type=iamf_mix_presentation:id=3:stg=0:annotations=en-us=Mix_Presentation,
submix=parameter_id=100:parameter_rate=48000:default_mix_gain=1.0|element=stg=0:parameter_id=100:headphones_rendering_mode=stereo:annotations=en-us=9.1.6_Submix|element=stg=1:parameter_id=100:headphones_rendering_mode=stereo:annotations=en-us=Stereo_Submix|layout=sound_system=stereo:integrated_loudness=1.0|layout=sound_system=9.1.6,