Beat grid offset is not calculated when BPM is in file tag

[Sean M. Pappalardo]

On a newly scanned library, if a file has a BPM already in one of its tags, Mixxx does not seem to attempt to figure out where the first beat is.

[RJ Skerry-Ryan (rryan)]

There's logic that is supposed to calculate the offset in this case. I wonder why it isn't working.

[RJ Skerry-Ryan (rryan)]

Can you paste the log output when you load a file like this? We currently print some debug messages about the decision to analyze or not so that would be useful to know.

[Sean M. Pappalardo (pegasus-renegadetech)]

Can't remember the track this originally happened on, but here's one where the offset was correct (at 0) and Mixxx detected a new one in the wrong spot. Is 0 not allowed?

Debug [Main]: New BeatGrid
Debug [Main]: Successfully deserialized BeatGrid
Debug [AnalyserQueue 1]: Prioritizing "What A Feeling feat. Kelly Rowland (Hardwell Club Mix)" "/media/Music&Video/DJ Pegasus/1852050_What_A_Feeling_feat__Kelly_Rowland_Hardwell_Club_Mix.aiff"
Debug [AnalyserQueue 1]: Analyzing "What A Feeling feat. Kelly Rowland (Hardwell Club Mix)" "/media/Music&Video/DJ Pegasus/1852050_What_A_Feeling_feat__Kelly_Rowland_Hardwell_Club_Mix.aiff"
Debug [AnalyserQueue 1]: AnalysisDAO fetched 0 analyses, 0 bytes for track 5470 in 1 ms
Debug [AnalyserQueue 1]: Beat calculation skips analyzing because the track has a BPM computed by a previous Mixxx version and user preferences indicate we should not change it.
Debug [AnalyserQueue 1]: First beat is 0 for grid so analyzing track to find first beat.
Debug [AnalyserQueue 1]: Beat calculation started with plugin "qm-tempotracker:0"
Debug [AnalyserQueue 1]: Vampanalyser BlockSize: 1024
Debug [AnalyserQueue 1]: Vampanalyser StepSize: 512
Note: nonZeroCount was 39123, is now 39123
Debug [AnalyserQueue 1]: Done building waveform for track 5470
Debug [AnalyserQueue 1]: Writing waveform from byte array: dataSize 400622 allSignalSize 400622 visualSampleRate 441 audioVisualRatio 100
Debug [AnalyserQueue 1]: AnalysisDAO saved analysis 33 "3236232 (915496 compressed)" bytes for track 5470 in 386 ms
Debug [AnalyserQueue 1]: Saved waveform analysis for trackId 5470 analysisId 33
Debug [AnalyserQueue 1]: Writing waveform from byte array: dataSize 3842 allSignalSize 3842 visualSampleRate 4.22738 audioVisualRatio 10432
Debug [AnalyserQueue 1]: AnalysisDAO saved analysis 34 "30822 (8807 compressed)" bytes for track 5470 in 137 ms
Debug [AnalyserQueue 1]: Saved waveform summary analysis for trackId 5470 analysisId 34
Debug [AnalyserQueue 1]: Waveform generation done 42.561 s
Debug [AnalyserQueue 1]: Beat Calculation complete
Debug [AnalyserQueue 1]: New BeatGrid

[RJ Skerry-Ryan (rryan)]

0 is currently assumed to be the same as not-detected. And it's true, it
hasn't been detected (since we can't load offsets from file metadata and so
on) .. it was purely luck that 0 was correct in this case, right? Or did
you set that by hand?

On Thu, May 17, 2012 at 1:38 PM, Sean M. Pappalardo <
<email address hidden>> wrote:

> Can't remember the track this originally happened on, but here's one
> where the offset was correct (at 0) and Mixxx detected a new one in the
> wrong spot. Is 0 not allowed?
>
> Debug [Main]: New BeatGrid
> Debug [Main]: Successfully deserialized BeatGrid
> Debug [AnalyserQueue 1]: Prioritizing "What A Feeling feat. Kelly Rowland
> (Hardwell Club Mix)" "/media/Music&Video/DJ
> Pegasus/1852050_What_A_Feeling_feat__Kelly_Rowland_Hardwell_Club_Mix.aiff"
> Debug [AnalyserQueue 1]: Analyzing "What A Feeling feat. Kelly Rowland
> (Hardwell Club Mix)" "/media/Music&Video/DJ
> Pegasus/1852050_What_A_Feeling_feat__Kelly_Rowland_Hardwell_Club_Mix.aiff"
> Debug [AnalyserQueue 1]: AnalysisDAO fetched 0 analyses, 0 bytes for track
> 5470 in 1 ms
> Debug [AnalyserQueue 1]: Beat calculation skips analyzing because the
> track has a BPM computed by a previous Mixxx version and user preferences
> indicate we should not change it.
> Debug [AnalyserQueue 1]: First beat is 0 for grid so analyzing track to
> find first beat.
> Debug [AnalyserQueue 1]: Beat calculation started with plugin
> "qm-tempotracker:0"
> Debug [AnalyserQueue 1]: Vampanalyser BlockSize: 1024
> Debug [AnalyserQueue 1]: Vampanalyser StepSize: 512
> Note: nonZeroCount was 39123, is now 39123
> Debug [AnalyserQueue 1]: Done building waveform for track 5470
> Debug [AnalyserQueue 1]: Writing waveform from byte array: dataSize 400622
> allSignalSize 400622 visualSampleRate 441 audioVisualRatio 100
> Debug [AnalyserQueue 1]: AnalysisDAO saved analysis 33 "3236232 (915496
> compressed)" bytes for track 5470 in 386 ms
> Debug [AnalyserQueue 1]: Saved waveform analysis for trackId 5470
> analysisId 33
> Debug [AnalyserQueue 1]: Writing waveform from byte array: dataSize 3842
> allSignalSize 3842 visualSampleRate 4.22738 audioVisualRatio 10432
> Debug [AnalyserQueue 1]: AnalysisDAO saved analysis 34 "30822 (8807
> compressed)" bytes for track 5470 in 137 ms
> Debug [AnalyserQueue 1]: Saved waveform summary analysis for trackId 5470
> analysisId 34
> Debug [AnalyserQueue 1]: Waveform generation done 42.561 s
> Debug [AnalyserQueue 1]: Beat Calculation complete
> Debug [AnalyserQueue 1]: New BeatGrid
>
> --
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> https://bugs.launchpad.net/bugs/1000807
>
> Title:
> Beat grid offset is not calculated when BPM is in file tag
>
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[Sean M. Pappalardo (pegasus-renegadetech)]

Luck. I'm having trouble reproducing the original issue now.

[Daniel Schürmann (daschuer)]

I close this old one now.

[Swiftb0y (swiftb0y)]

Mixxx now uses GitHub for bug tracking. This bug has been migrated to:
https://github.com/mixxxdj/mixxx/issues/6455