The V4L2 CCD driver has been problematic/temperamental for me, so have spent some time trying to figure out what is happening.
There seems to be four problems...
1. Exposure time for streaming. V4L2 detects range of 5 to 20000, but only certain values work. Through trial and error from shortest to longest the working values are 9,19,39,78,156,312,625,1250,2500,5000,10000,20000
2. Exposure time for still image capture. Divide the working values in item 1 by 10000 for working Ekos CCD Exposures. Cannot use values less than 2500 as Ekos CCD Exposure only allows 2 decimal digits. Could this be changed to support 3 decimal digits (eg. for Solar/Lunar exposures)?
3. Ekos CCD Frame size not updated when Capture Size is changed in INDI Control Panel. Causes indi_v4l2_ccd restarts. Clicking away from the CCD tab and back again will update Ekos.
4. Corrupt still images (wrapped images, bands across images). It seems to be a timing problem with the V4L camera read. Looking at the source code, I found in libindi/libs/webcam/v4l2_base.cpp a commented out "hack" using a dropFrame flag (in two places). If I uncomment and rebuild, no more corrupt still images!
1. Not sure about how V4L treat these values, maybe they're different from device to device.
2. Done, but only in Ekos for KDE 5 as work in KDE4 is now stopped. KStars-bleeding will be updated in the next few days to use KDE5 but only Ubuntu 14.10 and later supported.
3. This is not support to cause a restart, can we give more details, was it only the size changed or something else? what were the dimensions in INDI control panel vs. Ekos?
4. I added "Drop Frames" option to V4L2 driver, if you enable it (it's off by default) it will drop the frame, please test and see if it works.
Thanks knro, drop frames option is perfect and works well for me.
I have upgraded to KDE5 and built from the latest kstars and indi source, and cannot reproduce the indi restart problem (3) so no issue there either.
But kstars is now giving error "Unable to load video stream" and crashing with "Segmentation fault (core dumped)" when I turn on video streaming in INDI control panel, after capturing a still image in Ekos CCD.
It does not appear to be an issue with the indi driver (or drop frames option) as it does not restart, or need to be restarted.
Video streaming works again once I restart kstars. Kstars does not crash if I capture a still image, exit kstars, start kstars, enable streaming.
INDI is running the whole time with the V4L2 CCD connection on.
As per my initial post, INDI is running on RPI.
The following user(s) said Thank You: Jasem Mutlaq