[FFmpeg-devel] [PATCH / RFC] Deshake / stabilize filter

[Michael Niedermayer]

On Mon, Apr 12, 2010 at 12:49:47PM -0400, Daniel G. Taylor wrote:
> Hey,
>
> Attached is a filter I wrote over the weekend for fun to stabilize an input 
> video by shifting frames horizontally and vertically. It's fast (uses 
> MMX/SSE/etc) and fairly accurate.
>
> I am just learning about block matching, motion searches, and various other 
> concepts and this is an algorithm I came up with reading various things 
> online and in some free papers. The algorithm is described in the comments 
> of the patch in plain English. There are still a few things I'm confused 
> about / working on but here are some quick results from my Vado HD pocket 
> camera in a real world scenario:
>
> http://programmer-art.org/dropbox/deshake_dog_orig.mp4
> http://programmer-art.org/dropbox/deshake_dog_32.mp4
>
> And here is an unrealistic example to show the strengths and weaknesses of 
> the filter in its current state (e.g. no rotation support):
>
> http://programmer-art.org/dropbox/deshake_table_orig.mp4
> http://programemr-art.org/dropbox/deshake_table_32.mp4
>
> The filter is licensed under the LGPL and I'd like to:
>
>   1. Ask for comments, suggestions, etc to make it better
>   2. Get it into FFmpeg trunk

this filter is very interresting but
could you look at motion_est* please, the code there likely can be used.
Changing or extending motion_est* so it has a nice public API would for
this be required but i think its the better approuch than having
each filter and codec duplicate motion estimation.

[...]

> + * TODO:
> + *   - Compensate for rotation (requires full transform, slower)
> + *   - Zoom instead of filling frame edges (requires full transform, slower)

> + *   - Fill frame edges based on previous/next reference frames

1. allocate a larger internal picture
2. for each frame match its contents to the larger picture and copy the new
   frame in there. If no good match reset things and draw in the middle
3. output center portion of the larger internal picture or smooth motion
   to compensate for panning and output the resulting rectangle

With this you not only fill in cornrs fron the next/prev frames but even
more distant frames.
And it might work for something else too. If you pan a cammera over a static
scene the internal picture should then contain the whole thing stitched
together

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

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