Non-contiguous audio selection
Selecting a part of the waveform usually results in a contiguous selection, starting where you clicked the mouse up to the point where you released it.
A non-contiguous selection can be thought of as being composed of several simple selections, several regions are selected simultaneously. Here is how a non-contiguous selection can look like:
Although TwistedWave has always been able to handle non-contiguous selections, it has recently gained more visibility with the silence detector, because it uses a non-contiguous selection to mark the silences in an audio file.
Making a non-contiguous selection
When you click the waveform, the current selection is discarded, and you start making another selection. In order to make a non-contiguous, you can option-click, and the existing selection will remain, and you start adding to it.
Additionally, you can option-shift-click and drag the mouse to remove an area from the selection.
Exactly as with a simple selection, you can adjust a non-contiguous selection by clicking on its edges, or shift-clicking if you want to avoid accidentally deselecting everything by clicking just a bit too far.
What for?
What can this be used for?
The interesting point about non-contiguous selections is that all the effects that can be applied on a selection also work on non-contiguous selections, and if you want to apply an effect with the same settings on different parts of an audio file, instead of selecting a piece of audio, apply an effect, selecting another part, and applying again, you can select all the parts you want to process simultaneously, and apply the effect.
The nice part is that TwistedWave remembers the selection you applied the effect on. If you want to apply your effect with a different preset, hit undo, and the audio you were working on is automatically reselected.
Also, as indicated above, a non-contiguous selection is a very helpful tool to mark the silences automatically detected in the sound file.
Posted: January 20th, 2010 under Features.
Comments: 2
Comments
Comment from Townsend Coleman
Time: September 22, 2010, 7:33 am
Is there a way of being able to detect silences and delete those selected silent portions, WITHOUT the remaining audio sliding together into one contiguous file, but leaving the remaining audio in it’s original place, with silence in between? Better yet, is there a way of not only being able to do that, but also being able to replace the silence with a pre-determined length of silence (ie; .5″)? And if so, is there a way of being able to automate a fade-in and fade-out on each of the remaining portions of audio with a pre-defined length of fade? Thanks! TC
Comment from Thomas
Time: September 22, 2010, 10:34 am
Hi Townsend,
Yes, it is possible to make the detected silences completely silent without actually removing them. In the silence detection tool, select “Select Silences” instead of “Delete Silences”. Then, from the main menu, select “Effects / Silence”. This will make the detected areas completely silent.
It is also possible to make all the silences the same duration. Use the “Select Silences”, and then, from the main menu “Effects / Insert Silence…”. You will be asked for the duration of the silence to insert, and all the selected silences will be replaced with a constant duration silence.
For the fade in and out, you can select fade in and fade out from the Effects menu, but this will apply a fade on the whole duration of the silences. I was about to write that it was not possible yet to do this with TwistedWave, but I found this solution:
- Create a new document (File / New).
- Insert a silence (Effects / Insert Silence…). Make sure the silence is at leas as long as the longest silence in the file you want to process.
- Select all and copy to the clipboard.
- Close this new document.
- From the main menu, select “Edit / Special Paste Options…”.
- Select the “Replace” mode, check the option “Fade document”, uncheck “Fade clipboard”, set the attenuation to -infinite, and specify the duration of the fades in the “Fade in/out time” box. Press OK.
- Now, select the silences with the silence detector in “Select Silences” mode.
- Select “Edit / Special Paste” from the menu to apply all the fades in and out on the detected silences.
This is not a very straightforward process, but will do the job. I should definitely add the possibility to do these three kinds of silence deletions from the silence detection window. I will think about it for a future update.
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