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          Some Concrete Usages and TIPS, and Details Inside WaoN
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CONTENTS
--------
PART I : TIPS
  1) TIPS
  2) Detailed descriptions on some options and comments for usage
PART II : Inside of WaoN
  1) Policy of Selection of On/Off Event
    a) off-event
    b) on-event
    b-1) if this note is off at last step
    b-2) if this note is on at last step
    b-2-1) with and without -k option
    b-2-2) only with -k option
  2) Policy of Selection of Note (Frequency)
    a) without patch
    b) with patch

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                               PART I : TIPS

1) TIPS
-------

I think that the default setting (2048 samples for FFT, no window, etc)
is enough to judge how "waon" works.

Here are some more tips.

Ex.1) if you need more resolution in time, use -s (--shift) option as follows.

  $ ./waon -i waltz4DB.wav -o waltz4.mid -w 3 -n 4096 -s 2048

Ex.2) pipe to timidity to play resultant midi file.

  $ cat dolphineD.wav | ./waon -i - -o - | timidity -id -

Ex.3) if you want to analyse MP3,

  $ mpg123 -m -s reflectD.mp3 \
    | sox -t raw -r 44100 -s -w - -t wav - \
    | ./waon -i - 


2) Detailed descriptions on some options and comments for usage
---------------------------------------------------------------

  -p --patch    patch file may help to reduce multiple note containing
		the original sound.

NOTE SELECTION OPTIONS
  -c --cutoff   this may be negative number because sound signal is
		scaled in the range [-1,1], so that power may be
		less than 1.0.
		if you give large number, you may remove weak notes.

  -r --relative if you give this option, typically '-r 1',
		notes whose power is more than the average are selected.
		this means that only strong notes are selected
		in a laud part.
		if you want to pick up background weak notes,
		try without this option but only -c option.

  -k --peak     if you give this option, note-on event is detected
		where the power of a note has a peak in time.
		otherwise, note-on event is detected where its power
		become larger than on_threshold (at present,
		this is fixed in source).
		-k option may help when you want to apply for
		rapid sounds.
		but for slower music, this may cause too many
		on/off in a same tone.
		for this case, try without -k option.
                (the range of this option is from 0 to 128.
                the value 128 is equivelent without -k option
                because there is no difference bigger than 128.)

READING WAV OPTIONS
  -n            if you give larger number, you can get lower notes.
		but resolution in time become broader.

  -s --shift    if you give smaller number than -n option,
		virtually you get finer resolution in time.


-------------------------------------------------------------------------------                          PART II : Inside of WaoN

1) Policy of Selection of On/Off Event
--------------------------------------

Selection in frequency domain is relatively straightforward,
but there seems to be no general way of that in time domain.

It is obvious that this determines the quality of this kind of softwares.
If you have some idea, please let me know!

At present, I'm trying two way to detect on/off event, that is,
detection of over-threshold (no option -k) and peak detection
(option -k).

a) off-event: if (i_lsts[i] <= off_threshold)
     where off_threshold = 0 defined in source.
     'i_lsts[]' is velocity hopefully scaled in the range [0, 127].

               velocity ^      ..
                      2 |.     ..
                      1 |..   ...
      off_threshold ->0 +--*------> time
                           ^
  here is the position where off-event is placed

b) on-event:
b-1) if this note is off at last step:
       if (i_lsts[i] > on_threshold)

               velocity ^       
                     10 |.      .
                      9 |.     *.
      on_threshold -> 8 |.     ..
                        ---------
                      2 |.     ..
                      1 |..   ...
      off_threshold ->0 +--*------> time
                               ^
  here is the position where on-event is placed

b-2) if this note is on at last step:
b-2-1) with and without -k option:
       if (i_lsts[i] > (*on_lst[i]))
     where *on_lst[i] is the velocity of this note,
     velocity is overwritten by i_lsts[i].

               velocity ^       
                     11 |.        
                     10 |.      *.
                      9 |.     *..
      on_threshold -> 8 |.     ...
                        ----------
                      2 |.     ...
                      1 |..   ....
      off_threshold ->0 +--*---*---> time
                                ^ 
  velocity is overwritten by larger values here.

b-2-2) only with -k option:
       if (i_lsts[i] >= (*on_lst[i] + peak_threshold))
     where peak_threshold is given by -k (--peak) option.

               velocity ^       
                     36 |            *.
                     35 |            ...
    peak_threshold-->34 |            ...
         \           33 |            ...
           \            ----------------
             \       11 |.           ...
               \---->10 |.      *..  ...
                      9 |.     *...  ...
      on_threshold -> 8 |.     .........
                        ----------------
                      2 |.     .........
                      1 |..   ..........
      off_threshold ->0 +--*---*---------> time
                                     ^
        off- & on-event is placed here

  RESULTANT MIDI SIGNAL
    without -k option   |--    O<36>----
                        |  X
                        +--*---*-----*---> time

    with -k option      |--    O<10>-O<36>-
                        |  X         X
                        +--*---*-----*---> time
    O : note-on event
    X : note-off event

2) Policy of Selection of Note (Frequency)
------------------------------------------
a) without patch

    1. Search maximum in power spectrum and get the frequency.
    2. Set 0 into the power spectrum around the maximum.
       The area subtracting is up to the frequency of the local minimum
       of power in both sides.
    3. Search again until there is no peak in power spectrum.

b) with patch

    1. Search maximum in power spectrum and get the frequency.
    2. Subtract power of patch scaled to the maximum frequency.
    3. Search again until there is no peak in power spectrum.


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Copyright (C) 1998,1999 Kengo ICHIKI (ichiki@geocities.com)
