I see now I was just doing something silly thinking I was trying to copy some sophisticated trick that would sove things.

I can't remember now which object I had to deal with something like this.

anyway, in this last version, I have my own "perform" method that fails equally as before in some cases, but it is not as weird as before...

let me just copy it instead of linking to a github code that might change, here's the code section

static t_int *remap_perform(t_int *w){

    t_remap *x = (t_remap *)(w[1]);

    t_int n = (t_int)(w[2]);

    t_int nchans = (t_int)(w[3]);

    t_sample *in = (t_sample *)(w[4]);

    t_sample *out = (t_sample *)(w[5]);

    for(int i = 0; i < x->x_n; i++){ // channels to copy

        int ch = x->x_vec[i].a_w.w_float - 1; // get channel number

        if(ch >= nchans)

            ch = nchans - 1;

        for(int j = 0; j < n; j++){ // j is sample number of each channel

            if(ch >= 0)

                *out++ = in[ch*n + j];

            else

                *out++ = 0;

        }

    }

    return(w+6);

}

Em sáb., 22 de jul. de 2023 às 21:22, Alexandre Torres Porres <porres@gmail.com> escreveu:

ok, I was able to compile a version that does not blow pd up

obviously I have no idea of what I am doing and I did some things based on warnings I was getting, but then, I do copy the input first and then reorder the channels but I do get the exact same result as before, so it was all for nothing.

here's my new attempt, hopefully not too far from getting things right https://github.com/porres/pd-else/blob/master/Code_source/Compiled/signal/remap~.c#L34

cheers

Em sáb., 22 de jul. de 2023 às 21:02, Alexandre Torres Porres <porres@gmail.com> escreveu:

Em sáb., 22 de jul. de 2023 às 18:39, Christof Ressi <info@christofressi.com> escreveu:

if the input and output signals have the same channel count, they will alias each other, just like in regular single-channel objects.

actually, funny stuff happens for 4 multichannel input and 3 multichannel output, but I've seen that issue with single channel objects and I tried copying stuff from other objects in ELSE into this multichannel idea and failed.

You first need to copy the whole input signal to a temporary buffer (probably allocated in your object) and then copy the corresponding channels to the output signal.

I wonder if you can give me a better detailed strategy/steps. 

 

thanks