White noise in opusdec

Submitted by Alicia Boya García @ntrrgc

Link to original bug (#788045)

Description

The following Opus audio sample shows a considerable white noise while the person is talking when played with a GStreamer player.

https://people.xiph.org/~greg/opus_testvectors/correctness_gain_loud_speech.opus

Such artifact does not appear when the same file is played with a ffmpeg-based player such as mpv or Google Chrome.

Version: 1.x