Lexicon version: Current Beta Operating system (remove one): Windows
Bug description:
I imported a bunch of mp3 tracks into lexicon from an engineDJ USB, then exported them all to another, fresh/empty USB. I ended up with the classic 120 bpm issue.
The track I was testing with is Delta Heavy - E-N-D (Original Mix).mp3
Let me pre-empt the inevitable question about sample rate in the source engineDJ file:
Is the sample rate correct in the track that was imported? Yes. 44.1khz is reported in the mp3 via mediaInfo Sampling rate : 44.1 kHz as well as the source engineDJ table. For EngineDJ I referenced Engine Library Format · mixxxdj/mixxx Wiki · GitHub and used a bit of python to decode the sample rate against m.db:
from PySide6.QtCore import QByteArray, qUncompress
import struct
SELECT * from Track WHERE filename like '%E-N-D%';
SELECT beatData from PerformanceData where trackId = 3090;
>>> input = bytes.fromhex('00000082789C7378DAD1C0C0C0C0E098F04207C460648000269DEF26878A16BF3DF0E73F04F830412440C2E91F121C3DA07C3440BA3E00EA5527E6')
>>> data = qUncompress(QByteArray(input))
>>> uncompressed_data = bytes(data)
>>>
>>> struct.unpack('>d', uncompressed_data[0:8])
(44100.0,)
As you can see the sample rate is correct in the source engineDJ. I haven’t looked at the output USB yet.
Step by step to reproduce:
Import a bunch of mp3s and export them from/to engineDJ on USBs. Lots will suddenly have 120 bpm in engineDJ. Even affects totally fresh USBs
I sent the one file I was looking at in the example above, package ID 01KN3NTED6GPCNSDM42VRPGR3K. However I’m not sure if this is an issue similar to the Soundcloud track export that happens occasionally vs something consistent - I haven’t been using lexicon recently and I just tried it and found this track had an issue immediately. Hopefully its something that can consistently/easily repro
I sent the m.db as well, package ID 01KN3P30M9RRKH5V64DXGQ0CZQ - hopefully you can just import to lexicon a playlist with the single track, export to a fresh USB then see the issue in engineDJ desktop or the outputted m.db with the python script I used above. I gotta run but I’ll supply additional samples and investigation in a couple weeks
Thanks for looking. I’m traveling at the moment but when I get back I’ll do some additional testing. It seemed to be a random subset of tracks that had this issue, I didn’t see any particular pattern in terms of which tracks were broken. I haven’t tried repeatedly importing or repeatedly exporting to see if its the same set of tracks every time. One thing to note is that the issue only happens when you try to load the track after exporting to a USB. The metadata has the right bpm initially but then when you load the track, suddenly bpm changes to 120.
