Keysight doesn't match my audio file!
It is a relatively common issue filed as a bug report that Keysight's MIDI playback (during a render-to-video operation) does not match an audio file generated with the same MIDI file.
If this happens to you, this is undoubtedly an issue with the audio file, not Keysight's MIDI playback. In every single instance of this issue being reported, it has always turned out to have the same root cause: MIDI playback when generating the audio file is mismatched to the playback baked into the MIDI file itself. It's not Keysight's fault if you pass it a MIDI file without the expected tempo information.
Why does this happen?
Midi files contain tempo data to inform playback speed. Keysight follows the MIDI specification➚ on playback to the letter➚. However, Digital-Audio-Workstations (DAWs, like Ableton / Reaper / FL studio etc.) often have additional tempo layers that can modify or override the MIDI file's tempo.
When rendering audio from a DAW, the DAW will use these extra tempo layers. But when exporting a MIDI clip from a DAW, these extra tempo modifcations are not usually baked into the resulting MIDI file. Therefore, when the MIDI file is importing into Keysight, it isn't using the same playback speed as the audio file and will be desynchronised.
What can I do about it?
This is very dependent on the program being used, and the setup within that program, so it's impossible to give concrete advice. However, you could try:
- Check for any automation layers in your DAW
- Use a tool like MidiEditor (Windows)➚ to inspect for MIDI tempo events and check them against the tempo in the DAW
- See if there are any options to export MIDI clips from your DAW using any extra tempo automation layers