Help on Offset Tempo Map by half or double

[mgustavo]

Hi, I've been using Tempo Track to draw Tempo Map when I'm transcribing songs to music score.
But I've always failed when trying to make Tempo Map get to half or double (when it's done) to fit audio music better.
In an example, it's like when I thought a song was on 2/4 time signature but actually it is 2/2 - I want to keep the same beat so I'll need tempo map be 200% faster.
If I use Offset Tempo Map on Tempo Track it will do the trick but it seems dots won't move horizontally (x axis) when working with audio files, it won't follow music anymore. However when using MIDI clips it will work fine.
Does anyone knows a workaround to do this? Or maybe I'm missing something?
Thanks in advance!
 

Edited December 19, 2022 by mgustavo

[David Baay]

You need to select all audio clips and enable  Audiosnap and Follow Tempo in Autostretch mode in Clip Properties before making any tempo changes.

[mgustavo]

Hi, David! Thanks for your response! I'll give it a try!

Best regards

[mgustavo]

Hi @David Baay
I'd like to say that didn't work! However thanks for the suggestion, as it's an useful thing to do on other situation.
The result was that audio clip followed tempo map and became 50 % stretched! Maybe I was not clear on OP! 

What I'm aiming to do is simply change midi/staff content to its double, like when one writes "quarter note is equal to half note" on music score, when changing 2/4 time signature to 2/2, for example. The result is that audio would be the same, but notation would change.

I'll read more about Snap audio, but Tempo Track looks easier to deal with! 

[msmcleod]

Try this:

1. CTRL+A to Select All
2. Click on Clip Properties, and click on Audio Snap
3. Enable Audio Snap, and check "Follow Proj. Tempo"
4. While holding down CTRL, change the track filter back to "Clips"
5. Process->Offset Tempo Map
6. Choose % and 200%, and click OK

[msmcleod]

If you want to double the tempo, but keep the speed of the performance the same as it was:

If you followed any previous steps to enable AudioSnap/Follow Tempo for audio clips - you want to revert that.  So CTRL + A, go to clip properties, and disable Audio Snap.

The other important step is to ensure all audio clips have their time base set to Absolute - you can change it back to Musical afterwards, but they should be set to Absolute before we change tempo. 

The reason being, is that for example... at 120bpm bar 4 is exactly 3 seconds into the performance.  If we double the tempo, then any audio at bar 4 will now play 1.5 seconds into the performance. We don't want this  - we want it to play at exactly 3 seconds in.  Setting it to absolute will change the clip so it starts at "3 seconds" rather than "Bar 4".

If ALL of your audio clips start at 001:01:01, then you can skip setting them to absolute.

Unhide this section to see how to do this:

1. Open the Track Manager
2. Click the MIDI button to select all MIDI tracks, uncheck them, then click OK.
3. Click on the number of the first track to select it, then while holding shift click on the number of the last track.
4. Click on Clip Properties, and set the timebase to Absolute.
5. Press CTRL + SHIFT + A to unselect all.
6. Make your MIDI tracks visible again by opening the Track Manager, clicking the MIDI button, checking them all, and clicking OK.

Then:
1. CTRL + A to Select All
2. Choose Process -> Length from the main menu
3. On the dialog, the the percentage to 200 Percent. Ensure "Stretch Audio" is UNCHECKED, then click OK
4. Choose Project -> Offset Tempo Map from the main menu
5. Choose % and 200 percent, then click OK

 

[mgustavo]

Hi @msmcleod

Thank you very much for the explanation! It seems setting audio clip time base to absolute did the trick! 
Also changing midi clip's length to 200% looks essential to do the job!

However I'd like to report an issue that occurred - all worked fine but midi clips start point didn't sync with audio clip and tempo map! But that was easily fixed moving them a few bars ahead.
* There was 1 empty bar at the beginning, so after the procedure the song should start at bar 3, but it did on bar 4,5.
I guess that happened because tempo map was not accurate, as my job was just transcribe music to score. Maybe some imprecisions, as well as fast curves, for ex., did this issue.

Edited December 22, 2022 by mgustavo

[Lord Tim]

2 things:

1. I'm glad I didn't reply earlier - I entirely missed the point of what you were trying to do and would have given you poor information. Mark has nailed it, and even has taught me a few things!  

2. Speaking of teaching me a few things, @msmcleod how did you do that Reveal Hidden Contents thing in your post? That's awesome!

 

Edited December 23, 2022 by Lord Tim

[msmcleod]

23 minutes ago, Lord Tim said:

2 things:

1. I'm glad I didn't reply earlier - I entirely missed the point of what you were trying to do and would have given you poor information. Mark has nailed it, and even has taught me a few things!  

2. Speaking of teaching me a few things, @msmcleod how did you do that Reveal Hidden Contents thing in your post? That's awesome!

 

For the hidden contents, put your content in a spoiler tag:

{spoiler} your content here {/spoiler}

Replace the curly braces with square brackets.

[Lord Tim]

Champion! That's great!