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Imported midi automatically snaps to grid


prencaudio

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I've got midi created in pro tools of a live drum performance. Notes are not on grid. But when importing the midi into logic, it moves all notes to grid. I've tried all import methods and its all the same. Both daws are in max zoom

 

Screenshots show first note off grid in PT, Note on grid in logic

 

image-1.png.514c4d6e57f04116ab7918a34073e4e7.png

 

image-2.png.711d8fb565f9cf01133364cd9d9350b8.png

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MIDI Files have a limited time resolution called PPQ (Parts Per Quarter Note) and measured in "ticks". In Pro Tools there's a clock that measures time in samples, which is a much higher resolution. It's possible that a note that is off by a few samples in Pro Tools snaps to the nearest tick once exported to a MIDI file. To determine if that's what is happening, find out the exact MIDI position of your note in ticks in Pro Tools.
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In logic your note is not snapped to the grid - the period after the last 2 indicates it starts after the first tick but before the 2nd tick - I haven’t downloaded your file yet - but if you zoom all the way in on the start of that note you will see it is the same as protools - you are just zoomed out too far to see it -
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I have analyzed the attached file and it appears it is being imported correctly and the quantization is in the midi file.

When you export from protools there is an option called "write real-time properties" if you have that selected during the export - Protools quantization parameters are applied to the export. Did you have that option checked during the export? - can you try without it and see if that solves your issues.

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You can view the midi file in text format using this online tool

http://www.flashmusicgames.com/midi/mid2txt.php

 

It shows a resolution of 9600 which is 10 times higher than Logic internally.

So strictly speaking, Logic's midi import is not correct.

But I wonder if it really matters in practice.

Great! Thanks for sharing this tool. I have been looking for such a tool for a while and couldn't find one.

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Again, here is an example demonstrating the issue.

 

In the midi file a note of "KICK MIDI" starts at 729601 ticks.

With resolution 9600 we can calculate: 729601 modulo 9600 = 1,

meaning that the note starts 1 tick after the beat.

 

However, in Logic with lower resolution 960 this corresponds to 0.1 ticks,

which must be converted to an integer, i.e. truncated/rounded to 0.

Thus in Logic the note starts exactly on the beat.

 

The time interval of ticks in Logic is about 1 ms at 60 bpm.

So in this example the timing error on import would be 0.1 ms.

Generally the error due to rounding will be in the range +/- 0.5 ms.

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  • 1 month later...
I would believe that Logic compensate the audio delay accordingly.

Perhaps exporting from PT in audio then import that into Logic as audio, and then convert it to MIDI inside Logic, if needed. Since those are percussion, it should be relatively straight forward.

But the converted MIDi will again be "quantized" to the tick resolution 960 in Logic.

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