How to Fix Broken or Corrupted MP4 Video Files

MP4 or MPEG-4 Part 14 is the most used video compression format in the present world. However, sometimes you may not be able to open the file, or it doesn’t show its audio or video information. If this issue occurs for particular files in all video players, it indicates that the video is broken or corrupt.

The files become corrupted if they experience data loss during transmissions or read/write processes due to abrupt cutoffs or power failure. Fortunately, you can fix most broken mp4 files. In this article, we mention different ways in which you can perform the repair.

Can You Completely Fix Broken or Corrupted MP4 Video Files?

Depending on how corrupted your file is and the nature of the corruption, you may not be able to fix the file completely.

• Corrupt headers are the easiest to recover.
• You can repair the file if some small chunks are missing or corrupt.
• Audio information may not recover fully depending on the corruption.
• Heavily damaged files are extremely difficult to recover.
• If the file size shows 0 Kb, you can’t recover it.

How to Fix Broken or Corrupted MP4 Video Files?

Since all operating systems, including Linux and Windows, do not have built-in methods to fix broken or corrupt video files, you need to use third-party processes. You can either use video recovery software or repair your file online.

Also, before you begin, make sure to check if you can open the file with another video player. It is possible that your current player does not have the necessary video or audio codecs. In this scenario, you may think that some mp4 files as broken even when it is not the case.

We recommend VLC Media Player and Media Player Classic as they are free players that include almost all necessary codecs. You can also install all available codecs for your player.

If the file doesn’t play or shows issues in all players, apply the following solutions to repair it.

With Video Repair Software

There are many video repair software available on the internet which you can use to repair your corrupt MP4 files. You need a working reference video to repair the broken file in this way. You must record the reference video on the same device or software as the broken video. You also need to use the same configuration or settings for both files. The video duration does not matter.

Here, we use the free and open-source video repair software, Untrunc, to repair the MP4 file. It is a fully automated tool that you can use with both Command-line Interface (CLI) and Graphical User Interface (GUI). The GUI is suitable for Windows OS, but it is possible to use the CLI commands on different operating systems.

You can use the original Untrunc app from ponchio or use an improved version from anthwlock. In this section, we use the latter program on a Windows system.

If you don’t already have one, capture a new reference video accordingly and follow the steps below to repair the damaged MP4 file:

1. Download the latest Untrunc app from the GitHub Release page.
2. You can download either x86 (32-bit) or x64 (64-bit) version based on your system architecture. The 32-bit one will only use up to 4 GB of memory.
3. Extract the zip file and go inside the extracted folder.
4. Run untrunc-gui.
   
5. Now, click on the reference file.
6. Navigate to the reference video, select it and click Open.
7. Similarly, click on the truncated file, navigate to and select the damaged video. Then, click Open.
8. Click Repair to initiate the repair.
   

After the process completes, go to the output file (you can also see where it is on the description box within the Untrunc-gui program) and see if the repair was successful. Also, keep in mind that the file may have a few black frames at the beginning.

You can also use the Untrunc CLI to perform the repair. To do so,

1. Navigate to the folder with untrunc.exe through your File Explorer.
2. Click on the address bar, clear it and type cmd. Then, press Enter to open the Command Prompt on this directory.
   
3. Enter the command untrunc “Full path of working reference video” “Full path of broken video” while replacing the paths appropriately.
   
4. Alternatively, you can move both videos to the folder with untrunc.exe and only use the full name of the files in the command.
5. If you want to get a detailed description of the ongoing process while running the tool, you can append -v flag after typing the path of the broken video. For example,
   untrunc “D:\New\ref.mp4” “D:\New\cor.mp4” -v

Through Online Repair

You can also find many online video repair websites on the internet. While most of them don’t allow repairing large corrupt files without buying a subscription, you can use most to freely repair small files.

So, if you only have one or a few small MP4 files, using online repair might be a better option than downloading and using recovery software.