Jconv amp/cab sample

[funkmuscle]

will test later today for sure..


tried it, can't here the loaded IR files. You can see the wav files but no sound from the IR files...

[brummer]

It is'nt a realtime controll, when you see the file, there is nothing to hear. You need to run jconv after you have make your settup.

Same as befor, jconv settings create a *.conf file for jconv witch your selections, when you are fine, press "OK", the settings widget close, and then press "run jconv" to start jconv.

brummer

[funkmuscle]

ok...I get the length now.. sound better than before.. Actually I really like it..
The offset of all the IR files say 0, is that how they should read?

and the volume settings are not saved, I have the edit the .conf file...

[brummer]

Please provide a little more info, here is a *.conf file saved by guitarix, all is in like suggested:

Code: Select all

/cd /home/hermann/Projekte/freeverb/freeverb3-2.2.1/samples/IR
/convolver/new    2    2   128     8000  
/impulse/read    1  1   0.5     0       1210       4372       1  JCM9003-rm.wav
/impulse/copy    2  2   1  1
# /home/hermann/Projekte/freeverb/freeverb3-2.2.1/samples/IR/JCM9003-rm.wav
# /impulse/copy

gain = 0.5
delay = 0
offset = 1210
length = 4372

I get the same results when I use /impulse/read instead of /impulse/copy

Witch offset is shown in the tooltips when you have make a selection ? all way's 0 ?
Is the selected part persistent ?
Also, when you move a selection over the range, the values are clipped to the max/min range (the length of the file)
Please past in a *.config produced by guitarix to give me a chance to understand what go's up on your box.

[funkmuscle]

Code: Select all

/cd /home/harv/audio/Impulses/Verbs/rooms
/convolver/new    2    2   128     200000  
/impulse/read    1  1   0.20     0       167       35772       1  l960large_wood_room.wav
/impulse/read    2  2   0.20     0       167       35772       2  l960large_wood_room.wav
# /home/harv/audio/Impulses/Verbs/rooms/l960large_wood_room.wav
# /impulse/read

I set the volume for 2 but I get 0.20

[brummer]

I set the volume for 2 but I get 0.20

AHH, my fool,
But, I see offset and length is set correct, if you say me that when you set the volume to 5 you get 0.50 the fix will be fast.

[funkmuscle]

what about delay, I read that when is set to 500, that 5ms and that cuts off the noise at the start.

Which part of the IR file is the actual IR? Is it from the very far left to where it thins out or in between?

[brummer]

the gain setting is fixed in svn now, thanks for reporting.


the (green) marked part is the part witch will used. offset is the left site, length is the right side.
offset 0 and length 0 meens, use the complet file, offset cut the samples at the begin (left side), lenght cut the samples at the end of file (right side).
When there is no selection (right click with the mouse), the hole file will used.
offset and length will display as tooltip, when you move the mouse over the wave view widget.

So you select the part you wont to use : move the mousepointer to were you wont to have the offset point, press the mouse and move it to the point were you will set the length. The aktuell sample point in the file will display as tooltip (offset length).
When you have select a part and you not happy with it, you can move ti with the middle (weel) mouse button pressed, you can delet it with the right mousebutton pressed, and you can change the length when you press and move the right button.


The hole file is display in the wave view widget, depends on the length from the file (how many samples) the view is compressed in the vertical. Every file is displayd in 300 pix.
The horizontal view is never compressed.

You can see often some small hight impulses at the file begin, I experience that the offset after this Impulses make the sound more round. Often you seen like nothing to the end off the file, set the length befor that, remove mostly the reverb.

From what I understand the delay, is simply a delay, it cut's nothing, it just insert leeding sero's.
But yea, I will include it also.

[funkmuscle]

loving it dude... It works great on reverb IRs and guitar IRs...

[brummer]

Nice to hear that.

Now, when you have found your perfect settings for a IR file you can save it as "guitarix preset".
This way you can reload it any time you wont.

[funkmuscle]

yep... been doing that... thanx dude... been waiting for this.

[thorgal]

Hello,
I unfortunately did not try out guitarix yesterday evening but probably tonight.

I asked Fons Adriaensen about the convolver, whether one can tune it at runtime, etc. Here is his reply, very instructive (don't be too overwhelmed by the technical stuff )

> As far as I know, you're the author of jconv. Is there
> any chance you could make the jconv parameters realtime-settable,
> i.e. while the jconv engine is running ? Maybe a change of the IR
> file on the fly is not possible, but a realtime change of gain,
> offset, length and delay might be ?

> Another thing: while changing the IR file (jconv engine off),
> can the jack port connection be restored when the engine is turned on again ?

To start with the latter, the latest release of jconv
allows to define port names and connections in the config
file.

Jconv is just a command line shell around the zita-convolver
library, all the real work is done by an instance of the
zita-convolver class.

There is no simple yes/no answer to your first question.
What you describe as the parameters (gain, delay, offset,
length, etc) are in fact not run-time parameters at all.

They are used to create (during setup, not in real time)
the data structures inside the zita-convolver object, and
once this work is done, and processing starts, these
parameters have no function any more and are not even
preserved.

Now these data structures are rather complex - technically
they are 'an array of an array of 2-D sparse matrices',
the latter being implemented as trees. Imagine a 3-D block
sliced up in all three dimensions, but only some of the
smaller blocks it consists of exist, the remaining space
is empty.

Once the convolver is running this data is being used
by up to five real-time threads at different priorities.
There is no way to modify it in real time as this would
require memory allocation and modifying linked lists
while they are being used by other (real-time) threads.

What can be done (and the zita-convolver API already
allows this) is to overwrite those parts of the '3-D
block' that do already exists. So for simple applications,
such as reverb, you could overwrite the IR by a different
one as long it is not longer than the original one.
If the new one is shorter, then jconv would wast some
CPU cycles on the empty part at the end, since this
would still exist but be filled with zeros.

Jconv does not allow this, and never will. A new and
simpler version of it (to be used for reverb only)
will allow to do this, and a lot more. But don't
expect this any time soon - I do have other priorities
ATM. Also the API of zita-convolver is currently not
documented, as I want to keep the freedom to modify
it in incompatible ways. Doing this would force me
to rewrite all apps using it - there are many more
unpublished ones besided jconv. That's a price I'm
prepared to pay, but most other users probably not.

What you can do ATM is to start a new instance of
jconv and either crossfade between the two and stop
the old one or just swithc and accept the glitch.
Or make a config that contains multiple reverbs,
to different outputs or from different inputs, and
select the one you need in your app - this would of
course increase the CPU load.

--
FA

Laboratorio di Acustica ed Elettroacustica
Parma, Italia

[funkmuscle]

Wow!! That guy knows his stuff.
Freeverb3 which was made for all 3 platforms I think, can be changed in realtime.
I tried the vst and it can be adjusted.
There is not ladspa or interface for the linux version. Has anyone tried making an interface for that one? Maybe that one will work in realtime on linux.....

Still love what brummer did with jconv but realtime would be nice.

[thorgal]

funkmuscle,

have you checked memory usage and CPU usage changes as you tune your convolution parameters on the fly with the VSTs of yours ?

[funkmuscle]

@thorgal
yeah, it's way out of control... That's why I don't like using vsts... I just tried out freeverb3 to see what it was like. But that's vst running on wine so wouldn't that create the headache?
All the vsts I've tried take up too much memory and cpu....
I read at KVR that the guys use Freeverb3 or sIR on Windows with no issues because it's native. So my question is how would the Linux Freeverb3 run with an interface since that one is native to linux?
That's why I like jconv. Way less taxing on memory and cpu and latency performance is great too.

I'm happy to use guitarix and mess around till I fine what I need. Still saves me time compare to before.