rtpdump testcases in BE conformance test produce different bitstream on MacOs

Basic info

• Fixed point: 3a3a2ce7

Bug description

When running the BASOP BE conformance test on MacOS with Apple Clang v17 against the testvectors generated on the reference platform Ubuntu 24.04 with clang 18, I get the following non-BE cases:

FAILED conformance-test/test_26252.py::test_26252[Readme_IVAS_enc.txt--stvST48c.wav_stereo_bitrate_switching_from_13_2_kbps_to_128_kbps_48kHz_in_48kHz_out_DTX_on_EXT_out_rtpdump.192] - AssertionError: Output differs
FAILED conformance-test/test_26252.py::test_26252[Readme_IVAS_enc.txt--stv4ISM48s.wav_4_ISM_with_metadata_bitrate_switching_from_24_4_kbps_to_512_kbps_48_kHz_in_48_kHz_out_DTX_on_BINAURAL_out_rtpdump_PI_data.192] - AssertionError: Output differs
FAILED conformance-test/test_26252.py::test_26252[Readme_IVAS_enc.txt--stv51MC48c.wav_Multi_channel_5_1_bitrate_switching_from_13_2_kbps_to_512_kbps_48kHz_in_48kHz_out_BINAURAL_out_rtpdump_PI_data.192] - AssertionError: Output differs
FAILED conformance-test/test_26252.py::test_26252[Readme_IVAS_enc.txt--stvOSBA_2ISM_2OA48c.wav_OSBA_2ISM_2OA_at_bitrate_switching_13_2_to_512_kbps_48kHz_in_48kHz_out_BINAURAL_out_rtpdump_PI_data.192] - AssertionError: Output differs
FAILED conformance-test/test_26252.py::test_26252[Readme_IVAS_enc.txt--stv20sOMASA_3ISM2TC.wav_OMASA_vdir2TC_3ISM_at_br_sw_techs_13_2_to_512_kbps_start_160_kbps_48kHz_in_48kHz_out_BINAURAL_out_rtpdump_PI_data.192] - AssertionError: Output differs
FAILED conformance-test/test_26252.py::test_26252[Readme_IVAS_enc.txt--stvFOA48c.wav_SBA_FOA_bitrate_switching_from_13_2_kbps_to_512_kbps_48kHz_in_48kHz_out_DTX_on_BINAURAL_out_rtpdump_PI_data.192] - AssertionError: Output differs
FAILED conformance-test/test_26252.py::test_26252[Readme_IVAS_enc.txt--stv2MASA2TC48c.wav_MASA_2dir_2TC_bitrate_switching_from_13_2_kbps_to_512_kbps_48kHz_in_48kHz_out_DTX_on_BINAURAL_out_rtpdump_PI_data.192] - AssertionError: Output differs
FAILED conformance-test/test_26252.py::test_26252[Readme_IVAS_enc.txt--stvST48c.wav_Stereo_downmix_to_bit_exact_EVS_at_24400_kbps_48kHz_in_48kHz_out_rtpdump.192] - AssertionError: Output differs
FAILED conformance-test/test_26252.py::test_26252[Readme_IVAS_enc.txt--stv48c.wav_EVS_at_13_2_kbps_48kHz_in_48kHz_out_STEREO_out_rtpdump.192] - AssertionError: Output differs

All of these are RTP encoder testcases. From the Readme file, the files that are being compared are the bitstream files, not the separate rtp data files. Since the only differing cases are RTP cases, I wonder if it is intended that the -rtpdump switch has influence on the bitstream itself and how this might be influenced by OS/compiler.

Ways to reproduce

Run the BASOP BE conformance test on MacOS 15 with clang 17.