Problem with Tempo/BPM automation when exporting a track

[Kaze_Senshi]

Hello guys, I am creating a long videogame music medley with just a piano soundfont and a tempo automation track like in this video( https://www.youtube.com/watch?v=67M7iV28cSo ). Since I am used to show the piano GUI being playing on the video, the music timing must be exactly the same thing that I get when editing the song on LMMS. Also to get best quality I extract the song from LMMS with WAV format and insert it in the video in the edition time.

My problem is that sometimes when I export the track it seems that the track tempo/BPM goes crazy for a very short period in some random places where I set the tempo to change. For example, in a place that I make the BPM go directly from 90 to 99 it seems that it plays the song for less than 1 second using 200 bpm. This problem will destroy the video syncronization and checking every time after exporting the track is pretty annoying since the track has more than one hour. Which configurations can I use to get tight tempo automation as I listen to when I edit my song on LMMS?

I am using this following track exporting configuration:

• LMMS: 1.1.3
  File Format: WAV
  SampleRate: 48000 hz
  Bitrate: 320kbps
  Depth: 16bit Integer
  Interpolation: Sync Best (very slow)
  Oversampling: 1X
  Export as loop: (X)

Any help is welcome... Thanks

[musikbear]

music timing must be exactly the same thing that I get when editing the song on LMMS.

So you depend on two programs that must work in perfect synch ..
Not always possible..

make the BPM go directly from 90 to 99 it seems that it plays the song for less than 1 second using 200 bpm.

That should not happen!
Can you hear this also in normal playback, or 'only' in the exported version?

Which configurations can I use to get tight tempo automation as I listen to when I edit my song on LMMS?

Doubt configuration has anything to do with this

[Kaze_Senshi]

Hi, thanks for the answer musikbear:

So you depend on two programs that must work in perfect synch ..
Not always possible..

That is true but so far I got no problems with syncing LMMS playing the music with the audio generated by LMMS using the same project. It is easy to check if the sync works (just compare the first frame of the video and the last seconds of the video, if both are synced then the merging should be fine).

That should not happen!
Can you hear this also in normal playback, or 'only' in the exported version?

Yeap that shouldn't happen and it is my problem . I saw it only on the exported version two times in different points. When I edit the music on LMMS it plays fine. I would use the same audio from when I record the music being played on LMMS (to show the piano moving) but the audio from the video recorder is poor, because of that I prefer to remove the video audio and insert the audio exported by LMMS (which has maximum quality).

[musikbear]

I cant reproduce

If you try a 3oc as instrument, will that change anything?

Could it be that you have an additional global automation?
right-Click on the bmp controller, and choose 'remove global automation'
Was that it?

[Kaze_Senshi]

Today I exported the same project in the same way after restarting my computer and the issue didn't happen again. I have 2 different WAV files generated from the same file with different filesizes. Maybe a fast way to test the WAV sanity would be to render the project multiple times and get the WAV file that its filesize repeated more times on all generated WAV files.

If you try a 3oc as instrument, will that change anything?

What is a "3oc instrument"?

Could it be that you have an additional global automation? right-Click on the bmp controller, and choose 'remove global automation'

I don't remember to use global automation since I am using track automation to control the tempo on that project but when I have time I'll do that, export the song again and listen to it to see if I find something. Then I'll update this thread again.

[musikbear]

Today I exported the same project in the same way after restarting my computer and the issue didn't happen again.

So essentially : solved -right?

What is a "3oc instrument"?

petname for
https://lmms.io/wiki/index.php?title=TripleOscillator

export the song again and listen to it to see if I find something. Then I'll update this thread again.

Oki, np :)

[Kaze_Senshi]

Okay, I think that the problem is solved. Maybe it was caused because when I exported the track I was without restarting my computer for some days. I clicked to remove the global automation and it worked as usual.

I was expecting that if you export the same project two times with the same configs it should have the same filesize but this doesn't seem to be true. Should we create a bug ticket for that?

Anyway thanks for your help musikbear, happy new year

[musikbear]

I was expecting that if you export the same project two times with the same configs it should have the same filesize

How different are they, a few kb should not point to a proble4m, but if it is mb sized differences, then something odd is going, so what are the difference, and is it different sessions (was lmms closed then reopend between the exports)

happy new year :lol:

And to you :)