Problem in stereo during bitrate switching and frame erasure

Basic info

• Encoder and decoder (float): fffce66f
• Decoder fixed-point : 6ce1f51f

Bug description

sometime after the decoder verification, a new issue appeared in bitrate switching and frame lost for the stereo mode. The decoder is switching from 96 kbps to 128 kbps and then it loses 2 frames consecutively. The second lost frame shows a major artefact.

on the image below, from top to bottom,

• 1: Bad frame indicator (1 = frame lost)
• 2: element bit rate
• 3: float decoder around verification time, left channel
• 4: fixed point decoder around verification time, left channel
• 5: current float decoder, left channel
• 6: current fixed point decoder, left channel
• 7: diff between 3 and 4
• 8: diff between 5 and 6

Ways to reproduce

both the bitstreams with and without frame lost are uploaded to Box at :

_EXTERNAL_IVAS_BASOP_VERIFICATION\issues\issue-1048

dp03a6s07_-dtx_-stereo_sw_13k2_to_128k_10fr.bin_48.bit (no frame lost)

dp03a6s07_-dtx_-stereo_sw_13k2_to_128k_10fr.bin_48_eid.bfi (problematic bitstream)

command line :

IVAS_dec stereo 48 bit syn