[opus] opus Digest, Vol 68, Issue 6

[John Fredman]

>> Is there a defined format tag for Opus that should be used with the
>> WAVEFORMATEX structure? See wFormatTag
>> (http://msdn.microsoft.com/en-us/library/windows/desktop/dd390970.aspx).
>
> There isn't one. Putting Opus into RIFF is complicated by the fact that
> it requires both variable-duration and variable-size frames, though I
> suppose something could be done along the lines that FFmpeg used for
> Vorbis (though how you would handle issues like pre-skip, end trimming,
> and pre-roll, I have no idea).
>
> Why do you ask?**********************************

I'm investigating the possibility of adding Opus to ASF. I will
probably use WAVE_FORMAT_EXTENSIBLE instead:
"WAVEFORMATEXTENSIBLE allows you to  avoid having to register a new
format tag with Microsoft."

Preroll is supported by ASF. But I'm unsure if pre-skip and end
trimming can be supported. I guess one could live without it.