Toggle Waveform/Waveform (dB)

[edwinn]

Hello Audacity Forum, love this software!

I do a LOT of audio editing, mostly of lectures and some streaming radio shows, and often would like to TRIM the start and stop (intro, etc) and it's useful to toggle Waveform (dB) to see "down in the noise," to better select a Cut or Fade point.

Is there a way to assign hotkeys for Waveform? It would be FANTASTIC to have a TOGGLE function, back and forth between Waveform (dB) and Waveform.. to view intro and trail-out of segments for fading selection.


-Ed

[steve]

You can't assign a hot-key, but you can do the next best thing.

Press the "menu key" to open the track menu for the currently selected track (or "shift + M"), then press the appropriate "accelerator key" (the underlined letter):
"v" for "Waveform"
"w" for "Waveform (dB)"

[edwinn]

You can't assign a hot-key, but you can do the next best thing.

Press the "menu key" to open the track menu for the currently selected track (or "shift + M"), then press the appropriate "accelerator key"..

Thanks.. I thought about doing that, and wanted to ask and drop a suggestion at the same time.

-Ed

[edwinn]

Since the OP (orig post), have used the shortcut functions a lot.

There's a slight issue to raise. Let say.. I open TWO FLAC files, one atop the other in the display window. In WAVEFORM mode, there looks like some ripple or `audio data´ in the 0.5 sec lead-in to the audio where there should be SILENCE. However when switching one file (or both) to WAVEFORM (dB) mode, the Zero-line is flat as a pancake with NO data whatsoever.

Why is there data, or signal displayed in baseline WAVEFORM mode when there are all Zeros in the 0.5 sec lead-in segment?

Need a screencap for this?

-Ed

p.s. a feature when one could mouse-over the waveform and see amplitude and dB displayed real-time in the status bar would be a good eval feature.

[steve]

Normal "linear" waveform view shows sample values from +1 to -1, so all (valid) samples are displayed.
The equivalent numerical range for dB is 0 to -infinity. Of course we can't have an infinitely tall track, so the bottom of the range is not displayed. By default the displayed range is 0 to -60 dB, so any samples below -60 dB appear as "silence" (on the centre line). The lower limit of the dB range may be changed in Preferences: http://manual.audacityteam.org/o/man/in ... ences.html

[Gale Andrews]

Let say.. I open TWO FLAC files, one atop the other in the display window. In WAVEFORM mode, there looks like some ripple or `audio data´ in the 0.5 sec lead-in to the voice intro in both files where there should be SILENCE. However when switching one file (or both) to WAVEFORM (dB) mode, the Zero-line is flat as a pancake with NO data whatsoever.

Do you really have absolute silence at the start of those files?

If you have default -60 dB Waveform dB range set in Interface Preferences and the lead-in is say at -65 dB then you will see it in Waveform view but not in Waveform (dB) view.


Gale

[edwinn]

the bottom of the range is not displayed. By default the displayed range is 0 to -60 dB, so any samples below -60 dB appear as "silence" (on the centre line).

Thanks, that's clear.

I force the first 0.5 sec to `all zeros´ when editing the file, then export a s FLAC. The files in question were processed recently and exported as described. So there must be some encoding hash (or noise) introduced when FLACing?


-Ed

[edwinn]

Do you really have absolute silence at the start of those files?

If you have default -60 dB Waveform dB range set in Interface Preferences...

Ok, set the lower limit to -96 dB and there's S/N displayed. That must be FLAC encoding noise. Interesting!!

It's a measure of the noise floor. How kool is that !! <-- acting half my age here.

-Ed

P.S. will see about a screencap. The residuals appear to be `quantization noise´ with 3 or 4 recognizable levels.

[edwinn]

Now I have another wild-axx idea.
Is there a way to have a dual-display, showing both waveform and dB at the same time, for the same file?

In the graphics world, there's an OVERVIEW window which is usually sized much smaller that the edit window. Is that kind of thing possible?

[steve]

Is there a way to have a dual-display, showing both waveform and dB at the same time, for the same file?

Not yet, but there seems to be some interest by at least a couple of developers for adding that as a new feature in a future version of Audacity.
I agree that it could sometimes be useful. Sometimes it would be useful to display a waveform and a spectrogram, so a general feature of allowing multiple views of the same track data would be nice.

Currently, the closest you can get is to duplicate the track (Ctrl+D) and then set the track views as required - (not ideal, but occasionally a useful workaround).