What is MIME type "audio/aacp"?

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

audio/aacp is a MIME type for files that use Advanced Audio Coding compression. It labels audio streams that are highly efficient at reducing file size while keeping good sound quality.

This format is used in many multimedia containers. For example, it appears in files like MP4, M4A, 3GP, AAC, M4B, and M4P.

Efficient Compression: Lowers file size while maintaining quality.
Streaming Ready: Ideal for online media and broadcasts.
Versatile Use: Found in smartphones, tablets, and PCs.

For more technical details, visit Advanced Audio Coding on Wikipedia.

Associated file extensions

.mp4, .m4a, .3gp, .aac, .m4b, .m4p

Usage Examples

HTTP Header

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


    Content-Type: audio/aacp

HTML

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


    <a href="file.dat" type="audio/aacp">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', 'audio/aacp');    
      res.end('Content here');    
    }).listen(3000);

Associated file extensions

.mp4, .m4a, .3gp, .aac, .m4b, .m4p

FAQs

What is the audio/aacp MIME type used for?

The audio/aacp MIME type is primarily used to identify HE-AAC (High-Efficiency AAC) or "aacPlus" audio streams. It is widely used in internet radio broadcasting (such as SHOUTcast and Icecast) because it delivers high audio quality at very low bitrates compared to standard MP3s.

Is audio/aacp a standard IANA MIME type?

No, audio/aacp is not officially registered with the IANA. It is a de facto standard used by legacy streaming servers. For modern web development and standard file storage, the official types audio/aac or audio/mp4 are generally preferred.

How does audio/aacp differ from audio/aac?

While audio/aac is the generic type for Advanced Audio Coding, audio/aacp specifically indicates HE-AAC (aacPlus) profiles that use Spectral Band Replication (SBR). Some older players rely on the aacp label to trigger the correct decoding mode, though modern decoders usually detect the profile automatically.

Will HTML5 web browsers play audio/aacp streams?

Most modern browsers support the underlying AAC codec, but they may not recognize the non-standard audio/aacp Content-Type header. To ensure playback in an HTML5 <audio> tag, it is safer to serve files with standard types like audio/mp4 (for .m4a/.mp4) or audio/aac.

How do I configure Nginx to serve files as audio/aacp?

If you specifically need to serve files with this type, add it to your mime.types file or inside a types block in your server configuration. For example: types { audio/aacp aac; } associates the type with the .aac extension.

What file extensions are associated with audio/aacp?

This MIME type is most commonly seen with .aac raw streams or .m4a files containing HE-AAC audio. It may also appear in association with mobile formats like video/3gpp (.3gp) or protected audio files like .m4p.

Why does my media player show audio/aacp for a radio stream?

Internet radio servers often send audio/aacp headers to explicitly tell the client that the stream is aacPlus. This ensures the player knows to expect the high-efficiency profile, which is critical for maintaining quality on low-bandwidth connections.

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.