Re: [Polluriel détecté] Re: [sdiy] MIDI live interface project... suggestion

[Jean-Pierre Desrochers]

In fact that's what the MIDI interface is for.
NTSC video lines have around 60usec each to store anything
and the MIDI bits are 1/31250hz = 32usec wide each.
So the idea is to grab all the incoming MIDI bits, store them
in a large buffer and read them back to write them as 1's (100% peak white level)
and 0's (0% black level).
One MIDI byte is 32usec X 10bits= 320usec wide.
That represents around 320usec/63.5usec (one horiz. line width) = 5 horizontal lines time spent
to receive one MIDI byte. 
So we could write each received MIDI byte in let's say every 6th horiz. line
by putting 8 pulses on that line that represent the actual byte's 0's and 1's.
Almost no delay involved between the MIDI in and video out.
Any scenario possible here.
JP



 On Wed 16/12/09 20:23 , Blake Griffith blake.benjamin.griffith at gmail.com sent:
> Very Interesting but I am confused as to how the midi data is stored on a
> video file.. ???
> 
> On Wed, Dec 16, 2009 at 10:55 AM, Jean-Pierre Desrochers  wrote:
> 
> Hi list,
> This is a 'funky' project suggestion for anybody..
> 
> Some musicians use live MIDI controled devices
> (projectors, motors, visual effects, etc..)
> while playing some stuff at the same time
> on stage. These devices need some MIDI stream
> coming "normally" from a sequencer or a PC
> based MIDI software and a way to sync this all
> with the music on stage.. So we are talking
> about many instruments, sequencers, PC, etc..
> So what about a way to get rid of some stuff
> here and have a minimum of circuitry installed
> for live MIDI/music perfomance?
> 
> Here is the idea:
> 
> The project I think of is an interface
> that 'reads' an external MIDI stream (in studio)
> and... converts it to a NTSC video output
> that can be recorded using a video capture card.
> Obviously that capture card will at the same time
> record the music that needs to be in sync
> with the MIDI info..
> Now you have a 'video' that contains the MIDI information
> (I try to imagine the screen video that this would produce... !!)
> and the audio in a video file format, on a PC.
> You then burn a DVD with the saved video file.
> Finaly in a live performance,
> you play the DVD with a standard DVD player,
> connect the video out to the project interface to read back the
> MIDI stream out and at the same time play
> the musical audio tracks all sync together.. allways!
> 
> So on stage you only have this:
> 
> - DVD player
> - MIDI interface plugged to DVD player video out
> - Your normal audio mixing/amplifying stuff
> - All the normally used MIDI devices (projectors, etc..)
> 
> No more PC or sequencer stuff..
> 
> I'm sure I can forget something here
> but hey, this is just a suggestion on DIY list !
> 
> JP
> 
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