know, which of our USB 3 cameras you have.

Alm865
July 14, 2015, 05:44:39
We have a DFK AFU130-L53 USB3 camera thanks.

Stefan Geissler
July 14, 2015, 08:49:09
I think, I now see the problem. The MJPG encoder in Windows supports formats up to 1080p only. Anything above wont work. That means you need a suitable MJPG encoder.

But since the DFK AFU130-L53 provides YUY2 video formats only, you must speak about another camera. Which camera is this? If this is not a The Imaging Source camera, please understand, we do not give any support.

Stefan Geissler
July 14, 2015, 08:49:10
I think, I now see the problem. The MJPG encoder in Windows supports formats up to 1080p only. Anything above wont work. That means you need a suitable MJPG encoder.

But since the DFK AFU130-L53 provides YUY2 video formats only, you must speak about another camera. Which camera is this? If this is not a The Imaging Source camera, please understand, we do not give any support.