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Track position and speed stops updating

Posted: Tue Jul 15, 2014 12:14 am
by DanMay
I am using an IPhone 5 on my motorcycle to record lap information along with video. After doing the video overlay, the resulting overlay speed and track position information stops updating after a few laps. This does not always happen, but has occurred the last 3 of 6 times I have recorded.

Here is an example.
http://youtu.be/2HMvGeUQPAE?t=7m43s

Dan

Re: Track position and speed stops updating

Posted: Tue Jul 15, 2014 7:21 am
by Harry
I'd assume there is some problem with the data. It seems the GPS data position does not progress... The data itself seems to be available - the track shape is complete... Please export one of the laps to .hlptrl and send it to me (please add a link to the thread so I get the context). Have you used an external GPS for recording? If yes, which one?

Harry

Re: Track position and speed stops updating

Posted: Tue Jul 15, 2014 2:31 pm
by DanMay
I am not using an external GPS, just the internal IPhone 5 GPS. I will send you the data.

Re: Track position and speed stops updating

Posted: Tue Jul 15, 2014 2:58 pm
by DanMay
Harry,
I sent you two laps. Lap #5 was working properly, and Lap #6 stopped working. If you look at the video link above you will see the lap counter jump from "Lap #5/18" to "Lap #9/18". This may be a clue to what went wrong. When I overlayed the video, I started with Lap #1 and selected laps 1 - 9.

SO I am not sure if the problem was in the collection of the data, or the video overlay process.


Thank you for your help.
Dan

Re: Track position and speed stops updating

Posted: Tue Jul 15, 2014 4:39 pm
by Harry
Hi,

The two laps you sent look fine and are perfectly aligned (last position of #5 is the same as #6 of the next lap). During a multi lap overlay, a video is read frame by frame. LapTimer reads GPS positions in parallel and interpolates the frame's data from two consecutive each. It seems this parallel read fails when reaching the end of lap #5 - skipping to the end of the session - which is probably lap #9? Position and speed stay at the last known fix in lap #5.

I tried to reproduce the problem with the two laps, but it worked fine. As the export does not necessarily reflect the exact database layout, the data configuration may look different on your machine.

To drill into the problem, please export the complete session (select "Session" scope in Export) to both .CSV and .HLPTRL and send it again. Especially the CSV export may reveal the problem. In case this doesn't help, I need your full database (viewtopic.php?f=8&t=679). As the later is some effort, I leave it to you if it is worth it. :-)

- Harry

Re: Track position and speed stops updating

Posted: Tue Jul 15, 2014 9:08 pm
by DanMay
Thanks, I just sent the entire session.

Dan

Re: Track position and speed stops updating

Posted: Thu Apr 30, 2015 9:15 am
by johmei
I have the same issue using latest HLT with iPhone 6 and external XGPS 150A. This was my first trackday of the year and never encountered this on previous versions with iPhone 5. Every multilap (8+ laps each) overlay turned out like this. GPS data seems intact and min/max speeds show as supposed to. What was the problem, workaround or fix?
In the below session video/log it freezes the trackposition overlay when moving into lap 68.
Video: https://youtu.be/GIUcf5b7vh4?t=3m10s
Logs: https://www.dropbox.com/sh/1y9htlnmxoqs ... KRyJa?dl=0

Ps. the new RAM mount for iPhone6 held the phone really bad for video. Ds.

Re: Track position and speed stops updating

Posted: Thu Apr 30, 2015 9:29 am
by Harry
The freeze data issue for multi lap overlays will be fixed for the upcoming v19 of LapTimer (in 2 weeks).

When using the RAM Mount, make sure to get the metal version linked, furthermore, attach the suction cup in the top of the screen and let the lever point downwards (so the device is actually below the suctions cup). This will make a lot less vibration. The underlying problem is actually a different one: later iPhone version add a lot of stabilization stuff not well suited for moving pictures without a fixed focus (i.e. track drives). This means iPhone4s and 4Ses typically produce vids with less wobbling effects then the 6 and 6s do...

- Harry

Re: Track position and speed stops updating

Posted: Thu Apr 30, 2015 9:50 am
by johmei
Thanks for your quick reply and overall great work Harry! If I keep the data on the phone until v19 is released, will I be able to overlay this trackday correctly? Or is the problem related to data logging? Next track day May 23-24 so looking forward to the next update!

I might go back to one of the older phones next time. The problem there is storage capacity.. :(
Sony integration sounds interesting, might give that a shot as those cameras fit nicely on the helmet for POV.

Re: Track position and speed stops updating

Posted: Sun May 24, 2015 4:08 pm
by thekinn
Hi All,
I'm using v19.0.4 and am still having this issue with my iPhone5s. Data was good on the display to lap 35, and froze at the start of lap 36. Attached .hlptrl - please let me now if there is anything else I can provide.

Thanks,