Sample with heavy distortion at default settings (and up to ~160kbps)

[enzo1982]

Here's a sample that exhibits heavy distortion after encoding with FAAC at default settings (faac original.wav) and even up to ~160kbps (faac -b 160 original.wav): sample.zip

The ZIP contains the original sample (the first 2 seconds of Mariah Carey's song Migrate) and the .wav after encoding and decoding at FAAC's default settings.

Looking at the waveforms in Audacity, it's obvious that the distortions come from the energy suddenly dropping significantly for durations of 1-2 frames.

These drops do not seem to be regular compression artifacts, but look like being caused by a bug in the encoder.

I reproduced this using my custom built FAAC.dll in fre:ac and verified using the faac.exe from RareWares to rule out a build/compile issue.

Would be great if someone could have a look at this.