Motion Estimation function

[davFR]

Hi Everyone,

I would like to use Xvid's motion estimation (ME) function, in order to create a GPL video filter. My problem is that ME function seems deeply integrated into XviD code, and needs lots of parameters and a complicated structure (SearchData).

I would like to find in XviD code the function which only needs 2 consecutive frames and returns a MV matrix. I don't care for the moment if ME process is very long because I don't provide "ME hints" (i.e. MV matrix of the previous frame).

As anyone a clue about the function name I should look at?
I thought that maybe earlier Xvid or Mumosys code would be simpler? Has anyone remembrance of such a very modular function in previous XviD version?

Many thanks to all,

David.

[sysKin]

As I'm the author of current XviD's ME, I should be able to help. ;)

Estimation is not deeply integrated into the rest of XviD. The only 'entry point' is MotionEstimation() function itself. However, if you want a simple example of how the stuff works, I'd recommend you looked at GMEanalysis() in estimation_gmc.c - it only uses a fraction of the big struct, yet gives each macroblock (16x16) its motion vector.

Estimation for p-frames is a little more complex because it also searches for possible motion vectors of 8x8 blocks. I don't know if you need such precision for your filter, but if you do, compare the differences between CheckCandidate16I() and CheckCandidate16.

Ask any questions you have.

Regards,
Radek

[davFR]

Thanks, I'll take a look at it as soon I'm home:o)