[FFmpeg-devel] [PATCH] RoQ video encoder

Michael Niedermayer michaelni
Sat Jun 2 22:14:03 CEST 2007


On Sat, Jun 02, 2007 at 03:01:52PM -0400, Eric Lasota wrote:
> > and last, id like to repeat that pure CBR is a very bad idea
> > you could look at lambda as a value which says how much distortion
> > you would be willing to trade for 1 bit, so very wildly variing it between
> > frames to maintain a constant size per frame is like saying one bit of this
> > frame is worth X distortion while 1 bit in the next frame is worth 100*X
> > distrortion ...
> >
> > also id say libavcodec/ratecontrol.c could be used if you want ratecontrol
> > but this can easily be added later, that is after the encoder is in svn ...
> ratecontrol.c is laced with MpegEncContext dependencies, so I'll see if 
> I can learn something from it, but the rate control stuff is probably 
> gonna have to be done specifically for this the same way the motion 
> search was.

the motion estimation code was harder to use and it would have been
a alot of work to make the ME code less dependant on MpegEncContext
the situation with ratecontrol.c is not that bad ...

also ratecontrol is not mandatory so this would all have to be in
seperate patch(es) after the roq encoder is in svn ...

> Again, I know nothing about this sort of stuff, so if you have any 
> advice on an algorithm or approach to use, I'm listening.

well i cant give any advice on ratecontrol as that is not really
relevant now
i would like to get some clean, simple and efficient roq encoder in svn
first, after thats done we can improve it by using ratecontrol.c maybe
with making that less dependant on MpegEncContext but its not that hard
to just set the 5-10 variables of MpegEncContext which are needed ...

also we need to fix the bugs in the decoder and avoid code duplication
between decoder and encoder ...

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Democracy is the form of government in which you can choose your dictator
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