What is ANI File Format



A file with .ANI file extension is a graphics file format used by Microsoft for animated mouse cursors. The ANI file format is a specialized version of Microsoft’s Resource Exchange File Format (RIFF).

A RIFF file is composed of chunks. Chunks have three components: data-type identifier, chunk size integer and data. Two chunk types can contain chunks: RIFF and LIST. The RIFF chunk contains the whole file, whose type is defined in the form-type field.

Thus, an animated cursor contains a RIFF chunk where it is declared as ACON form-type. The RIFF chunk in turn contains two or more subchunks. One of these subchunks is of type LIST; and contains, in ICO subchunks, all the frames composing the animated cursor. Another subchunk is of type ANIH, and contains a header.

The header has several important fields:

Field name Description
NumFrames Number of distinct frames
NumSteps Number of animation steps
DisplayRate Default duration for frames
Width Total width in pixels
Height Total height in pixels

Number of bit/pixel

ColorDepth = 2BitCount

If each frame has a different duration, it is replaced by a rate chunk, which contains an array of DWORD values defining the duration of each animation step.

In addition, the RIFF chunk can also contain another LIST chunk with the form-type INFO. This chunk is composed of two subchunks, one containing the author’s name and the other containing the animated cursor’s title. This chunk is optional, and is not present if the icon doesn’t have author or title information.

Individual frames are in ICO format. ICO is a Microsoft’s file format for computer icons. Each ICO file contains several images that can be scaled up. The ICO format was introduced with Windows 1.0, containing 32×32 pixels monochrome images. Windows XP added 32-bit color and Windows Vista included 256×256 pixels. These ICO subchunks can contain not only icons, but also cursor resources and raw images. Raw images are BMP files stored without a header. They use the Width, Height, BitCount and NumPlanes information available from the anih chunk for decoding.

However, it should be noted that the information above is not from official sources, as official information is currently publicly unavailable.

How to Open ANI Files

There are many programs for Windows available that can open and repair ANI files, including:

  • Free File Viewer
  • InfanView
  • AniTurner
  • RealWorld Cursor Editor

What is the Digital Signature of an ANI File

ISO 8859-1: RIFF

Hexadecimal: 52 49 46 46

How to Recover Deleted ANI Files

Unintended deletions are a common feature of our modern digital lives. The great news is that a deletion, in reality, only means erasing a link to the data of the file. Thus, the most important part is still recoverable, until overwritten by another file.

This principle is the base of Disk Drill, a data recovery application that uses powerful algorithms to repair ANI files. This app works on a wide set of devices, including internal and external drives, USB based drives, memory cards, iPads and many more.

It is available for free!

Download Disk Drill data recovery app for Windows  for Mac

Steps for Recovering ANI Files Successfully

Once the installer is downloaded, do the following steps to recover ANI files:

Step 1: Install Disk Drill by clicking on the installer’s icon, and then follow the given steps. They are very clear and precise. The hard part is done by the program, the easy one by you.

Step 2: Open Disk Drill by clicking on the app’s icon. The program will automatically detect all connected devices. In addition, Disk Drill allows you to attach image files. These files are bit-by-bit copies of a digital drive. As they are an exact copy, they contain all deletions still not overwritten by the operating system. Their use is a standard practice in the field of Digital Forensics.

Step 3: Narrow the search by selecting .ani from the “Preferences” menu. This will result in a faster and more efficient ANI file recovery.

Step 4: Ask Disk Drill to begin with the ANI file recovery process. Once started, you can pause or cancel the procedure at any time. In addition, the program lets you save the session and continue later on, without you having lost any of the work already done.

Step 5: Once the ANI recovery is done, Disk Drill presents the results in the form of a list. This list can be narrowed down by using the filters by date or size available from the program. If Disk Drill couldn’t find the original name of a recovered file, it will assign a generic name, such as file0001.ani.

Step 6: Select the .ani file(s) that you need, and retrieve it (them) to a folder of your choice. Open each recovered file to ensure that they are in good form.

You have finished your ANI recovery!


All you need to know about graphics file format ANI updated: September 19, 2017 author: corvettus

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