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Video MIME types

Last updated on June 9, 2017

Video in the OpenX Ad Exchange is in Beta release only. For more information, please contact your OpenX Account Manager.

When you create a linear video ad unit, you choose MIME typesVideo creative formats supported by your video player. For example, video/mp4. for that ad unitIn OpenX, the smallest inventory component that represents the space on a site where ads display.. The MIME types you choose depend on your video player's compatibility and the inventoryAd space available on a website or app. The basic unit of inventory for OpenX is an ad unit. type of your linear videoAn ad or ad unit that displays in sequence with video content in a video player. Sequencing may be pre-roll, mid-roll, or post-roll. Can be accompanied by a companion ad. An example is a video ad that plays before a video starts, though static images may also serve. ad unit.

Create ad unit screen for Linear Video inventory

Introduction to MIME types

MIME types describe the type of file you are transmitting in a way that has meaning to the code base via which your video player and ad serverA complete digital advertising platform where publishers sell, manage, and deliver their advertising inventory across all digital formats. communicate. You are probably used to recognizing files based on their filename extensions, such as .mov for a Quicktime file. These filename extensions are associated with MIME types so your ad server or video player can communicate with each other and demand sources who want to serve ads to your linear video ad units.

Your video player is compatible with a particular set of MIME types. You need to identify those and specify the subset of them that is compatible with your ad unit's inventory type while creating a linear video ad unit. By doing this, you should receive only ads that are compatible with your video player and inventory type.

MIME type syntax


A MIME type's structure consists of a type and a subtype. The type and subtype are two strings which are separated by a forward slash (/). Spaces are not permitted, and lower case is the standard, though MIME types are not case sensitive.

In the case of OpenX Video, you find MIME types with a type of either application or video. For example, the Quicktime file referenced above has a type of video and a subtype of quicktime. The MIME type associated with a Quicktime file looks like this:


How to choose MIME types

It is very important to choose the correct MIME types. Choosing incorrect MIME types will make your ad unit available to incompatible ad types in the OpenX Exchange. Determine which MIME types to select based on two criteria:

  • Video player compatibility
  • Inventory type of your linear video ad unit

Overview of MIME type choices

MIME type Sample filename extension(s)


Important: Requires VPAIDVideo Player Ad-Serving Interface Definition, a type of API framework for interfacing between a video ad creative and a video player. 2.0 support.

application/ .m3u, .m3u8
application/x-mpegurl .m3u, .m3u8
video/3gpp .3gp
video/mp4 .mp4, .m4a, .m4p, .m4b, .m4r, .m4v
video/mpeg .m1v
video/ogg .ogg
video/quicktime .mov, .qt
video/webm .webm


Important: For desktop webRefers to the use of the Internet via a desktop computer web browser, specifically to differentiate from mobile web or mobile app. inventory only.

.flv, .f4v
video/x-m4v .m4v
video/ms-asf .asf, .wma, .wmv
video/x-ms-wmv .wmv
video/x-msvideo .avi

Links to common video player documentation for supported MIME types

As we find more MIME support documentation, we'll add it here.

Note: The following information is subject to change without notice to OpenX. When in doubt, please follow documentation for your video player's latest version.

Next steps

Now that you know about MIME types, you can create a linear video ad unit.

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