Is it possible to find sane loop points from samples automatically?

Link to good samples/soundfonts at http://wiki.linuxaudio.org/wiki/free_audio_data

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tavasti
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Is it possible to find sane loop points from samples automatically?

Post by tavasti »

I have HUGE amount of quality orchestral samples, properly categorized, having information about type and note. Getting Sonivox Orchestral plugins from discount, and decrypting samples, and there you go.

But to make great sfz from them, I would need to find loop points. Is there any even semi-proper tool for this?
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d.healey
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Re: Is it possible to find sane loop points from samples automatically?

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David Healey
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j_e_f_f_g
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Post by j_e_f_f_g »

First, you want to "even out" the sound of the waveform. A waveform with no pitch or volume fluctuations is easiest to loop. I use Adobe Audition's volume shaping tools and compressor (including multiband if needed) to smooth volume. I also use Adobe Audition's noise reduction to remove extraneous noise. I love it. Don't use Audacity's noise reduction. It introduces horrible artifacts. Then I use Antares autotune to remove pitch fluctuations. Don't use that zita thing. It's bad.

Next, you want to set your loop points on two samples close to 0 amplitude. And it's very important that the waveform shape around the start point resembles the shape around the end point as much as possible. (Use an FFT display to help deduce where the best match is). Finally, you need a wave editor with a good crossfade algorithm. Preferably a 50 percent crossfade -- not just 100 percent. I always try 50% first as it tends to be more subtle.

Waveosaur is my #1 choice for looping. It excels for that.

tavasti
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Re: Is it possible to find sane loop points from samples automatically?

Post by tavasti »

In fact those samples have loop information, just need to write sample decrypter in such way that also that is written to new sample file.

Used used Wavosaur to check loop points in few files, sound to be ok.
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d.healey
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Re: Is it possible to find sane loop points from samples automatically?

Post by d.healey »

I must be in the wrong place, I thought this was the LinuxMusicians forum :P
David Healey
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Loki Harfagr
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Re: Is it possible to find sane loop points from samples automatically?

Post by Loki Harfagr »

d.healey wrote:I must be in the wrong place, I thought this was the LinuxMusicians forum :P
Thought so as well :D

And in case of emergency CLI, which could be the case here since the script integration (or might be I read it perpendicularilly ;)
there's good old SoX, Q&D PoC examples:

Code: Select all

 sox in.wav output.wav silence 1 0.04 0.01% 1 0.04 0.01% : newfile : restart

Code: Select all

 sox in.wav output.wav silence 0 1 0.1 0.02% : newfile : restart

Code: Select all

  sox in.wav output.wav silence 0 1 0.3 1.1% : newfile : restart
Of course the thresholds and timings limits may have to be tuned according to the type of samples it would massage, to illustrate that I pasted 3 different settings/methods using the same input file and these examples works fine for separating the (most ever difficult testfile for slicers) recording of 60 ticks from a metronome played at various tempi and varying volume in 44 slices.
(note that the second version leaves ten times more slags than the fore while the third version leaves only six void files)

(Hope it helps, I reckon that's not clystar klaar ;)

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Babarosa
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Re: Is it possible to find sane loop points from samples automatically?

Post by Babarosa »

Polyphone sfz/sf2-editor includes a powerful loop editor function:
https://www.polyphone-soundfonts.com/en/

rghvdberg
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Re: Is it possible to find sane loop points from samples automatically?

Post by rghvdberg »

d.healey wrote:I must be in the wrong place, I thought this was the LinuxMusicians forum :P
the songs made with proprietary software will be played on Android devices, which have a linux kernel :wink:

tavasti
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Re: Is it possible to find sane loop points from samples automatically?

Post by tavasti »

Babarosa wrote:Polyphone sfz/sf2-editor includes a powerful loop editor function:
https://www.polyphone-soundfonts.com/en/
Yeah, have to now make example sfz, and then write script for creating full blown sfz. SFZ is great format, because it is text, so it is easy to make with script!
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tavasti
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Re: Is it possible to find sane loop points from samples automatically?

Post by tavasti »

rghvdberg wrote:
d.healey wrote:I must be in the wrong place, I thought this was the LinuxMusicians forum :P
the songs made with proprietary software will be played on Android devices, which have a linux kernel :wink:
Yeah, sorry for using windows software this time. I promise, won't happen again.

And for use in android, I am pretty sure I won't be copying 35G of samples to any Android device. Compositions might be started in mobile with sonatina & co, but finalize in Mixbus using bigger library.
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Latest track: https://www.youtube.com/watch?v=ycVrgGtrBmM
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