Tracks without preceding silence have first beat muffled

[Ferran Pujol]

Try with this two 1 bar 120 bpm kick loops. One has the kick starting at sample 0, just like Hydrogen rendered it. The other one has .1s of preceding silence inserted with audacity.

The first one has it's first beat muffled while the delayed one doesn't.

It happens with flac and wav files but mp3 seems to work fine.

[Ferran Pujol (ferranpujol)]

This screenshot shows what happens. The track of the top waveform is the .wav undelayed loop. The bottom one is the same file converted to 320 cbr mp3.

[Owen Williams (ywwg)]

I do see the waveform look muffled in the waveform display, but I'm not hearing any difference in the beats (I tested by setting up a 4 beat loop on the first beat)

However I would still believe this is an issue because we've historically had issues with the starts of tracks on vbr mp3s. Maybe this is a symptom of the same problem? Maybe we're skipping the first few bytes of data in every track?

[RJ Skerry-Ryan (rryan)]

I can confirm it looks like an issue in the visual waveform but not the audio.

[Daniel Schürmann (daschuer)]

The filters to generate the Waveform data, are optimized for Audio.
They fade in to avoid clicks.

I think that can be avoided by starting waveform analysis with settled filters.

However, the Audio is effected in the same Way.
If you seek to zero, the first beat is not as loud as the following.
If you scratch over the beat it has full loudness, since the filters a are settled.

[jus (jus)]

https://github.com/mixxxdj/mixxx/pull/615

[Swiftb0y (swiftb0y)]

Mixxx now uses GitHub for bug tracking. This bug has been migrated to:
https://github.com/mixxxdj/mixxx/issues/7776