Video Recovery case studies
The following are examples of damaged or corrupted video file that have been recovered by Cnw Recovery software. The most complex is the GoPro action camera, but most cameras have similar issues that CnW software can handle. Download the free demo to try the software
The camera had been used for some very exciting skiing event. These were on the ExFAT memory chip. The camera was then used to take a time lapse sequence of photos - but at this point something failed. The camera stored the time lapse photos over the main ExFAT directory and on the area of the disk with the directory and other critical information. The result was a memory chip that could not be read. The video had been recorded (by default) in high and low resolution so that the data was in 100s of fragments on the memory chip. CnW Recovery software pieced together the fragments from the GoPro camera to allow the video to be recovered and displayed.
GoPro Accidental deletion
Accidental deletion is always going to be an issue, and with FAT32 not good news. This customer had some aerial photography but deleted files that he thought had been copied to another device. He tried several software products which claim such recovery, but not one produced a single file. A tentative inquiry to CnW produced enough reassurance that the product would either work straight out of the box, or he would be supported until successful. In this case some tweaking was required, but even out the box, his videos were playable and complete. For the final tweaking, the customer sent the disk image to CnW SFTP server and within a few days he was very delighted with the perfect results produced.
Samsung camera not finalised
Not being finalised is a fairly common problem. Maybe the memory chip was removed, or in another example, the camra was dropped. On these occasions it is necessary to recreate all the meta data, ie the ‘moov’ atom for the video. This is helped by making sure there is a good example of a working file on the same device. CnW software can then make a fragment into a playable video. NB, this can be rather complex, and can occasionally require some tweaking from CnW. If the user has a bought a licence, this tweaking is free, but just requires the chip to be sent or FTPed to CnW.
One example of this was a complete gymkhana event being recorded, and then accidently deleted. The memory had been edited by deleting some files before hand and so the MTS files were no long continuous. CnW managed an almost perfect recovery by knowing how to join the fragments together.
AVCHD/MTS on a film shoot
This was an interesting job as the camera used was one of a few in a professional film shoot. Again the customer did try other software, but this produced thousands of fragments rather than about 100 shots. The matching was not 100% perfect, but having to do a few manual edits, rather than a few thousand edits was acceptable.
There are not many failures, but one example was due to the use of other not very good recovery software. This software produced thousands on clips, a few seconds long. The user then wrote these clips back to the original memory chip overwriting the original data. Unfortunately, each memory clip was only about 80% of the original data so it would not be possible to join the clips with nasty breaks in the video every few seconds.
The important lesson is to ALWAYS keep your original data. NEVER overwrite it until you are 110% sure that everything has been recovered and verified. It is always cheaper and safer to buy a new memory chip and one use the existing one a few weeks later when absolutely sure all recovery is OK.
Again this failure was due to user error. The shot some video (sequence 1). He then formatted the memory chip and shot more video (sequence 2). he the formatted the memory chip and shot a bit more video (sequence 3). He then tried to get back sequence 1. If sequence 1 had been longer than either sequence 2 or 3, some recovery may have been possible. However his required video was about 10 minutes, and sequence 2 was about 1 hour. In such cases, all of sequence is overwritten and lost for ever.
The moral, if you start over writing my mistake STOP. Recovery may be possible.
In this case a video was partially overwritten by camera failure. However, the index of the video still existed and Cnw Recovery software could use the index to find most of the original video and reconstruct the file. Many recovery routines just search for the start of the file, but Cnw can at time reconstruct from the end.
Panasonic Lumix GH4
The Lumix GH4 camera has been seen to record data in various ways. The mdat is recorded separately from the ftyp and moov. However in one example all the header ftyps and moovs were recorded at the start of the memory chip, and then all the mdats (video data) was recorded further up the memory chip. Recovery invloved analysing the headers and deciding which mdat atom belonged to which header. Fortunately, the mdats are typically sequential runs of video frames.