What is MIME type "application/x-troff-msvideo"?

A MIME type is a string that tells browsers and other tools how to handle a particular kind of file.

application/x-troff-msvideo is a MIME type used for multimedia files in the AVI format.
It tells applications that the file contains interleaved audio and video data. This lets a media player or browser pick the right tools to play the file correctly.
The name hints at its roots in the Unix troff text-formatting system. Historically, some tools converted formatted documents into video files using this container format.

Main use: Delivering and playing multimedia content with synchronized audio and video tracks.
Other uses: Converting formatted documents into video output and ensuring legacy systems handle the format correctly.
Key fact: The MIME type bridges older text-processing tools with modern video playback applications.

For more details on the file format, check resources like AVI file information.

Associated file extensions

.avi

Usage Examples

HTTP Header

When serving content with this MIME type, set the Content-Type header:


    Content-Type: application/x-troff-msvideo

HTML

In HTML, you can specify the MIME type in various elements:


    <a href="file.dat" type="application/x-troff-msvideo">Download file</a>

Server-side (Node.js)

Setting the Content-Type header in Node.js:


    const http = require('http');    
    
    http.createServer((req, res) => {    
      res.setHeader('Content-Type', 'application/x-troff-msvideo');    
      res.end('Content here');    
    }).listen(3000);

Associated file extensions

.avi

FAQs

What is the application/x-troff-msvideo MIME type used for?

This MIME type is used to identify AVI (Audio Video Interleave) multimedia files, specifically within contexts involving legacy Unix systems or the troff text-formatting suite. It signals to the operating system that the file contains synchronized audio and video data, much like the more common video/x-msvideo type.

Is application/x-troff-msvideo the standard MIME type for AVI files?

No, this is a non-standard or legacy MIME type. The most widely accepted MIME types for AVI files are video/x-msvideo or video/avi. You will typically only encounter application/x-troff-msvideo in older server configurations or specific document-to-video conversion pipelines.

How do I open a file with the application/x-troff-msvideo content type?

Since the underlying content is a standard AVI video, you can open it with almost any modern media player. Popular tools like VLC Media Player, Windows Media Player, or MPlayer will handle the file correctly, regardless of the specific MIME label attached to it.

Why does my browser download the file instead of playing it?

Browsers often do not natively support the AVI container, and the application/ prefix suggests a generic binary or document rather than a video stream. To fix this for web delivery, you should convert the video to MP4 (H.264) and serve it with a video/mp4 MIME type, or ensure your server sends the video/x-msvideo header.

Why does the MIME type name include "troff"?

The name references troff, a classic Unix text-formatting system. Historically, this MIME type was used when software tools converted formatted troff documents into video output (AVI) for display or archiving, creating a bridge between text processing and multimedia playback.

How do I configure Apache to serve AVI files with this type?

If you specifically require this legacy type, add the following line to your .htaccess file or httpd.conf: AddType application/x-troff-msvideo .avi. However, for broad compatibility, it is recommended to use AddType video/x-msvideo .avi instead.

Is application/x-troff-msvideo safe to open?

Generally, yes, but AVI files can contain various codecs or even malicious scripts if the player is vulnerable. Always ensure your media player is up-to-date and scan files from unknown sources with antivirus software before opening them.

General FAQ

What is a MIME type?

A MIME (Multipurpose Internet Mail Extensions) type is a standard that indicates the nature and format of a document, file, or assortment of bytes. MIME types are defined and standardized in IETF's RFC 6838.

MIME types are important because they help browsers and servers understand how to process a file. When a browser receives a file from a server, it uses the MIME type to determine how to display or handle the content, whether it's an image to display, a PDF to open in a viewer, or a video to play.

MIME types consist of a type and a subtype, separated by a slash (e.g., text/html, image/jpeg, application/pdf). Some MIME types also include optional parameters.

How do I find the MIME type for a file?

You can check the file extension or use a file identification tool such as file --mime-type on the command line. Many programming languages also provide libraries to detect MIME types.

Why are multiple MIME types listed for one extension?

Different applications and historical conventions may use alternative MIME identifiers for the same kind of file. Showing them all helps ensure compatibility across systems.