MIDI Timing

[liveinthemix]

quake2 napisat ću ti ne?to ?to sam pokazao na jednom od svojih predavanja...check this:In the past i've posted a few results of some midi timing tests i'd ran using different sequencers. I came to the conclusion that sequencing on a Mac using a Unitor 8 could be pretty good. However i've recently been further testing, but this time checking how multi midi out ports are addressed.
I had Hinton Instruments make me up a neat little box where i can plug two midi cables in, and then run two audio cables out so as to record midi data as audio pulses. As the unit is just wires working at the speed of light, no conversion time/latency is added. Just the same as making a midi plug to audio jack cable.
I reran my Unitor 8 test, sending from 8 midi tracks of 16ths in Logic 9, to the eight ports on the Unitor 8. I took audio recordings from ports 1 and 8, and then checked the difference between each track in the sample editor. The timing between port 1 and 8, was that port 8 was behind port 1 by around 7ms. If i muted tracks 2 to 7, thus no longer sending to ports 2 to 7 on the Unitor, the delay between ports 1 and 8 dropped to around 1ms. Therefore you could not compensate for the delay with a track parameter.
The Unitor 8 was crap then....
I then ran the same test with a Motu Express 128 USB interface, which I bought brand new on a gamble. I installed the latest Motu drivers, and ran the exact same test again. This time there was NO DELAY between midi ports 1 and 8 on the Motu. The audio recordings start waveform for midi note on data lined up perfectly, as did the second byte for the note off data. The same test was carried out in Live 8, and again the same results. Now i've established that the Motu sends midi note on/off data simultaneously across its midi ports, i'll be checking jitter. But i can say that so far early checks seem to indicate a value of around 1.5ms - 2ms worst case. Most of the time it's actually smaller than this.

To be fair i also ran the same test, checking for parallel transmission across midi ports on my Notator + Atari/ Log3/ Unitor2 setup. There two was delay between ports Atari main out A, and Unitor2 port F of around 2.5ms - 3ms. I checked other ports and found jitter to be around 1ms, while other ports would jitter by worst case 2.5ms.

I believe the result i've so far found for the Motu Express 128 are all down to the MTS drivers (Midi time stamping drivers) OSX core midi is meant to support this at OS level, but unless the Midi interface itself has this capability it'll just act like any other dumb MIDI device, and midi events will be sent out as quickly as they arrive and can be serviced.

[liveinthemix]

The latest versions of most MIDI + Audio sequencers offer extremely high resolution for the timing of both MIDI and audio events. Emagic's Logic Audio is renowned for its tight timing of 960ppqn (pulses per quarter note) and Steinberg's release of Cubase 5.0 raised this resolution even further to 15360 fractions per quarter note. Although this internal resolution is always used, you can choose a lower display resolution such as 7860, 1536, 480, or 384 ticks per quarter note, which makes it quicker and easier to position things on screen.
Some musicians expected all their MIDI timing errors to disappear once such high timing resolution was offered by sequencers, but unfortunately this only deals with part of the problem. While the start times and lengths of both audio and MIDI events are being time-stamped to an accuracy of 1/15360th of a quarter note, they still each have many more hurdles to jump before you hear the end result, such as passing the PCI buss and surviving the interruption of the many background tasks of the Windows operating system.

[DaBear]

mene je MIDI prestao odavno da nervira !
Cim se pojavila opcija - render to audio - ja sam postao happy!

MIDI mi sluzi samo da zabelezim groove / liniju / temu i posle SVE radim u audiju. Mute MIDI track i hide...navucem audio na grid ili ga shift-ujem levo desno (na sitno, vrednosti su u samplovima..sitno!) dok ne dobjem zeljeni efekat.
Delay je uvek tu, cak i kad radis bounce soft sintija..lepo se vidi.
Sad kad mogu da otvorim 10 soft sinteva i samplera u Pro Toolsu..i da ne padaju - nista vise mi ne treba.

Groove se da uraditi "na uvo" !

[liveinthemix]

DaBear moram ti priznati da i ja vrlo vrlo često radim na tom principu...pogotovo u klubskoj produkciji...Svatko si stvara svoj sistem, a uho je i dalje najjači i jedini relevantni parametar...