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Old 08-12-2019 | 02:50 PM
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Default Motec V2 camera MP4 files

I've been using a Motec V2 camera. I am happy with this unit expect one feature- That is when the video recording gets to a certain amount of data the recording then continues in a different MP4 file. In a half hour run session I typically have two MP4 files. Between the two recorded files there's a 0.6 second loss. Usually its not a problem. But there's one particular recorded lap I wanted to study but the switch over happened to occur during this lap. Does any know if that 0.6 second of loss recording can be retrieved or it is just gone forever?
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Old 08-12-2019 | 03:57 PM
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I don’t believe there is a buffer in the camera that would save that short snippet. Had not heard from any of two dozen different V2 customers about that problem, but I will ask and find out.
Old 08-17-2019 | 08:25 AM
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I don’t recall losing any time with my V2, but i’ll take a look in the next day or so to confirm
Old 08-20-2019 | 10:43 AM
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This doesn't help with a session in the past but for the future, is there any sense perhaps in reducing the recording resolution?? I've been using the top 1080p rez and running sessions typically less than a half hour total but I'd imagine that maybe using one of the 720p formats would reduce the file size (and thus extend the time before it flips to a second file) by quite a bit.

[ Actually since there are a couple of V2 users here, what are people using for the recording format in general?? I'd assumed that highest rez is best but I have to say that I ran into some problems editing V2 file output that was 1080 nominally 30 FPS because in reality the FPS is rather less than that (more like 26 ish) which stresses some editing program, especially resulting in offsets on the audio track when you import the clips I've been thinking about using a different recording format to combat that issue.]
Old 08-20-2019 | 11:13 AM
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I'll try and remember to ask MoTeC Joe about this when I see him this weekend. He will most likely have a best practice.
Old 08-20-2019 | 11:14 AM
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Originally Posted by Tom-TPC Racing
I've been using a Motec V2 camera. I am happy with this unit expect one feature- That is when the video recording gets to a certain amount of data the recording then continues in a different MP4 file. In a half hour run session I typically have two MP4 files. Between the two recorded files there's a 0.6 second loss. Usually its not a problem. But there's one particular recorded lap I wanted to study but the switch over happened to occur during this lap. Does any know if that 0.6 second of loss recording can be retrieved or it is just gone forever?
Tom, are you pulling into i2 Pro and viewing in the analysis window? That'a what I would do first.
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Old 08-21-2019 | 09:56 PM
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I spoke to Joe Hullett on something else and asked him about this. He said he needed more information, but that converting the video files to .avi might make it smoother and the restore some of the missing transition.
Old 08-22-2019 | 06:25 AM
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So AVI is a container format that can contain virtually any kind of video/audio data that has been compressed (or not) with more or less any codec you can imagine so "convert to AVI" doesn't really tell you enough to get a result. One anecdotal correlation to what Joe said -- Chris Brown suggested that converting the V2 files to uncompressed video format inside an AVI file format could potentially be smoother for playback. You can do this using ffmpeg (I'm sure there are other tools but this is the one Chris points to) from the command line but the required parameters to make that utility work are pretty intricate and depend on the input format as well.

At any rate, point being that to get the conversion "right" one would need a bit more specific guidance.

[by the by: I did some uncompressed video conversion following Chris' suggested recipe and in my experience, the only reason that you'd want to do this is if the machine you are working on is older/slower -- on my surface pro I can look at video in i2pro to the point of going forward _and_ backward frame-by-frame without doing any conversion from the original MP4 formatted file. The potential to unlock hidden frames that an MP4 CODEC/player won't show seems unlikely but would be an interesting reason to convert perhaps if true...fascinated to see what happens if someone tries this!]



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