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Time-stretching allows you to preprocess samples on the fly to adjust them to your project's tempo.
FL Studio's time stretching algorithms preserve pitch & aren't applied at runtime, but as a high-quality sample preprocessor which is run on the fly as needed. This allows higher quality output and no CPU is spent for constantly processing the samples during playback. The only exception is "resample" stretching which won't preserve pitch and is very light on processor resources.
The non-realtime time stretching algorithms adjust the samples to match project's base tempo. This means that if you adjust your base tempo and there are samples which use time stretching, you will be prompted to process all samples for the new setting. Dynamic tempo changes during the song (tempo automation) can't be compensated for, so resampling is used to keep the time stretched samples in sync.
To disable time stretching for the sample, turn the Time knob maximum to left (set to 0). This is the default mode which won't use resampling during dynamic tempo changes to preserve sync.
Pitch Shift (PITCH) - Allows you to shift the sample pitch while preserving its length. Since this kind of processing is not possible if the stretching method selected is "resample", the method is automatically changed to "auto" after tweaking this knob.
Time Multiplicator (MUL) - Use this knob as a modificator to the sample length. Using the multiplicator you can quickly, for example, stretch the sample to twice its length without the need to modify the Time setting.
Time Stretch (TIME) - This parameter sets the sample length (sample "time") using tempo-based measures (bars, steps etc.), so that you can link the sample with the base project tempo. While adjusting the knob you can see the assigned time value in the hint bar, as well as the computed "actual" tempo FL Studio gets for the sample tempo according to the set length. If the tempo is too high or too low, you'll see a note "unrealistic tempo" shown instead. Right-click menu: the right click menu for this parameter shows some handy presets & the autodetect command which makes an attempt to autodetect the tempo of the sample (the results may vary depending on the source material). NOTE: Audio clips will adjust the Time property accordingly when stretched;
Stretch Method (combo box) - Selects the time stretch method. Several of the methods feature the high-quality ZPlane Elastique engine which performs the processing as a precalculated effect as needed. Resample is the most basic stretching method and it doesn't preserve pitch (note that some Sampler Plugins change that, for ex. Granulizer). This is the only method which is applied at runtime during playback, so it responds to dynamic tempo changes.
- Elastique (drums) is a transients aware algorithm which is best suited for time-stretching drum loops.
- Elastique (tonal) is best used with vocals and complex audio material (such as full songs).
- Elastique (slices) auto-slices the source sample (if it has no loaded slices) and stretches it using the same algorithm found in the Fruity Slicer plugin. Slice map also performs the auto-slice step (if no slices are loaded from the sample) but it plays the sample without creating transitions to "stitch" the individual slices. This method is best used on some drum loops.
Auto performs an automatic selection of one of the methods covered here as follows:
- if the sample has no loaded slices/regions: elastique (drums) is used;
- if there are regions, and the stretch is moderate or extreme: elastique (slices) is used;
- if there are regions loaded, and the stretch is minor: slice map is used.
