ChannelLayout
            enables to specify the channel layout more flexibly than the predefined layouts of the ChannelMappingFamily.

            To utilize the ChannelLayout for OpusSampleEntry, the ChannelMappingFamily field should be set to 255.
            Even when the ChannelMappingFamily field is set to another value, the assignment of each output channel to
            loudspeaker position specified by the ChannelMappingFamily would be changed as specified by the ChannelLayout.
            The pro