Jitter buffer

Jitter buffers or (De)jitter buffers are used to counter "jitter" introduced by packet networks so that a continuous playout of audio ( or video) transmitted over the network can be ensured. The maximum jitter that can be countered by a de-jitter buffer is equal to the buffering delay introduced before starting the play-out of the mediastream.

Some systems use sophisticated delay-optimal de-jitter buffers which are capable of adapting the buffering delay to changing network jitter characteristics. These are known as adaptive de-jitter buffers and the adaptation logic is based on the jitter estimates computed from the arrival characteristics of the media packets. Adaptive de-jittering involves introducing discontinuities in the media play-out which may appear offensive to the listener / viewer. Adaptive de-jittering is usually carried out for audio play-outs which feature a VAD/DTX encoded audio, that allows the lengths of the silence periods to be adjusted, thus minimizing the perceptual impact of the adaptation.