[PD-dev] tilde object rework ideas

[Antoine Rousseau]

> probably "s_length" might be called "s_frames"

I'm not sure about that: in many APIs the word "frame" means one
"multi-channel sample", e.g 2 samples for a stereo stream.



Le ven. 2 sept. 2022 à 09:36, IOhannes m zmoelnig <zmoelnig at iem.at> a
écrit :

> On 9/2/22 01:00, Christof Ressi wrote:
> > Hi Miller,
> >
> > this sounds great! First-class multi-channel support would be a real
> > game changer.
>
>
> yes. that would be so cool!
>
>
> >> typedef struct _signal
> >> {
> >>      int s_n;            /* *TOTAL* number of points in the array */
> >>      t_sample *s_vec;    /* the array */
> >>      t_float s_sr;       /* *TOTAL* samples per second */
> [...]
> >>      t_float s_rate;     /* sample rate */
> >>      int s_length;       /* number of points in each channel */
> >>      int s_nchans;       /* number of channels */
> >>      int s_overlap;      /* number of times each sample will appear */
> >> }
> > Personally, I would keep s_n as the number of samples /per channel/. The
> > total number of samples is simply s_n * s_nchans. Existing externals -
> > that do not know about s_nchans - would effectively operate on the first
>
> i think the idea is that with "s_n = s_nchans * s_length" existing
> externals would automatically process *all* channels.
>
> that's nice if the external does not do any delays or so (as they would
> automatically become multi-channel aware), but not so nice if they *do*
> things in the time domain (as there would be weird cross-talk between
> the channels).
>
> i'm not favouring any of the two approaches, just wanted to point their
> differences.
>
> i somewhat agree with christof's implication, that it's probably best to
> not have redundant data in the struct.
> - 's_n = s_nchans * s_length' (or 's_totalsamples = s_nchans * s_n')
> - 's_sr = s_rate * s_overlap * s_nchans'
>
> (my issue being, that with redundancy it's more likely to have
> inconsistent data; what if the struct says 's_n = 128; s_nchans = 3;
> s_length = 1024'?)
>
> apart from that:
> probably "s_length" might be called "s_frames" as this seems to be the
> less ambiguous term.
>
> and i would personally prefer "s_samplerate" and "s_channels".
> that would make for an easy distinction: the abbreviated names "s_n" and
> "s_sr" are the convoluted ones, whereas the long names have the data
> you'd expect.
>
>
>
> > channel and ignore the rest. Newer multi-channel-aware externals, on the
> > other hand, may use all the channels.
> >
> > I also think that DSP objects would need a new API method to create
> > multi-channel /outputs/. The general idea is that the /input /channel
> > counts are taken from upstream, but the /output /channel counts are
> > specified by the object and passed downstream. (There might be objects
> > where input and output channel count differs; any kind of
> > merger/splitter/mixer objects comes to my mind.)
>
> +1
>
> vgmasdrf
> IOhannes
> _______________________________________________
> Pd-dev mailing list
> Pd-dev at lists.iem.at
> https://lists.puredata.info/listinfo/pd-dev
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.puredata.info/pipermail/pd-dev/attachments/20220902/39670923/attachment.htm>