Corruption in the 7z archive headers even when size is accurate indicates a major issue.
Corruption in the 7z archive headers even when size is accurate indicates a major issue.
Hello, I'm facing a tough issue. I've been saving my gameplay recordings in videos and compressed them using .7z with ultra compression. Unfortunately, the archive got corrupted somewhere, and I tried using WinRAR but couldn't open or extract it. No experience with hex editing, and several programs don't support fixing .7z files. I've lost hours of footage, and it's really frustrating. Please help me recover this data.
first of all, why? compressing media is pointless and waste of energy. My bet is on archive being corrupted by your nas, I am not sure what you are using there but if you are using something like ZFS with redundant disks you might be able to get away by scrubbing the disk and just copying the file back to your PC.
No notable changes were made in the videos that require saving. They aren’t available on platforms like Twitch or YouTube VOD. Your recordings are already compressed, so further compression won’t save much space and may worsen data quality.
I don't have it on Twitch or YouTube—it saved space because none of these videos were rendered. They're just raw MP4 files recorded in .7z format by OBS Anyhow. Compressing them that way isn't helping me recover anything. I even had a backup, but it's corrupted too. Worse than the one I see showing up as 247TB with zero bytes on the disk; this one here matches the correct size.
The archive is damaged, and I’m not sure it can be salvaged except with specialized help. Prioritize your backup drive, as there’s a higher chance of retrieving that version. Use CrystalDiskInfo to assess the drive’s condition. If possible, run chkdsk to restore readability. Moving forward, avoid compressing video files with 7zip—MP4 is already compressed. A single bit error in a video stream can cause noticeable issues, while a corrupted archive affects everything.
Using a hex editor comes easily enough. Identifying the exact changes needed is challenging. Repairing a damaged .7z file will be nearly impossible. You’d likely have to decompress it manually until you hit a section that can’t be processed, then try to bypass the faulty segment. Someone with expertise might help, but it’s unlikely they’ll offer free assistance. If your video files are excessively large, consider tools like Handbrake or ffmpeg to re-encode them using a more efficient codec and/or higher compression. Video formats can offer superior compression compared to 7zip, since they’re tailored for video and allow lossy compression. A typical zip compressor isn’t designed for video and must preserve data, making recovery less likely if bytes are lost. This isn’t the case for a general archive—if a portion is corrupted, the rest may still be salvageable, as only a small amount of data is usually affected.