Re: MIDI processing question
Re: MIDI processing question
- Subject: Re: MIDI processing question
- From: "Bob Lang" <email@hidden>
- Date: Fri, 2 Apr 2004 09:15:04 +0100
Hi all
I did some testing yesterday and the driver I'm using (Edirol UM-1)
appears to deliver packets in ascending time stamp order.
Actually, this is the first time I've ever bothered looking at the time
stamps, and now I realise I'm confused: What exactly does the time
stamp mean? It's a huge number and I can't find anywhere in the
documentation to explain it (apart from a reference to *absolute*
time and I'm sure Einstein exploded that notion).
It takes around 1mS to send one midi message, so midi time stamps
don't need to be any more accurate than that, yet the number seems
to be ticking at sub micro-second intervals - complete overkill.
Please, what is it and where is it explained in the documentation?
Many thanks
Bob
----- Original Message -----
From: "Herbie Robinson" <email@hidden>
To: <email@hidden>
Sent: Thursday, April 01, 2004 11:12 PM
Subject: Re: MIDI processing question
>
At 1:46 PM +0200 4/1/04, Kent Clelland wrote:
>
>hi doug & bill and everyone else.
>
>I' m experiencing some unexpected behaviour in MIDI processing and
>
>before I go coding myself in circles I want to check and see if my
>
>expectations aren't maybe a little bit too high ; -)
>
>
>
><SNIP>
>
>
>
>1) it is the MIDI driver's responsibility to deliver MIDI packets in
>
>the correct order.
>
>[ OR ]
>
>2) it is the application developer's responsibility to (re)sort all
>
>recieved MIDI packets.
>
>
>
>
>
>Thanks in advance!!!
>
>
>
>
I agree with you. Producers of packet streams should be required to
>
produce them with ordered time stamps (when the time stamps are
>
non-zero). This would include drivers when producing input and
>
applications when producing output. Mergers of MIDI streams should
>
ensure that the output remains sorted and should assume that the
>
inputs have been sorted. This could entail splitting up
>
MIDIPacketLists
>
>
--
>
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>
** http://www.curbside-recording.com/ **
>
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>
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