SBA Decoder @ 13.2 and 16.4kbps crashes if decoded bitstream starts with SID

Basic info

• Commit SHA: 790747d7
• Platform: all

Bug description

When the first frame in a to-be-decoded bitstream for SBA at low bitrates is an SID, the decoder crashes in a segfault.

Ways to reproduce

Example command line with attached bitstream: ltv48_HOA3_SBA_b13_2_dtx_wb_cbr_sidstart_500frames.192

./IVAS_dec 7_1_4 16 ltv48_HOA3_SBA_b13_2_dtx_wb_cbr_sidstart_500frames.192 out.wav

To generate test bitstreams that start with an SID, one can use the cut_bs.py script from here:

./scripts/cut_bs.py --sid bs bs_that_starts_with_sid

Note that the bitstream will be of zero length if no SID frame header is found.