# Best buf-based slicer for keeping track of onsets \*and\* offsets?

**URL:** https://discourse.flucoma.org/t/best-buf-based-slicer-for-keeping-track-of-onsets-and-offsets/1435
**Category:** Usage Questions
**Created:** [May 2, 2022, 2:54pm UTC](https://discourse.flucoma.org/t/best-buf-based-slicer-for-keeping-track-of-onsets-and-offsets/1435 "2022-05-02T14:54:21Z")
**Posts on this page:** 1
**Showing post:** 5

<div class="post-metadata">

### Author: ![weefuzzy](https://discourse.flucoma.org/user_avatar/discourse.flucoma.org/weefuzzy/32/362_2.png) [@weefuzzy](https://discourse.flucoma.org/u/weefuzzy)
#### Post date: [May 5, 2022, 3:50pm UTC](https://discourse.flucoma.org/t/best-buf-based-slicer-for-keeping-track-of-onsets-and-offsets/1435/5 "2022-05-05T15:50:07Z")

</div>

> [@rodrigo.constanzo](#):
>
> Hmm, I would have thought that “segmentation” took this kind of stuff into account, but I guess the expectation is more to have things be done butt-to-butt.

Audio DSP has solved fewer problems than you might think. But this is also one reason I prefer ‘slicing’ to ‘segmentation’. Basically, the whole notion of detecting the end of a sound is just much trickier. For one thing, it’s not especially clear that there’s an obvious perceptual mechanism to try and mimic: I don’t think we’re often terribly alert to the moment when a sound stops, unless we’re concentrating on that particular thing.

> [@rodrigo.constanzo](#):
>
> I’ve not really played with novelty enough to know what tweaking all the parameters meaningfully does, but is it always so “spike”-y like in the help file?

IIRC the help file uses quite a small kernel size so that the time scales are pretty short, hence spiky. The bigger you make the kernel, the smoother the curve (but greater the latency). Novelty slice uses a pretty simple peak picker, just looking for inflection points where a sample is greater than either of its neighbours, which is basically `[zl stream 3] -> [expr ...`. Offhand I don’t know what a _minima_ in the novelty curve might denote, offset-wise, but it might be useful as a switch type of thing to start then looking for when the signal amplitude goes below some point.

---

_[View the full topic](https://discourse.flucoma.org/t/best-buf-based-slicer-for-keeping-track-of-onsets-and-offsets/1435)._