SOME MP4 video files won't open.

MouldyOldDough

I have downloaded and am using VLC - yet some of my MP4 video files will not open - they show as a parking cone - others will open.

As far as I can see - there's absolutely no difference between the individual files (they are all between 200Mb and 400Mb in size).

I have updated VLC 

Windows media player no longer plays MP4's either.

Any suggestions as to a fix ?

PHK

MP4 is a container format. That means that the video and audio ( and subtitles etc if it has them ) is wrapped together as one but the actual data could be encoded in any of a number of different formats. 

You'll, need a a bit of software that plugs into windows to allow VLC or Media Player to play those files. It's called a codec. 

The source of the video files should be able to tell you the format. Otherwise, media player or VLC should prompt you to find the appropriate codec. 

facade

Right click on the offending file and select "open with"  and choose windows media player and see if it plays.

You can permanently change the player by messing with file associations, or  just right click on an example of the file and pick "open with" then "chose another app" click the player you want to use and then click the "always" button.

I suspect that the files are corrupt though, or VLC would play them.

get hold of mediainfo from mediaarea dot net and install it, then you can right click a file, or just hover over it and find out what it is.

Tiexen

MouldyOldDough said:

I have downloaded and am using VLC - yet some of my MP4 video files will not open - they show as a parking cone - others will open.

As far as I can see - there's absolutely no difference between the individual files (they are all between 200Mb and 400Mb in size).

I have updated VLC 

Windows media player no longer plays MP4's either.

Any suggestions as to a fix ?

You can try this:

https://www.codecguide.com/download_kl.htm

Download K-Lite Codec Pack

Already contains everything you need to play all common audio and video file formats.

Supports playback of:

• AVI, MKV, MP4, FLV, MPEG, MOV, TS, M2TS, WMV, RM, RMVB, OGM, WebM
• MP3, FLAC, M4A, AAC, OGG, 3GP, AMR, APE, MKA, Opus, Wavpack, Musepack
• DVD and Blu-ray (after decryption)
• and many more audio and video formats!

Provides lots of useful functionality, such as:

• Subtitle display
• Hardware accelerated video decoding
• Audio bitstreaming
• Video thumbnails in Explorer
• File association options
• Broken codec detection
• and much more!

outtatune

Before you start installing codec packs, check what codec the files use. 

Mediainfo is pretty good.
https://www.videohelp.com/software/MediaInfo

bob2302

IIWY I'd check if the files are playable on another device, they may simply be corrupted. 

Maybe there's something different on Windows, but I've never seen a video file where VLC needed an extra codec.

virgo17

MouldyOldDough said:

I have downloaded and am using VLC - yet some of my MP4 video files will not open - they show as a parking cone - others will open.

As far as I can see - there's absolutely no difference between the individual files (they are all between 200Mb and 400Mb in size).

I have updated VLC 

Windows media player no longer plays MP4's either.

Any suggestions as to a fix ?

You don't say where you are getting your mp4 files from.

Over time I have come across mp4 files that contain a non Latin printable character in the filename. VLC will show the traffic cone based on the extension but may be unable to fully read the name. Try renaming the offending files to something simple lite 'video1.mp4' and see if they play.