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Very high MLD for ParamISM (ISM4) 24.4kbps SWB with +10dB input and DTX enabled

Basic info

  • Float reference:
  • Fixed point:
    • Encoder (fixed):8633801a
    • Decoder (fixed):

Bug description

There is very high MLD (46.12) reported for item bm6ba1s14 for input level +10dB. Looking at the difference signals of float - BASOP there seem to be some issue with gains, especially with objects 1 and 3:

Screenshot_2025-05-16_at_14.44.39

There is also a clear segment at timestamp 9.160 sec where there is a clear energy burst across all active objects:

BASOP

Screenshot_2025-05-16_at_14.36.51

float

Screenshot_2025-05-16_at_14.37.01

Ways to reproduce

Box folder: ...\Box_EXTERNAL_IVAS_BASOP_VERIFICATION\issues\issue-1590

./IVAS_cod -dtx -ism 4 bm6ba1s14.0.csv bm6ba1s14.1.csv bm6ba1s14.2.csv bm6ba1s14.3.csv -max_band SWB 24400 32 bm6ba1s14_32.10dB.wav bm6ba1s14[10dB].dec.192
./IVAS_dec EXT 32 bm6ba1s14[10dB].dec.192 bm6ba1s14[10dB].dec.wav

It should be noted that this happens for other sampling rates and with dtx off for this particular item but also for quite a few other items, for the cases where the input level is +10dB

Edited by fotopoulou