[PD-dev] tilde object rework ideas

[Antoine Rousseau]

Sorry forget it, "frames" actually corresponds with the comment
 /* number of points in each channel */".

Le ven. 2 sept. 2022 à 10:55, Antoine Rousseau <antoine at metalu.net> a
écrit :

> > 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
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>> Pd-dev at lists.iem.at
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>>
>
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