title: What is the cause of this green and yellow ffmpeg artifact?
body: <p>I'm trying to convert a series of image frames into a video with <code>ffmpeg</code>. For some of the image series, I am getting a strange yellow/green artifact and I'm not sure what setting in the conversion is causing the artifact or the best way to fix it.</p>
  
  <p>The command I'm using for the conversion is</p>
  
  <pre><code>ffmpeg -f concat -safe 0 -i inputs.txt -c:v libx264 -pix_fmt yuv420p -r 10 -vf "scale=1024:-2" -movflags +faststart video.mp4
  </code></pre>
  
  <p>A reproducible example with three image files and an associated <code>inputs.txt</code> file indicating the files and associated durations can be downloaded <a href="https://www.dropbox.com/s/a3golifkg8ntxrm/ffmpeg_issue.zip?dl=0" rel="nofollow noreferrer">here (Dropbox link)</a></p>
  
  <p>Here's the resulting artifact</p>
  
  <p><a href="https://i.stack.imgur.com/eLdrg.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/eLdrg.png" alt="enter image description here"></a></p>
  
  <p>And the GIF of the output</p>
  
  <p><a href="https://i.stack.imgur.com/2zbjX.gif" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/2zbjX.gif" alt="enter image description here"></a></p>
  
  <p>What settings could be causing this artifact, and what can I do to try to reduce/remove the artifact from the video? This happens on both versions of <code>ffmpeg</code> that I have tried:</p>
  
  <pre><code>ffmpeg version 3.4.1 Copyright (c) 2000-2017 the FFmpeg developers
    built with Apple LLVM version 9.0.0 (clang-900.0.39.2)
    configuration: --prefix=/usr/local/Cellar/ffmpeg/3.4.1 --enable-shared --enable-pthreads --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-gpl --enable-libmp3lame --enable-libx264 --enable-libxvid --enable-opencl --enable-videotoolbox --disable-lzma
  
  ffmpeg version 3.1-tessus Copyright (c) 2000-2016 the FFmpeg developers
    built with Apple LLVM version 6.0 (clang-600.0.57) (based on LLVM 3.5svn)
    configuration: --cc=/usr/bin/clang --prefix=/opt/ffmpeg --as=yasm --extra-version=tessus --enable-avisynth --enable-fontconfig --enable-gpl --enable-libass --enable-libbluray --enable-libfreetype --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopus --enable-libschroedinger --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzmq --enable-version3 --disable-ffplay --disable-indev=qtkit --disable-indev=x11grab_xcb
  </code></pre>
  
  <p>Any insight is appreciated.</p>