# HG changeset patch
# User jwe
# Date 816549371 0
# Node ID 21fe2afb3692abea75cc9ea5f0461242aeb4b313
# Parent  e91ac27650dc7a2f6f46db3155ffc431a2f0e49f
[project @ 1995-11-16 19:16:11 by jwe]
Initial revision

diff --git a/scripts/audio/Makefile.in b/scripts/audio/Makefile.in
new file mode 100644
--- /dev/null
+++ b/scripts/audio/Makefile.in
@@ -0,0 +1,73 @@
+#
+# Makefile for octave's scripts/audio directory
+#
+# John W. Eaton
+# jwe@bevo.che.wisc.edu
+# University of Wisconsin-Madison
+# Department of Chemical Engineering
+
+TOPDIR = ../..
+
+script_sub_dir = audio
+
+srcdir = @srcdir@
+top_srcdir = @top_srcdir@
+VPATH = @srcdir@
+
+include $(TOPDIR)/Makeconf
+
+INSTALL = @INSTALL@
+INSTALL_PROGRAM = @INSTALL_PROGRAM@
+INSTALL_DATA = @INSTALL_DATA@
+
+SOURCES = *.m
+
+DISTFILES = Makefile.in $(SOURCES)
+
+FCN_FILES = $(wildcard $(srcdir)/*.m)
+FCN_FILES_NO_DIR = $(notdir $(FCN_FILES))
+
+all:
+.PHONY: all
+
+install:
+	$(top_srcdir)/mkinstalldirs $(fcnfiledir)/$(script_sub_dir)
+	for f in $(FCN_FILES_NO_DIR) ; do \
+	  rm -f $(fcnfiledir)/$(script_sub_dir)/$$f ; \
+	  $(INSTALL_DATA) $(srcdir)/$$f $(fcnfiledir)/$(script_sub_dir)/$$f ; \
+	done
+.PHONY: install
+
+uninstall:
+	for f in $(FCN_FILES_NO_DIR) ; \
+	  do rm -f $(fcnfiledir)/$(script_sub_dir)/$$f ; \
+	done
+.PHONY: uninstall
+
+clean:
+.PHONY: clean
+
+tags: $(SOURCES)
+	ctags $(SOURCES)
+
+TAGS: $(SOURCES)
+	etags $(SOURCES)
+
+mostlyclean: clean
+.PHONY: mostlyclean
+
+distclean: clean
+	rm -f Makefile
+.PHONY: distclean
+
+maintainer-clean: distclean
+	rm -f tags TAGS
+.PHONY: maintainer-clean
+
+local-dist:
+	ln $(DISTFILES) ../../`cat ../../.fname`/scripts/audio
+.PHONY: local-dist
+
+dist:
+	ln $(DISTFILES) ../../`cat ../../.fname`/scripts/audio
+.PHONY: dist
diff --git a/scripts/audio/lin2mu.m b/scripts/audio/lin2mu.m
new file mode 100644
--- /dev/null
+++ b/scripts/audio/lin2mu.m
@@ -0,0 +1,36 @@
+function y = lin2mu (x)
+  
+# usage:  y = lin2mu (x)
+#
+# x is a vector of an 8- or 16-bit linearly encoded audio sample,
+# This is transformed into a mu-law encoded vector.
+
+# Written by AW (Andreas.Weingessel@ci.tuwien.ac.at) on Oct 17, 1994
+# Copyright Department of Probability Theory and Statistics TU Wien
+
+  if (nargin != 1)
+    usage ("y = lin2mu (x)");
+  endif
+
+  if (! is_vector (x))
+    error ("lin2mu: x must be a vector");
+  endif
+  
+  # transform 8-bit format to 16-bit
+  if (max (abs (x)) <= 128)
+    x = 256 .* x;
+  endif
+
+  # determine sign of x, set sign(0) = 1.
+  sig = sign(x) + (x == 0);
+
+  # take absolute value of x, but force it to be smaller than 32636;
+  # add bias 
+  x = min (abs (x), 32635 * ones (size (x))) + 132;
+
+  # find exponent and fraction of bineary representation
+  [f, e] = log2 (x);
+
+  y = 64 * sig - 16 * e - fix (32 * f) + 335;
+
+endfunction
diff --git a/scripts/audio/loadaudio.m b/scripts/audio/loadaudio.m
new file mode 100644
--- /dev/null
+++ b/scripts/audio/loadaudio.m
@@ -0,0 +1,63 @@
+function X = loadaudio (name, ext, bit)
+  
+# usage:  X = loadaudio (name [, ext [, bit]])
+#
+# Loads audio data from the file "name.ext" into the data vector X. 
+# Default value for the "ext" argument, which has to be written
+# without the initial ".", is "lin".
+# Currently, the following audio formats are supported:
+# *) mu-law encoding with extension "mu", "au" or "snd"
+# *) linear encoding with extension "lin" or "raw"
+# 
+# The `bit' argument can be either 8 (default) or 16.
+# Depending on the value of bit, linearly encoded files are
+# interpreted as being in 8 and 16 bit format, respectively, and
+# mu-law encoded files are transformed to 8 and 16-bit linear
+# format, respectively.
+
+# Written by AW (Andreas.Weingessel@ci.tuwien.ac.at) on Apr 10, 1994
+# Last modified by AW on Oct 29, 1994
+
+  if (nargin == 0 || nargin > 3)
+    usage ("loadaudio (name [, ext [, bit]])");
+  endif
+
+  if (nargin == 1)
+    ext = "lin";
+  endif
+
+  if (nargin < 3)
+    bit = 8;
+  elseif (bit != 8 && bit != 16)
+    error ("loadaudio: bit must be either 8 or 16");
+  endif
+
+  name = [name, ".", ext];
+  num = fopen (name, "r");
+
+  if (strcmp (ext, "lin") || strcmp (ext, "raw"))
+    if (bit == 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"))
+    [Y, c] = fread (num, inf, "uchar");
+    # remove file header
+    m = max (find (Y(1:64) == 0));
+    if (! isempty (m))
+      Y(1:m) = [];
+    endif
+    X = mu2lin (Y, bit);
+  else
+    fclose (num);
+    error ("loadaudio does not support given extension");
+  endif
+
+  fclose (num);
+  
+endfunction
+
+
+
diff --git a/scripts/audio/mu2lin.m b/scripts/audio/mu2lin.m
new file mode 100644
--- /dev/null
+++ b/scripts/audio/mu2lin.m
@@ -0,0 +1,54 @@
+function y = mu2lin (x, bit)
+  
+# usage: y = mu2lin (x [, bit])
+#
+# If x is a vector of audio data with mu-law encoding, mu2lin (x)
+# holds the same data with linear encoding.
+# The optional argument bit specifies whether the input data is 
+# 8 bit (default) or 16 bit.
+
+# Written by AW (Andreas.Weingessel@ci.tuwien.ac.at) on Oct 18, 1994
+# Updated by AW (Andreas.Weingessel@ci.tuwien.ac.at) on Oct 27, 1994
+# Copyright Department of Probability Theory and Statistics TU Wien
+
+  if (nargin == 1)
+    bit = 8;
+  elseif (nargin == 2)
+    if (bit != 8 && bit != 16)
+      error ("mu2lin: bit must be either 8 or 16");
+    endif
+  else
+    usage ("y = mu2lin (x [, bit])");
+  endif
+
+  if (! is_vector (x))
+    error ("mu2lin: x must be a vector");
+  endif
+  
+  exp_lut = [0; 132; 396; 924; 1980; 4092; 8316; 16764];
+
+  # invert x bitwise
+  x = 255 - x;
+
+  # determine sign of y
+  sig = (x > 127);
+
+  # determine exponent and fraction of y
+  e = fix (x / 16) - 8 .* sig + 1;
+  f = rem (x, 16);
+
+  sig = 1 - 2 .* sig;
+  y = (pow2 (f, e + 2) + exp_lut (e)) .* sig;
+
+  # convert to 8-bit
+  if (bit == 8)
+    ld = max (abs (y));
+    if (ld < 16384)
+      sc = 64 / ld;
+    else
+      sc = 1 / 256;
+    endif
+    y = fix (y * sc);
+  endif
+
+endfunction
diff --git a/scripts/audio/playaudio.m b/scripts/audio/playaudio.m
new file mode 100644
--- /dev/null
+++ b/scripts/audio/playaudio.m
@@ -0,0 +1,62 @@
+function playaudio (name, ext)
+  
+# usage: playaudio (name [, ext]) 
+#        playaudio (X)
+#
+# `playaudio ("name" [, "ext"])' plays the audio file "name.ext". The
+# default value for the "ext" argument, which has to be written
+# without the initial ".", is "lin".
+# Currently, the following audio formats are suppored:
+# *) linear encoding with extension "lin" or "raw", played using
+#    /dev/dsp 
+# *) mu-law encoding with extension "mu", "au" or "snd", played
+#    using /dev/audio 
+#
+# `playaudio (X)' plays the audio data contained in the vector X.
+
+# Written by AW (Andreas.Weingessel@ci.tuwien.ac.at) on Apr 11, 1994
+# Last modified by AW on Nov 7, 1994
+# Copyright Dept of Probability Theory and Statistics TU Wien
+
+  file = octave_tmp_file_name ();
+
+  usage_msg = "playaudio (name [, ext])  or  playaudio (X)";
+  
+  if (nargin == 1 && is_vector (name) && ! isstr (name)) 
+    # play a vector
+    [nr, nc] = size (name);
+    if (nc != 1)
+      if (nr == 1)
+	name = name';
+	nr = nc;
+      else
+	error ("playaudio: X must be a vector");
+      endif
+    endif
+    X = name + 127;
+    num = fopen (file, "w");
+    c = fwrite (num, X, "uchar");
+    fclose (num);
+    system (sprintf ("cat %s > /dev/dsp", file));
+    unlink (file);
+  elseif (nargin >= 1 && isstr (name))
+    # play a file
+    if (nargin == 1)
+      name = [name, ".lin"];
+    elseif (nargin == 2)
+      name = [name, ".", ext];
+    else
+      usage (usage_msg);
+    endif
+    if (strcmp (ext, "lin") || strcmp (ext, "raw"))
+      system (sprintf ("cat %s > /dev/dsp", name));
+    elseif (strcmp (ext, "mu") || strcmp (ext, "au") || strcmp (ext, "snd"))
+      system (sprintf ("cat %s > /dev/audio", name));
+    else
+      error ("playaudio does not support given extension");
+    endif
+  else
+    usage (usage_msg);
+  endif
+
+endfunction
diff --git a/scripts/audio/record.m b/scripts/audio/record.m
new file mode 100644
--- /dev/null
+++ b/scripts/audio/record.m
@@ -0,0 +1,39 @@
+function X = record (sec, sampling_rate)
+
+# usage:  X = record (sec [, sampling_rate])
+#
+# Records sec seconds of audio into the vector X.
+# The default value for the sampling_rate is 8000, ie. 8kHz.
+# The program waits for you to hit the ENTER key, then the recording
+# starts immediatly.
+
+# Written by AW (Andreas.Weingessel@ci.tuwien.ac.at) on Sep 19, 1994
+# Last modified by AW on Oct 5, 1994
+# Copyright Dept of Probability Theory and Statistics TU Wien
+
+  if (nargin == 1)
+    sampling_rate = 8000;
+  elseif (nargin != 2)
+    usage ("X = record (sec [, sampling_rate])");
+  endif
+
+  file = octave_tmp_file_name ();
+
+  input ("Please hit ENTER and speak afterwards!\n", 1);
+
+  cmd = sprintf ("dd if=/dev/dsp of=%s bs=%d count=%d",
+                 file, sampling_rate, sec)
+
+  system (cmd);
+
+  num = fopen (file, "r");
+
+  [Y, c] = fread (num, sampling_rate * sec, "uchar");
+
+  fclose (num);
+
+  unlink (file);
+
+  X = Y - 127;
+
+endfunction
diff --git a/scripts/audio/saveaudio.m b/scripts/audio/saveaudio.m
new file mode 100644
--- /dev/null
+++ b/scripts/audio/saveaudio.m
@@ -0,0 +1,71 @@
+function saveaudio (name, X, ext, bit)
+  
+# usage:  saveaudio (name, X, [, ext [, bit]])
+#
+# Saves a vector X of audio data in the file "name.ext".
+# The format of the audio file is determined by ext which has to be
+# written without an inital ".";  default value for ext is "lin". 
+#
+# Currently, the following audio formats are supported:
+# *) mu-law files with extension "mu", "au" or "snd"
+# *) linearly encoded files with extension "lin" or "raw"
+# If the data is saved linearly, the bit argument decides whether an
+# 8-bit (default) or a 16-bit format is used.
+
+# Written by AW (Andreas.Weingessel@ci.tuwien.ac.at) on Sep 5, 1994
+# Last modified by AW on Oct 29, 1994
+# Copyright Dept of Probability Theory and Statistics TU Wien
+
+  if (nargin < 2 || nargin > 4)
+    usage ("saveaudio (X, name [, ext [, bit]])");
+  endif
+
+  if (nargin == 2)
+    ext = "lin";
+  endif
+
+  if (nargin < 4)
+    bit = 8;
+  elseif (bit != 8 && bit != 16)
+    error ("saveaudio: bit must be either 8 or 16");
+  endif
+
+  [nr, nc] = size (X);
+  if (nc != 1)
+    if (nr == 1)
+      X = X';
+      nr = nc;
+    else
+      error ("saveaudio: X must be a vector.");
+    endif
+  endif
+
+  num = fopen ([name, ".", ext], "w");
+
+  if (strcmp (ext, "lin") || strcmp (ext, "raw")) 
+    if (bit == 8)
+      ld = max (abs (X));
+      if (ld > 127)   # convert 16 to 8 bit
+	if (ld < 16384)
+	  sc = 64 / ld;
+	else
+	  sc = 1 / 256;
+	endif
+	X = fix (X * sc);
+      endif
+      X = X + 127;
+      c = fwrite (num, X, "uchar");
+    else
+      c = fwrite (num, X, "short");
+    endif
+  elseif (strcmp (ext, "mu") || strcmp (ext, "au") || strcmp (ext, "snd"))
+    Y = lin2mu (X);
+    c = fwrite (num, Y, "uchar");
+  else
+    fclose (num);
+    error ("saveaudio does not support given extension");
+  endif
+
+  fclose (num);
+  
+endfunction
diff --git a/scripts/audio/setaudio.m b/scripts/audio/setaudio.m
new file mode 100644
--- /dev/null
+++ b/scripts/audio/setaudio.m
@@ -0,0 +1,21 @@
+function setaudio (w_type, value)
+  
+# usage: setaudio ([w_type [, value]])
+#
+# executes the shell command `mixer [w_type [, value]]'
+
+# Written by AW (Andreas.Weingessel@ci.tuwien.ac.at) on Oct 5, 1994
+# Updated by AW on Nov 3, 1994
+# Copyright Department of Probability Theory and Statistics TU Wien
+
+  if (nargin == 0)
+    system ("mixer");
+  elseif (nargin == 1)
+    system (sprintf ("mixer %s", w_type));
+  elseif (nargin == 2)
+    system (sprintf ("mixer %s %d", w_type, value));
+  else
+    usage ("setaudio ([w_type [, value]])");
+  endif
+  
+endfunction