[PD-dev] call for discussion: native video for Pd

[Christian Klippel]

hello,

Am Samstag, 27. Mai 2006 21:03 schrieb Miller Puckette:
> I used to think the same thing, that floating-point computation would
> never be feasible on video... but Mathieu has demonstrated that, if you
> schedule the computations carefully, you can do blindingly fast video
> crunching in floating-point.  Trouble with it is simply that it takes
> much more storage space, so you end up using a lot of memory bandwidth
> (a read or write to external memory costs the same as tens or hundreds of
> CPU cycles these days).
>

uhm.... blindingly fast? i dont believe that .... unless you use sse/sse2 for 
the floating point ops. and even then you would be slower. the alu for 
integer math is much quicker and has a lower latency as the fpu. also, on a 
p4 for example, you have actually 2 alu's for integer stuff ....

to put it in other words: how comes that demuxing/converting a lot of audio 
channels (for example from a hammerfall) takes a considerable amount of cpu, 
if using floats would be blindingly fast? and even on 16 channels of audio 
you dont have that much data as with a simple full pal-sized video ....

> But anyway, I'll probably make it conditionally compilable in other
> formats so we can just benchmark it and find out for sure.
>

why conditional? why not runtime-selectable, per branch/subpatch?
i mean, there are quite some formats actively in use, like rgb(a), yuv, 
hsb ... 

> cheers
> Miller
>

greets,

chris