Pros and Cons of File Durations?

[Rob S.]

Hi. I just ordered my first dashcam and have a question about how to choose the file duration.

The video specs will be 1920 x 1080, 30 FPS and 15 MB/S bitrate. Obviously, the longer the duration, the larger the file size, but outside of that are there any other considerations when choosing the duration of time of each file? Thanks!

ETA: I currently have a 32GB SD card and will be purchasing a larger 128GB SD card soon, for what that's worth. TIA!

 

[Nigel]

If you only had a 2GB card then a 10 minute duration wouldn't work well as you would only ever have the file currently being written, but with a 32GB or bigger I don't believe there is any reason to choose one size over another.

If you change it then it may be a good idea to format the card so that it doesn't get very fragmented but I don't think even that is necessary on recent dashcams.

 

[sludgeguts]

For me, it depends on how much driving you are doing.
1min clips are just silly - the cam is constantly working hard - recording whilst saving.
For my day job (driving) I use 3 min clips - I can locate the files I need very quickly from the times I note down but I chose 3 mins as it doesn't take very long for that clip to transfer to my PC.
For my car, I rarely have any need to look at the clips so I tend to opt for the larger duration.
Another thing I do with all my cams is disable the g-sensor. I have found that even reasonable roads will set it off - and that is just more stuff for the camera to save.

 

[jokiin]

If you only had a 2GB card then a 10 minute duration wouldn't work well as you would only ever have the file currently being written.

Which is one of the reasons you don't see 2gb listed as a supported card size, they're generally slower cards also which is another problem

8gb is perhaps the smallest practical size, with a smaller card a shorter recycle time might be preferable but otherwise there's not really any difference

 

[Nigel]

Which is one of the reasons you don't see 2gb listed as a supported card size, they're generally slower cards also which is another problem

I tested the Mini 0806 with a 2GB card, worked fine even on 5 minute files although you only end up with between 5 and 10 minutes of recorded video which isn't very sensible.

1min clips are just silly - the cam is constantly working hard - recording whilst saving.

If you work out how much extra data is written to the card, it is fairly insignificant compared to the huge size of the files whatever file size you choose..

 

[jokiin]

2gb card can work, sort of, lock a file or two and it quickly becomes a problem

 

[CheckYourLights]

I'm in the 1 min camp.
Feels easier to go through things I want to save.

 

[Nigel]

I'm in the 1 min camp.
Feels easier to go through things I want to save.

I normally view things in Registrator Viewer first and that joins them all together anyway and then saves the exact length you want to save as a single file. So the only time I see the file size is if I view them in-camera and I find that easier with longer clips since what you want to view is more likely to be in the file you select. I very rarely view footage in camera though.

 

[Mtz]

Smaller cards are only if you want to use the camera as event recorder. Had an event, stop recording, take out the card and hope you will not have another one. But some dashcams can be set to record only events (based on G-Sensor).

Smaller files are the best for persons which are not good in editing videos. If you want to join many videos you can have the time to learn how to do it, but if you want to quickly offer only the part of the event is easy to share just that 1 minute file.

enjoy,
Mtz

 

[Rob S.]

Thank you for all the replies. What I will do is experiment around with different durations and see how large the files are and take it from there. I can see where having large files could become an issue if more than a few of those are locked depending on the size of the SD card.

I've yet to play around with any viewing and editing software specifically for a dashcam yet. The camera is GPS enabled so I'm looking forward to that feature when it arrives.

 

[CheckYourLights]

I normally view things in Registrator Viewer first and that joins them all together anyway and then saves the exact length you want to save as a single file.

I do this as well. I can't really put my finger on it. I have just always been a 1min clip person.

 

[reverend]

I had issues with a few cams on 1 minute settings at loop time where they'd struggle - I usually go for 2 or 3 minutes these days to make life for the camera easier.

The 0806 seems to have brought my Kingston card to a crawl after a few weeks use - even Registrator Viewer hangs while trying to hang all the files together.

A CBR camera definitely has an easier life in this respect in terms of finding contiguous free space (assuming the camera SDK support it). I know of one that has the option but it works better with CBR as it can just delete the file and reuse the same blocks.

 

[Nigel]

The 0806 seems to have brought my Kingston card to a crawl after a few weeks use - even Registrator Viewer hangs while trying to hang all the files together.

Is that the Class 4 card?

 

[reverend]

Yeah it's working perfectly in the camera, just RV hanging for five mins on startup. I've formatted it and done some more driving today so going to see what happens now it's just in the 0805 for a few days.

I'm not sure if RV gets the GPS info just from the video files or also from the files within the GPS folder - will scope that out later

 

[Nigel]

I'm not sure if RV gets the GPS info just from the video files or also from the files within the GPS folder - will scope that out later

I'm fairly certain it scans through all the video files to retrieve the GPS information as long as they contain it, I guess if they don't then it will look for a GPS folder. Since the GPS info is stored in a datastream alongside the video, the disk probably has to retrieve every single sector so for a 128GB card it has to retrieve all 128GB! It does take a while for all the distance/mph info to appear even with a fast card if the card is big.

 

[reverend]

It turns out RV is actually reading both files from the word go when it sees the GPS folder:



I've deleted the GPS folder and it still took the same time to enumerate everything - I think the card is playing up big time and could soon be going in the bin if it's not better after a full format

 

[jokiin]

What size is the card and how is it formatted? Was it done in the camera or elsewhere?

 

[reverend]

32GB Kingston Class 4 mate - it was fine a couple of weeks back but random IO speed is in the gutter now.

It's doing a full overwrite via SDFormatter at the moment to see if that brings it back to life

 

[jokiin]

Not sure their file handling is suited to class 4 cards, particularly if you're using a short recycle time value

 

[reverend]

It was working fine for weeks though mate on there - I can see it's not optimal with a VBR video clip, GPS file, VBR video clip and so on it'll get messy and not contiguous after a few loops but even post format it's really slow and hanging RV.

On the plus side it's under warranty so worst case it'll be getting swapped out