g.726标准的adpcm的matlab实现,包含编码性能的测评
代码片段和文件信息
属性 大小 日期 时间 名称
----------- --------- ---------- ----- ----
文件 113192 2010-03-11 20:13 speech_codingspeech_coding.pdf
文件 37 2010-03-11 20:17 speech_coding
eadme.txt
文件 1071 2003-05-21 00:25 speech_codingqualitymnru.m
文件 1194 2003-05-21 00:25 speech_codingqualitysegsnr.m
文件 149453 2002-05-27 17:21 speech_codingqualitymosamr_decoder.exe
文件 175747 2002-05-27 17:21 speech_codingqualitymosamr_encoder.exe
文件 10210 2002-05-27 13:25 speech_codingqualitymosamr_readme.txt
文件 769352 2002-05-27 17:21 speech_codingqualitymoscygwin1.dll
文件 4054 2003-05-27 09:29 speech_codingqualitymosencode_decode.asv
文件 4136 2003-05-27 09:43 speech_codingqualitymosencode_decode.m
文件 175601 2002-05-27 17:21 speech_codingqualitymosg722_decoder.exe
文件 176792 2002-05-27 17:21 speech_codingqualitymosg722_encoder.exe
文件 7121 2002-05-27 13:25 speech_codingqualitymosg722_readme.txt
文件 70144 2002-05-27 17:21 speech_codingqualitymosg729_decoder.exe
文件 110592 2002-05-27 17:21 speech_codingqualitymosg729_encoder.exe
文件 5632 2002-05-27 13:25 speech_codingqualitymosg729_readme.txt
文件 461 2001-08-20 16:30 speech_codingqualitymosspeechin.m
文件 95744 2003-05-21 18:02 speech_codingqualitymossamplesf18.raw
文件 95744 2003-05-27 09:49 speech_codingqualitymossamplesf28.raw
文件 133118 2001-08-20 16:30 speech_codingqualitymossamplesf48.raw
文件 130208 2001-08-20 16:30 speech_codingqualitymossamplesf58.raw
文件 280692 2001-08-20 16:30 speech_codingqualitymossamplesf68.raw
文件 122880 2001-08-20 16:30 speech_codingqualitymossamplesf98.raw
文件 95744 2003-05-21 18:03 speech_codingqualitymossamplesm18.raw
文件 95744 2003-05-21 18:03 speech_codingqualitymossamplesm28.raw
文件 296564 2001-08-20 16:30 speech_codingqualitymossamplesm38.raw
文件 115440 2001-08-20 16:30 speech_codingqualitymossamplesm48.raw
文件 95744 2003-05-27 09:52 speech_codingdataf18.raw
文件 95744 2003-05-27 09:52 speech_codingdataf28.raw
文件 133118 2003-05-27 09:52 speech_codingdataf48.raw
............此处省略50个文件信息
function [Isrdoutdqoutyoutaioutbiouttdouttroutalout] = ...
adpcm(sl N format);
%ADPCM Adaptive differential pulse code modulation.
% [I SR] = ADPCM( SL N) encodes the PCM coded input signal SL
% with N kbit/s adaptive differential pulse code modulation (ADPCM)
% where N is selected from 40 32 24 or 16 kbit/s.
% If N is not specified the bit rate is set to N = 32 kbit/s.
%
% By default the input signal SL is assumed to be represented with
% 14-bit signed-magnitude uniform PCM i.e. its amplitude range is
% -8191 <= sl <= 8191. This input format is also selected by
% ADPCM(SL N ‘lin‘). If the input signal is 8-bit logarithmic PCM
% (mu-law in accordance with LIN2MU) ADPCM( SL N ‘mu‘) has to
% be used.
%
% The first output is I the encoder output signal which represents
% the bit stream over the channel. The samples of I are from the
% discrete alphabet -2^(N/8-1) ... +2^(N/8-1). The second (optional)
% output is the reconstructed speech signal SR (scaled approximately
% between -8191 and +8191) which would be the output of the corres-
% ponding ADPCM decoder in the case of error-free transmission of I.
%
% If more than two outputs are specified a whole list of
% diagnostic outputs (internal variables of the algorithm) becomes
% available:
%
% [ISRDDQYAIBITDTRAL] = ADPCM( SL N);
%
% with the following interpretation:
%
% D prediction difference signal
% DQ quatized prediction difference signal
% Y scale factor for adaptive quantizer
% AI recursive predictor coefficients (2-column matrix)
% BI non-recursive predictor coefficients (6-column matrix)
% TD tone detector signal
% TR transient detector signal
% AL speed control for scale factor adaptation
%
% Note that this latter option is VERY memory intensive as all
% variables are vectors/matrices of the size of the input signal.
%
% This function uses also APUPDATE AIUPDATE BIUPDATE.
% The decoder is provided by I_ADPCM.
%
% References:
% The algorithm follows closely the ITU-T (former CCITT)
% recommendation G.726 “40 32 24 16 kbit/s Adaptive Differential
% Pulse Code Modulation (ADPCM)“. The recommendation specifies
% various fixed-point formats for the internal variables which are
% not simulated in this MATLAB implementation. However most of the
% variable names etc. are consistent with the recommendation.
% 1995-05-16 Martin Kummernecker
% 1995-08-30 Gernot Kubin (g.kubin@ieee.org)
% input argument checks default bit-rate and format setting
if (nargin < 1) | (nargin > 3)
disp(‘ADPCM: 1 to 3 input variables required!‘)
help adpcm return
end
if nargin == 1
N = 32;
disp(‘***** N = 32 kbit/s *****‘);
end
a = N==[40 32 24 16];
if (sum(a) ~= 1)
N = 32;
disp(‘***** N = 32 kbit/s *****‘);
end;
if nargin <= 2
format = ‘lin‘;
end;
if isstr(format) ~= 1
error(‘ADPCM: Input format must be string variable!‘)
elseif strcmp(format‘mu‘)
属性 大小 日期 时间 名称
----------- --------- ---------- ----- ----
文件 113192 2010-03-11 20:13 speech_codingspeech_coding.pdf
文件 37 2010-03-11 20:17 speech_coding
eadme.txt
文件 1071 2003-05-21 00:25 speech_codingqualitymnru.m
文件 1194 2003-05-21 00:25 speech_codingqualitysegsnr.m
文件 149453 2002-05-27 17:21 speech_codingqualitymosamr_decoder.exe
文件 175747 2002-05-27 17:21 speech_codingqualitymosamr_encoder.exe
文件 10210 2002-05-27 13:25 speech_codingqualitymosamr_readme.txt
文件 769352 2002-05-27 17:21 speech_codingqualitymoscygwin1.dll
文件 4054 2003-05-27 09:29 speech_codingqualitymosencode_decode.asv
文件 4136 2003-05-27 09:43 speech_codingqualitymosencode_decode.m
文件 175601 2002-05-27 17:21 speech_codingqualitymosg722_decoder.exe
文件 176792 2002-05-27 17:21 speech_codingqualitymosg722_encoder.exe
文件 7121 2002-05-27 13:25 speech_codingqualitymosg722_readme.txt
文件 70144 2002-05-27 17:21 speech_codingqualitymosg729_decoder.exe
文件 110592 2002-05-27 17:21 speech_codingqualitymosg729_encoder.exe
文件 5632 2002-05-27 13:25 speech_codingqualitymosg729_readme.txt
文件 461 2001-08-20 16:30 speech_codingqualitymosspeechin.m
文件 95744 2003-05-21 18:02 speech_codingqualitymossamplesf18.raw
文件 95744 2003-05-27 09:49 speech_codingqualitymossamplesf28.raw
文件 133118 2001-08-20 16:30 speech_codingqualitymossamplesf48.raw
文件 130208 2001-08-20 16:30 speech_codingqualitymossamplesf58.raw
文件 280692 2001-08-20 16:30 speech_codingqualitymossamplesf68.raw
文件 122880 2001-08-20 16:30 speech_codingqualitymossamplesf98.raw
文件 95744 2003-05-21 18:03 speech_codingqualitymossamplesm18.raw
文件 95744 2003-05-21 18:03 speech_codingqualitymossamplesm28.raw
文件 296564 2001-08-20 16:30 speech_codingqualitymossamplesm38.raw
文件 115440 2001-08-20 16:30 speech_codingqualitymossamplesm48.raw
文件 95744 2003-05-27 09:52 speech_codingdataf18.raw
文件 95744 2003-05-27 09:52 speech_codingdataf28.raw
文件 133118 2003-05-27 09:52 speech_codingdataf48.raw
............此处省略50个文件信息
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