video stabilization and rolling shutter compensation with the open source combo Virtualdub + Deshaker plugin

Sometimes you couldn't bring a tripod, gave your best to keep the camcorder steady, but you had to zoom in and the built-in stabilization left over some movements.

Shaky movies can be stabilized afterwards on the PC, but it's a frowned upon option for purists: You can choose between cut-off blocks appearing on the edges and crop them later, which leaves individual remaining pixels as they are (the most purist option), or loose picture quality by zooming in and hide the cuttings (the standard but most dirty option).
So, it's a pretty dirty thing to do! But if the shakying is mild and you don't care about some quality loss, or if the things you care about are in the middle and don't care about cropping, it's ok even for a purist.

Finally found a open source combination which gave good results and was not too complicated:
virtualdub + deshaker

The website of deshaker is quite self-explanatory, and there exist many good tutorials on the web (i got only german ones). I only want to put the hint.

Great bonus:
more recent versions of deshaker can also compensate for the ugly rolling shutter artifact, a design flaw that all CMOS based consumer cameras have. Deshaker can compensate for this, as long as the movement originates from the camera not the object. Fore more details on the percentage value check deshaker homepage (for my cam I had to pick 38% instead of default 88%).

my current material is interlaced. To minimize encoding/decoding (inherent quality loss), it's possible to deinterlace and deshake at once by simple putting yadif and deshake as the second filter in the filter chain. The deshaker first and second pass run in parallel with yadif deinterlacer (which had to do the same work twice). If you are abundant of disk space, you can deinterlace into a lossless container (such as huffyuv), and do the deshakeing on this one, this way speeding up things without quality loss.

yadif: excellent open source bobbing deinterlacer

I made some really nice videos on my last hollidays with my canon hv20. Unfortunately, somehow, the cam unnotedly reset some settings and I recorded everything in the interlaced mode instead of using the progressive mode (interlaced: made for old TV, but not PC screens, using a dirty old trick, giving double the temporal resolution, but only half the spatial resolution: alternating interlaced half-images aka "fields". progressive: half the framerate, but full "true" pictures aka "frames"). That's bad because this way, I need to deinterlace all the stuff I might want to use for my purposes (that is the process to convert from interlaced to progressive. It's a dirty thing, in principle).
The good thing is, that you can get the double progressive framerate out of it. Normally, this variant of deinterlacing, called "bobbing" or "blending", depending on the scenes, involves big quality loss, but there exist really smart algorithms now which result in quite good quality (meaning few deinterlacing artefacts).
Although common NLE video editors like FinalCutExpress do offer deinterlacing, and some of them also bobbing, often their built-in algorithm are not particularly good (Vegas 8 interpolate deinterlacer allows quite good bobbing though).

There are several good free open source deinterlacers. The hero of the hour, is yadif. It offers you all important variants of deinterlacing, including bobbing. The results are really good, one of the bests out there, but even better, considering the quality, the speed is excellent (adaptive motion compensation can be a veeery slow task). Yadif is included in players such as VLC and (k)mplayer. For encoding/transcoding matters, you can get it along with virtualdub (windows only. mpeg2/ac3/wmv plugins) and avidemux (mac, linux, windows).

Be careful: the outcome quality depends largely on the codec choice and it's parameters. That's what be the next post about