Outlier MLD score for McMASA BASOP decoder with rate switching

Basic info

• Float reference:
  • Encoder (float): d3f01fcf
  • Decoder (float): d3f01fcf
• Fixed point:
  • Decoder (fixed): b5d31923

Bug description

There is a bit of an outlier MLD score of about 8 for float ENC to BASOP DEC with McMASA and rate switching with rendering to MONO (so direct downmix of transport channels). In the same processing set, other mode combinations produce maximum of 2 MLD with BASOP decoder. The spectrogram is this but cases having lower MLD have pretty similar spectrogram and diff.

Ways to reproduce

Use this rate switching pattern mcmasa_7_1_4_techs_start_48k_20frames.bin

IVAS_cod -mc 7_1_4 -max_band swb mcmasa_7_1_4_techs_start_48k_20frames.bin 48 ltv48_MC714.wav test_0013.bs
IVAS_dec MONO 48 test_0013.bs 0013_ltv48_MC714.wav_mcmasa_7_1_4_techs_start_48k_20frames_48-48___MONO.wav

Same thing happens with -max_band fb and results in MLD 7.