Adjustable Fade

[steve]

Labelling of gain sliders
If we specify which gain slider is which and the user enters them the wrong way round, I think just let the plug-in "correct" it.

If we don't specify which slider is which, it might make more problems than it's worth trying to give the sliders an understandable label. I think it would be least confusing to use "High/Low" for an unspecified slider, but I can't think of anything better than

High or Low Gain (dB)
Gain to complete fade (dB)

at the moment.

Normally we prefer to avoid text in the ;info line other than credits and license details, but in the case of this plug-in I'm starting to think that brief explanatory text in the ;info line may be justified.

If this were a built-in effect there would be several options open to us:

• The "Gain" controls could have a labelled box around them (like in the Leveller effect).
• Disabled controls could be greyed out.
• Controls could respond to preset choices.

Unfortunately none of these are available for Nyquist plug-ins.

Something like this for the gain controls would be perfectly clear:

sliders.png (4.99 KiB) Viewed 1752 times

But sadly this is not supported in Nyquist plug-ins.
To work around this limitation I think that for this plug-in it may be justified to have brief explanatory text in the ;info line.

[steve]

Would something like this be sufficiently clear?

Adjustable Fade GUI.png (37.99 KiB) Viewed 1755 times

The defaults are as shown.

Options:

Fade type

• Simple (Linear)
• Sine ('S' shape)
• Logarithmic
• Exponential

The default fade shape for "Simple (Linear)" is linear.
The default fade shape for "Sine ('S' shape)" is "S" shaped raised cosine.
The default fade shape for "Logarithmic" is an "Equal Power" curve.
The default fade shape for Exponential is a "medium curvature" exponential curve.

Fade In, Out, Up or Down

• Fade In
• Fade Out
• Fade Up
• Fade Down

For the gain controls, -96 dB is interpreted as absolute silence (-inf dB).

[steve]

Version 24

adjustable-fade-24.ny

(4.84 KiB) Downloaded 108 times

[Gale Andrews]

You wanted a "logarithmic" fade, by which I assume you meant what Soundtrack Pro call an "Exponential Fade" as in the Envelope Tool.

Thanks for your work on the log/exponential curves. Presets or modifiable, I think we want these, both logarithmic (fade in becoming "slower") and exponential (fade in becoming "faster").

This effect does not have EQ. I was referring to "Pro Fade Out", which has a first order Butterworth filter with a corner frequency that slides down from half the sample rate to 100 Hz.

I did not mean Equalisation, but equal power. When the curve slider was +/- 1.25, the equal power point was +0.5. Now an "equal power" curve is achieved when you choose a logarithmic type with a zero mid-fade setting, if I understand it aright. I think this is OK and the preset "types"are all good.

we can go back to a layout similar to version 23 (which looks like the favourite so far)

My "favourite" on balance was still your modification of my suggestion with the single preset control turning off all the other controls (which included a fade direction control).

Irrespective of what the default should be for the "single preset" control, that version meant that the majority who will be fading only with presets only ever need to change one control. It's less confusing than the "two"preset controls" version, only one preset of which actually disables the sliders. I'm inclined to think the preset that disables the sliders should be at the top, even if we keep the v24 layout.

I note you support the "Use Controls" default in the "single preset" alternative on the basis of the requests for a "quick linear fade from say 0.8 to 0.2, much simpler and quicker than the Envelope Tool". I am still not convinced "Use Controls" would be the correct default because so many more people would be changing it more than they otherwise need to. I think you may have a valid question whether linear should be the default.

I still contend this plug-in does not offer 0.8 to 0.2 in any "simple/quick" way, because many of the voters within those want % or target level controls (I state the "target" votes as a fact only, I'm not getting into the practicalities of that here).

Getting to v24 in detail. my first impression is that the idea of different fade up/in/down/out settings instead of just fade direction has quite considerable potential for confusion.

• If you leave the sliders alone, "fade in" and "fade up" produce identical results for both linear and sine types, but if you move the sliders then of course fade in and fade up produce different results (for all types, the sliders have no effect with "fade in").
• If you leave the sliders alone, "fade in" and "fade up" produce different results for both log and exp types.
• Exponential fade up (without moving the sliders) seems to rise too late to be useful.
• Exponential fade in (where the sliders have no effect ) rises earlier, but although this is "from silence", the only fade up that looks identical to it (in waveform view) is from -61 dB. I know I should look in Waveform dB view, but it still "looks" odd.
• Log/exponential fade in/out are described as being "from silence" but can they be without "jiggery pokery"?
• Many people may feel that -96 dB is "silence" (I thought earlier versions of this plug-in treated it as such?

Although I know "why" you changed to not specifying which slider is which (to try and show that the sliders only worked with Fade Up/Down) I think that with the other confusions listed above, it's a mistake not to use "High Point Gain"/ "Low Point Gain". Otherwise, there are just too many up/down/in/out statements and choices.

So, do we really need Fade Out/In/Up/Down rather than just "Fade In", "Fade Out" (or "Fade Up", "Fade Down" if you must) and "Use Controls"?



Gale

[steve]

My "favourite" on balance was still your modification of my suggestion with the single preset control turning off all the other controls (which included a fade direction control).

Could you point to, or post, which one that was.

Exponential fade up (without moving the sliders) seems to rise too late to be useful.

Yes. That's why I didn't use that for the "Fade In" option.
Fade Up would be even worse if it went down to -145 dB (like the Envelope Tool).

Exponential fade in (where the sliders have no effect ) rises earlier, but although this is "from silence", the only fade up that looks identical to it (in waveform view) is from -61 dB. I know I should look in Waveform dB view, but it still "looks" odd.

I think that the Exponential Fade In and Fade Out "presets" produce nice sounding exponential fades.
The technical description for these fades is that it is an exponential curve from -60 dB to 0 dB, normalized to a range from silence to unity gain (reverse for the Fade Out).

Log/exponential fade in/out are described as being "from silence" but can they be without "jiggery pokery"?

The "jiggery pokery" is "normalizing" the range.
Without normalizing the range an exponential fade will only reach silence when the format runs out of bits, which is -96 dB for 16 bit format, -145 dB for 24 bit, and around -1000 dB for 32 bit float.

Without normalization, this is an exponential fade in that fades in from 32-bit float silence. As you can imagine, it's not very useful because it is totally inaudible until almost the end.

firsttrack000.png (6.94 KiB) Viewed 1721 times

Many people may feel that -96 dB is "silence" (I thought earlier versions of this plug-in treated it as such?

Yes, version 24 also treats -96 dB as silence.

What this means for the exponential curve with the sliders is that at -95 dB a full-scale signal that is faded in will fade in from -95 dB. At -96 dB it will be faded in from -96 dB, but then normalized so that it starts from silence. I considered leaving the Fade Up and Fade Down Exponential fades not-normalized, but decided to normalize at -96 dB for consistency with all the other fades.

A pragmatic approach is required for exponential fades as a "true" exponential fade in from silence would be silent for the entire selection, with the gain rising to unity on, or after the final sample.

[steve]

I did not mean Equalisation, but equal power. When the curve slider was +/- 1.25, the equal power point was +0.5. Now an "equal power" curve is achieved when you choose a logarithmic type with a zero mid-fade setting, if I understand it aright.

Yes, the default Logarithmic curve (Mid-fade = 0) is an "equal power" shape.

"Sine ('S' shape)" with Mid-fade = +0.5 is a similar but very slightly different "equal power" shape.

[steve]

the majority who will be fading only with presets only ever need to change one control. It's less confusing than the "two"preset controls" version, only one preset of which actually disables the sliders.

Now that we have the Log and Exp fades and nice default values for Linear, "S" curve and Logarithmic, the other way to avoid the "two preset control" would be for all of the "presets" to be fully adjustable. That is, with the Mid-fade, and Gain sliders at default, the "choice" options would be:

• Simple In
• Simple Out
• Sine In
• Sine Out
• Log In
• Log Out
• Exponential In
• Exponential Out

If we don't mind truncating the last couple of characters we could include descriptions of the default shapes in parentheses:

• Simple In (Linear)
• Simple Out (Linear)
• Sine In ('S' Curve)
• Sine Out ('S' Curve)
• Log In (Eq Power)
• Log Out (Eq Power)
• Exponential In
• Exponential Out

The only feature that we lose with this is the "Normalized Logarithmic" Fade In/Out. However, the "Simple" type with a negative Mid-fade setting provides a very similar shape should it be required.

What we gain by this is:

• 1 click fade selection.
• Sliders always work.
• Only one "preset control".
• Fade shape and direction selected in one click.
• Additional ;info text not required.

I'll mock-up the GUI and post it shortly.

[steve]

Here's the mock-up for a possible version 25.
The gain scales are -96 dB to +24 dB

v25-dB.png (29.6 KiB) Viewed 1721 times

Here's the same but with linear percent gain rather than dB.
The gain scales are 0 to 200%, which is equivalent to -inf to +6 dB.

v25-percent.png (29.63 KiB) Viewed 1721 times

There are pros and cons to both dB and linear scales for the gains.

1. Linear scale works very nicely if you want to reduce the level to say 1/4 of the original level - just set the gain to 25%. With a dB scale it is a little more difficult unless you know that 1/4 of the original level is -12 dB (one click on the slider).
2. Above unity gain a linear scale has a limited range. +24 dB is 1585 % which is obviously impractical on a linear scale.
3. The dB scale works well in conjunction with the Amplify and Normalize effects. For example, to fade up to exactly 0 dB, the end of the selection can be "measured" using the Amplify effect to find the current peak level, then the "High Point Gain" set to that level.
4. The dB scale does not go down to silence, so where silence in required the low end of the scale (-96 dB) must be "interpreted" as silence,
5. The linear scale does go down to silence, but an Exponential fade from or to silence will produce only silence, which will "look" like a bug.
6. The "standard" way to specify gain in both hardware and software is in dB.

The deal breakers for me are items 2 and 3.

Here is the same but with a choice of dB or Linear percent scales. In my opinion it looks cluttered and it is confusing that some of the controls do not work (but are not grayed out). It offers ample opportunity to get the wrong result by not noticing that the "Gain percent" (or Gain dB) sliders are disabled by default. It also looks more intimidating because it's a "big scary complicated screen with lots of sliders".

v25-dB-and-linear.png (39.46 KiB) Viewed 1721 times

And here's the .NY file for the GUI:

Adjustable-Fade-v25-GUI.ny

(996 Bytes) Downloaded 93 times

[Gale Andrews]

My "favourite" on balance was still your modification of my suggestion with the single preset control turning off all the other controls (which included a fade direction control).

Could you point to, or post, which one that was.

This one http://forum.audacityteam.org/viewtopic ... 17#p192917 .


Gale

[steve]

This one viewtopic.php?p=192917#p192917 .

Thanks. Yes I quite like that one too. Are you (or anyone else, because this is not only between Gale and myself) tempted by "Adjustable-Fade-v25-GUI.ny"?