G.711.1 Annex D and G.722 Annex B - New ITU-T superwideband codecs

Miao, Lei; Liu, Zexin; Hu, Chen; Eksler, Vaclav; Ragot, S.; Lamblin, C.; Kovesi, B.; Sung, Jongwoo; Fukui, Masahiro; Sasaki, Shinya; Hiwasaki, Yusuke

doi:10.1109/icassp.2011.5947537

Cited by 8 publications

(5 citation statements)

References 3 publications

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“…Layering Annex D enhancement and SHB coding on top of G.711.1 codestreams creates four additional superwideband modes with bitrates of 96-128 Kbps [16]. The G.711.1 Annex D algorithm was developed jointly as a superwideband extension for ITU-T Recommendation G.722 [18], [19], [17], the first ITU-T wideband voice standard, which uses a linear phase PQMF bank to encode wideband input in a two-channel adaptive DPCM scheme.…”

Section: Background On Multirate Filter Banks In Digital Coding Smentioning

confidence: 99%

“…Annex D of G.711.1 [16], [17] extends the G.711.1 layered codestream to support "superwideband" (14 KHz) input sampled at 32 Ksps with 16-bit precision. The superwideband input is split into two 16 Ksps subbands by a 32-tap linear phase PQMF bank similar to the PQMF bank in the G.711.1 core encoder.…”

Section: Background On Multirate Filter Banks In Digital Coding Stand...mentioning

confidence: 99%

“…While ( 67) is not satisfied by the scaling action γ defined by ( 6) and (17), is there any way to redefine gain-scaling (e.g., using exponential functions) to make γ satisfy (67)? If so, K + K = K + K implies that γ K E and γ K E would have to commute for all E ∈ S and K , K ∈ R. In fact, something even stronger would have to be true.…”

Section: B Automorphic Scaling Operationsmentioning

confidence: 99%

“…Since S H B ∩ S H B = ∅, a basic result in group theory [83, Proposition III.19], [79, Corollary I.4.3] says that these cosets are identical, S H B = S H B .This coset duplication can be eliminated by taking advantage of the fact that (48) is closed under scaling, i.e., that D K B H = B H . Using(17) and D-invariance of C H , an arbitrary element of H = S H B H can be written…”

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confidence: 99%

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Group-Theoretic Structure of Linear Phase Multirate Filter Banks

Brislawn

2013

IEEE Trans. Inform. Theory

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Unique lifting factorization results for group lifting structures are used to characterize the grouptheoretic structure of two-channel linear phase FIR perfect reconstruction filter bank groups. For Dinvariant, order-increasing group lifting structures, it is shown that the associated lifting cascade group C is isomorphic to the free product of the upper and lower triangular lifting matrix groups. Under the same hypotheses, the associated scaled lifting group S is the semidirect product of C by the diagonal gain scaling matrix group D. These results apply to the group lifting structures for the two principal classes of linear phase perfect reconstruction filter banks, the whole-and half-sample symmetric classes. Since the unimodular whole-sample symmetric class forms a group, W, that is in fact equal to its own scaled lifting group, W = S W , the results of this paper characterize the group-theoretic structure of W up to isomorphism. Although the half-sample symmetric class H does not form a group, it can be partitioned into cosets of its lifting cascade group, C H , or, alternatively, into cosets of its scaled lifting group, S H . Homomorphic comparisons reveal that scaled lifting groups covered by the results in this paper have a structure analogous to a "noncommutative vector space."

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Section: Background On Multirate Filter Banks In Digital Coding Smentioning

confidence: 99%

Section: Background On Multirate Filter Banks In Digital Coding Stand...mentioning

confidence: 99%

Section: B Automorphic Scaling Operationsmentioning

confidence: 99%

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confidence: 99%

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Group-Theoretic Structure of Linear Phase Multirate Filter Banks

Brislawn

2013

IEEE Trans. Inform. Theory

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“…A method for switching the new spectral masking on and off based on the frequency-domain sparseness analysis is also proposed. This method has been introduced to ITU-T Recommendations G.711.1 Annex D [7], [8] and G.722 Annex B [8], [9] (SWB extensions of G.711.1 [10]- [12] and G.722 [13], [14]), which were standardized in November 2010.…”

mentioning

confidence: 99%

Adaptive Spectral Masking of AVQ Coding and Sparseness Detection for ITU-T G.711.1 Annex D and G.722 Annex B Standards

Fukui

Sasaki²,

Hiwasaki

et al. 2014

IEICE Trans. Inf. & Syst.

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SUMMARYWe proposes a new adaptive spectral masking method of algebraic vector quantization (AVQ) for non-sparse signals in the modified discreet cosine transform (MDCT) domain. This paper also proposes switching the adaptive spectral masking on and off depending on whether or not the target signal is non-sparse. The switching decision is based on the results of MDCT-domain sparseness analysis. When the target signal is categorized as non-sparse, the masking level of the target MDCT coefficients is adaptively controlled using spectral envelope information. The performance of the proposed method, as a part of ITU-T G.711.1 Annex D, is evaluated in comparison with conventional AVQ. Subjective listening test results showed that the proposed method improves sound quality by more than 0.1 points on a five-point scale on average for speech, music, and mixed content, which indicates significant improvement. key words: speech and audio coding, standardization, ITU-T G.711.1 Annex D, ITU-T G.722 Annex B, super-wideband (SWB) extension, algebraic vector quantization (AVQ)

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