hendrik on 19 Dec, 2019 10:22 AM
tempo and key estimation accuracy of v5.2.3 should be a bit better than in previous versions. Whether you want to re-run analysis is entirely up to you. If you just have a few thousand tracks or accuracy is super-important to you, I say go for it and let it run.
For tempo, the increased accuracy will manifest in fewer so-called octave errors, i.e. error by a factor of 2 or 1/2.
I've noticed in the BPM column of the library listing, sometimes the 2nd (rightmost) BPM number is in a dimmed font. Other times it is "standard" weight. Does that signify anything? Just curious.
Also, I spot checked a few tracks and the new 5.2.3 tempo and key calculations are in some cases producing different results than before. Sometimes the actual tempo changes by just a small fraction, sometimes it results in an octave change, just as you said. Also, I noticed some key changes. So I decided to reanalyze everything. I do like accuracy. One thing of interest: It appears to be better at actually generating the metadata per track. 80,000 tracks in and the Task Queue has yet to generate an "I can't figure this out" message for any track. In the older version, every now and then it threw an error on a "random" track. (It probably wasn't actually random, but I didn't investigate further.) 12 hours in, two days to go.
On Thursday, December 19, 2019, 4:22:05 AM CST, hendrik <[email blocked]> wrote:
hendrik on 20 Dec, 2019 09:58 AM
the tempo algorithm always produces two values and a so-called salience value which is inspired by the P-score metric used in the MIREX automatic tempo estimation task. The salience value indicates which of the two values seems more likely (it actually attempts to model tempo perception—different people perceive tempo differently). In the UI this is reflected by the second value and letting it appear either gray or black depending on how likely it is that someone would actually perceive the track in that tempo. You can see the perceptual distribution/certainty by hovering over the value with the mouse. The tooltip shows the actual number.