Decoder crash for MC 7.1+4 at 64-96 kbps with LFE content when rendered to 7.1+4
Basic info
Bug description
Decoder crashes (with segmentation fault) with some 7.1+4 samples that contain LFE when processed through McMASA bitrates 64-96 kbps and synthesized to 7.1+4. The stack during the crash is following
shl_o basop32.c:787
shl_ro enh1632.c:396
shl_r enh1632.c:426
ivas_lfe_synth_with_filters_fx ivas_dirac_output_synthesis_dec.c:5739
ivas_jbm_dec_tc_fx ivas_jbm_dec.c:1387
IVAS_DEC_GetTcSamples lib_dec_fx.c:1440
IVAS_DEC_GetSamples lib_dec_fx.c:1076
decodeG192 decoder.c:1723
main decoder.c:604which points out that this happens within the LFE synthesis algorithm for McMASA on these bitrates. Notably, lower bitrates do not crash where there is a different LFE coding algorithm in use.
Ways to reproduce
Not showing in automated tests (for some reason) but can be reproduced with the attached noise file (12 channels of noise with LFE being 50 Hz LP filtered). This happens also with professionally mixed 7.1+4 files (which we cannot share) but I verified that crash is in the exact same place using this synthetic sample.
Use, e.g., commands
./IVAS_cod_ref -mc 7_1_4 96000 48 test714.wav test.bit
./IVAS_dec 7_1_4 48 test.bit test_out.wavEdited by Tapani Pihlajakuja