Noise in LFE channel at the start of a stream
When encoding a 6 channel WAV file containing an inaudible level of noise with opusenc.exe on win64 platform, the LFE channel in the resulting opus file contains a short impulse of noise with a bandwidth of 4 kHz. This does not happen when a file starts with absolute silence. Problem happens with any recent version including libopusenc 0.2.1-16-ge4285b5. It is audible in a downmix when the LFE is played on full range speakers.
To reproduce, create a short silent audio file and add shaped dither.