Sunday, 18 December 2016

VLC Media Player not Playing MP4 Videos? How to Fix

An illegal copy of an MP4 video file or probably a corrupted MP4 video file will certainly not play on VLC media player. Another valid reason for MP4 video not playing on a Mac or Windows based VLC player is due to incorrect “video output modes”. Improper MP4 file video codec also disables the MP4 video file and prevents it from playing correctly on VLC player.

Summarising all Problems

(1) Damaged MP4
(2) Video Output Modes
(3) Codec

Including above three extreme scenarios, below mentioned problems might also share an impact on the working of the MP4 video file:

(4) Virus/Malware Problem
(5) Damaged file extension
(6) Improper file conversion

I. Corrupt MP4

A corrupt or fake MP4 will not work smoothly on your VLC media player. Or it may not even attempt to launch itself on VLC player. The reason behind this could be the corruption of MP4 video file header. A damaged header will not read the video file at all and hence it will not play itself. Other than the header damages, an MP4 video file may receive sound, video movement and slider corruption making the media player play the file abruptly. You will receive the video, but it won’t play itself correctly. It may have blurredness, audio problems and video movement issues. 

Solution – there isn’t a free option available for repairing a corrupt MP4 video file through VLC or other media player. Perhaps, a part of video corruption could be fixed but certainly not the header file. Due to lack of a default video repair mechanism, a video file repair utility is required. Stellar Phoenix Video Repair fills this gap by fixing header, sound, slider and movement corruption of MP4 video files. Moreover, this product supports repairing of other video formats such as MOV, M4V, M4A, etc.

II. Video Output Modes

Solution – 

On Mac, run VLC media player and go to its System Preferences:

a) Go to Video, and check “Enable Video.”
b) Check “Window Decorations.”
c) In Output Mode select X11 video output(XCB)
d) Save all your settings

III. Video Codec

Your MP4 video file may not be corrupt but still you wonder why it gets failed to run on VLC player? Because of the incompatible video codec contained in the MP4 video file that isn’t supported by your installed VLC player.


a) Update VLC media player on your Mac and Windows.
b) Download video codec packs from trusted websites like the CNET.
c) Use the third party video converter and to convert the MP4 file correctly.

IV. Virus and Malware Attacks

Viruses and malwares more frequently attack Windows PC than Macs. More and newer threats continuously make attempts to infiltrate your OS and corrupt the existing files. Many times, such malware and viruses damage the video file to an extent where they became non-playable.

Solution – Update your anti-virus application virus database and rescan the computers hard disk.

V. Damaged File Extension

The three letters suffixed along a file name carries immense importance in their execution. The ____.mp4 file extension is helpful for the OS (or OS X) to identify the type of file. If the file extension is re-written, removed or compromised then the video (be it MP4 or any) will be affected. 

Solution – Rename the file extension correctly. You may also take the help from free Exe fixers applications that can repair the file extensions.

VI. File Converter

A file converter application may not do the job correctly and hence your output becomes corrupted. 

Solution – Download a trusted video file converter application from CNET and try converting your video again.