[FFmpeg-user] ffmpeg reports no colorkey filter

[qw]

Hi,


I use the below command to run colorkey filter, but ffmpeg report there is no colorkey filter:


[root at localhost ffmpegOverlay]# ffmpeg -i ./transparent_3.png -vf colorkey=green ./transparent_3_test1.png
ffmpeg version 2.7.1 Copyright (c) 2000-2015 the FFmpeg developers
  built with gcc 4.4.7 (GCC) 20120313 (Red Hat 4.4.7-11)
  configuration: --enable-gpl --enable-libx264
  libavutil      54. 27.100 / 54. 27.100
  libavcodec     56. 41.100 / 56. 41.100
  libavformat    56. 36.100 / 56. 36.100
  libavdevice    56.  4.100 / 56.  4.100
  libavfilter     5. 16.101 /  5. 16.101
  libswscale      3.  1.101 /  3.  1.101
  libswresample   1.  2.100 /  1.  2.100
  libpostproc    53.  3.100 / 53.  3.100
Input #0, png_pipe, from './transparent_3.png':
  Duration: N/A, bitrate: N/A
    Stream #0:0: Video: png, rgba(pc), 256x256, 25 tbr, 25 tbn, 25 tbc
[AVFilterGraph @ 0x1d1e900] No such filter: 'colorkey'
Error opening filters!


I find ffmpeg supports colorkey filter as shown below. But why does ffmpeg report there is no colorkey filter?
http://ffmpeg.org/ffmpeg-filters.html#colorkey


Thanks!


Andrew