Audio midi file matching

[kenrob2037]

Hi All,

I'm running the latest Logic, and when I import an audio and midi file from the same song created in Sibelius, the midi file is always shorter than the audio file. It may have something to do with the reverb tail, but even when all reverb is off, I get the same result.

I've tried stretching the midi track but that just makes it weird. 

Is there any way to make the the length of the audio and midi tracks match each other exactly?

Rob

Edited January 12, 2023 by kenrob2037

[fuzzfilth]

1. How much difference is there ? A Bar ? A minute ? 12 milliseconds ?

2. Why is this a problem ?

[kenrob2037]

There's about a bar, maybe two bars difference. It's a problem because the timing is out. Being shorter, the midi track always finishes before the audio track.

[David Nahmani]

8 minutes ago, kenrob2037 said:

the midi track always finishes before the audio track.

Before the end, is the timing already off? 

Is the sample rate of the audio file (listed in the Project Audio browser) the same as the project file sample rate (File > Project Settings > Audio)? 

[kenrob2037]

Yes, the timing is off at the beginning and all way through. From memory, my audio file is a WAV, 16 bit, 44hrz. I'll check if it's the same in the Logic setting. Will that affect it if it's not?

Edited January 12, 2023 by kenrob2037

[wonshu]

Is the timing off consistently or does it drift apart more and more?

RE: Sample Rate: yes, if the sample rate of the audio file is 44.1 and the sample rate of the project is 48k the file will be played back slower (IIRC) or the other way around. But it will be wrong.

Edited January 12, 2023 by wonshu

[David Nahmani]

7 minutes ago, wonshu said:

if the sample rate of the audio file is 44.1 and the sample rate of the project is 48k the file will be played back slower (IIRC) or the other way around.

It's the other way around: a 44.1kHz file played back at 48kHz will be played back faster, at a slightly higher pitch, much like an analog tape played too fast, or a 33rpm record played back at 45rpm (for those of us old enough to remember that).

[kenrob2037]

I checked my sample rates, both the Logic project and the audio files coming out of Sibelius are at 44.1 khz.

As mentioned, I have two tracks, one piano and the other oboe. The piano sound quality is great, but the oboe is poor. So I export the piano as audio and the oboe as midi, so I can use a much better oboe in Logic, but the two files are quite different in their timing and the oboe midi is shorter.

You can see the difference in tack length in the attached screenshot. In Sibelius both are the same length.

Any thoughts?

Rob

 

[fuzzfilth]

Do the Tempos of Sibelius and Logic Match ?

[kenrob2037]

1 hour ago, fuzzfilth said:

Do the Tempos of Sibelius and Logic Match ?

Yes.

[kenrob2037]

The plot thickens.

I decided to create a new song in Sibelius, for piano and violin. The total length was 1:38

I exported the file as audio at 44.1 khz. Then I exported the midi and checked both in the Mac music player, they both said they were 1:38 in length.

But then, I dragged the audio and midi files into Logic, and you can see the results of what logic did in the attached screenshot. 

The longer audio file maybe due to the reverb tail. The audio file has reverb, the midi does not, but I also had the sustain pedal on the piano.

So I got rid of the sustain pedal notation, and turned off all reverb in Sibelius, and re-exported the audio and midi files like before. It made no difference. See screenshot 2.

So for some reason, Logic is adjusting the length of the midi file. In logic, the midi runs for 1:33 and the audio, 1:38.

Got be baffled.

Any thoughts?

Rob

[fuzzfilth]

Here's what I would do to troubleshoot this:

First, make the waveform display something meaningful either by vertically zooming it or with Region Gain in the Inspector. Do the starts of the first and last notes line up visually between audio and MIDI Regions ?

• If yes, move on, nothing to see here, note sustain, decay and/or reverb make the tail of the audio Region longer, which is normal
• If no, does the start of the first note line up ?
  • If no, make sure Sibelius' and Logic's tempo and sample rate are the same and that Sibelius does not add a measure of count-in or similar differently between MIDI and audio.
  • If yes, but both takes drift apart, do the MIDI Region's notes actually fall on Logic's grid ?
    • If no, ask on LPH for a free MIDI File Reader where you can verify this very odd error.
    • If yes, do L and S really run at the same tempo, even if you let them run in parallel ?
      • If no, try to find some other evidence of this massive flaw on the interweb to determine who's to blame, then file a bug report to either Apple or whoever owns S.
      • If yes, the MIDI is fine and the audio is the problem. Are both sample rates really the same, even when checking the file's sample rate in, say, Quicktime player ?
        • If no, make sure S exports at what it says it does.
        • If yes, complain to fuzzfilth who let you jump through hoops for nothing.

Edited January 13, 2023 by fuzzfilth

[David Nahmani]

I would also suggest running some tests with a simple performance of four quarter notes of piano in two or three 4/4 bars, exported the same piano both as audio and MIDI, and import that into Logic, see if that lines up.