[vorbis] Newbie question

[msmith at labyrinth.net.au]

Carsten Orthbandt <carsten.orthbandt at sek-ost.de> said:

> I'm new to OggVorbis (btw: we're about to use it in a game...) and
> am curious about page sizes when decoding ogg streams. With every
> stream I tested, I get either 512 or 4096 byte packages from ov_read().
> While this is fine with me, I'd like to know if there is a upper limit
> to this chunk size. If it's variable, how do I find out what the max
> chunk size for the open stream is?
> I know that I can limit the amount of data ov_read retrieves through
> the size param, but I'd like to drive it with the best possible size
> and no artificial restrictions on my side. But if there was a remote
> possibility of ov_read() returning big chunks (>64 kbyte), i'd rather
> know that in advance.

In theory, it could return up to (sample size)*(number of channels)*4096. So,
if you restrict yourself to stereo (or mono, which is obviously less), and you
decode to 16 bit samples (2 bytes), the maximum is 16kB. This is a
format-imposed maximum, no encoder actually produces streams that'll do that.
In actual real-world streams, you can halve that to 8 kB (8192 bytes) (I
_think_ there are some encoding modes that will do that, though I haven't
checked). 

> 
> On a side note: this is on Win32 and I'd like to note that I had
> serious trouble linking the static libs with /MT code. I Finally
> resorted to building a single oggvorbis lib with all source included.

We're mostly not windows experts - the win32 build files often have some
problems, and we'd _really_ appreciate any help with issues like these.

Mike

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