[FFmpeg-devel] Scale, Rotate, Translate Matrix Op.

Joshua Grauman jnfo-c at grauman.com
Mon Jun 13 07:26:06 CEST 2011

I need arbitrary rotations to fix slight rotational errors...

I'll try to look at those functions. Thanks.


> On Monday 13 June 2011 03:26:15 Joshua Grauman wrote:
>> Unfortunately, I can't get the perspective filter to do a rotate. Does
>> anyone know if it is capable of doing them? I calculated the 4 coordinates
>> based on a rotated rectangle, so I thought it should work.
> Have you tried the transpose filter? it does 90 degree rotations.
> ffmpeg -i input.avi -vf transpose=1
> argument should be between 0 and 3.
> There are also vflip and hflip filters.
>> Also, on another note. The patch I found to do matrix transformations
>> isn't a filter as far as I can tell from looking at the code. It looks
>> like it's just a function to do the actual matrix transformation. How hard
>> would it be to write a filter to make use of this code? Any stub filters I
>> can look at? Anyone willing to give me a hand at doing it? Thanks!
> Writing a filter shouldn't be too hard, look at libavfilter/vf_transpose.c for
> example. All callbacks are well documented in libavfilter/avfilter.h

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