Multiple-image Network Graphics

"MNG" redirects here. For other uses, see MNG (disambiguation).

Multiple-image Network Graphics

Filename extension	.mng
Internet media type	video/x-mng (unofficial)
Type of format	computer animation
Container for	PNG, JNG
Extended from	PNG

Multiple-image Network Graphics is a public graphics file format for animated images.

MNG is closely related to the PNG image format. When PNG development started in early 1995, developers decided not to incorporate support for animation, because the majority of the PNG developers felt that overloading a single file type with both still and animation features is a bad design, both for users (who have no simple way of determining to which class a given image file belongs) and for web servers (which should use the image/foo MIME type for stills and video/foo for animations--GIF notwithstanding). However, work soon started on MNG as an animation-supporting version of PNG. Version 1.0 of the MNG specification was released on January 31, 2001.

File support

Application support

MNG is currently not as widely supported as PNG. Nonetheless, Gwenview has native MNG support, and MNG plugins are available for some web browsers. Mozilla browsers and Netscape 6.0, 6.01 and 7.0 included native support for MNG until the code was removed in 2003 due to code size and little actual usage, causing complaints on the Mozilla development site. As a result, a MNGzilla project was started to offer patched Mozilla and Firefox browsers. By contrast, Firefox supports MNG rival APNG natively.

Neither Internet Explorer, Opera, nor Safari currently support MNG natively. Recent Sony Ericsson phones support MNG files in their themes. The Sphere game engine supports the use of MNG files for animations. GIMP can export images as MNG files. Imagemagick can create a MNG file from a series of PNG files. If MPlayer is linked against libmng, as it usually is, MPlayer and thus all graphical front-ends like KMPlayer and Gnome MPlayer can display MNG files.

Type	Application		Native support	Plugin
Image processing applications
	Gnome MPlayer		Yes	-
	GIMP		Partial	-
	Gwenview		Yes	-
	KMPlayer		Yes	-
	Konvertor		Yes	-
	ImageMagick		Yes	-
	MPlayer		Yes	-
	XnView		Yes	-
Web browsers	Gecko-based	Iceweasel and other rebranded Mozilla products by the Debian project	No	Un­known
		Mozilla Firefox	up to 2003	Yes
		Mozilla Application Suite	up to 2003	Un­known
		Mozilla SeaMonkey	No	Un­known
	KHTML-based	Konqueror	Yes	-
	Presto-based	Opera	No	Yes
	Trident-based	Internet Explorer	No	Yes
	WebKit-based	Web	No	Un­known
		Google Chrome/Chromium	No	Un­known
		Midori	No	Un­known
		Safari	No	Un­known
Mobile phones	Sony Ericsson support MNG files in their themes		Yes	-
other	Sphere game engine		Yes	-

Server support

Popular web hosting servers are not configured to handle mng files.

The MNG developers hope that in time MNG will begin to replace GIF for animated images on the World Wide Web, just as PNG has already begun to do for still images. However, with the expiration of LZW patents and existence of alternative file formats such as Flash and SVG, combined with lack of MNG supporting viewers and services, web usages were far less than expected.

Technical details

The structure of MNG files is essentially the same as that of PNG files, differing only in the slightly different signature (8A 4D 4E 47 0D 0A 1A 0A in hexadecimal, where 4D 4E 47 is ASCII for "MNG" – see Portable Network Graphics: File header) and the use of a much greater variety of chunks to support all the animation features that it provides. Images to be used in the animation are stored in the MNG file as encapsulated PNG or JNG images.

Two versions of MNG of reduced complexity are also defined: MNG-LC (low complexity) and MNG-VLC (very low complexity). These allow applications to include some level of MNG support without having to implement the entire MNG specification, just as the SVG standard offers the "SVG Basic" and "SVG Tiny" subsets.

MNG does not yet have a registered MIME media type, but video/x-mng or image/x-mng can be used. MNG animations may be included in HTML pages using the <embed> or <object> tag.

MNG can either be lossy or lossless, depending whether the frames are encoded in PNG (lossless) or JNG (lossy).

Alternatives

GIF is often used. APNG is an alternative to MNG, non-standard yet gaining foothold in the World Wide Web. Yet another alternative would be using animated SVG images with embedded PNG or JPEG graphics. More commonly in present-day applications, animations (particularly interactive animations) are achieved using Adobe Flash. Another option for the Web is to write JavaScript code that loads still PNG or JPEG images of each frame, and displays them one by one for a specified time interval. Apart from requiring the user to have JavaScript support and choose to enable it, this method can be CPU and bandwidth intensive for pages with more than one image, large images, or high framerates, and does not allow an image to be saved as one image file or posted on image-based sites such as flickr or imageboards.

External links

• MNG Home Page
• List of browsers that support MNG images
• MNGzilla - An attempt to create a Mozilla variant that has MNG support included
• MNG testcases