Author Topic: Strangely broken MP3 samples  (Read 1058 times)

saga

  • Posts: 2130
Strangely broken MP3 samples
« on: 9 Nov '15 - 01:58 »
It's been a while since I used MP3 samples in MO3, but I cannot recall having the following problems, so it might be sample-specific, or specific to this LAME version I use...

Consider the attached IT file with a bidi-looped sample. MO3 seems to unroll the bidi loop, but depending on the chosen quality level the loop length is incorrect, or the sample is completely detuned. For the reference, I'm using LAME 3.99.5 and the "LAME (VBR)" / "LAME" presets in MO3. Try encoding the example sample at some low bitrates and the problem should be obvious.

Ian @ un4seen

  • Administrator
  • Posts: 19987
Re: Strangely broken MP3 samples
« Reply #1 on: 10 Nov '15 - 15:43 »
The problem is that LAME 3.99.5 is automatically converting the data to a lower rate when the VBR quality is set very low, which means the rate and length of the sample no longer matches the original, and it sounds detuned when played at the original rate. That seems to have begun in LAME 3.98. I'll update the MO3 encoder calibration to check for that. In the meantime, it's probably best to stick with LAME 3.97 or older.