One of the common video file formats popular among professional videographers and post production studios is MXF. It is short from Material eXchange Format and is compliant with the SMTPE standards for professional video and audio content.
Just like with other video file types, there are cases when MXF files may get corrupted, so that they canít be opened or edited with any video production software. For professional videographers and studios this may seem to be a disaster, as the footage may be invaluable and such that canít be re-produced. Luckily though there is a way to repair corrupt MXF files. In this article weíre going to cover this topic in detail.
How do MXF files usually get corrupted?
MXF files became popular due to their ability to hold full timecode, extensive metadata and multiple media streams encoded with different video and audio codecs. In particular, MXF files are commonly used with the XDCAM, XAVC, DNxHD, Canon XF, Sony RAW and Cinema DNG formats. Most of the high-end cameras, such as BlackMagic, Canon EOS C300, XF305, Sony PWM-200, etc. record video files in the MXF containers.
Like other common video file types, MXF is basically a media container, although it has a more complex structure. It consists of 3 main blocks. The main block, letís call it the Body, contains core media data Ė video and audio tracks. There are also service blocks Ė the Header and Footer. These are almost identical and contain metadata, such as length, size, bitrate, codecs, framerate, resolution, etc. of the video and audio tracks contained in the Body container.
Unfinalized MXF files
The most common reason when MXF files get corrupted is interrupted recording. This is when a camera couldnít finalize the file due to unexpected loss of power. Here are just a few examples of how this may happen:
- Your battery may run low on power an shut off the camera unexpectedly.
- Or, you may have accidentally powered off your camera before pressing the Stop button.
- Another case is when your memory card gets corrupted. Or, there may be not enough space on the card to finalize the file.
- There also may be cases when a camera gets damaged and shuts off while recording the video.
Essentially, in all the cases described above, a camera may fail to save metadata and build indexes for the recorded video and audio tracks. The metadata/indexes are usually saved at the end of the MXF files when you press the Stop button. But if the camera was powered off by an accident, it may have not enough time to build the indexes and save the metadata.
As a result, the MXF container may contain valid video and audio tracks, but have damaged or empty Header and Footer. Usually, such corrupt MXF files canít be played back or edited with a video production software.
Accidentally deleted MXF files
This is another common reason when MXF files get corrupted. Whether youíve deleted the file by an accident or quick-formatted your memory card, there are data recovery tools that claim they can recover your deleted video files.
However, after recovering an MXF file with such tools, you may end up with noting, but junk data. The recovered file may look like the original MXF file, but wonít play back. This is because most of the recovery tools canít handle file fragmentation properly. They just canít locate all chunks of the video and audio streams of the MXF files, which are usually scattered across the media storage. Moreover, generic data recovery tools canít build indexes and metadata, and they also are not smart enough to rebuilt a complex nested structure of the MXF containers. As a result, your recovered MXF file may be a complete mess of randomly merged data, totally unusable and unrecoverable.
How to repair corrupt MXF files properly?
Unfortunately, there are no tools or software that can repair corrupt MXF files automatically. You canít just take a header from a valid MXF video file and put it into the damaged MXF file. This is how most of the generic video repair tools work, but this approach canít be applied to MXF files. To repair MXF files, their container structure and indexes need to be rebuilt from scratch.
Luckily though, there are professional video repair companies that offer MXF file repair services. One such company is Restore.Media. Their engineers analyze video and audio tracks in the MXF files and then build Header/Footer and indexes from scratch.
For MXF files deleted from fast flash memory cards, such as P2, and the HFS file system, Restore.Mediaís video engineers have developed a unique tool that can scan the memory card or its image and locate actual video and audio data, filtering indexes and other service data out. Collected video/audio data in such a way can then be merged into continuous tracks, while metadata/indexes can then be re-created from scratch.
Recently, Restore.Media has published a detailed guide on how to repair corrupt MXF files, you can find the article on this page.
Repairing MXF files is not a trivial task. If youíve got a corrupted MXF video, be sure to make a backup before sending the file to any recovery services. Having a backup of the source file, gives you the opportunity to try different recovery services until the damaged file is finally fixed. Also, make sure to check a preview of the repaired file before paying for the recovery services.
If you deleted MXF files from a memory card, it is important to not overwrite them with new data. Also, it is a good idea to create a RAW image of the memory card. You will be able to send the image to data recovery services and use it as a backup. You can find a comprehensive guide on how to create a RAW image of your flash memory card on the Restore.Mediaís blog.
We hope, this article gave you a handful of insights and ideas on how to act to repair MXF files. If you have any questions, please leave a comment down below.