[vorbis] Slow stream opening (Was Re: Average Bitrate Calculation)

Alen Ladavac alen at croteam.com
Thu Oct 4 09:13:42 PDT 2001



> Vorbisfile will not try to parse stream structure in a non-seekable
> stream.  Doing things this way is perfectly valid, and a good trick.
> You just won't know total stream length or average bitrate.
> Everything will still work.

Actually, it would be handy to still be able to reset to 0 (for looping),
but I guess that adding that would make the interface too asymmetric.
I do that by re-opening the stream now and it works perfectly.
Maybe noting the caveeat and known workaround in the vo_open docs would be
useful for the future users.

> All streams are VBR, even when they aren't :-) Ogg/Vorbis is never
> CBR, even if an encoder mostly fakes it.  Vorbisfile is slower at a
> full open than a non-seekable open, but it shouldn't be absurd...
> Could you send me the file presenting all the trouble?

I don't think it is due to some file. It happens on any file. You see, the
music is played in an fully interactive environment here (a game), with
responsiveness under 50msec. When a new music is started, if it takes more
than a few milliseconds, it is very noticeable.
The solution with non-seekable streams works great. I just wanted to put a
note on the newsgroup, so that people know that the caveeat exists and be
aware of it.

Alen

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