Function `imult1616()` is used to compute a signal length in the ACELP decoder rescaling at https://forge.3gpp.org/rep/sa4/audio/ivas-basop/-/blob/main/lib_dec/acelp_core_dec_ivas_fx.c?ref_type=heads#L751: ``` Rescale_exc( st->hMusicPF->dct_post_old_exc_fx, exc_fx, bwe_exc_fx, st->hGSCDec->last_exc_dct_in_fx, st->L_frame, imult1616( st->L_frame, HIBND_ACB_L_FAC ), 0, &( st->Q_exc ), st->Q_subfr, NULL, 0, INACTIVE ); ``` Note that `HIBND_ACB_L_FAC = 5 /2` but `imult1616()` converts it to 2. Thus for st->L_frame = 256 imult1616( st->L_frame, HIBND_ACB_L_FAC ) returns 512 while it should be st->L_frame * HIBND_ACB_L_FAC returns 640 I guess the fix should consist of: ``` #ifdef FIX IF( EQ_16( L_frame, L_FRAME ) ) { Rescale_exc( st->hMusicPF->dct_post_old_exc_fx, exc_fx, bwe_exc_fx, st->hGSCDec->last_exc_dct_in_fx, st->L_frame, L_FRAME * HIBND_ACB_L_FAC, 0, &( st->Q_exc ), st->Q_subfr, NULL, 0, INACTIVE ); } ELSE { Rescale_exc( st->hMusicPF->dct_post_old_exc_fx, exc_fx, bwe_exc_fx, st->hGSCDec->last_exc_dct_in_fx, st->L_frame, L_FRAME16k * 2, 0, &( st->Q_exc ), st->Q_subfr, NULL, 0, INACTIVE ); } #else Rescale_exc( st->hMusicPF->dct_post_old_exc_fx, exc_fx, bwe_exc_fx, st->hGSCDec->last_exc_dct_in_fx, st->L_frame, imult1616( st->L_frame, HIBND_ACB_L_FAC ), 0, &( st->Q_exc ), st->Q_subfr, NULL, 0, INACTIVE ); #endif ``` or simply in ``` #ifdef FIX Rescale_exc( st->hMusicPF->dct_post_old_exc_fx, exc_fx, bwe_exc_fx, st->hGSCDec->last_exc_dct_in_fx, st->L_frame, L_FRAME32k, 0, &( st->Q_exc ), st->Q_subfr, NULL, 0, INACTIVE ); #else Rescale_exc( st->hMusicPF->dct_post_old_exc_fx, exc_fx, bwe_exc_fx, st->hGSCDec->last_exc_dct_in_fx, st->L_frame, imult1616( st->L_frame, HIBND_ACB_L_FAC ), 0, &( st->Q_exc ), st->Q_subfr, NULL, 0, INACTIVE ); #endif ```