[iacb] size=218
 - configurationVersion: 1
 - descriptorsSize: 207
   obu: Type=IA Sequence Header Size=8 Start=2
   obu: Type=Codec Config Size=22 Start=2
     IAMF Context:
       Codec Configs (1):
         CodecConfigID=0 Codec=opus SampleRate=48000 NumSamples=960 RollDistance=-4
       Audio Elements (0):
       Mix Presentations (0):
       Param Definitions (0):
   obu: Type=Audio Element Size=43 Start=2
     IAMF Context:
       Codec Configs (0):
       Audio Elements (1):
         AudioElementID=300 Type=Scene CodecConfigID=0 NumSubstreams=16 NumLayers=1
           Layer[0]: Custom 16-Channel Layout
             OutputGain: 0/0
           Substream[0]: ID=0
           Substream[1]: ID=1
           Substream[2]: ID=2
           Substream[3]: ID=3
           Substream[4]: ID=4
           Substream[5]: ID=5
           Substream[6]: ID=6
           Substream[7]: ID=7
           Substream[8]: ID=8
           Substream[9]: ID=9
           Substream[10]: ID=10
           Substream[11]: ID=11
           Substream[12]: ID=12
           Substream[13]: ID=13
           Substream[14]: ID=14
           Substream[15]: ID=15
       Mix Presentations (0):
       Param Definitions (0):
   obu: Type=Audio Element Size=13 Start=2
     IAMF Context:
       Codec Configs (0):
       Audio Elements (1):
         AudioElementID=301 Type=Channel CodecConfigID=0 NumSubstreams=1 NumLayers=2
           Layer[0]: Stereo (System A - 0+2+0)
             OutputGain: 0/0
           Substream[0]: ID=16
       Mix Presentations (0):
       Param Definitions (0):
   obu: Type=Mix Presentation Size=121 Start=2
     IAMF Context:
       Codec Configs (0):
       Audio Elements (0):
       Mix Presentations (1):
         MixPresentationID=42 Labels=[en-us]
           en-us: Default Mix Presentation
           Submix[0]: NumElements=2 NumLayouts=2
             Element[0]: AudioElementID=300 HeadphonesMode=Binaural
               DefaultMixGain: 0/256
                 en-us: 3OA audio element
             Element[1]: AudioElementID=301 HeadphonesMode=Binaural
               DefaultMixGain: 0/256
                 en-us: stereo audio element
             Layout[0]: Type=Loudspeakers
               SoundSystem: Stereo (System A - 0+2+0)
               Channels: 2
               IntegratedLoudness: -5147/256
               DigitalPeak: -123/256
             Layout[1]: Type=Binaural
               SoundSystem: Binaural
               Channels: 2
               IntegratedLoudness: -32768/256
               DigitalPeak: -32768/256
       Param Definitions (3):
         Type=MixGain ParameterID=999 ParameterRate=48000 Duration=0
           Mode=1 NumSubblocks=0
           AudioElementID=300
         Type=MixGain ParameterID=995 ParameterRate=48000 Duration=0
           Mode=1 NumSubblocks=0
           AudioElementID=301
         Type=MixGain ParameterID=998 ParameterRate=48000 Duration=0
           Mode=1 NumSubblocks=0
