gistfile1.txt

ffmpeg -i sc.mp4 "[2:v] scale=-1:240 [cam]; [1:v][cam] overlay" -r 30 -c:v libx264 -crf 17 -preset ultrafast -c:a ac3  sc2.mp4
ffmpeg version 2.2.1 Copyright (c) 2000-2014 the FFmpeg developers
  built on Apr 10 2014 16:26:13 with gcc 4.8.2 (GCC) 20140206 (prerelease)
  configuration: --prefix=/usr --disable-debug --disable-static --enable-avresample --enable-dxva2 --enable-fontconfig --enable-gnutls --enable-gpl --enable-libass --enable-libbluray --enable-libfreetype --enable-libgsm --enable-libmodplug --enable-libmp3lame --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librtmp --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libv4l2 --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-libxvid --enable-pic --enable-postproc --enable-runtime-cpudetect --enable-shared --enable-swresample --enable-vdpau --enable-version3 --enable-x11grab
  libavutil      52. 66.100 / 52. 66.100
  libavcodec     55. 52.102 / 55. 52.102
  libavformat    55. 33.100 / 55. 33.100
  libavdevice    55. 10.100 / 55. 10.100
  libavfilter     4.  2.100 /  4.  2.100
  libavresample   1.  2.  0 /  1.  2.  0
  libswscale      2.  5.102 /  2.  5.102
  libswresample   0. 18.100 /  0. 18.100
  libpostproc    52.  3.100 / 52.  3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'sc.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf55.33.100
  Duration: 00:00:07.01, start: 0.005333, bitrate: 7073 kb/s
    Stream #0:0(und): Audio: ac3 (ac-3 / 0x332D6361), 48000 Hz, stereo, fltp, 192 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
    Stream #0:1(und): Video: h264 (High 4:4:4 Predictive) (avc1 / 0x31637661), yuv444p, 640x480, 1090 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:2(und): Video: h264 (High 4:4:4 Predictive) (avc1 / 0x31637661), yuv422p, 320x240, 7983 kb/s, 30 fps, 30 tbr, 15360 tbn, 60 tbc
    Metadata:
      handler_name    : VideoHandler
[NULL @ 0x9a1c20] Unable to find a suitable output format for '[2:v] scale=-1:240 [cam]; [1:v][cam] overlay'
[2:v] scale=-1:240 [cam]; [1:v][cam] overlay: Invalid argument