attachments.help.src

speech signal process tools

If a label file exists, its contents will be read and displayed by the
labeler.  Otherwise, a new label file is created.  Label files are
ordinary text files with a short header followed by lines
corresponding to each boundary marked.  These lines contain the time
in seconds, a number indicating the color of the boundary marker and
the label text string.  Label files may be generated or edited at will
using any text manipulation program as long as the format is adhered
to.  Boundary times need not be ordered chronologically.

Labeling is best performed by moving the mouse, with no buttons
pressed, in the label window.  When the label cursor is at the
appropriate time location, depressing the right button will show the
label menu.  The selected label will be applied at the location of the
cursor upon release of of the right button.  The same operations may
be performed in any of the waveform windows by selecting the "label"
menu item, but response is slower and two right button clicks will be
required.

Labels and comment fields of arbitrary content and length may be
directly typed in at the label cursor location without pressing any
mouse buttons.  An existing label may be edited by placing the cursor
exactly on its boundary mark and then using the keyboard.  The
"Delete" key removes characters right to left; "Return" causes
the label file to be rewritten to reflect the current state of the
display (this is automatically done for menu-selected labels).
Multiple, separately displayable label fields may be entered by
separating them with the "separator" character (generally a
semi-colon, but any character may be used) specified in the label file
header.  Selection of the menu item corresponding to "*DEL*" will
cause the entire label nearest the cursor to be removed.

Label "fields" are delimited in the label file by the "separator"
character.  Blank or null fields are indicated by two or more
consecutive (or blank-separated) delimiters.  Which fields will be
displayed by the labeler is determined by the "Active fields:" item in
the Labeler panel.  The fields are numbered consecutively starting at
one.  Up to 32 space-separated numbers may be entered on one line in
any order to indicate the corresponding active fields.  If the
"Label File" item is blank when this is done, the display of all label
files will be effected, otherwise only the specified file's display will
be effected.

Multiple label files are displayed time-aligned in the labeler window
with the most recently created/loaded file at the top.  Enter the
relative or absolute pathname of the label file(s) in the Label File
panel item after the "Object" item has been correctly established.
Alternately, one or more label files may be loaded with the "make"
command via a "send" from a waves command file (see below).  If the
labels get crowded, the window may be resized with the usual Sunview
ritual.  As the cursor is moved horizontally and vertically, the time
and corresponding label file name are displayed in the window's frame.
Label files may be removed from the display (and saved in updated
files) by selecting the menu item corresponding to "*UNLOAD*" in the
labelmenu while the horizontal crosshair is in the file's display region.

Two D/A playback features are supported in the labeler.  A left button
press while in the labeler window causes the marked segment containing
the cursor to be played.  A middle button press causes the segment
delimited by the cursor and the label boundary immediately to the left
of the cursor to be played.

All functions normally available in waves are active in conjunction
with the labeler.  NOTE: The label file does NOT automatically adjust
to time changes caused by waveform segment deletion or insertion.  It
is recommended that no waveform editing be performed on files being
labeled.  Selecting the "QUIT" item in the Labeler panel will update
and close all label files and "disconnect" label from waves.

Waves can be controlled by a command file (see
$WAVES_DOC/waves.help: "COMMANDS AND COMMAND FILES").
Commands in these files may be passed through to label via the "send"
command to waves.  The following additional commands are recognized by
label:

----------------------------------------------------------------------
message		keywords		arguments
----------------------------------------------------------------------
make			>> MAKE A NEW, OR LOAD AN EXISTING LABEL FILE <<
		file		label file pathname to be displayed or created
		color		colormap entry to use for the segment boundary
				marks (new label files only).  Numbers in the
				range of 115-125 are best.
		name		name of a "waves" display object to synchronize
				the labels with.
	        signal		a particular signal in display object.  If
				omitted, the label window will always attach to
				the most recently displayed signal.
activate		>> SET ACTIVE LABEL DISPLAY FIELDS <<
		file		label file who's display is to be changed.
		name		display object containing the file.  If file
				and/or name is omitted, the Label File and/or
				Object from the Labeler panel will be used.
		fields		one or more blank-separated numbers specifying
				the display fields to be enabled.
unload			>> CLOSE, UNLOAD AND REMOVE DISPLAY OF A LABEL FILE <<
		name		name of display object containing label file
		file		name of the label file to be closed
kill			>> REMOVE ALL OR PART OF A LABEL DISPLAY OBJECT <<
		name		name of an existing label display object which
				is to be partly, or completely distroyed.
		file		file name of a particular label display to be
				destroyed.  Note that the actual label file
				is updated to reflect the state of the display
				before the display is removed.  If file is
				omitted, all of object <name> will be removed.
labelmenu		>> SPECIFY AN ALTERNATE LABEL MENU SOURCE FILE <<
		menufile	UNIX path name of the desired menu.  This
				may be changed at any time while labeling.
set			>> SET GLOBAL PARAMETERS IN LABELING PROGRAM <<
		label_height	height (in pixels) of the labeling window
		menufile	same as in "labelmenu" above and "Label
				Menu File:" in control panel.
		active_fields	same as "fields" above under "activate"
				and "Active Fields:" in control panel.
		object		same as "name" above under "make" and
				"Object:" in control panel.
		labelfile	same as "file" above under "make" and
				"Label File:" in control panel.
----------------------------------------------------------------------


The following c-shell script demonstrates how label might be used with
a waves command file:

----------------------------------------------------------------------
#!/bin/csh
echo waves set middle_op 'blow up; function' > /tmp/wave$$
echo waves set ref_size 3 ref_step 2.5 ref_start 0.0 >> /tmp/wave$$
foreach f ($*)
  set bn = `basename $f`
  echo waves make name $bn file $f loc_x 0 loc_y 150 height 200 >> /tmp/wave$$
  echo waves attach function label >> /tmp/wave$$
  echo waves send activate name $bn fields 1 3 5 >> /tmp/wave$$
  echo waves send make name $bn  file $f.1.lab color 125 >> /tmp/wave$$
  echo waves send make name $bn  file $f.2.lab  color 118 >> /tmp/wave$$
  echo waves pause >> /tmp/wave$$
  echo waves kill >> /tmp/wave$$
  echo waves detach >> /tmp/wave$$
end
waves /tmp/wave$$
rm -f /tmp/wave$$
----------------------------------------------------------------------

This above script is called with some signal file pathnames as
arguments.  Lines 2-3 set some waves system globals; 5 generates an
object name which will be common to waves and label; 6 displays the
signal; 7 attaches the label program; 8 specifies to label that label
fields 1, 3 and 5 are to be displayed; 9-10 load (or generate) two
label files with different colored markers; 11 pauses the command
script to permit interaction with the programs; 12 destroys all
displays; and 13 detaches label.  Note that the attach and detach
operations are performed within the loop to prevent label's default
behavior which is to generate a single label file with a name of the
form $bn.lab.  If this behavior is desired, the script could be
rewritten:

----------------------------------------------------------------------
#!/bin/csh
echo waves set middle_op 'blow up; function' > /tmp/wave$$
echo waves set ref_size 3 ref_step 2.5 ref_start 0.0 >> /tmp/wave$$
echo waves attach function label >> /tmp/wave$$
echo waves send activate fields 1 3 5 >> /tmp/wave$$
foreach f ($*)
  set bn = `basename $f`
  echo waves make name $bn file $f loc_x 0 loc_y 150 height 200 >> /tmp/wave$$
  echo waves pause >> /tmp/wave$$
  echo waves kill >> /tmp/wave$$
end
echo waves detach >> /tmp/wave$$
waves /tmp/wave$$
rm -f /tmp/wave$$
----------------------------------------------------------------------


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		SPECTRUM ANALYSIS: spectrum
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Attaching spectrum to waves provides spectral analysis facilities for
one dimensional, short integer signals (e.g. standard PCM files).
Spectrum also displays spectral "slices" from spectrograms and
spectrogram-like signals (e.g. "eih-grams").  Spectra may be compared
by overlaying on a common plot.  Analysis is performed by selecting a
signal segment with the waves waveform cursor or markers and then
selecting the "spectrum" menu item with the right mouse button.  Note
that this operation will only succeed if performed in a window
displaying a one-dimensional short-integer signal or a "spectrogram"
for which a file exists on disc.  After the spectrum is computed and
displayed, the right and left waves markers are moved to the analysis
window limits.

The spectrum analysis parameters are available for modification in a
control panel.  When one of the analysis parameters is changed, the
active spectra are recomputed using the new parameters.  When spectral
"slices" are being displayed from a "spectrogram" file, the analysis
parameters in the panel have no affect.

The "Function" item will cycle through the spectral estimation methods
available on left button clicks.  Currently available methods are: log
magnitude spectrum using a radix-2 FFT (log-mag-DFT), inverse log
magnitude spectrum of an autocorrelation LP model (log-mag-DFT-LPC);
and inverse log magnitude of a covariance LP model (log-mag-DFT-CLPC).
These spectra are all scaled to dB re unity.  All computations are
performed in double precision arithmetic.  The minimum size FFT used
is 512 points, zero-padded as necessary.

The "Window type:" item permits selection of the time weighting
function to be applied before analysis.  Note that for the covariance
LPC computation, rectangular weighting is always used.

"Window size(sec):" specifies the total window duration.  The size of
the FFT used to perform the computations is expanded (in powers of 2)
as necessary to accommodate the data.  The window size must be chosen
so that no more than 4096 waveform samples are included (sample-rate
dependent).  Note that the "Window size(sec):" item is only effective
for input when the "Window limits from:" item is set to "Local."  When
it is set to "Host," the window size and location are both determined
by the left and right marker positions in the waves windows when the
"spectrum" item is selected from a waves menu.

The "Preemphasis coeff:" item allows the coefficient, a, of the
1st-order prefilter {H(z) = 1 - a*(z**-1)} to be adjusted.  This
preemphasis is applied to all signals before spectrum computation.
When this preemphasis is applied, one extra sample is used from the
input sequence to initialize the filter memory and maintain the
requested window size.

"Analysis order:" sets the order for LPC analysis (if specified by
"Function").  The maximum order available is 30.

Left mousing the "Reticle:" item will toggle the spectrum reticle on
and off.  Note that the reticle dynamically adjusts itself to the
window size.

"Filt. Int:" and "Int. Coef:" are explained below.

The spectrum display window has a frequency/amplitude cursor which may
be moved with the mouse.  Numeric display of frequency and amplitude
are available in the upper-left corner of the window.  The time
corresponding to the center of the analysis window is printed in the
display's frame.  The cursor may be left at a particular frequency by
removing the mouse pointer from the window with the middle button
depressed.  The spectrum display window may be resized at will using the
standard Sun ritual.

The currently displayed spectrum (in blue) will be copied into the
reference spectrum (in red) if the right mouse button is pressed inside
the spectrum display window.  The reference spectrum will then remain
unchanged, permitting comparison with other spectra, until the right
button is again pressed.  The amplitude at the spectrum cursor
location for the reference spectrum is also printed (in red) in the
upper left of the spectrum window.

When linear prediction has been used to compute an all-pole spectrum,
the LP coefficients may be used to inverse filter the original signal
(yielding a residual signal).  This operation can be initiated by
pressing the left mouse button in the spectrum window after either
"log-mag-DFT-LPC" or "log-mag-DFT-CLPC" computations have been
performed.  The amount of the original signal (centered on the
analysis window) to be inverse filtered is determined by the "Filt.
Int:" panel item (sec).  The inverse filtered signal is integrated (to
convert pressure to volume velocity) using a leaky integrator with the
coefficient determined by the "Int. Coef:" panel item (0.0 implies no
integration).  The resultant signal is then stored in a file and
displayed in a regular waves waveform window.

The program "spectrum" was written as an example of how attachments
work.  It is well documented and can be adapted to a variety of needs.
Feel free to copy and modify it to your needs.  It may be found in
$WAVES_SRC/c/spectrum.c.


++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
			DEBUGGING, ETC.: stub
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

When debugging waves or an attachment, it is often handy to see just
what messages are being sent in various contexts.  Sometimes it may be
handy to have "mark" messages sent directly to a file or some
"non-attachment-like" unix process.  The "stub" facility provides this
capability.  When "stub" is entered as the attachment name (either in
the waves control panel or in a command file), waves sends messages
pretty much as it would to a real attached process, except that they
are written to stdout.  When stub is "attached," waves does not expect any
response to its messages (i.e. it does not block as usual in return_value()
waiting for "ok," "null" or "returned" responses).

When stub is attached, waves accepts messages (of the type specified above)
directly from stdin and responds exactly as it would to an attached
process sending the same messages.