Raw Data and Raw Video - time syncronization.

Any discussion on using LapTimer. Please use this forum in case you need guidance on how to use LapTimer or perform a certain operation
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corsairprime
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Raw Data and Raw Video - time syncronization.

Post by corsairprime »

I am attempting to use Race Render as a video rendering application on my home PC. I am able to save both the raw data and the raw video files as input to the Race Render program.

The question I have for the forum is this:
1. When you are at a track and are going to record your lap you usually set all you sensors (GPS, OBDII, etc.) before you start the session to see that the Laptimer app is seeing them.
2. What I am trying to figure out is, when does the GPS and OBDII data recording begin? If you leave it on automatic mode I am assuming that the video and the data feeds are recorded when the laptimer passes the start finish line and continues on for the length of the track session. Is that correct?
3. What happens when your start the video recording immediately even before you enter the track? Does it still begin both video and data recording ate the same time? I have to think that it does.

The trouble I am having is lining up the visual with the displayed OBDII and GPS data. It may be that there are markers in the video file and the data file that are only visible to the Harry's Laptimer app. Syncing the same two files up in RaceRender might just be a luck of the draw kind of thing.

Any guidance you can give is much appreciated. The rendering on the phone works ok, it's just that it is easily interrupted and takes a long time to complete. it's not like a PC that only has the task you set it to perform. The phone is always doing something else in the background that could terminate your overlay.

Thank you for listening at least.
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Harry
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Re: Raw Data and Raw Video - time syncronization.

Post by Harry »

Using automatic recording, LapTimer will start recording data and video once you passed s/f. While you will have data from the beginning, video will start around 2 seconds late for the first lap. The common work around is to combine manual and automatic timing by enabling "Manual Timing" in LapTimer's Settings and press Start while in Timer View and before leaving the pit. This will create a recording (incomplete lap) for the distance from pit to s/f and automatic recordings for all laps. Video will be continuous starting in the pits.

Data recordings are always split into laps in LapTimer. But in case you export a full session to some logging format (NMEA, CSV, VBO), they will be joined to continuous plot again.

- Harry
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corsairprime
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Re: Raw Data and Raw Video - time syncronization.

Post by corsairprime »

Harry,

Thank you for the advice. I will have a chance to try this out next weekend on track.
Rajan288
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Re: Raw Data and Raw Video - time syncronization.

Post by Rajan288 »

Harry wrote: Tue Nov 02, 2021 12:07 pm Using automatic recording, LapTimer will start recording data and video once you passed s/f. While you will have data from the beginning, video will start around 2 seconds late for the first lap. The common work around is to combine manual and automatic timing by enabling "Manual Timing" in LapTimer's Settings and press Start while in Timer View and before leaving the pit. This will create a recording (incomplete lap) for the distance from pit to s/f and automatic recordings for all laps. Video will be continuous starting in the pits.

Data recordings are always split into laps in LapTimer. But in case you export a full session to some logging format (NMEA, CSV, VBO), they will be joined to continuous plot again.

- Harry
Will the video also include the 2seconds delay.
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Harry
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Re: Raw Data and Raw Video - time syncronization.

Post by Harry »

When overlaying the first lap of a session, you will see that the lap time starts at around 2 seconds too. In other words, these 2 seconds are handled correctly.

- Harry
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