Synching sequential video clips with one data log.

[Candive]

I am currently using RaceRender 3.6.5 Ultimate. My typical workflow with my Olympus Tracker is to turn logging on and leave it on. Video clips are taken during the logged period. The log may be 60 min long while the video clips may amount to 10 - 15 minutes. The final cut video will be around 3 - 5 minutes long. So I have one data log and many video clips. Since the log and clips are time stamped, its not difficult to synch the two. I'm not sure why RaceRender doesn't have the function to automatically synch based on time stamp but that is another issue.

The problem is, I can't sych the multiple clips to their appropriate place in the data log in one project either individually or in a group. My work around is to create a project for each clip; synch each to the same data log and then produce a video with the appropriate overlay for each clip. Then I take these new clips and join them together to create the final video in RaceRender or a third party video editor. Therefore I need to render the video twice to obtain the final version; once for the clips and again for the joined video (this workflow may lose visual definition in the process).

My alternative is to turn logging on and video on throughout the entire filming session ending up with one data log and one video. I then bring the two together in Racerender and generate a video file with the overlay. I then import this file into a 3rd party video editor and do my final cutting and editing to produce the final video. The advantage with this workflow is I don't have to deal with multiple clips but I do end up with a lot of video waste and battery life is shortened because I'm logging and filming all the time. Like the first workflow, this process renders the video twice to get the final version.

Is there a better way? Am I missing something?

[Gorblimey]

You might want to check this page on how to losslessly concatenate two mp4 videos using ffmpeg.

[Candive]

Thanks Gorblimey,
That will definitely solve the re-rendering issue. As a newbie to RR (just bought the license 2 days ago) I was hoping to be told that one can actually tag multiple video clips to the data log within the same project and then produce a single video. It looks like the current version doesn't have this capability. So my workflow as stated above is the only way to link the clips to the log and then use your suggestion to concatenate the individual clips. Perhaps this idea can be incorporated in a future version of the system.

[Candive]

Actually, I believe I worked it out

The trick is to import the data log more than once. Say you had 4 video clips;you import the same log, 4 times. Then you trim each log according to the start and duration of each clip. You join the videos in a group and you join the logs together in the same sequence as the video clips. The data is now in synch with the video! If the programmers for RaceRender develop some simple transitions in a future version, a nice video can be created. Hint Hint

I'll provide a simple example for other newbies out there. Say I go out for a 60 minute trail ride on my bike. I start my log and video capture the first 10 minutes of the ride. I then turn off the video for the next 45 minutes (the data logging remains on) For the final 5 minutes, to the finish, I turn the video capture back on. So my data log is 60 minutes, and I have 15 minutes worth of video; 10 min at the beginning and 5 min at the end.

In RaceRender, I create a new project and import both video clips. I also import the data log twice (RR will number them sequentially). For the first data log, I trim the log to the first 10 minutes. in the second log I trim it to the last 5 minutes. I join the two video clips into a group and I do the same for the data logs. The videos and data are in synch and I render the final video.

Happy Days!