|
|
|
 | | | |
| | | |
CD track/waveform resampling (Pro version only)
This is accessible from the Tools → Resample menu.
Note: For soundcards only, CD tracks must be 44100 or a CD player will not play it at the correct speed
Resampling is a very interesting topic, especially when connected to the preview screen in SeeDeClip, because that allows you to actually see what this really does.
|
|
The example is resampled to 4x sampling or a sampling rate of 176400/sec. In this case the default sinc length needed to be extended to 32 samples or the resultant waveform was all squiggley (technical term for ripple - see below).
Use the preview feature with this because resampling can be really really slow, like coffee break slow.
Resampling is a little slow and 'idiosyncratic' as there are a number of trade-offs.
It uses a simple convolution of a sinc function windowed with a Kaiser filter window
The Sinc function has a number of poles and the more you use, the slower but more accurate the filtering is.
After you have re-sampled a waveform, check the loudest parts in a waveform editor for ripple, and increase the Sinc window length as required, or change the Kaiser α or β (a single property referred to as beta here).
|
|
The newly resampled output is built up from the finite impulse effect each of the source samples has, a process known as bandlimited interpolation. For further reading you may be interested in Julius O. Smith III at Stanford.
Note: When previewing a resample output you cannot switch between analog/digital on the graph, you have to click on the digital box next to the preview button, and then press preview again to regenerate the new graph.
- De-select Digital to create an analogue graph preview.
-
Orig includes the original waveform (dimmer colours).
Analogue preview of resampling to 176400 samples/sec.
|
| | | | |
| | | | |
|
|
