Why video files get corrupted
Video corruption happens more often than you'd expect. Files can become unplayable due to interrupted transfers, camera shutdowns mid-recording, SD card errors, incomplete downloads, or software crashes during editing. The result: videos that won't open, play with glitches, have no audio, or show a black screen.
Common sources of corrupted videos include:
- GoPro / action cameras — battery dies mid-recording, leaving a truncated file
- Drone footage (DJI) — signal loss or emergency landing corrupts the recording
- Dashcam recordings — power cut or SD card failure
- iPhone/iPad recordings — storage full or app crash during recording
- Screen recordings — system crash during capture
- Incomplete downloads — network interruption leaves a partial file
What types of corruption can be fixed?
Missing moov atom
The most common corruption. The moov atom contains the video's index and is normally written at the end of recording. If recording stops abruptly, this index is missing and the file won't play at all.
Broken container structure
The MP4/MOV container's internal structure is damaged. The video data exists but the file's "table of contents" is broken.
Corrupt frames
Individual frames within the video are damaged, causing visual glitches, green blocks, or freezing at certain points.
Audio/video desync
The audio and video tracks have drifted apart, causing lip sync issues or audio that plays at the wrong time.
Truncated files
The file was cut short — the video plays partially then stops, or shows the wrong duration.
Metadata damage
File metadata is corrupted — wrong duration, missing codec info, or incorrect resolution reported.
How to Repair Videos on Mac — Step by Step
Download Star Video Downloader
Get the free app from starvideoapp.com. The repair tool is a Pro feature — upgrade for a one-time $5 payment.
Open the Repair tab
Launch the app and click the "Repair" tab in the sidebar. You'll see a drop zone ready for your corrupted files.
Add your corrupted video files
Drag and drop broken video files into the repair tool. Supports MP4, MOV, MKV, AVI, M4V, 3GP, WebM, and TS formats.
Scan for damage
The app uses ffprobe to analyze each file and detect the type and severity of corruption. You'll see a damage report with specific issues found.
Click Repair
Hit Repair and the multi-stage pipeline runs automatically, trying progressively more aggressive strategies until the file is fixed. The repaired file is saved alongside the original.
Tip: Always keep the original corrupted file. The repair tool creates a new fixed copy — it never modifies your original file.
How the Multi-Stage Repair Works
Star Video Downloader uses a 6-stage repair pipeline powered by ffmpeg. Each stage tries a different repair strategy, and the tool automatically advances to the next stage if the previous one doesn't fully fix the file:
- Container rebuild — remuxes the file to fix structural issues (instant)
- Faststart optimization — moves the moov atom to the correct position (instant)
- Error-tolerant remux — copies streams while ignoring minor errors (fast)
- Corrupt frame discard — skips damaged frames while preserving good ones (fast)
- Audio resync — re-synchronizes audio and video tracks (medium)
- Full re-encode — re-encodes the entire file as a last resort (slower, best recovery chance)
Stages 1–4 preserve original quality with no re-encoding. Stage 6 uses high-quality settings (CRF 18) to minimize quality loss while recovering as much content as possible.
Star Video Downloader vs fix.video
- Price: $5 one-time for unlimited repairs vs $6–$24 per file at fix.video
- Privacy: 100% offline — no uploading private videos to a server
- File size: No limits vs upload-based restrictions
- Speed: Instant local processing vs waiting for server upload + processing + download
- Bonus: Also includes video downloading from 1000+ sites and format conversion
Frequently Asked Questions
Can I repair a corrupted MP4 file on Mac?
Yes. Star Video Downloader's repair tool can fix corrupted MP4 files including missing moov atoms, broken indexes, corrupt frames, and audio desync issues — all offline on your Mac.
How much does video repair cost?
Unlimited video repairs are included with Star Video Downloader Pro for $5 one-time. This compares to services like fix.video that charge $6–$24 per file.
What types of video corruption can it fix?
The repair tool handles missing moov atoms, broken container structure, corrupt frames, audio/video desync, truncated files, and metadata damage. It uses a multi-stage pipeline that escalates from light fixes to deep repair.
Does the repair tool upload my files?
No. All repair processing happens locally on your Mac using ffmpeg. No files are uploaded to any server, and there are no file size limits.
Repair Corrupted Videos on Your Mac
Offline. Private. No file size limits. Unlimited repairs for $5 one-time.
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