VAQ redirects here. For the US navy squadrons numbered VAQ-nnn see

Variance Adaptive Quantization (VAQ) is a video encoding algorithm that was first introduced in the popular open source video encoder x264

X264

x264 is a free software library for encoding video streams into the H.264/MPEG-4 AVC format. It is released under the terms of the GNU General Public License.-History:...

. It was later ported to programs which encode video content in other video standards, like MPEG-4 ASP or MPEG-2

MPEG-2

MPEG-2 is a standard for "the generic coding of moving pictures and associated audio information". It describes a combination of lossy video compression and lossy audio data compression methods which permit storage and transmission of movies using currently available storage media and transmission...

.

In the case of Xvid, the algorithm is intended to make up for the earlier limitations in its Adaptive Quantization

Quantization (signal processing)

Quantization, in mathematics and digital signal processing, is the process of mapping a large set of input values to a smaller set – such as rounding values to some unit of precision. A device or algorithmic function that performs quantization is called a quantizer. The error introduced by...

mode. The first Xvid library containing this improvement was released in February 2008.