How to conform track so its bars, beats line up with other track? (And obtain tempo map for later?)

[bhuether]

Hi, this is sort of related to my post here:

Wow, this topic is far more complicated than it would seem!

So here is my scenario:

I recorded a video of me playing guitar. That resulted in Track1.  It is a solo guitar performance, played in 3/4 time, but sometimes I am letting notes be held, tempo is drifting. 

Then I recorded the same guitar part but I recorded at studio quality.  Played same way, but again with tempo drifting.  I want to replace the video audio with this high quality audio and have the audio sync'd to my actual playing.  Yes - this is how I prefer. Most people say do the opposite. But my goal is to have the quality audio in good sync with the video of me playing.  The recordings aren't that far off time wise and so I am not worried about artifacts.

Where I am at:

- I used the video audio file and applied Smart Tempo. I don't need this file to stretch. It is basically the master track for establishing the grid. In Smart Tempo project settings I wasn't sure about choosing "On", "Bars", "Bars and Beats".  Also in resolution I wasn't sure about Smooth versus beats. Very little info about these nuances... In Control bar I chose "Adapt".

- I then set things to 3/4, edited the bar/beats locations, chose in Smart Tempo editor "Apply Region Tempo to Project" and kept default box checked in the pop up window.

- Next I imported the quality audio and used Smart Tempo on it, with "Keep" selected above in control bar.  I edited in Smart Tempo editor so that I identified bars/beats.

What I need:

1) Conform quality audio so that its bars/beats match to the video audio.

But now what??  In screenshots you see the Smart Tempo editor result for both tracks. 

If I turn on flex for the quality audio track it is going to apply the project tempo changes. I don't want that. How the video audio varied in tempo is not related to how the quality track varies in tempo. I just need for the quality version to have its bars/beats stretched so that they match the project bar/beats that were established when I used Smart Tempo on the video audio.

Maybe for the quality audio track Smart Tempo is not what I need? Maybe it is a quantize function of some sort? If that is the case, how can I tell Logic to use the bars/beats for that track that I already established for the track?

2) Have Tempo map ready for MIDI tracks to be added and be in sync. I suppose I get this result automatically from the first Smart Tempo run I did on the video audio.

Anyway, really hoping someone can shine some light here.

 

thanks

 

 

 

[Atlas007]

Have you tried Groove tracks?

[zplane]

 

The reference track(s) to create the tempo map are often one or more drum tracks recorded with consistent kick, snare, hi-hat, etc. hits at 1/4, 1/8 note or finer resolution.   Analyzing tracks with the most frequent and consistent rhythmic events creates an accurate global tempo map for added tracks to follow.   Logic can import a set of tracks and analyze them for tempo as a "multitrack set", e.g., multiple drum track audio file stems. You select which tracks in the multitrack set to extract the tempo from.  Likewise it helps to apply the project tempo map to imported audio with beats/transients within a few beats of the audio used to create the tempo map.

Normal playing usually does not jump from 85-90 bpm across consecutive measures.  If your global tempo track starts out with jumps like this, then it is probably not accurate, i.e., not enough transients/beats at regular intervals to analyze.  You could go into the tempo list event window and edit it to smooth out the jumps.  I think Logic also has a smooth tempo function.  I have not found guitar tracks to be good references for tempo maps.

Say you had 4 players in an instrumental group all playing in time (no drums or percussion).  You can try tapping in time to the recorded audio using a MIDI controller to record a sample of a hi-hat hit with a drum VI (at least 1/4 notes).  Then you can use the recorded hi-hat audio file to create the project tempo map.

If you align both audio tracks in the arrange window and nudge/shift one so they both start at the same time, maybe they sync rhythmically.   if you can't tap in time to both, then the tap strategy above won't work. If you align the start times, and trim the files to have the same start/end time, you could export them.  Then try selecting both those files to import into a new project (no existing tempo map) as a multitrack set - and select both for tempo analysis.  That may not help if there's not enough or conflicting rhythmic/transient info there.

Beat mapping is the most reliable way I've seen to conform a new track with the track(s) already used to create the tempo map.   You have to do beat mapping from left to right in the time line since everything to the right can be affected by changing where the beats fall on the left.  Sometimes correcting only a few beats on the left helps to correct the alignment of everything to the right.   If dragging a beat marker causes a huge shift/glitch in tempo or alignment, then you should undo it, and look for a different beat to align.