High definition wireless video transmission using Pyramid Vector Quantisation

Robust video transmission using Pyramid Vector Quantisation

“…The excellent error resilience of PVQ was demonstrated in [7] for the case of a MIMO WLAN scenario, and is extended here for the new RD optimised algorithm. The simulation environment is depicted in Figure 4.…”

“…Using less than 8 bits per coefficients leads to noticeable contouring artefacts, whereas using more than 8 bits per coefficient gives imperceptible improvement in quality. For the U and V colour components, 6 bits per coefficient has been found to be adequate [7].…”

“…In [7] the authors showed that intra-mode PVQ was a strong candidate for indoor wireless transmission of HD video. Intra-mode coding was used since inter-frame encoding leads to temporal error propagation which significantly degrades the viewing experience.…”

“…In particular, MIMO WLANs such as 802.11n can provide the source throughput required by HD intraonly codecs [8]. In this paper we build on [7] by presenting a novel and efficient rate distortion algorithm for HD video encoding using PVQ. The presented algorithm provides the optimal set of PVQ encoding parameters which minimise distorion.…”

“…I(x, y) n times to obtain M subbands [s1, s2, s3, ..., sM ] Scalar Quantise Subband s1 Calculate subband energies σ 2 k and group to form v Sort v to obtain vs; vs ← sort(v) BT ←Target Bitrate; ψ ← 0 Start :Calculate B k,ψ using equation (4) ∀k = 2, 3, ..., (M − ψ) For Subbands k = 2, 3, ..., (M − ψ) if (B k,ψ ≤ 0) {ψ ← ψ + 1; goto: Start} ψmin ← ψ; For ψ = ψmin : 1 : ψmax{ For Subbands k = 2, 3, ..., (M − ψ){Calculate encoding parameters Z k , N k using[7] and Vector Quantise subband} Save encoding parameters and Generate Reconstruction R ψ (x, y) Calculate Distortion D ψ and save in Distortion Vector D} Find Dmin = min(D) and select the corresponding parameter set 'J' as optimal encoding parameter set. Peform Bit Level encoding using 'J' } vector, and iii) the number of bits needed to encode each vector.…”