[FFmpeg-devel] Frame blending filter

[Mark Himsley]

On 20/05/2011 16:31, Stefano Sabatini wrote:
> On date Friday 2011-05-20 12:36:57 +0200, Robert Krüger encoded:
>>
>> Hi,
>>
>> I'm trying to make slomos smoother, e.g. interpolating 25fps to
>> 50fps to have a smooth 50% slomo when the resulting 50 fps is played
>> back at 25 fps. My understanding is that no filter for that kind of
>> thing exists currently as part of ffmpeg. AFAIK ffmpeg just
>> duplicates frames when increasing frame rate or allows framerate to
>> be interpreted differently using the setPTS filter.
>>
> 
>> As a "cheap" alternative to real frame interpolation (which would
>> probably involve motion vectors, I suppose btw. are these exposed in
>> public API at the moment?) I'm thinking about playing around with a
>> frame blending filter, i.e. one that computes frames as a weighted
>> average between a adjacent frames in the original material. Does
>> anyone have a recommendation, which existing filter would be a good
>> starting point to get into the topic?
> 
> You can find blending utils in overlay, exporting them in a separate
> file may be a good idea. Then you may need some form of buffering
> depending on the framerate that you want to achieve, maybe you can get
> some idea from the fps filter in the soc repo (one of the few never
> integrated).

An interlaced aware, frame blending, frame rate converter would be very
useful for ~30i => 25i conversions. I, for one, would start using it
immediately.
An interlaced aware, motion estimation, frame rate converter is the
Holey Grail for ~30i => 25i conversions, and would be fantastic.


> And of course if you plan to integrate the filter into FFmpeg I'll be
> glad to help.
> 
>> Thanks very much,

-- 
Mark