_encrypted = f.bool_child ("Encrypted");
_audio_channels = f.number_child<int> ("AudioChannels");
/* We used to allow odd numbers (and zero) channels, but it's just not worth
_encrypted = f.bool_child ("Encrypted");
_audio_channels = f.number_child<int> ("AudioChannels");
/* We used to allow odd numbers (and zero) channels, but it's just not worth