Lensfun is a library that applies lens correction to an image using a
database of cameras/lenses (you provide the camera and lens models, and
it uses the corresponding database entry's parameters to apply lens
correction). It is licensed under LGPL3.
The lensfun filter utilizes the lensfun library to apply lens
correction to videos as well as images.
This filter was created out of necessity since I wanted to apply lens
correction to a video and the lenscorrection filter did not work for me.
While this filter requires little info from the user to apply lens
correction, the flaw is that lensfun is intended to be used on indvidual
images. When used on a video, the parameters such as focal length is
constant, so lens correction may fail on videos where the camera's focal
length changes (zooming in or out via zoom lens). To use this filter
correctly on videos where such parameters change, timeline editing may
be used since this filter supports it.
Note that valgrind shows a small memory leak which is not from this
filter but from the lensfun library (memory is allocated when loading
the lensfun database but it somehow isn't deallocated even during
cleanup; it is briefly created in the init function of the filter, and
destroyed before the init function returns). This may have been fixed by
the latest commit in the lensfun repository; the current latest release
of lensfun is almost 3 years ago.
Bi-Linear interpolation is used by default as lanczos interpolation
shows more artifacts in the corrected image in my tests.
The lanczos interpolation is derived from lenstool's implementation of
lanczos interpolation. Lenstool is an app within the lensfun repository
which is licensed under GPL3.
v2 of this patch fixes license notice in libavfilter/vf_lensfun.c
v3 of this patch fixes code style and dependency to gplv3 (thanks to
Paul B Mahol for pointing out the mentioned issues).
v4 of this patch fixes more code style issues that were missed in
v3.
v5 of this patch adds line breaks to some of the documentation in
doc/filters.texi (thanks to Gyan Doshi for pointing out the issue).
v6 of this patch fixes more problems (thanks to Moritz Barsnick for
pointing them out).
v7 of this patch fixes use of sqrt() (changed to sqrtf(); thanks to
Moritz Barsnick for pointing this out). Also should be rebased off of
latest master branch commits at this point.
Signed-off-by: Stephen Seo <seo.disparate@gmail.com>
At present, box size is clipped to frame size before being drawn,
which can lead to the box not fully covering animated text which is
longer than one or both frame dimensions.
Since ff_blend_rectangle correctly takes care of clipping, it is skipped
here which results in correct box sizing
This filter does HDR(HDR10/HLG) to SDR conversion with tone-mapping.
An example command to use this filter with vaapi codecs:
FFMPEG -init_hw_device vaapi=va:/dev/dri/renderD128 -init_hw_device \
opencl=ocl@va -hwaccel vaapi -hwaccel_device va -hwaccel_output_format \
vaapi -i INPUT -filter_hw_device ocl -filter_complex \
'[0:v]hwmap,tonemap_opencl=t=bt2020:tonemap=linear:format=p010[x1]; \
[x1]hwmap=derive_device=vaapi:reverse=1' -c:v hevc_vaapi -profile 2 OUTPUT
Signed-off-by: Ruiling Song <ruiling.song@intel.com>
HMS is formatted as HH:MM:SS.mmm, but, HH part is not limited to
24 hours. For example, the the drawn text may look like this:
243029:20:30.342. To present the timestamp in more readable and
user friendly format, this patch provides an additional option
to limit the hour part in the range 0-23.
Note: Actually the above required format can be obtained with
format options 'localtime' and 'gmtime', but, milliseconds part
is not supported in those formats.
These files depend on libavformat, and the vf_srcnn filter
currently is the only thing utilizing these dnn_* files and
already happens to have a dependency on libavformat.
This fixes compilation in cases where libavformat is not a
dependency for libavfilter.
Reported by Kam_ on IRC.
Generates color bar test patterns based on EBU PAL recommendations.
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Tobias Rapp <t.rapp@noa-archive.com>
Paul B Mahol
Stephen Seo
Gyan Doshi
Danil Iashchenko
Ruiling Song
Jun Zhao
Shlomi Fish
Pedro Arthur
Sergey Lavrushkin
Mark Thompson
Pavel Koshevoy
Vishwanath Dixit
Jan Ekström
John Cox
James Almer
Tobias Rapp