The quality of time stretching and pitch shifting/scaling in general is dependant from the kind of audio material.djmontyq wrote:Opinions, please. Is the MPEX in Cubase/SONAR outclassed by any plug-ins or other hosts' proprietary audio tools. I found Pitch 'n' Time to be excellent but it doesn't work as a plug and is quite pricey...
Is it polyphonic material?
Is it monophonic material?
Is is rhythmic material?
All those questions are very important for the best algorithm of choise. So it is very much a question how the user is familiar with the different techniques and what technique one attempts to use for what matter.
Example: Dry(!) monophonic human and instrumental voices need a higly pitch synchronous algorithm with formant correction (at pitch modifications). Also a specialized "voiceless parts" detection and handling.
Even those algorithms wouldn't work at polyphonic material at all, so there has to be an completely different (more general) algorithm on base of granular synthesis and resampling.
Both of the techniques above will not work that good with rhythmic material (transient repeation), so a combination of beat slicing and one of the methods above is required to deliver satisfactory results.
You cannot say which algorithm in general the best is for even that reason.
Therefore Melodyne for instance has an entire brunch of different algorithms and a complex logic behind the automatic selection (complex auto-analysis of the audio material - which needs pretty much time to pre-calculate).
