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Low frame rate and resolution in low light


(Michael) #1

Hi All,

We just purchased a Blue2 ROV late last year to include as a cheaper option for our clients when we need to fly to projects (checked luggage rather than sending 150kg airfreight).

I tested the Blue2 ROV out with a local client which had a indoor flocculation tank today, and even with the 4 LEDs at 100%, the frame rate was very low making the video file jerky. I had changed the file format to .mov to make the export into our post production software easier, but have since changed it back to .mkv.

Is there any way to check the frame rate or adjust settings for the video to enable smoother video recording? At the moment the video is unusable for professional presentations. Luckily I had a GoPro hero4 attached to the ROV as well, recording in 1080p50 which produces very good video.

Any ideas on how to fix this in low light conditions, ive seen other recordings at depth that don’t seem to have these issues, so its either an issue with my camera, or settings somewhere that aren’t setup correctly.

Cheers,

Michael


(Luis Gamez) #2

hey @rovinnovations

I believe you´ve purchased the BR2 before the low light camera was released hence first check if you have the low light camera or the old camera.

To troubleshoot the poor streaming video check here

that sort out my problems before so I wish this could help you a little bit until BR engineers reply to you.

cheers,
LG


(Marcus) #3

Hey Michael,

Fancy seeing you here! I had a similar issue with mine. When I checked the pair of of conductors going to the topside fathom board, the crimp terminations (not sure what they’re called) were loose and not maintaining good contact. I stripped and tinned the conductors and it immediately fixed the problem. I also checked the ROV onboard fathom board to make sure they were ok…Might be worth checking.

Cheers,
Marcus


(Michael) #4

Thanks Luis, I will certainly go through the various points on the link you posted and see if any of them make a difference.

Hey Marcus, yeah we purchased the Blue2 late last year as both a backup ROV as well as a smaller option for clients that we can offer to reduce the overall cost of quotes when we travel for a job. Heading to Darwin next week with it, which is why I wanted to sort out the issues we had.

There was times of pixellation as well during the low light dive, so it does sound like a loss of bandwidth to the laptop…

Will keep you updated on the progress.

Cheers,
Michael


(Jacob) #5

This does sound like a bandwidth issue. If you continue to have issues, please let us know the results of each of the troubleshooting points that Luis pointed out.


(Marcus) #6

I noticed I had another lag issue recently…The troubleshooting that Luis posted was great, deleting “intra 1” from the camera settings worked a treat.

Bandwidth results went from latency 9s, Upload 48, Download 69 to latency 5, Upload 72, Download 89…

Thanks


(Michael) #7

Hi Marcus and everyone who replied.

I ended up doing a couple of things, firstly I purchased a new 100gigabit ethernet cable, secondly I ensured that the ROV software was using the graphics card in the PC. I then tried to replicate the issues we saw on site by putting the ROV in a dark room. The video itself appeared fine with no lagging or pixillation at all. As a redundant backup I installed the software on my MacBook Air, attached an ethernet to USB adapter and tried it using the Mac as an operational platform. The quality of the video image I feel was far superior on the Mac than the PC, however this is probably purely due to the monitors on the different computers.

Testing the parameters I had the following - Latency was around 2.7, upload was 72 and download was 73 so I believe that this is probably fairly acceptable for most situations. I haven’t tried removing anything from the camera settings (the intra 1 that you mentioned Marcus), but I will keep an eye on the lag and see if it occurs again.

Do we know what format the camera outputs? Is it 1080p30 or something different? I just noticed that pausing the recording video and taking screenshots tends to produce a fairly “soft” image where it looks like the focus is off slightly. This is probably due to a lower frame rate but im not 100% sure.

Cheers,


(Jacob) #8

The Pi camera is outputting H264 1080p30. Removing the --intra 1 setting is recommended, however this only applies to an outdated version of the software. You can update the software by going to http://192.168.2.2:2770 in a browser, connecting the ROV to a wifi network, then go to the system page and click ‘Update’ in the companion section. You can also change camera settings and output format with the new software.

70Mbps is a good number.

The video performance on Windows is not very consistent. Mac and Linux do have consistently better performance in my opinion. I’ve been working on improving things on Windows for some time, but it’s proving difficult given the amount of variables involved. I’m happy to troubleshoot with anyone running Windows having issues, though, it helps me improve things.