Helpful ReplyScale MIDI tempo changes

Author
Post
Essentials Only Full Version
vorxio
Max Output Level: -90 dBFS
  • Total Posts : 13
  • Joined: 2017/01/17 15:42:55
  • Status: offline
2018/03/29 20:38:14 (permalink)

Scale MIDI tempo changes

In order to synchronize the MIDI output with an audio track, I found that it is very handy to slow down the audio up to 4 times (I don't know if it is possible in Sonar, but I use Audacity to do the slowdown); then I use the Time window (view Tempo)  in sonar to "align" MIDI notes with the audio track (without altering their position in the bars).
 
But now I have a MIDI track in which the initial time is 4 times slower, and it has many time changes in it.
 
Is there a way to scale the whole MIDI 2x or 4x faster (i.e. not only scale the initial time, but also the internal time changes)?
 
Thank you in advance.
#1
List Solutions Only

1 Reply Related Threads
    brundlefly
    Max Output Level: 0 dBFS
    • Total Posts : 14250
    • Joined: 2007/09/14 14:57:59
    • Location: Manitou Spgs, Colorado
    • Status: offline
    Re: Scale MIDI tempo changes 2018/03/29 22:00:17 (permalink) ☄ Helpfulby vorxio 2018/03/31 18:51:05
    It is possible to scale tempos, but requires jumping through some hoops (see below). It would be highly preferred to work with original tempo audio, and use Set Measure/Beat At Now to align the timeline (and thus MIDI) to the audio, using a combinaiton of eyes and ears to find which transients correspond to which measures/beats.
     
    Here's the drill for scaling tempo changes (since you'll probalby be importing unstretched audio after the tempo  change, you can skip step 1.):
     
    1. Enable Auto-stretch (a.k.a. Clip Follows Project in Auto-stretch mode) on all audio clips.     
    2. Select a MIDI or audio clip that runs the length of the project (or select in the timeline).     
    3. Go to Process > Fit to Time.     
    4. Convert the current Thru time to total frames (usually 30 frames/sec).     
    5. Divide that by the desired tempo change factor (e.g. 1.10 to get a 10% increase, 0.90 for a 10% decease).     
    6. Round and convert that new value back to minutes:seconds:frames.  
    7. Select Modify by Changing: Tempo Map, and enter the new Thru time.    
    8. Click OK.

    SONAR Platinum x64, 2x MOTU 2408/PCIe-424  (24-bit, 48kHz)
    Win10, I7-6700K @ 4.0GHz, 24GB DDR4, 2TB HDD, 32GB SSD Cache, GeForce GTX 750Ti, 2x 24" 16:10 IPS Monitors
    #2
    Jump to:
    © 2024 APG vNext Commercial Version 5.1