update packages

[CreaPhase.git] / octave_packages / m / audio / loadaudio.m

diff --git a/octave_packages/m/audio/loadaudio.m b/octave_packages/m/audio/loadaudio.m
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+## Copyright (C) 1995-2012 John W. Eaton
+##
+## This file is part of Octave.
+##
+## Octave is free software; you can redistribute it and/or modify it
+## under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 3 of the License, or (at
+## your option) any later version.
+##
+## Octave is distributed in the hope that it will be useful, but
+## WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+## General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with Octave; see the file COPYING.  If not, see
+## <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {} loadaudio (@var{name}, @var{ext}, @var{bps})
+## Load audio data from the file @file{@var{name}.@var{ext}} into the
+## vector @var{x}.
+##
+## The extension @var{ext} determines how the data in the audio file is
+## interpreted; the extensions @file{lin} (default) and @file{raw}
+## correspond to linear, the extensions @file{au}, @file{mu}, or @file{snd}
+## to mu-law encoding.
+##
+## The argument @var{bps} can be either 8 (default) or 16, and specifies
+## the number of bits per sample used in the audio file.
+## @seealso{lin2mu, mu2lin, saveaudio, playaudio, setaudio, record}
+## @end deftypefn
+
+
+## Author: AW <Andreas.Weingessel@ci.tuwien.ac.at>
+## Created: 10 April 1994
+## Adapted-By: jwe
+
+function X = loadaudio (name, ext, bps)
+
+  if (nargin == 0 || nargin > 3)
+    print_usage ();
+  endif
+
+  if (nargin == 1)
+    ext = "lin";
+  endif
+
+  if (nargin < 3)
+    bps = 8;
+  elseif (bps != 8 && bps != 16)
+    error ("loadaudio: BPS must be either 8 or 16");
+  endif
+
+  name = [name, ".", ext];
+  num = fopen (name, "rb");
+
+  if (strcmp (ext, "lin") || strcmp (ext, "raw") || strcmp (ext, "pcm"))
+    if (bps == 8)
+      [Y, c] = fread (num, inf, "uchar");
+      X = Y - 127;
+    else
+      [X, c] = fread (num, inf, "short");
+    endif
+  elseif (strcmp (ext, "mu") || strcmp (ext, "au")
+          || strcmp (ext, "snd") || strcmp(ext, "ul"))
+    [Y, c] = fread (num, inf, "uchar");
+    ## remove file header
+    m = find (Y(1:64) == 0, 1, "last");
+    if (! isempty (m))
+      Y(1:m) = [];
+    endif
+    X = mu2lin (Y, bps);
+  else
+    fclose (num);
+    error ("loadaudio: unsupported extension");
+  endif
+
+  fclose (num);
+
+endfunction