Corrupt recordings - trouble shooting

pearl

#1

For almost 2 years we are running successfully 3 Pearls for lecture recording at the Heinrich-Heine-University in Düsseldorf and produced about 350 videos with them.

Unfortunately we had serious problems with our recordings in the past 3 months resulting in corrupt files, which cannot be opened by any program. During recording, everything looks right, the sources are displayed, the recording button is blinking and the time is running.

But after the downloading the files (up to 4 GB), the preview is not generated and there are no videoinformations like start, and length. In these cases, the mov container recorded with the recorder including Auto A and Auto B has a length of exactly 10 seconds.

I changed already all connections, cables and splitters, cameras searching for the reason, but could not find it.
The fault occured often with a USB-C displayport. Could this be the reason?

Does anybody have the same problems and found a solution? I would be greatful for helping comments.


#2

There were some known compatibility issues with the MOV recordings the Pearl produces and some media player applications, such as Windows Media player. I believe this is due to us recording in a fragmented format in order to be more fault tolerant. What application are you using to play these back? Have you tested any others, for example VLC?

Retesting now with the newly released firmware and I am not longer reproducing these issues, everything seems to play it back properly now. This must be due to our implementation of the constant framerate encoding for MOV and MP4 files in firmware 4.4.0. I would recommend updating.


#3

Hello Adam,
thanks a lot for you fast reply.
Yes I have tested to play the files with VLC, Quicktime, Premiere, Camtasia and Handbrake without success. Yesterday I installed the latest firmware 4.4 g on one of the Pearls. The testing in the office was successful and gives hope. Next week will be the next live lecture recording. Hope it will work fine.
I will come back to you with the results,


#4

Ok sounds good, hopefully this resolves it!


#5

Curious to hear if you identified a cause. The only time I’ve run into those corrupt files is when someone accidentally turned off the Pearl before stopping the recording.


#6

Hi JesseM,

Different file types have innately different levels of fault tolerance. Of course, it is always best to stop a recording manually. But if power loss like this is a concern you may want to consider a file format like AVI or MPEG-TS as these handle a power loss much better than either MP4 or MOV do.


#7

Hi Adam,
in the past 7 days we could do 8 proper recordings on 2 different Pearls. It looks like the new firmware fixed my issue.
My setup is recording MP4 and MOV files, for easy postproduction with camtasia 3 on a MAC, which identifies the single video tracks automatically as single layers, which Premiere cannot do.

Looking back, it think it was somewhere end of June, after installing a new firmware, when the problem occured the first time.

1 Pearl is not yet tested under live conditions, which was the most troublesome. If this one runs fine also everything is ok. I will try it next week


#8

Of course, if a power cut occurs, the reason is clear, why recording is corrupt :slight_smile:
Than the problem is obvious


#9

Glad to hear that so far the new firmware is working for you. Please let me know if you encounter any remaining issues.

Power cuts are certainly always going to be a hassle. If this is a concern you may want to add a Recorder that records in AVI or MPEG-TS while you also record MP4 or MOV normally. This way you would have some form of backup present.


#10

Well, I did’t face the problem of powercuts yet.