The best replacement for ffmpeg is mencoder.

The best alternatives to ffmpeg are rated as following:
★★★★★  mencoder
★★★  x264
★★★  handbrake
★★★  avconv
★★  xvid
★★  gstreamer
★  lame
★  libav
★  directshow
★  ffdshow
★  faac
★  x264 handbrake
★  h264
★  lav
★  handbrake cli
★  h 264
★  hcenc
★  mpeg2enc
  264
  coreavc
  mplayer
  h.264
  mp4box
  mcoder
  libavcodec
  ffmbc

Your alternative for ffmpeg is not listed? Suggest!
Speaking about ffmpeg, one probably shouldn't forget about libfaac.

Other search terms related to ffmpeg and their ratings are:
★★★★★ libfaac
★★★★ x264
★★★★ libfdk_aac
★★★ libx264
★★★ yasm
★★ audacity
★★ h264
★ transcoding
★ aac
★ opencv
★ amr
You have in mind a companion for ffmpeg and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of ffmpeg in all years. Click on graph for more.
ffmpeg
mencoder
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