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Author Topic: WHILE RECORDING, IF THE POWER SUDDENLY CUT OFF, ZERO KB RECORDED FILE.  (Read 4426 times)
mete
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« on: December 01, 2006, 05:15:46 pm »

We are studying about a project in which is used Neuros MPEG4 Recorder 1. While dealing with this project, we had a problem. This problem is:
While recording, if the power suddenly cut off, we always see that the capacity of recorded file inside the memory card shows 0 (zero) KB. So, we are not able to get recorded files in sudden cut off power.
a. Has this problem been solved in any firmware? (or Neuros MPEG4 Recorder 2)
b. Is this problem caused whether from software or hardware?
c. Is there any way to recover this type of files?
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dongle
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« Reply #1 on: December 02, 2006, 03:41:10 pm »

I think this "problem" will be common to any device that encodes video on the fly. The encoding process does not render a single frame and then write it to a file. It uses a rolling buffer to select pixels that have changed and then apply the compression nescessary to capture movement as well as parts of the image that have remained static. The process is complex and cannot be interrupted by closing the file after each frame which would normally protect the integrity of the file.

This effect can be seen when replaying a divx file in VLC player or similar. If you move the cursor to say half way through its length the display looks strange and smeared, it then snaps into place as the file finds a special reference frame to lock onto and normal play resumes.

If the file has not been closed properly then the master file table (on the recording medium) cannot be updated and the file will not exist. This means that tools used to recover deleted or corrupted files will not work as neither situation applies.

It is possible that a desktop pc, which has more processing power, may be able to do this differently but I am not going to test this theory !.

The only way to limit this is to record short clips which will reduce the risk or ensure that power cannot be removed by operating from a battery or UPS ec.
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budwzr
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« Reply #2 on: December 07, 2006, 09:53:58 pm »

I think the answer is simply that the file cannot be closed properly, and therefore there is no entry in the FAT. Quite possibly the file contains the video up to the point of power loss, but with no index information, it cannot be retrieved. Maybe if you transfer it to a pc and "save as" another name, it might work.

Bud
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biking_brian
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« Reply #3 on: August 23, 2009, 02:50:37 pm »

I made a battery pack for my Neuros, but it wasn't fully charged, so I lost power and I have a 0 KB file.  However, I know the data is on the card somewhere, as Windows shows there is 1.2 GB used up on my CF card (and I have no other files on the card).  Can anyone recommend a utility to find the data?
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kunio2012
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« Reply #4 on: September 22, 2009, 03:51:19 am »

Even if it is there, I doubt that it's a completely saved and usable data. Just reformat your card to clean it up.
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