"Show Clipping" Options

[steve]

Crossed posts with Gale.

I think we are agreed the threshold for meters and Show Clipping should match by default.

I am neutral about that, I can see arguments for and against, but if the do have the same (default) threshold, then I think it must be 1 sample. The ability to easily find a single sample at 0 dB is too important to lose.

I see no need compelling need for the thresholds to match if the user chooses a non-default setting.

agreed.

It would probably be less confusing for users of Show Clipping if that stayed at unconfigurable one sample threshold,

+1

I'm tending to think the meters should indeed default to clip (initially) on one sample. Do you object to that if the clip indicator has an option to fade?

That seems reasonable to me, but then I don't think that the current system is unreasonable.

[Gale Andrews]

I agree with Steve that "indicating audible damage is impossible to do accurately". The documentation does not AFAIK indicate that a red line in Show Clipping necessarily indicates audible damage. It says:

A solid block of red in the waveform will almost certainly indicate multiple or extended runs of lost audio information above 0 dB, resulting in severe distortion.

I also agree that the current system is generally "reasonable" - until the user turns Show Clipping on and starts comparing the red lines with meter clipping. The discrepancy then appears if it might be a bug, given that one normally expects settings that are unconfigurable to be the same wherever they are used.

I think we are agreed the threshold for meters and Show Clipping should match by default.

I am neutral about that, I can see arguments for and against, but if the do have the same (default) threshold, then I think it must be 1 sample. The ability to easily find a single sample at 0 dB is too important to lose.

I agree. And I think we should make the default a single sample for meters too, combined with an option for > "n" samples to hold the meter clip indicator on, and the ability to change the clipping threshold for meters only to > 1 sample. Those new options will go in Meter Preferences because they only apply to the meters.

If Koz wants a way for Show Clipping to have a configurable number of samples, then that's additional to the above.

But is there some other alternative here, that keeps Show Clipping at an unconfigurable threshold of a single clipped sample, but indicates different clipping runs differently? For example, make only a run of (say) four samples have red lines. A run of two or three samples are only orange lines, and a run of one sample is a yellow line. If you zoom out such that multi-sample clipping can only be represented by a single clipping line, that line must be red if any of its constituent clipping lines are red.

If that is not insane, should the Meter Toolbar clipping colour scheme be the same?

I'm ignoring colour clashes with track name display in the waveform for now.


Gale

[steve]

If that is not insane,

I don't think that it's insane, but I think it is getting more complicated than necessary. I think that we all agree that ideally there should be no warning lines at all, that is, there should always be at least a little headroom, and Edgar has explicitly said that if the waveform reaches 0 dB then he wants a hard slap. One or two thin red lines are not a "hard slap", so I don't think we should water down the warning further.

[Gale Andrews]

If that is not insane,

I don't think that it's insane, but I think it is getting more complicated than necessary. I think that we all agree that ideally there should be no warning lines at all, that is, there should always be at least a little headroom, and Edgar has explicitly said that if the waveform reaches 0 dB then he wants a hard slap. One or two thin red lines are not a "hard slap", so I don't think we should water down the warning further.

It's still true though that if you are zoomed a long way out you really don't know what those couple of red lines constitute. They could be harmless clipping at a single sample, or dozens of clipped samples.

You could object that yellow and orange imply safety in the gradient meters so are not an appropriate indicator for only one or two clipped samples. Perhaps some might like number of clipped samples to show up on hover, or something else. However without some differential indication I don't see any other way to leave Show Clipping at default one sample threshold (which most of us want) and meet Koz's complaint that Show Clipping doesn't easily distinguish different widths of clipping.

Rather than have another 60-message discussion that leads nowhere in the end, I hope we can make some improvements here. AFAIK most of us agree or don't object to Meter Toolbar clipping at one sample if there is an option for the clipping indicator to fade. Right? Doing that would remove the threshold mismatch between Show Clipping and Meter.


Gale

[steve]

AFAIK most of us agree or don't object to Meter Toolbar clipping at one sample if there is an option for the clipping indicator to fade. Right?

We're not going to succeed in providing all things for all people, but that seems to offer most things to most people, so +1

[Edgar]

AFAIK most of us agree or don't object to Meter Toolbar clipping at one sample if there is an option for the clipping indicator to fade. Right?

We're not going to succeed in providing all things for all people, but that seems to offer most things to most people, so +1

The lines remain visible after playback or recording is stopped, and are reset when a new playback or recording session is started

This is not reliably true with divorced meters on SVN HEAD (13567, 8 November 2014) on Windows.

The 2 pixel wide latched vertical clipping indicator in the meter is (on modern high resolution monitors) almost invisible. While I realize that for these meters every pixel of resolution is important, I think that it is especially important that, the smaller the meter, the more visible the latched indicator should be. To make it even less visible, it is immediately adjacent to the saturated blue "Maximum Peak Level" because, by definition, the worst clipped sample will be the maximum peak level. Visually, these 2 tiny indicators blur into one dark purple (almost invisible) bar. My solution would be to make the width of all of the vertical bars at least 3 pixels with the latched clip indicator 4 pixels. This would make the math a lot better for the 3 pixel bars because the center pixel would equal the target value and rounding errors would not occur. It would only cost us 2 pixels of meter resolution.

Personally, I am -1 on fading the latched clip indicator (in case anyone is talking about that). However, I would make the unlatched clip indicator fade (currently it just disappears instantaneously after a brief period of time) if we make the fade time proportional to the number of sequential clipped samples. The 1st time a clipped sample is encountered the (left hand) red bar on the meter would display and set a timer for X seconds; each sequentially subsequent clipped sample would add a diminishing value (.9X, .8X, .7X etc.) to the amount on the timer; we could even make the bar slightly larger if more than N sequential samples clipped.

clip.png (1.36 KiB) Viewed 920 times

In the above image I have photoshopped wider indicators on the top channel of the meter.

[kozikowski]

The fade option can be cheated by a temporary latch. I've seen systems that just stay bright for a second or two rather than fading. I'm good with that. I'm sure that's far easier to code. In my first encounter with the current flashers I kept waiting for them to turn off by themselves.

All the processes and arguments are covered in the option panel so far. If you want the thing to flash at 0dB, then by all means select that in your option panel. That's not the default. The default is actual sound damage — that "three over" thing, or as close as can be achieved with high probability. We have too many highly processed songs that live at 0 dB giving an entirely wrong impression of damage. Also see MP3 level shifting. That may or may not create damage, but it would be rough to find out with the current tools.

I'm perfectly in accord with making the flashers bigger for anyone who wants to get into the real estate discussion.

I'm this close to firing up my Cool Edit and/or Audition and see how they did it. I know in Cool Edit, the meters are the whole width of the program window. Grand idea.

Koz

[kozikowski]

A defect in the Clipping Indicator produces a different useful tool, the Peak Programme Indicator. There is no single solution. There needs to be a formal Peak Programme Indicator and the Clipping Indicator needs to be fixed to respond only to probably clipping damage.

Koz

[Gale Andrews]

The lines remain visible after playback or recording is stopped, and are reset when a new playback or recording session is started

This is not reliably true with divorced meters on SVN HEAD (13567, 8 November 2014) on Windows.

Can you make steps to show that? Note that if you click in the playback meter this now removes the peak and clipping indicator in the playback meter.

The 2 pixel wide latched vertical clipping indicator in the meter is (on modern high resolution monitors) almost invisible.

+1 but to my mind we should either move the clipping indicator or give it a visibly wide separator. That would help me more than thicker bar colours.

Personally, I am -1 on fading the latched clip indicator (in case anyone is talking about that). However, I would make the unlatched clip indicator fade (currently it just disappears instantaneously after a brief period of time) if we make the fade time proportional to the number of sequential clipped samples. The 1st time a clipped sample is encountered the (left hand) red bar on the meter would display and set a timer for X seconds; each sequentially subsequent clipped sample would add a diminishing value (.9X, .8X, .7X etc.) to the amount on the timer; we could even make the bar slightly larger if more than N sequential samples clipped.

Currently the clip indicator should not disappear unless reset by the user or by starting playback or recording.

Yes if user configures the clip indicator to stay on, it should just stay on, as now.

I don't care if the "unlatched" clip indicator fades or disappears instantaneously. The Recent Peak indicator appears to disappear almost instantaneously and I'm fine with the clipping indicator doing that.

Gale

[Gale Andrews]

There needs to be a formal Peak Programme Indicator

I suggest we leave that out of discussion for now and concentrate on agreeing changes to the tools we have.

the Clipping Indicator needs to be fixed to respond only to probably clipping damage.

Do you mean the clip indicator in the meters or Show Clipping? There is no way to fix either, because "probably clipping damage" depends on the material and the equipment. The meters can be "fixed" by the user choosing the "number of samples threshold" and the "number of samples to force the clipping indicator to hold" from the Meters Preferences (as appropriate to the material and their equipment).

And given the above, let the meters default to 1 sample clipped initiates and holds on the clipping light by default, then we have solved one significant discrepancy between meters and Show Clipping.

Show Clipping can be fixed (if we need to) by differentiating the clipping lines in one of the ways I suggested, or by letting the Show Clipping number of samples threshold be configurable. If we let the number of samples be configurable, there still needs to be a sensible way of displaying a run of the chosen minimum number of samples when zoomed in. The default Show Clipping threshold must remain at 1 sample. The Show Clipping threshold control must either go in Preferences (not the Meter Preferences), or there must be a separate Show Clipping threshold chosen (somehow) in View Menu.

If we differentiate Show Clipping lines, the same differentiation could be applied to the meter clipping light, so number of samples to trigger or to disappear wouldn't be required at all. Do I take it real world hardware meters have their clip indicators fade or disappear, not hold?

Given Show Clipping is not default, I don't think our meter clip indicators should disappear by default.


Gale