[Vorbis-dev] Mapping = 1 Ambisonic Vorbis flag
ricardo at justnet.com.au
Thu Sep 11 17:06:44 PDT 2008
>> When we start distributing 4th order stuff (which requires >16 speakers) we can get around this by having missing channels simply silent. Vorbis compression is very efficient at coding silence. Thanks to Gregory Maxwell for this excellent suggestion on the sursound forum.
> Fons killed that proposal already on the sursound list. The Ambisonics decoder have to be setup before the playback starts. A silent channel is still a channel that at any point in time could become non-silent.
By the time we need higher orders, the decoders will need to be so complex that allocating buffers and then freeing them would be trivial.
A simple way to guarantee there's always something to be detected is to specify the first eg 256 samples to have at least a -80dB FS noise type signal. We'd have to choose a noise type that wouldn't be killed completely by the coupling or compression.
Aaron's experience with video is that metadata is always lost. The only thing that survives is the data itself. If we're clever, we could have this code the metadata itself .... down boy! Down! Shaddup! .... 8>D
I'm in favour of simplicity and letting complexity sort itself out when the time comes.
Make sure you do important things as simply and as good as you can and leave complexity for little / never used stuff.
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