[interllect123]

if all you want is to allow your users to upload .mp4 format videos to the server/database, then you could have them attach videos to a post and view it from there....

firstly you will need to use a custom video player like a regular html5 <video> tag or jwplayer (just any ppapi video player that will play mp4's should work.... not a npapi video player like divx though as those are now considered not secure by most modern browsers...i.e. depreciated).

secondly (if you havent already done this) you will need to allow mp4 files to be uploaded as an attachment, by going to "AdminCp>Attachments>Attachment Manager" submenu ... click "add a new extension", then add these values to the corrisponding fields:
Extension = "mp4"
Max File-size (in bytes) = "9999999999"
Mime Type & Headers = "Content-Type: video/mp4"
then Save

now thirdly (and lastly) inside of "AdminCp>Styles & Templates>Style manager" find the master/parent style (or just go through each individual template) and select "Edit Template" in the drop down then click "go", now on the displayed list of templates find "Postbit Templates (double click it) > postbit_attachment (then double click it to 'edit' the templates code)" and type this below the line that ends with "</li>":

For html5 video tag:

<vb:if condition="$show['member']">
<vb:if condition="$attachment[attachmentextension] == mp4">
<video width="620" height="540" controls>
  <source src="attachment.php?{vb:raw session.sessionurl}attachmentid={vb:raw attachment.attachmentid}&amp;d={vb:raw attachment.dateline}" type="video/mp4">
  <source src="attachment.php?{vb:raw session.sessionurl}attachmentid={vb:raw attachment.attachmentid}&amp;d={vb:raw attachment.dateline}" type="video/ogg">
Your browser does not support the video tag.
</video>
</vb:if>
</vb:if> 
<vb:if condition="$show['guest']">
<a href="/register.php">Register for free</a> today to download files or play them directly in our embedded media player
</vb:if>
</center>

For JWplayer:

<script src="https://content.jwplatform.com/libraries/[jwplayer_api_key].js"></script> 
<vb:if condition="$show['member']">
<vb:if condition="$attachment[attachmentextension] == mp4">
<div id="container{vb:raw attachment.attachmentid}"></div>
  <script>
    jwplayer("container{vb:raw attachment.attachmentid}").setup({
      file: "attachment.php?{vb:raw session.sessionurl}attachmentid={vb:raw attachment.attachmentid}&amp;d={vb:raw attachment.dateline}"
    });
  </script>
</vb:if>
</vb:if>
<vb:if condition="$show['guest']">
<a href="/register.php">Register for free</a> today to download files or play them directly in our embedded media player
</vb:if>
</center>

you can do the same thing with mp3s too but using an audio mp3 player instead (like the html5 audio tag or wimpy player)... its a bit of a hacked up way of doing it but i hope that helped anyway ... it works well for me and I'm using vbulletin 4.2.4 ... it may even work for vbulletin 5 not sure