[OSC_dev] OSC / MIDI comparison papers

[Angelo Fraietta]

Andy W. Schmeder wrote:

> On Jan 15, 2008, at 3:26 PM, cyrille henry wrote:
> 


> 
>> -The "Hardware Transport Independent" is in direct conflict with "Data 
>> rate":
>> osc is hardware transport independant, so we can use osc with a 
>> 9,6Kb/s serial line.
OSC is not hardware transport independent - rather, it does not define a 
transport layer

According the the OSC paper I read (Wright, Matthew, and Adrian Freed. 
"Open Sound Control: State of the Art 2003), there was an assumption of 
+10 MBS for the transmission medium

I think you would also need to take into account the processing power of 
the device that is supposed to respond to the OSC message. How many 
instruction cycles are required to parse the inbound OSC message.

> 
> 
> MIDI has a defined hardware transport, OSC does not, so a direct 
> comparison isn't really possible.  

A comparison is possible on the equivalent ISO layer. For example, if my 
computer was sending a MIDI message to the synthesis engine on the sound 
card, the data is never transmitted at lower ISO layers - the data never 
runs at 32KB on the computer - but nobody says that it is not MIDI 
because it it did not go through a MIDI cable

The limits are therefore given for
> the typical case which is MIDI cable vs ethernet.

This is like comparing the weight of a ball on earth with a truck in 
outer space. Even through the mass of the truck is significantly 
greater, the gravity on earth makes the ball heavier.

> 
> The limits may not apply to MIDI when it is used in a pure software 
> context or over alternative transports (e.g. RTP-MIDI and possibly some 
> USB MIDI devices).

Shouldn't a comparison be made over

> 
> 
>> -Curent OSC transport layer is not really microcontroller friendly. 

There is no transport layer for OSC - only layers 6 and 7  (and possibly 
4 if include the size of the packet as a function of this layer)


>> few dollars microcontroller can easilly deal with midi, but not with 
>> curent osc implementation.
>> a osc implementation on a microcontroler is lots more difficul than midi.
> 
> 
> More difficult perhaps, but in actuality, not by much.  There are 
> several implementations of OSC on microcontrollers.

I know, I have developed three of them. Also, my Smart Controller was 
the first OSC to Control voltage converter.

> 
> I would argue that such implementations are in fact easier to work with. 

At the higher level, there is no real difference one the patch has been 
defined.


Are there any papers that are critical of OSC? - I have only seen papers 
that say how good it is.

If you know of any, please let me know.


-- 
Dr Angelo Fraietta
A.Eng, A.Mus.A, BA(Hons), Ph.D.

PO Box 859
Hamilton NSW 2303

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