[theora] theora problems

Romulo Rego roremeol at gmail.com
Mon Jan 22 04:43:02 PST 2007


I've been trying to use libtheora-experimental (libtheoraenc and
libtheoradec) to encode a webcam feed in real-time, to be decoded

also in realtime by a second party via XXX-IP, with - unfortunately - not so
good results.

I'm using custom written functions to convert from RGB8 to YUV420 and back
and, although not much processor-efficient, they do

what they're supposed to nicely.

Unfortunatelly, I get a lot of "block-artifacts" in the process. With one
webcam, the image starts all "blocky" and then, if you keep

the image still, it gets better. If you move a bit, blink an eye... Then the
block appear where the motion occured, but disappear

again under the same conditions. Besides that, objects far from the webcam
tend to get invariably all "blocky". Oh... with another

webcam the image is ALWAYS "blocky". Ideas? FPS settings?

I've been trying to play around with the encoder settings to no avail. Same
problems arise in those same webcams.

I don't know if libtheora-experimental is ready for use. I tried to do it
with libtheora but had some problems with access violations

in theora_decode_init(). Perhaps an uninitialized value? Finally gave up to
try libtheora-experimental with these results.

Ideas? Has anyone tried to accomplish this (real-time webcam
encoding-decoding) with theora and succeded (or not?)

P.S. Please, send me some feedback because my messsages are not going to the


-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.xiph.org/pipermail/theora/attachments/20070122/c76c49ad/attachment.htm

More information about the theora mailing list