MOV file only playing half of the recorded footage

[RedBadger]

Hi, I've recorded some footage using a Camsports HD-S 720p HatCam which has 4Gb of internal memory - this is enough for approx 1 hour 30 minutes of footage. The file I've got is 3.7Gb but when I play the file, it says there is only 34 minutes of footage. Normally 30 minutes would take up just 1.3Gb. I've tried various recovery tools but they all say that the file is just 34 minutes long. Anyone come across anything similar or know if I can recover the missing hour ?

Thanks in advance
RB

[DB83]

Post a mediainfo report of the video.

Have you played the video to confirm the quoted run-length ?

[hech54]

There is a good chance that you either calculated wrong or you misread the product description:

HDS 720p is fully self contained. It has a built-in 4gb memory and and built-in rechargeable battery that will give around 90 mins of action packed filming.

Two resolutions are possible, either 1280 x 720p or D1: 720 x 576p both at 30fps

http://www.proactioncameras.co.uk/hds-720p-camsports/prod_168.html

[Cornucopia]

My guess is that the bitrate for the D1-sized footage allows for 90 minutes, but the bitrate for the 720p footage only allows for ~30 minutes. If this weren't true, the bitrates would have to be of similar amount, and that wouldn't make sense: a 720p image REQUIRES MORE bitrate to maintain a decent image than a D1 image requires (most other things being equal). Simple imaging physics that you can't get around.
I would also guess that their marketing won't tell you that, because then it makes the device look less attractive.

Scott

[DB83]

A very quick'n dirty calculation would give 32 min at 16 Mbps.

Respectable DVD quality would be 5.5 Mbps for 4 gig in 90 mins.

The mediainfo report will show what the video was recorded at and back up the above comments from hech and Scott.

[RedBadger]

Thanks for your comments guys - the MediaInfo detail does seem to give the reason. The BitRate for this camera is 15Mbps but the BitRate for the other identical (?) cameras that I use that do record up to 1 hour 30 mins at 720p is just 6Mbps. Looks like I'm buggered !

[Cornucopia]

I'm sorry to hear that, but I wasn't surprised - you can't cheat the math!

Scott