04-01-2018 дата публикации
Номер: US20180007484A1
When compressing an HOA data frame representation, a gain control () is applied for each channel signal before it is perceptually encoded (). The gain values are transferred in a differential manner as side information. However, for starting decoding of such streamed compressed HOA data frame representation absolute gain values are required, which should be coded with a minimum number of bits. For determining such lowest integer number (β) of bits the HOA data frame representation (C(k)) is rendered in spatial domain to virtual loudspeaker signals lying on a unit sphere, followed by normalisation of the HOA data frame representation (C(k)). Then the lowest integer number of bits is set to 1. A method for decoding a compressed Higher Order Ambisonics (HOA) sound representation of a sound or sound field , the method comprising:receiving a bit stream containing the compressed HOA representation, and{'sub': e', 'e, 'claim-text': {'br': None, 'sub': e', '2', '2', 'MAX, 'i': 'K', 'β=┌log(┌log(√{square root over ()}·O)┐+1)┐.'}, 'decoding the compressed HOA representation based on a lowest integer number β, wherein the lowest integer number βis determined based on'}{'sub': MAX', '1≦N≦N', {'sub2': 'MAX'}, '1', 'O', 'MAX', '1', 'O', '2, 'sup': (N)', '(N)', '(N)', '(N)', '2', '2, 'wherein K=maxK(Ω, . . . , Ω), N is an order of the compressed HOA representation, Nis a maximum order of interest of the compressed HOA representation, Ω, . . . , Ωare directions of virtual loudspeakers, O=(N+1)is a number of HOA coefficient sequences, and K is a ratio between the squared Euclidean norm ∥Ψ∥of a mode matrix and O,'}{'sub': 'MAX', 'wherein e>0, and'}{'sub': 'MAX', 'wherein √{square root over (K)}=1.5.'}2. An apparatus for decoding a compressed Higher Order Ambisonics (HOA) sound representation of a sound or sound field , the apparatus comprising:{'sub': 'e', 'a processor configured to receive a bit stream containing the compressed HOA representation, the processor further configured to ...
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