Decoder accessing uninitialized variable... Re: [theora-dev] Using Theora in games?

Alen Ladavac alenl-ml at
Thu Feb 26 06:23:55 PST 2004

To follow up on my tries to test splayer on Win32 (see below). I got some
time to check it and turns out that it crashes in debug version, because
MSVC.NET adds runtime checks in debug version. According to those checks,
this piece of code...

pbi->FragMVect[FragIndex + 1].x = MVect[1].x;
pbi->FragMVect[FragIndex + 1].y = MVect[1].y;

(from DecodeMVectors() in theora_static/decode.c) generates this error:
"Run-Time Check Failure #3 - The variable 'MVect' is being used without
being defined.".

  memset(MVect, 0, sizeof(MVect));

at beginning of the function "fixes" the problem. But maybe someone who
understands what is actually going on in there should look into it. This
might be cause of some other hidden errors.

Other than that, splayer works great. Decoding speed is even better than I
have expected (from one little test that I tried). Overall, I'm impressed,
especially considering that this is all in "alpha" stage. Still have to
check actual picture quality, tough I doubt there can be much problems

What I am more concerned about would be:

1) streaming bandwidth variations and
2) decoder memory usage.

Are there any known numbers on those two? I had some problems with #1 when
trying to stream WMV files from a DVD, since WMV has some weird ideas on how
to interleave audio and video making it skip forth and back a few seconds
across a stream in order to find audio. This either requires large buffers,
or makes DVD drive seek around lowering its data rate significantly.

Thanks in advance,

<p>----- Original Message -----
From: "Alen Ladavac" <alenl-ml at>
To: <theora-dev at>
Sent: Sunday, February 15, 2004 16:21
Subject: Re: [theora-dev] Using Theora in games?

<p>> Aha! Downloaded another version (older than mine ???) and it works now.
> Thanks a bunch.
> I've succeeded in encoding a test video, and the player showed some
> (greenishly-noisy :/) picture, then it crashed. Well, now I'll have to
> up my sleeves. See you later....
> Alen

<p><p>--- >8 ----
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