Файл: E-mu E 6400 EOS 4.0 manual.pdf

6 - Sample Edit

Background: Using Cut, Copy, Paste and Undo

Background: Using Cut, Copy, Paste and Undo

Imagine a printout of a sample. Now imagine that you have a pair of scissors capable of cutting a piece out of that sample (or a copy of that piece if you don’t want to affect the original), as well as a clipboard to neatly hold the cut or copied piece. Now imagine that you can either perfectly insert the clipboard contents at any given point in any sample, or mix the clipboard contents in with any sample, starting at any designated point. The Emulator can do all this, and all electronically. Auto Correlation and Crossfade functions are also provided for seamless transitions between the cut, copied, and pasted parts.

Sample 00

CLIPBOARD DATA. The clipboard will retain data until replaced by other data to be copied, cut, or backed up. This occurs with several operations where you want to be able to undo an action that doesn't work.

Undo and Redo

During several sample edit operations such as cut, paste, and sample rate conversion, the sample being processed will automatically be backed up and stored on the main hard disk drive. If you do not like the results of the processing, you can call up the Undo function, and restore the original sample from the main drive. (Ah, if only life itself were so simple.) Best of all, the processed sample will now move onto the main drive. Thus, if you decide you liked the processed version better after all, you can actually undo the undo. (Redo.)

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Background: About Looping

Insufficient Hard Disk Drive Memory

The display will inform you if there is not enough memory to back up a sample onto the hard disk drive. You then have two choices: either free up some additional memory by erasing banks on the hard disk drive, or call up the Undo function and disable the backup process. Of course, if backup is disabled, you will not be able to undo an operation.

Typical Applications

Typical cut/copy/paste applications would be to splice the beginning of one sample to the end of another, or to mix two samples together to conserve memory. (Do this by copying an entire sample, then pasting it at the beginning of the second sample using the mix option.) You can splice an attack transient on to a synthesizer waveform loop to produce realistic sounds that take up virtually no memory, or take out a pop or click in a sample. Another possibility is, flanging and chorusing. Paste (mix) a sample to itself, offset from the beginning by a few hundred samples or so, to thicken up the sound.

Background: About Looping

Sampling is the process of storing sounds in digital memory. Since each individual sample (not the complete sample, but each element of the sample) requires one memory slot, memory requirements increase if you sample long sounds or use high sampling rates.

How Looping Works

Looping is a technique that can extend a sound’s length without using lots of memory. It is based on the fact that many sounds start off with a complex attack transient, then settle down to a comparatively steady sound. Listen carefully to a plucked guitar string. The first part of the sound consists of a complex mixture of pick noise and several harmonics; after a while, the string decays down to a pretty steady repetitive waveform.

Since the latter part of the waveform is repetitive, there is no need to waste memory sampling several seconds of it. Instead, you can mark off a loop of the repetitive section, and play that looped section for as long as the key is held down. After playing to the end of the loop, the sound jumps back to the beginning of the loop and play through the loop again. This process repeats until you release the key playing back the sample.

Auto Correlation

First of all, just what does auto correlation mean? Auto correlation simply means automatic correlation or comparison. The computer analyzes the signal around the loop points you have specified and then moves the start or end point of the loop until it finds a section of the wave that closely matches the section around the start point. If the Fix Size parameter is On, the Start point of the loop is adjusted. If Fix Size is Off, the End point in the loop is adjusted. Auto correlation may be used again and again with the computer moving the analysis window slightly each time to try to zero in on the optimum loop.

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6 - Sample Edit

Background: About Looping

Creating Attack & Decay Characteristics for the Looped Portion

One potential problem is that the loop repeats at the same level. This is usually acceptable for sustaining instruments (flute, organ, brass, etc.), but is unacceptable for plucked or struck sounds, which decay over time. Fortunately, the Dynamic Processing module provides a means to shape the attack, sustain, and decay characteristics of a sample. You can create a decay during the looped portion, and simulate pluck or struck sounds.

Artificial Decay can be applied to a looped sound.

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6 - Sample Edit

Background: About Looping

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6 - Sample Edit

Cut Section

Utilities

The Sample Utilities menu contains several important sample editing functions.

• Cut Section

• Copy Section

• Paste Section

• Truncation

• Taper

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6 - Sample Edit

Cut Section

If the sample is stereo, a 4. Press the Cut function key (F1). The following screen appears. (If the

5.Specify the Start and End points for the portion of the sample to be cut.

6.The left and right cursor keys will change the start and end points so that they automatically fall on positive zero-crossing points in the waveform.

7.Press OK to cut the section or Cancel to return to the main Sample Edit screen.

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6 - Sample Edit

Copy Section

8.If you are not happy with the resulting cut or want to compare before and after, press the Undo function key (F6).

Copy Section

Portions of a sample can be cut, copied, and pasted to other samples, or the samples from which they came. The Copy function allows you to duplicate a section of a sample, and store that duplicate in a special part of memory called the clipboard.

v To Copy a Section:

1.Press the Sample Edit key. The LED illuminates and the main sample edit screen appears.

2.Select the sample to be copied using the Data Entry Control, INC/DEC keys, or the numeric keypad.

If the sample is stereo, a 3. Press the Utils function key (F1). A second row of function keys

•The Copy Section display is identical to the display in Cut Section. See Cut Section for a full description of the controls.

6.Press OK to cut the section or Cancel to return to the main Sample Edit screen.

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