[FFmpeg-user] [libvistab] bicubic interpolation low exposure artefacts

[Vukovics Mihaly]

Hello Guys,

when using vidstabtransfor to stabilize videos with BICUBIC 
interpolation, the low exposure (0?) pixels are turned to white, causing 
white artefacts in the video.
Using other than bicubic interpolation(none, linear, bilinear) works well.

It is indepentdent to other setting like postprocessing, video codec and 
others.

You may check the results here: 
http://informatik.hu/ffmpeg-vidstab-artefacts-bicubic.png

Tried the Windows build from zeranoe:

$ ffmpeg -version
ffmpeg version N-87306-g6743351 Copyright (c) 2000-2017 the FFmpeg 
developers
built with gcc 7.2.0 (GCC)
configuration: --disable-static --enable-shared --enable-gpl 
--enable-version3 --enable-cuda --enable-cuvid --enable-d3d11va 
--enable-dxva2 --enable-libmfx --enable-nvenc --enable-avisynth 
--enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls 
--enable-iconv --enable-libass --enable-libbluray --enable-libbs2b 
--enable-libcaca --enable-libfreetype --enable-libgme --enable-libgsm 
--enable-libilbc --enable-libmodplug --enable-libmp3lame 
--enable-libopencore-amrnb --enable-libopencore-amrwb 
--enable-libopenh264 --enable-libopenjpeg --enable-libopus 
--enable-librtmp --enable-libsnappy --enable-libsoxr --enable-libspeex 
--enable-libtheora --enable-libtwolame --enable-libvidstab 
--enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx 
--enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 
--enable-libxavs --enable-libxvid --enable-libxml2 --enable-libzimg 
--enable-lzma --enable-zlib
libavutil      55. 75.100 / 55. 75.100
libavcodec     57.106.101 / 57.106.101
libavformat    57. 82.100 / 57. 82.100
libavdevice    57.  8.101 / 57.  8.101
libavfilter     6.105.100 /  6.105.100
libswscale      4.  7.103 /  4.  7.103
libswresample   2.  8.100 /  2.  8.100
libpostproc    54.  6.100 / 54.  6.100

And also self built on Debian Linux 8:

$ ffmpeg -version
ffmpeg version N-87278-g183216b Copyright (c) 2000-2017 the FFmpeg 
developers
built with gcc 4.9.2 (Debian 4.9.2-10)
configuration: --enable-libvidstab --enable-gpl --enable-libx264 
--enable-libx265 --enable-nonfree --enable-libass --enable-libfdk-aac 
--enable-libfreetype --enable-libmp3lame --enable-libopus 
--enable-libtheora --enable-libvorbis --enable-libvpx --enable-libxvid
libavutil      55. 74.100 / 55. 74.100
libavcodec     57.105.100 / 57.105.100
libavformat    57. 82.100 / 57. 82.100
libavdevice    57.  8.100 / 57.  8.100
libavfilter     6.105.100 /  6.105.100
libswscale      4.  7.103 /  4.  7.103
libswresample   2.  8.100 /  2.  8.100
libpostproc    54.  6.100 / 54.  6.100

Command line used to encode:

$ ffmpeg -y -t 3 -i VI000053.mp4 -vf 
vidstabtransform=:optalgo=gauss:maxangle=0.12566370614:interpol=bicubic:maxshift=54:smoothing=30:optzoom=0:zoom=0:input=VI000053-stab.trf:crop=keep 
-vcodec utvideo VI000053-stab.avi

Br,
Mihaly