At 11:40 AM 10/19/02 -0400, Steve Pelikan wrote:
>I'm putting together a progam that will perform audio editing and signal
>processing procedures and would appreciate any suggestions for features to
>be included --- especially features that would be useful for dealing with
>natural sounds. The goal at first is to provide procedures that aren't
>generally available on currently distributed programs. Since people use a
>variety of editors --- what are the most useful features of your favorite
>program?
>
>The program is writen mostly in Java so that it shouldm run on ost
>platforms. It will be sufficiently modular that others can easily
>add/contribute code. I'd be particularly interested in hearing from someone
>who could contribute Java/C/C++ code to design (higher order) FIR/IIR
>filters.
>
>
>But ANY suggestions would be appreciated.
>
>Thanks,
>
>Steve Pelikan
Steve:
What a terrific project. My compliments. Now that is really COOL!
As an early user of Cool (1996), who has recommended this product to
hundreds of recordists, I have every year sent suggestions to the folks at
Syntrillium that three new things were really needed to add to their editors.
I have NEVER received even a single acknowledgement for my email
submissions, and now that Cool Edit Pro 2.0 is out, and incorporates none
of these suggestions, I am boycotting their future products. Ahhh, for
the days when you could email Dave Johnston, the inventor, and get a
response in an hour. Please note, I am cc.-ing them this posting, as
well. Maybe I can finally stir up something!
1. Look for sound piece "x" in file "y", or in all files in directory "\z"
This feature, which the original Canary implemented, is really a simple
cross-correlation summation, as we did long-hand in the 1960's. Canary
took forever (15 minutes?) on old Apple Macs to look for a 2 second piece
in a twenty second recording, but it was very useful for comparing some
original sound you had recorded with published sounds, which you might
suspect were your own stuff, used with or without permission. It is sort
of a "keep them honest" tool. I recall the Cornell folks said it was very
simple to implement. Of course, with deliberate distortions, like
time-stretching, or pitch shifting, correlation summed values are
significantly disguised, but it is still of some use to us nature
recordists, I think.
2. Cool always displays their spectra according to Kay Electronic's
original format - frequency vertically, in linear format, and time
horizontally, also linear. We all on this group have been asking for a
pseudo-semi-log vertical scale, more like a music scale, where each OCTAVE
is granted so much vertical pixels, rather than a fully linear form where
each kilohertz is granted a fixed unit. Syntrillium has ignored this
request, as far as I know.
3. Make the filter-construct screen oriented the same as the spectrum
screen: frequency varying vertically. Cool provides a very powerful
editing band pass filter tool, including drawing your own complex filter
curve, with clicks and drags. Unfortunately, their frequency curve editing
screen plots frequency HORIZONTALLY, inexplicably orthogonal to how it is
displayed on the very file you are trying to edit! I have been wrestling
with this right-angle re-representation in my own work now for over six
years, and it does not get much easier!
Cool does have what I say are three essential features to it, that you
might try to 'preserve':
1. you can "preview" how it will sound, as you click and drag your curve,
more or less, live; although it is really a pre-listen, NOT a
preview. This might be extended to a real preview, where the spectrum
display would change visibly, as well. This would be much more useful to
me, actually.
2. you can set the frequency axis in this edit screen to either LINEAR or
LOG, and go back and forth building the same curve as you go. That is, the
curve nodes you click-set in one mode, re-appear correctly represented in
the other mode, and then back again. This allows the nodes in the lower
frequencies to be set accurately in LOG mode, then switch to LINEAR to
adjust the higher bands more easily.
3. you can name and save to disk any curve or pair of morphed curves, and
lastly
4. you can MORPH between any two such curves, and then designate a
TRANSITION curve, that specifies, in the time domain, how the software
switches from curve "A" over to curve "B", and back again, if you want.
I use this feature to its fullest. Example: I often have a recording where
unwanted bird "X" calls six times, and I make the transition curve to
exactly remove each of the six sound intrusions, and I make curve "A" have
the same number of nodes, but placed nearly flat in overall response, and
curve "B" have the unwanted sound sharply filtered out. When it is
finished, the recording sounds like you just turned down the gain quickly
on the unwanted sound at exactly the right times.
To restore some naturalness, I often select a part of the same recording
with neither wanted nor unwanted species. I copy it to a new file. I then
construct a filter manually that mirrors the removal filter ("B"),
essentially generating a non-intrusive noise profile that complements the
missing sound domain. I then mix paste correct length pieces of this
shaped noise into the holes left by the morph filter, leaving a recording
that sounds fairly natural, of only the "wanted" species sounds, all at
their natural level, timing and frequency levels. [I am sure that Lang
Elliott is shuddering, should he have read this far, but I hasten to add
that MY purpose is only to instruct folks to learn about what to listen
for, species by species, on my shoe-string budget, and is not to provide
people with "natural" sounds, they might substitute for actually going out
into the field.]
I realize how difficult it is to describe or understand this tool without
seeing and hearing someone use it.
I have repeated posted to this list, how useful this tool is, and offered
specific examples privately to numerous members, including exact
screen-shots of how to use it, and so far, I think I am the only person to
successfully employ it to actually "delete" specific noises, such as
removing repeated blue-jay calls from a long recording of another bird. I
am afraid that with most users, the mind just boggles at all this.
The results are so spectacularly useful, I cannot believe I am the only
person using Cool to its fullest, and would love to be proven wrong! Maybe
I/we can prepare a videotape ("over the shoulder"). It can be a kind of
fun challenge.
Anyway, your "paint out a noise" would put this feature to shame, if it is
able to incorporate the usefulness of the items already available. You
might seriously consider a "paint and replace" procedure, automatically
performing what I do over a period of hours. It would be necessary for the
user to "paint" a quiet place where such non-intrusive noise could be
sampled and copied.
I will cooperate in any way with your project. I can provide before,
during and after WAV files, etc. Whatever you need. My java is barely
budding, rudimentary, though.
Marty Michener
MIST Software Associates
PO Box 269, Hollis, NH 03049
coming next week : EnjoyBirds - software that migrates with you.
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