Kindly Assist with Recovering a Camstudio avi

[filmer01]

Please help me to understand how to recover a video with the avi format generated by Camstudio after a computer crash. Two files were created: temp20140907.avi (1,026,543 KB) and mciDF48.tmp (422,913 KB). I tried opening them in VirtualDub and DivFix++ with no success. I have tried methods such as this https://www.youtube.com/watch?v=cZhM6aBm6yY . Are there other programs or program settings to try? Is there a way to import the broken video into any programming language and try to recover it from there?

[Baldrick]

1.4MB? That is very small for video...

How long did you record?

[filmer01]

1.4MB? That is very small for video...

How long did you record?

Apologies for using Kb instead of Gb but 1,026,543 Kb = 1.026 Gb, not too small. A friend of mine made the video and I think it was at least 1hr long.

[Baldrick]

What video codec did you use in camstudio?

You can also try avidemux.

[filmer01]

What video codec did you use in camstudio?

You can also try avidemux.

Thanks for the follow up, ‘Microsoft Video 1’ was the codec used due to compatibility with the OS used – Windows 8. I will try AviDemux.

[filmer01]

When I tried to open the avi in Avidemux I got the error: ‘cannot find a demuxer for temp20140907.avi’ ‘could not open the file’. Same for mciDF48.tmp and I tried the 32 and 64 bit versions of Avidemux.

[jagabo]

Do MediaInfo or GSpot show details of the AVI files?

[filmer01]

Do MediaInfo or GSpot show details of the AVI files?

Thanks but unfortunately the only details MediaInfo and Gspot showed with either of the files were the file sizes.

Btw, for those reading this thread do not click on the auto tagged link for MediaInfo above, the d/l file asked if installing conduit search was wanted and trust me you don’t want that. Use this d/l page instead: http://mediaarea.net/en/MediaInfo/Download .

[Baldrick]

Do MediaInfo or GSpot show details of the AVI files?

Thanks but unfortunately the only details MediaInfo and Gspot showed with either of the files were the file sizes.

Btw, for those reading this thread do not click on the auto tagged link for MediaInfo above, the d/l file asked if installing conduit search was wanted and trust me you don’t want that. Use this d/l page instead: http://mediaarea.net/en/MediaInfo/Download .

Don't talk crap. We are hosting EXACT same version as they. They also say that it includes adware/ad supported. See http://mediaarea.net/en/MediaInfo/Download/Windows

But just download the portable version or mediainfoxp to avoid ad installers.

[filmer01]

Oh, so sorry I surely appreciate your organization hosting the files in that case though! I jumped to a conclusion about the file difference I very much appreciate all the help and welcome any other repair ideas!

[Vidd]

I would guess, since there was a crash before the file finished writing, that the avi file does not have a complete header or it has a corrupt header. You should be able to use a hex editor to determine the state of the header. You might have to manually add or fix the header enough so that a recovery program would be able to re-index the avi.

You mention DivFix++, but I've had much better luck using DivFix 1.10/1.13.

[jagabo]

Yes, if MediaInfo shows no useful information the file doesn't have a valid AVI header. You'll have to try using a hex editor to copy the header data from a good AVI file (created by the same software) over the header area of the bad file. Be sure to keep a backup of the bad file.

Since you have VirtualDub use can use its built in hex editor (Tools -> Hex Editor). Open the bad file and post a screen cap of the beginning of the file. It should look a lot like this:



On the very left is the offset into the file (in hex), then 16 hex values of 16 bytes of the file, then 16 ASCII text characters for those bytes that can represent text. Note that the first four bytes read "RIFF". All AVI files start out with those four characters. You can also see other text tokes common to AVI files, LIST, hdrlavih, strlstrh, vids, a fourcc that identifies the codec used -- HFYU in this case, etc. My guess is you will see all zeros because the program writes the header at the very end of the capture process.

[filmer01]

I definitely appreciate the help! You are correct the header is blank. I tried copying over the header info from a good file of the same software but it didn’t work. When I try to open it in virtual dub it reports that it is an ‘invalid avi file: the main ‘movi’ block is missing.’ This brings me to the question, how big is the header section? On the good and bad files there is a space with all zeros are listed at the beginning of the file to a certain 000007F0 point. Is that the end? How similar should copied in headers probably be?

[jagabo]

The header includes several optional chunks so it varies in size. But particular programs usually use the same chunks in the same location. Try copying everything up to the first LIST....movi chunk.

[filmer01]

Some good news! Got the video to be opened in virtual dub and reindex it after adding the header to the ‘movi’ line. However the video is scrambled as shown in the picture. I may need a header from a video closer in configuration to the way the original was made. If there are other things I can try I would appreciate the advice also.

[filmer01]

Excellent news! After fixing the header and having virtual dub reindex it appears the graphical portion of the video was fully recovered! Thanks everyone very much for the generous help!! This video is about neuroscience and it is valuable content for the person doing the neuroscience research! I’d share it but am unsure of the privacy/copyright details of posting it on the internet.

My friend said there could audio that was recorded with the video that does not seem to playback. Any reason audio would not be recovered if the video plays back? Any way to check if there was audio and what further steps might be taken to recover it? A mciDF48.tmp file was saved along with the temp avi, could that be relevant to the audio?

[filmer01]

One more detail, after what appears to be the header in the video file I see a '00db' code in the file and I searched and found no '01wb' in the file or in the mciDF48.tmp file. Used this for info: http://linux.die.net/man/1/aviindex .

[jagabo]

Congrats on restoring the video stream!

I believe having no "01wb" chunks means there was no audio data.

[Baldrick]

Great!

How did you fix the header?

[filmer01]

@jagabo Thanks, I know unfortunately the way that looks, if anyone knows where else the audio data could be or how to get it please tell me

@Baldrick Thanks and huge thanks to all who assisted here, through coping over the RIFF to the MOVI part of a different video recorded the same way and day to the header of the incomplete file in a hex editor it worked. The part after the header was a 00db code and virtual dub was able to pick right up from there and reindex it once opened in there!