-
公开(公告)号：EP1464047A4
公开(公告)日：2005-12-07
申请号：EP03705707
申请日：2003-01-08
发明人： JABRI MARWAN A , WANG JIANWEI , GOULD STEPHEN
CPC分类号： G10L19/173
摘要： Transcoding a CELP based compressed voice bitstream from source codec to destination codec relate to embodiments of a system and method. The method includes processing a source codec input bitstream to unpack (1) CELP parameters from the input CELP bistream and may interpolate (2) the unpacked CELP parameters from is a difference of destination codec parameters and source codec parameters exists. If the method maps (4) CELP from source codec format to a destination codec format, the parameter mapping strategy may be singly preset or selected (3). The method inludes encoding the CELP parameters for the destination codec and processing a destination CELP bitstream by packing (7) the CELP parameters for the destination codec.
-
公开(公告)号：EP1554809A4
公开(公告)日：2007-11-21
申请号：EP03757539
申请日：2003-10-24
发明人： JABRI MARWAN A , CHONG-WHITE NICOLA , WANG JIANWEI
CPC分类号： G10L19/173
摘要： An apparatus and method for mapping CELP parameters between a source codec and a destination codec. The apparatus includes an LSP mapping module, an adaptive codebook mapping module coupled to the LSP mapping module, and a fixed codebook mapping module coupled to the LSP mapping module and the adaptive codebook mapping module. The LSP mapping module includes an LP overflow module and an LSP parameter modification module. The adaptive codebook mapping module includes a first pitch gain codebook. The fixed codebook mapping module includes a first target processing module, a pulse search module, a fixed codebook gain estimation module, a pulse position searching module.
-
3.发明公开
公开(公告)号：EP1579427A4
公开(公告)日：2007-05-16
申请号：EP04700933
申请日：2004-01-09
CPC分类号： G10L19/173
摘要： A method and apparatus for a voice transcoder that converts a bitstream representing frames of data encoded according to a first voice compression standard to a bitstream representing frames of data according to a second voice compression standard using perceptual weighting that uses tuned weighting factors, such that the bitstream of a second voice compression standard to produce a higher quality decoded voice signal than a comparable tandem transcoding solution. The method includes pre-computing weighting factors for a perceptual weighting filter optimized to a specific source and destination codec pair, pre-configuring the transcoding strategies, mapping CELP parameters in the CELP parameter space according to the selected coding strategy, performing Linear Prediction analysis if specified by the transcoding strategy, perceptually weighting the speech using with tuned weighting factors, and searching for adaptive codebook and fixed-codebook parameters to obtain a quantized set of destination codec parameters.
-
-
搜索结果
3 条记录 (耗时 0.009 秒)
