New Photosounder effect tutorials/knowledge base

[A_SN]

I started writing tutorials that detail as precisely as possible how to reproduce most classical audio processing effects. I started since a couple of days ago with several ways to EQ, envelopes and compression/expansion/limiting/noise gating. I'd like to know what you think of it while I'm still working on it, if that's helpful and how I could make it more helpful, or just if there's any kind of effect not on the list you'd like me to cover.

http://photosounder.com/tutorials.php

I guess I should have started doing that a long time ago (since clearly most people aren't going to guess all those things by themselves, I myself realised we could do many things in Photosounder that I hadn't thought of before while researching/writing these tutorials) but I only had the idea to start doing that systematically like two days ago .

[fhunktion]

Thanks for these they make it easier to get you head around some of the concepts better.

[A_SN]

Thanks for these they make it easier to get you head around some of the concepts better.

Yeah, I eventually realised that the new concepts introduced since v1.8.0 weren't well understood, that the videos don't help much and that no one would guess all those things on their own so I have to explain them detailedly. Glad that helps. Right now I'm pretty busy with coding but I'll try to write some more whenever I can.

[Dunc]

Had a look at the tutorial page. Looks good and I sorta understood it from first time reading (which is good for me )

I noticed you had list of effects at the bottom of the page, which I presume you will get round to do tutorials for when you get a chance.
Anyway, just wondering if you could do a tutorial for Doppler Shift at some point ?
Apart from a old Synthedit program (which doesn't seem to work on my Win 7/Reaper DAW) there isn't another free/cheap VST for doing this. I've tried coupling a couple of VST's together to do pitch shift and amplitude/pan changes, but it doesn't seem to cut it really and something about it doesn't sound right.

Of course, if somebody is reading this and knows of a program that's not from Waves or somebody else expensive that can do Doppler Shift then point me in the right direction...

Anyhow, I'm hoping that Photosounder could do this.

[audio_dude]

Hi,

just a short message to thank you, A_SN, for the tutorials/knowledge base! It's very helpful, so keep the tuts comin'!

Thank you, and keep up the good work!
Photosounder is a very cool piece of software!

[A_SN]

Had a look at the tutorial page. Looks good and I sorta understood it from first time reading (which is good for me )

I noticed you had list of effects at the bottom of the page, which I presume you will get round to do tutorials for when you get a chance.
Anyway, just wondering if you could do a tutorial for Doppler Shift at some point ?
Apart from a old Synthedit program (which doesn't seem to work on my Win 7/Reaper DAW) there isn't another free/cheap VST for doing this. I've tried coupling a couple of VST's together to do pitch shift and amplitude/pan changes, but it doesn't seem to cut it really and something about it doesn't sound right.

Of course, if somebody is reading this and knows of a program that's not from Waves or somebody else expensive that can do Doppler Shift then point me in the right direction...

Anyhow, I'm hoping that Photosounder could do this.

Yeah the list of effects at the bottom is what I plan to do. That's no exhaustive list though, I made it by googling common effects and listed the ones I think can be done with Photosounder (which is almost all of them). Meaning if you can think of some more you should ask me, like you did with the doppler shift one .

You can replicate a doppler shift with Photosounder, but there are a few caveats compared to the real thing. The most important one is that in Photosounder it'll be a pitch shifting kind of thing, whereas the real effect isn't actual pitch shifting (if it was it wouldn't occur naturally) but some resampling kind of thing, whatever it's called, but you can't do that in Photosounder, you can do pitch shifting, but pitch shifting uses the lossy resynthesis mode (well, aren't all pitch shifting algorithms lossy?), so there'll be a quality hit. There's also the fact that unlike a dedicated doppler algorithms that computes every parameter over time, here you'll have to draw your pitch shifting in a free-hand way, and same thing with the volume envelope that you'll apply to it, so that's a bit of a guesswork you have to do, although actually there are simple ways to figure out how it's done (when I write the tutorial I'll make sure to show the formulas and curve shapes).

So it won't be perfect, but basically you can achieve this by drawing, on a new layer, an horizontal line that is shaped like a S and that transitions over a very few semitones. Then set that layer to Vertical Propagation, then a layer on top of it for the volume envelope, something kind of bell shaped. It's pretty simple stuff.

Hi,

just a short message to thank you, A_SN, for the tutorials/knowledge base! It's very helpful, so keep the tuts comin'!

Thank you, and keep up the good work!
Photosounder is a very cool piece of software!

No problem, glad to know that helps, I'll try to write some more whenever I can.

[xx JPRacer xx]

Just had a quick look at it's really nice. It's another way of thinking and that's what I have the most problem now. For me it's much more abstract. By seeing what's possible with your other tutorials this will really help.

It's been a while that I used Photosounder and I'm sure that it was possible to use linear motion on the controls. I hate circular motion. Am I missing something?

[A_SN]

Just had a quick look at it's really nice. It's another way of thinking and that's what I have the most problem now. For me it's much more abstract. By seeing what's possible with your other tutorials this will really help.

It's been a while that I used Photosounder and I'm sure that it was possible to use linear motion on the controls. I hate circular motion. Am I missing something?

It never had linear motion on the knobs, however it's on my todo list as you're not the only one who hates it .

[jonahs]

Thank you.

For future topics. I'd like to know how convolution works in the layer menu, reverse order and I'm also still confused about what propagation actually does. (Am I missing a more in depth manual?) I think I'm familiar with convolution somewhat due to Logic and it's IR utility, but I'm not able to experiment with convolution in photosounder to understand it because photosounder can really take a long time to process and then produce no sound.

[A_SN]

Thank you.

For future topics. I'd like to know how convolution works in the layer menu, reverse order and I'm also still confused about what propagation actually does. (Am I missing a more in depth manual?) I think I'm familiar with convolution somewhat due to Logic and it's IR utility, but I'm not able to experiment with convolution in photosounder to understand it because photosounder can really take a long time to process and then produce no sound.

Convolution is a bit hard to explain without showing an example graphically (so I'll make sure to use some graphics when I do tutorials using that), but basically it replaces every pixel for the sum of the layers below the Convolution layer with the entire layer. So what it means is if your convolution layer is a vertical stacks of tiny dots, then the result of it will be as many vertical copies of the sum of the layers below (what you see before doing the convolution) as there are dots on that layer.

It can get really really slow if there are too many non-black pixels on the Convolution layer, as it needs to make as many copies as there are of those pixels. Vertical and Horizontal Propagations are also forms of convolution (they should be called convolutions instead of propagations but few people really know what a convolution is so I thought propagation makes more sense), except that instead of working in 2D in which each point represents a full copy of the 2D image, these only work on rows or columns. So while Convolution can do things like arpeggiating something or giving a uniform blurring, vertical propagation can do things like creating harmonics from a pure tone (by making copies at harmonic distances) or chords, the important distinction with Convolution is that you can make those vary over time, or even just pitch shift (by doing vertical propagation with a curve that represents your desired change in pitch over time) whereas Horizontal Propagation can be used for time effects, such as reverb, echo, making copies of an instrument, who knows what else it can do a lot of things really. You can see Vertical Propagatin in effect in this video http://www.youtube.com/watch?v=aIjXp2KwW8U at the last part to do the oscillating pitch shifting thing (that I refer to as FM synthesis in the video because that's pretty much what it does in the end) and in this video http://www.youtube.com/watch?v=undU5wWnUdU to flatten the pitch of a melody using the properties of autocorrelation (convolving something with its reversed self, in this case the basic pitch).

Of all of these it's Horizontal Propagation that behaves like classical audio convolution does, so everything that audio convolution does you can reproduce with Horizontal Propagation. All you have to do to is to have layers that look like what would be used in the audio convolution, as in, your sound to apply an effect on and what a convolution kernel for the effect you want looks like when loaded in Photosounder. For example an EQ would look like a straight vertical line which intensity varies vertically (but it's just more elegant to horizontally average this and use Multiply instead as it's not something that has any time effect), an echo would look like a repeating vertical line, etc... The other two don't really behave fully like anything known before, which means a lot of effects done with them are quite novel.

I didn't write about this in the manual because frankly it's quite impossible to explain properly, mostly without supporting media.

For reverse order operations, that for when you want either subtraction or division in the reverse order, it's just an easy way to switch the two terms in each operation, since the order matters for these.

[jonahs]

Thank you! That information is going to make it easier to experiment.