.VQA
Encyclopedia
Vector Quantized Animation, known by its acronym VQA is a file format
File format
A file format is a particular way that information is encoded for storage in a computer file.Since a disk drive, or indeed any computer storage, can store only bits, the computer must have some way of converting information to 0s and 1s and vice-versa. There are different kinds of formats for...

 originally developed by Westwood Studios
Westwood Studios
Westwood Studios was a computer and video game developer, based in Las Vegas, Nevada. It was founded by Brett Sperry and Louis Castle in as Westwood Associates, and renamed to Westwood Studios when it merged with Virgin Interactive in...

 for video encoding in their game The Legend of Kyrandia
The Legend of Kyrandia
The Legend of Kyrandia is a fantasy point-and-click adventure game trilogy with comedy elements, created by Westwood Studios, and released for DOS, Amiga, FM Towns and Apple Macintosh...

 and monopoly.

Description

The VQA format was used in every Westwood game released between 1995 and 2000. Each VQA file consists of a series of chunks aligned in a tree structure, beginning with the chunk FORM, which is the parent of every other chunk in the file. All data are in little endian
Endianness
In computing, the term endian or endianness refers to the ordering of individually addressable sub-components within the representation of a larger data item as stored in external memory . Each sub-component in the representation has a unique degree of significance, like the place value of digits...

. Audio in VQA files are in the .AUD file format.

Version 1

Version 1 was used in the third part of the The Legend of Kyrandia
The Legend of Kyrandia
The Legend of Kyrandia is a fantasy point-and-click adventure game trilogy with comedy elements, created by Westwood Studios, and released for DOS, Amiga, FM Towns and Apple Macintosh...

 series. It allowed the use of 256 colors and a maximum resolution of 640*480 (but most videos were encoded in 320*156). Version 1 VQAs must always use 8-bit sound. A frame rate set to higher than 10 renders the VQA unplayable to Legends of Kyrandia. Setting any value in the header chunk to zero makes the video use the default value.

Version 2 (C&C VQA)

Version 2 was used in Command & Conquer
Command & Conquer
Command & Conquer, abbreviated to C&C and also known as Tiberian Dawn, is a 1995 real-time strategy computer game developed by Westwood Studios for MS-DOS and published by Virgin Interactive. It was the first of twelve games to date to be released under the Command & Conquer label, including a...

, its prequel Command & Conquer: Red Alert
Command & Conquer: Red Alert
Command & Conquer: Red Alert is a real-time strategy computer game of the Command & Conquer franchise, produced by Westwood Studios and released by Virgin Interactive in...

, Dune 2000
Dune 2000
Dune 2000 is a real-time strategy video game, released by Westwood Studios in 1998 for Microsoft Windows, and later ported to the PlayStation. It is a partial remake of Dune II, which is also based on Frank Herbert's Dune universe. The story of the game is similar to Dune II, and is continued in...

 and Lands of Lore 2. The main changes were the introduction of 16-bit sound, frame rates higher than 15 and the removal of default values (using 0 in the header chunk results in unplayable video).

Version 3 (15 bit Hi Color VQA)

The biggest addition of Version 3 is the support of videos with 32,768 colors. The maximum value of the colors entry in the header chunk is still 256 but setting it to 0 will default to HiColor mode.
Another modification is that if the first byte of the chunk is set to 0×00 then the frame is not encoded using the standard Format80 algorithm
Algorithm
In mathematics and computer science, an algorithm is an effective method expressed as a finite list of well-defined instructions for calculating a function. Algorithms are used for calculation, data processing, and automated reasoning...

.

Encoding / Decoding

There is only one known encoder for VQA files except the encoder used by Westwood.

The video codec VQA files use is very asymmetrical meaning the encoding process is very time consuming whereas the decoding algorithm is among the simplest and fastest out there.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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