Best MP4 video repair tools | Why they may not work at all
In this post we’ll look at some MP4 Video Repair tools. Digital video and digital photography is booming. Today almost every one caries a device capable of capturing digital photos and video, the smart-phone. And on top of that there are millions of people owning digital camera’s and action cams (GoPro etc.) shooting terabytes of footage each day. I read somewhere that 300 hours of video is added to Youtube every minute! It is my estimate that a good portion of all that video is originally shot in MP4 format.
What is MP4?
The MP4 file is a container for digital video and audio, but apart from that it may also include other data.. It is based on the Apple MOV format. The format describes how data is stored much like a file system describes how data is stored on a hard disk. You may probably have seen the phrase ‘H.264’ in combination with MP4. H.264 describes how video data is encoded, it’s called a codec. The video inside a MP4 container is often H.264 encoded. A video player needs to understand both the MP4 format and H.264 encoding to properly play the file.
An MP4 file typically contains a header, data and an index. Problems arise in modern cameras that also include additional data such as thumbnails, audio and low resolution video all in the same container which makes repair of these files complex. A file is typically larger than what the recording device can buffer, so data needs to be flushed to the storage medium regularly, increasing the odds the file becoming fragmented.
Basic layout of a MP4 video file:
- Header (ftyp atom)
- Video data (mdat atom)
- Index information (moov atom)
Typical accidents when shooting video -or- why people are looking for MP4 video repair
Typical accidents or why people are looking for MP4 video repair tools: Most common incident is probably the video never being finalized due to the device running out of power. This means the container itself is never finalized, but neither the file system (something else we need to include in the equation). In human language it means the the final index for the video file was never written, nor was the file system updated. So, we are dealing with orphan data within the file as well as in the file system.
Another reason that prompts the need for MP4 video repair tools is that files are corrupted after using undelete or file recovery software. Due to the nature of the video files themselves and the fact that they are commonly recorded on FAT32 or exFAT formatted file systems, recovery of such files is difficult. The file allocation table is the meta structure that tells the locations of clusters allocated to files in both the FAT32 and the exFAT file system. This structure is zeroed when for example a memory card is formatted. If a file is deleted, the entries in the FAT for that file are zeroed. It means that the undelete or file recovery software has no way to determine which clusters belong to the deleted file. It will therefor assume the file is stored in one piece (which it often is not).
MP4 Video Repair Tools
In short, video repair tools need to locate the video data. They need to reconstruct a header which contains important data needed to decode the video data. And, then they need add a valid index. It is common for MP4 video repair software to ask for a reference file show with the same camera/device and settings from which it can steal a header.
Video repair utilities and services
Pricing is per video.
aero Quartet is a video repair service. It’s service is deleivered though a web-interface or a Mac utility (Treasured). The service requires a reference file. It can also recover video files from a corrupted memory card. Noteworthy it that if you use the Mac application there is no need to upload the entire video file. The software will upload a sample. You do not get a repaired video returned, instead your are sent a ‘solution’ called a repair kit that is then used to locally repair your video file(s).
Stellar Phoenix Video Repair tool
Pricing: $49.99 for a one year subscription
Stellar’s tool will initially try to repair the tool without a reference file, but will prompt for one if repair fails.
Pricing is per video.
Restore.Media is another MP4 video repair service and will also prompt you for a reference file. Before this turned into a paid service, the software behind this service was a freeware. Here you can view a guide and video on using the freeware variant.
Video Repair Tool from grau GmbH.
Price is $99
Trial version repair half of the corrupted video. So, for a 2 minute video it will save only the first minute. The tool will ask for a reference file that was shot with the same camera and settings. This software appears to be the one most people report success with.
Freebie: Windows shell for untrunc
Price is $0
The tool I offer on this page is nothing than a tools that wraps around ‘untrunc’. I am afraid I can not be of much help with regards to using the actual tool to repair corrupt MP4 based videos but if you find any bugs in the ‘mp4repair.exe’ then let me know This is a 0.9.0 version but I can not predict how much more time I can spend on it. For using untrunc and in what types of situation it can be used I mus refer to your Google skills at this time.
Untrunc (original, Linux): https://github.com/ponchio/untrunc
Untrunc-w (Windows): https://github.com/SuslikV/untrunc-w
ffmpeg (used for video playback + untrunc-w): https://www.ffmpeg.org/
And why MP4 video repair software might not work …
JPEG Recovery LAB
Price is $39.95
So, as discussed a few of the common causes are related to the file system. More precise, the file not properly or not all referenced by the file system. Add file fragmentation and the inability of undelete and file recovery software to deal with that and it is clear that repair may not work at all. Repair of video files is limited to video data already inside the file. If parts are missing due to incorrectly recovered video files, the video will be incomplete.
In many cases it may be worthwhile to approach this from a lower level. Ideally we use a tool to scan the media for MP4 video data and re-assemble that into playable video files. Although the name may suggest otherwise, that is exactly what JPEG Recovery LAB does: JPEG Recovery LAB scans the media (memory card) for video and audio fragments and re-assembled that into playable files.
JPEG Recovery LAB will not ask for a reference file as usually it will find one or more while scanning the memory card. To reconstruct a file for orphaned video data it can steal a header from one of the complete files.