[Lmuse-developer] Added "Adjust Wave Offset" to new Wave Editor in SVN trunk

[. T. <ter...@ro...>]

Hello.
MusE audio fans looking for some basic latency relief will want to test 
 the new improved Wave Editor in the SVN trunk.

In particular, there is now a menu item "Adjust Wave Offset" (in frames). 
This adjusts a Wave Event's starting frame into the wave file.
It makes the wave move to the LEFT.Wave Offset is a parameter unique to Wave Events, 

 above and beyond Wave Event position and Wave Part position.
It does not touch the Wave Event position nor the Wave Part position.

This is good news for audio fans because currently it is the only way to
 adjust something by FRAMES rather than TICKS. *See related news below.

This makes it good for basic recorded wave latency compensation
 especially with large Jack periods.

Here's how it works: 
Say you want (or need) to run Jack with large period sizes like 2048 samples.
When you record a Wave Part whose audio comes from an Audio Input Track
 routed from a PHYSICAL Jack port, there will be latency in the resulting recorded
 wave equal to the Jack period, meaning the wave is out of alignment with the true
 recorded time. 2048 samples is a long time, pretty severe.

Until now there was no way to compensate for it.
So now using the new improved Wave Editor simply adjust the recorded 
 Wave Event's Wave Offset to the Jack period (example 2048) and the 
 wave will then be aligned properly.

If the Audio Input Track's Jack ports happen to form a send-and-return path 
 coming from an Audio Output Track, you likely should DOUBLE the amount.

Note this is not a perfect system: For example If the source of recorded 
 audio comes from two different physical Jack ports at the same time, 
 each with DIFFERING inherent latency, then Wave Offset will be useless.
So it is recommended to stick with ONE Jack port per Audio Input Track,
 IF that Audio Input is to be RECORDED to a Wave Track.

An ultimate latency compensation system is much lower-level (at the 
 mixing level)  and more or less fully automatic.
Some effort is being put into this here, but it's pretty hairy - some gotcha's
 to sort out.

Related news: A new MusE branch was started to deal with providing proper
 "Sample" and "Minute:Second:Frame:Subframe" and "Tick" Time Scales 
 (in addition the current Bar:Beat:Tick) and movement/cutting/pasting etc,
 anything dealing with TIME, for users who need to work with linear time,
 rather than musical time. It's gonna be quite a while before the branch could 
 even be compilable though.

Cheers. Happy recording. Hope this little feature helps "offset" any troubles.

Tim.