[PD] Loop point : a way to make it smooth?

[Lorenzo]

-------- Original Message --------
Subject: Re: [PD] Loop point : a way to make it smooth?
From: Andy Farnell <padawan12 at obiwannabe.co.uk>
To: Pierre Massat <pimassat at gmail.com>
CC: pd-list at iem.at
Date: 10/10/2010 09:48 PM
> Ah yes, I see the constraint,
> well, what kind of source material is it?
>
> There's the zigzag (forward and back) method that
> always seems to work well with textures and pad
> like sounds. Have you tried that?
>
> Andy
>
> On Sun, 10 Oct 2010 21:32:21 +0200
> Pierre Massat<pimassat at gmail.com>  wrote:
>
>    
>> I think i know what you mean. The problem here is that it has to be live
>> somehow. I don't how they do it in live loopers like the ones some singers
>> use on stage.
>> Thanks for your reply anway!
>>
>> 2010/10/10 Andy Farnell<padawan12 at obiwannabe.co.uk>
>>
>>      
>>>
>>> There's a simple way to put this.
>>>
>>> There is an art to looping.
>>>        
Some hints which can be useful both with the source material and the 
looping algorithm (but as Andy says much depends on the source):
- zeros: the start and end of the loop should ideally be a zero (or be 
exactly the same number). Some sound editors (like mhwaveedit on linux) 
will find zero-crossings for you. Another way to go might be 
"cross-fade" at the start and end of the loop: that is have a small 
fade-in at the beginning and a short fade out at the end, but results 
vary a lot.
- Finding the right "period" for the loop, on some sounds you'll want 
something very short on some pretty long
- Avoid looping "attacks" part, for example of a piano sample avoid all 
the part at the beginning and loop only when the sound "stabilises"


Lorenzo
>>> It should be possible in a simple sound editor.
>>>
>>> You might find the best way (to save time)
>>> rather than spending dozens of hours to
>>> improve the technicalities of your looping code,
>>> is to give it to someone who is great
>>> at making loops who will do it in 20 seconds.
>>>
>>> It's also worth saying that it's very much about
>>> the source material. Some things are just not
>>> loopable in the way you think they might/should
>>> be. It takes a lot of practice to find out
>>> and hear immediately what needs doing.
>>>
>>> Andy
>>>
>>>
>>>
>>> On Sun, 10 Oct 2010 20:55:00 +0200
>>> Pierre Massat<pimassat at gmail.com>  wrote:
>>>
>>>        
>>>> Hi all!
>>>>
>>>> I've made a looping patch for a friend who needs to create a musical
>>>>          
>>> piece
>>>        
>>>> for her school. She's complaining about the fact that she hears when the
>>>> sample loops back to it's beginning. I tried to envelop it using a table
>>>>          
>>> to
>>>        
>>>> control the volume which just ramps up from 0 to 1 during X ms (X being
>>>> adjustable), outputs 1 during most of the sample except for the last X ms
>>>> where it ramps back down. The ramps are not linear, they have sort of an
>>>> inverse square shape. This doesn't really do the trick.
>>>> I've been thinking of writing the sample to 2 tables, one delayed by the
>>>> length of the sample minus X ms, so that i can play both tables and
>>>>          
>>> switch
>>>        
>>>> between the two to avoid having to bring the volume to 0 at one point.
>>>>          
>>> The
>>>        
>>>> sample needs to be X ms longer.
>>>> Is there another way to go? I've been doing some research on the web, but
>>>> i've found no satisfying answer.
>>>> Thanks!
>>>>
>>>> Pierre
>>>>          
>>>
>>> --
>>> Andy Farnell<padawan12 at obiwannabe.co.uk>
>>>
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>>>        
>
>