--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/scripts/audio/wavwrite.m	Tue Dec 06 20:38:21 2005 +0000
@@ -0,0 +1,116 @@
+## Copyright (C) 2005 Michael Zeising
+##
+## 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 2, 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, write to the Free
+## Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+## 02110-1301, USA.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {} wavwrite(@var{filename}, @var{y})
+## Write @var{y} to the canonical RIFF/WAVE sound file @var{filename}. A sample 
+## rate of 8000 Hz and 16-bit samples are assumed. Each column of the data 
+## represents a separate channel.
+##
+## @deftypefnx {Function File} {} wavwrite(@var{filename}, @var{y}, @var{fs})
+## Set the sample rate to @var{fs} Hz.
+##
+## @deftypefnx {Function File} {} wavwrite(@var{filename}, @var{y}, @var{fs}, @var{bits})
+## Set the sample rate to @var{fs} Hz and resolution to @var{bits} bits.
+##
+## @end deftypefn
+##
+## @seealso{wavread}
+
+## Author: Michael Zeising <michael.zeising@stud.uni-erlangen.de>
+## Created: 06 December 2005
+
+function wavwrite (filename, y, samplesPerSec, bitsPerSample)
+  BYTEORDER = "ieee-le";
+  
+  # parse arguments
+  if (exist ("samplesPerSec","var") < 1)
+    warning ("wavwrite: sample rate set to 8000 Hz")
+    samplesPerSec = 8000;
+  endif
+  if (exist ("bitsPerSample","var") < 1)
+    warning ("wavwrite: sample resolution set to 16-bit")
+    bitsPerSample = 16;
+  endif
+  
+  # determine sample format
+  switch bitsPerSample
+    case 8  
+      format = "int8";
+    case 16 
+      format = "int16";
+    case 32 
+      format = "int32";
+    otherwise
+      fclose (fid);
+      error ("wavread: sample resolution not supported");
+  endswitch
+  
+  # calculate filesize
+  channels = size(y)(2);
+  n = size(y)(1);
+  
+  ckSize = n*channels*(bitsPerSample/8);       # size of data chunk
+  
+  # open file for writing binary
+  [fid, msg] = fopen (filename, "wb");
+  if (fid < 0)
+    error ("wavwrite: %s", msg)
+  endif
+  
+  # write RIFF/WAVE header
+  c = 0;
+  c += fwrite (fid, "RIFF",        "uchar");
+  c += fwrite (fid, ckSize + 36,   "ulong", 0, BYTEORDER);   # file size - 8
+  c += fwrite (fid, "WAVEfmt ",    "uchar");
+  c += fwrite (fid, 16,            "ulong", 0, BYTEORDER);   # size of fmt chunk
+  c += fwrite (fid, 0x0001,        "short", 0, BYTEORDER);   # sample format code (PCM)
+  c += fwrite (fid, channels,      "short", 0, BYTEORDER);   # channels
+  c += fwrite (fid, samplesPerSec, "ulong", 0, BYTEORDER);   # sample rate
+  c += fwrite (fid, samplesPerSec*channels*bitsPerSample/8, "ulong", 0, BYTEORDER);   # bytes per second
+  c += fwrite (fid, channels*bitsPerSample/8,               "short", 0, BYTEORDER);   # block align
+  c += fwrite (fid, bitsPerSample, "short", 0, BYTEORDER);   # bits/sample
+  c += fwrite (fid, "data",        "uchar");
+  c += fwrite (fid, ckSize,        "ulong", 0, BYTEORDER);   # size of data chunk
+  
+  if (c < 25)
+    fclose (fid);
+    error ("wavread: writing to file failed")
+  endif
+  
+  # scale samples
+  switch bitsPerSample
+    case 8
+      y = floor (y*127 + 127);
+    case {16,32}
+      y = floor (y*((2 ** bitsPerSample) / 2 - 1));
+  endswitch
+  
+  # interleave samples
+  l = n*channels;
+  for (i = 1:channels)
+    yi(i:channels:l) = y(:,i);
+  endfor
+  
+  # write to file
+  c = fwrite (fid, yi, format, 0, BYTEORDER);
+  
+  fclose (fid);
+  
+endfunction