[theora] questions about quantization and motion compensation

Franz photo.franz at gmail.com
Fri Aug 27 01:45:08 PDT 2010

Hello everybody,

my name is Francesco, I am an italian student graduating in physics. I'm
studing the Theora video codec and making some comparative tests.
Unfortunately i'm not able to find some informations that could be useful.
If someone could make clear some concepts, (or tell me where i can find
these informations), i'll be very happy. ( I've yet read the Theora Format
Specification). I'm sorry if many questions could appear trivial, but many
things are new for me....

1) Theora uses 64 different quantization matrices 8x8: have these matrices a
particular shape?What's the numerical distribution?

2)Talkink about motion compensation, what type of alghoritm is used for the

3)Coding some video i've seen tha using ffmpe2theora can be fixed some
quality levels, using the option -v (that allows value from 0 to 10). I've
apologized that in this case the encoder uses some particular quantization
matrices, is this right? If it's right, could be possible to know the
matrices used for a fixed quality level? (for example “-v 6” , that is the
default value?)

Thank you all in advance for availability!
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