Mixxx developer here -- can confirm our VBR decoding code is slightly less reliable than CBR! It&#x27;s easier when you know exactly how many samples you&#x27;re going to get out of a frame. We rewrote a bunch of this in 2.1 (coming in Q1 2016) so hopefully a few odd VBR quirks we had got fixed.<p>The warbling definitely sounds like our pre-2.0 time stretching algorithm to me. The new one in 2.0 is much better.