Issue when switching between different stereo modes (mostly for bitrate switching)

A problem has been sometime observed when switching from stereo MDCT (48kbps and up) to a lower bitrate (> 48kbps).

in the figure above, we can see 2 different problems, the first one happens when the bitrate (or element mode) is switching from MDCT, the second one happens when switching to and during MDCT.

• The first problem was due to a wrong re-initialization of Q_syn when switching stereo mode (this have to be validated by Ittiam, but that is my understanding from what I have found in the code
• The second problem was because of a non-update of a memory

A branch will be create and a fix proposed soon