Troubleshooting guide
How to repair an MP4 after a PC crash
A PC crash during recording can leave an MP4 that looks normal in File Explorer but shows 0 seconds, will not open, or fails in every editor. Do not overwrite it. In many cases, the footage is still inside the file and the missing piece is the MP4 index.
First: protect the original file
Before trying any repair, copy the broken MP4 to another folder or drive. Work only on the copy. Do not trim, rename repeatedly, convert, or upload your only original to a random repair site. If the crash was caused by a failing drive, copy the file to healthy storage before doing anything else.
What usually happened
MP4 recordings need final metadata so players know where frames and audio samples live. A forced shutdown, blue screen, battery loss, or disk-full event can interrupt that final write. The file can be huge because the media data was written, but it can still be unplayable because the table of contents is missing or incomplete.
| Symptom | What it usually means |
|---|---|
| Player shows 0 seconds | The MP4 index cannot be read |
| VLC refuses to open the file | The file may be missing final metadata, not necessarily footage |
| Editor imports audio but no video | Video stream metadata may be incomplete or mismatched |
| File size looks correct | Good sign: the raw media data may still be present |
Try the least destructive repair path
- Copy the broken file and repair the copy.
- Try a local stream-copy repair first.
- If that fails, record a short clean reference clip using the same recorder and settings.
- Use the broken file plus reference clip to rebuild the missing metadata.
- Preview the repaired output before paying for or replacing anything.
If the file came from OBS, the reference clip method is often the right approach. Record 10 seconds with the same resolution, frame rate, and encoder, then use that healthy file as the template for the broken one.
Avoid destructive guesses. Re-encoding tools, online converters, and random "fix headers" commands can make a copy worse. They should never touch your only original file.
Try local repair before uploading the file
StreamSalvage repairs crashed OBS-style MP4 files on your PC, previews the result for free, and exports for $29 only if the repair works.
Download StreamSalvage for WindowsPrevent it next time
If the recording came from OBS, switch to MKV and remux to MP4 after recording. That keeps the recording usable even if OBS or Windows crashes. If you must record MP4 directly, use fragmented MP4 and test the workflow before relying on it.
Frequently asked questions
Can an MP4 be repaired after a PC crash?
Often yes. If the crash happened while recording, the video and audio data may still be present but the MP4 metadata may be missing. A local repair tool can try to rebuild that metadata.
What should I do before trying to repair the file?
Make a copy of the broken MP4 and work only on the copy. Do not trim, convert, overwrite, or upload your only original file before you have a backup.
Why does the MP4 show 0 seconds after a crash?
A 0-second duration usually means the player cannot read the MP4 index. The recording data may still exist, but the file was not finalized before the crash.
Do I need a reference file to repair a crashed MP4?
A reference file is not always required, but it often helps. Record a short clean clip with the same camera, screen recorder, or OBS settings so the repair has matching metadata to rebuild from.