Endurance Racing Issues


First off want to say I'm a big fan of this app. Excellent functionality, quick bug fixes, simple and easy to understand layout!

I have been tinkering with video and VBO exports for an endurance race that I did last month. I have run into two main issues, and have one request.

1) The first issue is the automatic video linking becomes slightly misaligned after consecutive video files. I run Racechrono on a Samsung Galaxy J7 Crown, and capture Front and Rear video using 2x Gopro Hero 5 blacks. I have 29 consecutive MP4 video files, that are each 17:42 in length, and that is just for the front! (105Gb of video). After adding the files, and synching the first, the following few videos are pretty good, but after the 5th or 6th it starts to have a noticable deviation between the data and the Video. This occurs both on Analysis, and Export (Video and VBO exports). I tried to re-sync later videos, but it seems to shift the whole sequence of videos. Is there any way to break the automatic sync after they have all been 'initialized', and then manually sync the video sequence?

2) The second issue is that, when including video in the VBO export function, there is a glitch when adding 2 video tracks. It seems that the videos are indexed when they are added, but if there are 2 video tracks (such as Front camera and Rear camera) and they are added non-sequentially, then the video indexes are jumbled in the VBO export. Circuit Tools requires the indexes to be sequential.

3) The last thing is more of a feature request. RaceChrono has difficulty exporting large file sizes. I tried to export a video of the first 2 hour stint from the race, with the rear camera as PIP. As it was exporting the video, it progressed slower and slower as the file was created. One thing I noticed is that it was exporting to the internal memory of the phone, and with this long of a file, the memory ran out pretty quickly. It did break apart the video into a second chunk, but it had taken over an hour at that point that I gave up on the export. Is there any way to add functionality to specify maximum file sizes, or file saving location?

Thank you for creating such an awesome app!


  • 1) Did you use an external GPS and if you did which one? It's possible that the GPS time moved backwards at some time, causing the videos to slightly misalign. Some old GPS like Qstarz BT-Q818X/XT are notorious for doing this. I've seen also videos corrupting causing the sync to go off. But generally GoPro videos should keep the sync really well.

    When the files are "linked after" each other, you can re-sync them only in one block. The files using the standard GoPro file naming schemes will be automatically synced after each other. If you want to sync them disconnected, you'll have to rename the files. Then you can link the ones you want after each other as a block, and create several of these blocks.

    2) Yeah might be. This feature is not really working very well to be honest, as it's not a documented feature in Circuit Tools. But if you send the session to me tracks(at)racechrono.com then I can look at it when/if I have time.

    3) Well this is most interesting to me. RaceChrono writes only to a file, so if the memory usage increases gradually, there must be a memory leak. I have never noticed this happening, but to be honest I have not exported over one hour videos lately. If the memory leak is in the Android internals, then I cannot do much about it. But if there's a bug in RaceChrono, then definitely I want to take a look at it.

    RaceChrono breaks the the exported video to 4 GB chunks (or was it 2 GB cannot remember) by default, as long as you keep the "Split video files" setting enabled.
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