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update Octave Project Developers copyright for the new year In files that have the "Octave Project Developers" copyright notice, update for 2020.
author John W. Eaton <jwe@octave.org>
date Mon, 06 Jan 2020 22:29:51 -0500
parents b442ec6dda5c
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1891570abac8 update Octave Project Developers copyright for the new year
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1 ## Copyright (C) 1995-2020 The Octave Project Developers
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2 ##
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3 ## See the file COPYRIGHT.md in the top-level directory of this distribution
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4 ## or <https://octave.org/COPYRIGHT.html/>.
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5 ##
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6 ##
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7 ## This file is part of Octave.
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8 ##
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9 ## Octave is free software: you can redistribute it and/or modify it
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10 ## under the terms of the GNU General Public License as published by
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11 ## the Free Software Foundation, either version 3 of the License, or
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12 ## (at your option) any later version.
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13 ##
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14 ## Octave is distributed in the hope that it will be useful, but
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15 ## WITHOUT ANY WARRANTY; without even the implied warranty of
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16 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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17 ## GNU General Public License for more details.
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18 ##
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19 ## You should have received a copy of the GNU General Public License
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20 ## along with Octave; see the file COPYING. If not, see
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21 ## <https://www.gnu.org/licenses/>.
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22
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23 ## -*- texinfo -*-
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24 ## @deftypefn {} {@var{y} =} mu2lin (@var{x}, @var{n})
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25 ## Convert audio data from mu-law to linear.
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26 ##
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27 ## Mu-law values are 8-bit unsigned integers. Linear values use @var{n}-bit
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28 ## signed integers or floating point values in the range -1 @leq{} @var{y}
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29 ## @leq{} 1 if @var{n} is 0.
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30 ##
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31 ## If @var{n} is not specified it defaults to 0.
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32 ## @seealso{lin2mu}
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33 ## @end deftypefn
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34
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35 ## Author: Andreas Weingessel <Andreas.Weingessel@ci.tuwien.ac.at>
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36 ## Created: 18 October 1994
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37 ## Adapted-By: jwe
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38
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39 function y = mu2lin (x, n = 0)
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40
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41 if (nargin == 2)
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42 if (n != 0 && n != 8 && n != 16)
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43 error ("mu2lin: N must be either 0, 8, or 16");
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44 endif
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45 elseif (nargin != 1)
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46 print_usage ();
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47 endif
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48
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49 ulaw = [32124, 31100, 30076, 29052, 28028, 27004, 25980, 24956, ...
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63 120, 112, 104, 96, 88, 80, 72, 64, ...
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64 56, 48, 40, 32, 24, 16, 8, 0 ];
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65
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66 ulaw = [ -ulaw, ulaw ];
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67
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68 ## Set the shape of y to that of x overwrites the contents of y with
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69 ## ulaw of x.
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70 y = x;
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71 y(:) = ulaw(x + 1);
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72
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73 ## Convert to real or 8-bit.
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74 if (n == 0)
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75 ## [ -32768, 32767 ] -> [ -1, 1)
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76 y /= 32768;
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77 elseif (n == 8)
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78 ld = max (abs (y (:)));
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79 if (ld < 16384 && ld > 0)
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80 sc = 64 / ld;
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81 else
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82 sc = 1 / 256;
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83 endif
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84 y = fix (y * sc);
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85 endif
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86
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87 endfunction