title: invalid frame size error while using WxH in ffmpeg
body: <p>I am trying to convert a video to images.</p>
  
  <pre><code>ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg 
  </code></pre>
  
  <p>But every time it shows error in Windows CMD :</p>
  
  <pre><code>Invalid frame size: WxH.
  </code></pre>
  
  <p>The full Error code is posted below</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>C:\Users\HP\Desktop\New folder&gt;ffmpeg -i "C:\Users\HP\Desktop\foo.mp4" -r 1 -s WxH -f image2 afoo-%03d.jpeg
  ffmpeg version 3.4 Copyright (c) 2000-2017 the FFmpeg developers
    built with gcc 7.2.0 (GCC)
    configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-bzlib --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libshine --enable-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 --enable-libvidstab --enable-libvorbis --enable-cuda --enable-cuvid --enable-d3d11va --enable-nvenc --enable-dxva2 --enable-avisynth --enable-libmfx
    libavutil      55. 78.100 / 55. 78.100
    libavcodec     57.107.100 / 57.107.100
    libavformat    57. 83.100 / 57. 83.100
    libavdevice    57. 10.100 / 57. 10.100
    libavfilter     6.107.100 /  6.107.100
    libswscale      4.  8.100 /  4.  8.100
    libswresample   2.  9.100 /  2.  9.100
    libpostproc    54.  7.100 / 54.  7.100
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'C:\Users\HP\Desktop\foo.mp4':
    Metadata:
      major_brand     : isom
      minor_version   : 512
      compatible_brands: isomiso2avc1mp41
      encoder         : Lavf56.40.101
    Duration: 00:00:45.05, start: 0.000000, bitrate: 1163 kb/s
      Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709), 854x480 [SAR 1:1 DAR 427:240], 1032 kb/s, 25.02 fps, 25 tbr, 90k tbn, 50 tbc (default)
      Metadata:
        handler_name    : VideoHandler
      Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 125 kb/s (default)
      Metadata:
        handler_name    : SoundHandler
  Invalid frame size: WxH.</code></pre>
  </div>
  </div>
  </p>
  
  <p>I tried with multiple video formats and video sizes but still not working :(</p>
  
  <p>I've checked whether it is really 'x' and I typed it by hand.
  <a href="https://stackoverflow.com/questions/39780949/invalid-frame-size-while-using-ffmpeg">This question</a> implies about the 'x' problem and mine is different.</p>