[FFmpeg-user] wrong colors in animated GIF

[Michael Koch]

Hi,

I'm using this animated GIF as input http://gosper.org/sidereal.gif
and process it with the most simple FFmpeg command line:

ffmpeg -i sidereal.gif -y out.gif

Why are the colors wrong in the output?

I did already try to add   -vf format=pix_fmts=rgb24   but the output is 
the same.

Michael



C:\Users\mKoch\Desktop>c:\ffmpeg\ffmpeg -i sidereal.gif -y out.gif
ffmpeg version N-94982-gea673a0edb Copyright (c) 2000-2019 the FFmpeg 
developers

   built with gcc 9.2.1 (GCC) 20190918
   configuration: --enable-gpl --enable-version3 --enable-sdl2 
--enable-fontconfi
g --enable-gnutls --enable-iconv --enable-libass --enable-libdav1d 
--enable-libb
luray --enable-libfreetype --enable-libmp3lame 
--enable-libopencore-amrnb --enab
le-libopencore-amrwb --enable-libopenjpeg --enable-libopus 
--enable-libshine --e
nable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame 
--enable
-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 
--enable-libx265 -
-enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib 
--enable-gmp --enab
le-libvidstab --enable-libvorbis --enable-libvo-amrwbenc 
--enable-libmysofa --en
able-libspeex --enable-libxvid --enable-libaom --enable-libmfx 
--enable-ffnvcode
c --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec 
--enable-dxva2 -
-enable-avisynth --enable-libopenmpt --enable-amf
   libavutil      56. 35.100 / 56. 35.100
   libavcodec     58. 58.101 / 58. 58.101
   libavformat    58. 32.104 / 58. 32.104
   libavdevice    58.  9.100 / 58.  9.100
   libavfilter     7. 58.102 /  7. 58.102
   libswscale      5.  6.100 /  5.  6.100
   libswresample   3.  6.100 /  3.  6.100
   libpostproc    55.  6.100 / 55.  6.100
Input #0, gif, from 'sidereal.gif':
   Metadata:
     comment         : Created by Wolfram Mathematica 9.0 : www.wolfram.com
   Duration: 00:00:24.10, start: 0.000000, bitrate: 2782 kb/s
     Stream #0:0: Video: gif, bgra, 1000x1000, 10 fps, 10 tbr, 100 tbn, 
100 tbc
Stream mapping:
   Stream #0:0 -> #0:0 (gif (native) -> gif (native))
Press [q] to stop, [?] for help
Output #0, gif, to 'out.gif':
   Metadata:
     comment         : Created by Wolfram Mathematica 9.0 : www.wolfram.com
     encoder         : Lavf58.32.104
     Stream #0:0: Video: gif, bgr8, 1000x1000, q=2-31, 200 kb/s, 10 fps, 
100 tbn,
  10 tbc
     Metadata:
       encoder         : Lavc58.58.101 gif
frame=   19 fps=0.0 q=-0.0 size=     210kB time=00:00:01.81 bitrate= 
950.2kbits/
frame=   38 fps= 36 q=-0.0 size=     256kB time=00:00:03.71 bitrate= 
565.3kbits/
frame=   56 fps= 36 q=-0.0 size=     512kB time=00:00:05.51 bitrate= 
761.2kbits/
frame=   74 fps= 36 q=-0.0 size=     768kB time=00:00:07.31 bitrate= 
860.7kbits/
frame=   93 fps= 36 q=-0.0 size=    1024kB time=00:00:09.21 bitrate= 
910.8kbits/
frame=  112 fps= 36 q=-0.0 size=    1024kB time=00:00:11.11 bitrate= 
755.1kbits/
frame=  131 fps= 36 q=-0.0 size=    1280kB time=00:00:13.01 bitrate= 
806.0kbits/
frame=  150 fps= 36 q=-0.0 size=    1536kB time=00:00:14.91 bitrate= 
843.9kbits/
frame=  169 fps= 36 q=-0.0 size=    1792kB time=00:00:16.81 bitrate= 
873.3kbits/
frame=  187 fps= 36 q=-0.0 size=    2048kB time=00:00:18.61 bitrate= 
901.5kbits/
frame=  206 fps= 36 q=-0.0 size=    2304kB time=00:00:20.51 bitrate= 
920.3kbits/
frame=  225 fps= 36 q=-0.0 size=    2304kB time=00:00:22.41 bitrate= 
842.2kbits/
frame=  241 fps= 36 q=-0.0 Lsize=    2688kB time=00:00:24.01 bitrate= 
917.0kbits
/s speed=3.57x
video:2688kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB 
muxing
overhead: 0.000727%