CS-MIPI-SC132 lost frames
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Hi!
We are experiencing consistent lost frames with software trigger at shutter speed from roughly 12ms to 22ms. At other shutter speeds there are no lost frames or they are extremely rare.
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@veye_xumm
Yes, we have thoroughly studied every article related to the camera. There seems nothing we are doing wrong. -
@vpr
Since you did not provide details, I cannot help you with the analysis. You can try this method below for frame rate detection.v4l2-ctl -d /dev/video0 --set-fmt-video=width=1280,height=1024,pixelformat=UYVY--stream-mmap --stream-count=-1 --stream-to=/dev/nullI suggest you provide more information. Otherwise I cannot help you.
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@veye_xumm
We currently do not have a camera to try this on. Hopefully one arrives soon. But it is weird that this only happens at specific range of dmeshutter. Dmeshutter is set before each frame is triggered. -
@vpr Can you give me an example,, what is the frame interval of the trigger when you set the exposure time to 22ms?
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The range is approximately from 3 to 15 frames per second at varying intervals. We set dmeshutter value before every frame.
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@vpr
It is not recommended that you frequently modify the exposure time.
From sensor datasheet:The exposure time and gain are written in the first frame (frame N) and take effect in the third frame (frame N+2). -
Well, this is obviously not true. As we change dmeshutter right before the frame and always get it correct with the new shutter value. As for dmegain it indeed requires to be set 1 frame in advance (not 2). Although I do not understand why it works this way if we are setting those values directly to the sensor and what is the reason of making direct settings to the sensor as opposed to setting it in the ISP if it would converge only after N frames even with direct setting.
Anyway the problem we are experiencing is with lost frames rather than incorrect shutter/gain values.
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@vpr The information in the previous post is from the sensor's datasheet. Based on what you said, I think this N+2 might be for video streaming mode.
http://wiki.veye.cc/index.php/Camera_module_Trigger_Mode_manual
Please note this article, part1.3.2 section.If you think there is nothing wrong with your configuration, please provide a way to reproduce the problem on my side. Otherwise I can't help you.
