[XviD-devel] inter48x48

[Marco Al]

Marc FD wrote:

> mad = mean absolute difference ??
> i see the pb. XviD can't see that the two frames are the same because it
> compares
> frames from the last already encoded frames. A raw copy would take two much
> memory ??

Not really, its just more work. A whole image mad routine could
probably be made to be bandwith limited though with a little
prefetching. Which would mean it would take on the order of a milli
second, which makes the time it takes irrelevant.
 
>> Please note that it is _wanted_ that you can feed the same frame in the
>> codec twice and _not_ have the second one skipped. Think e.g. of high
>> quantizers, then after processing the first frame, there will be large
>> errors. The second frame (in theory identical frame) will be much closer
>> to the internal, so after processing the second step, the internal image
>> will match the "real" image much closer, which is good for future ME.
> 
> 100% agreed. I already thinked of that it's why i wanted "perfect" frames to
> be dropped

No you do not agree 100% ... because what he described is pretty much
what is happening right now, and you want it changed :)

The first (couple of) encoded frame still has errors which is why subsequent
frames arent dropped. If you just checked for identical frames with the
unencoded frames errors present in the first encoded frame would remain
visible for all the subsequent "identical" frames.

Marco