title: Convert flv to mp4 using ffmpeg
body: <p>I'd like to convert flv file to mp4 file which is sent through RTMP protocol to Wowza server. The flv file details are..</p>
  
  <pre><code>video codec - Sorenson Spark
  Audio codec - Nellymoser 16khz
  </code></pre>
  
  <p>I'm currently using the following code is as follows...</p>
  
  <pre><code>ProcessBuilder processBuilder = new ProcessBuilder(ffmpegApp, "-i", filenameIn,
                  "-ar", "22050", filenameOut);
  </code></pre>
  
  <p>When I start process buider I'm getting following error info...</p>
  
  <pre><code>FFmpeg version SVN-r23607, Copyright (c) 2000-2010 the FFmpeg developers
  built on Jun 15 2010 04:09:35 with gcc 4.4.2
  configuration: --target-os=mingw32 --enable-runtime-cpudetect --enable-avisynth --enable-gpl --enable-version3 --enable-bzlib --enable-libgsm --enable-libfaad --enable-pthreads --enable-libvorbis --enable-libtheora --enable-libspeex --enable-libmp3lame --enable-libopenjpeg --enable-libxvid --enable-libschroedinger --enable-libx264 --extra-libs='-lx264 -lpthread' --enable-libopencore_amrwb --enable-libopencore_amrnb --enable-librtmp --extra-libs='-lrtmp -lpolarssl -lws2_32 -lwinmm' --arch=x86 --cross-prefix=i686-mingw32- --cc='ccache i686-mingw32-gcc' --enable-memalign-hack
  
  
  libavutil     50.19. 0 / 50.19. 0
  libavcodec    52.76. 0 / 52.76. 0
  libavformat   52.68. 0 / 52.68. 0
  libavdevice   52. 2. 0 / 52. 2. 0
  libavfilter    1.20. 0 /  1.20. 0
  libswscale     0.11. 0 /  0.11. 0
  [flv @ 01a0d0a0]Unsupported audio codec (4)
  Last message repeated 54 times
  [flv @ 01a0d0a0]Could not find codec parameters (Audio: [4][0][0][0] / 0x0004, 5512Hz,   1 channels)
  [flv @ 01a0d0a0]Estimating duration from bitrate, this may be inaccurate
  Input #0, flv, from 'C:\Program Files (x86)\Wowza Media Systems\Wowza Media Server         3.6.2\content\iStream.flv':
   Metadata:
   duration        : 11
   creationdate    : Tue Aug 13 13:21:15
   Duration: 00:00:11.19, start: 0.000000, bitrate: N/A
  Stream #0.0: Video: flv, yuv420p, 192x144, 1k tbr, 1k tbn, 1k tbc
  Stream #0.1: Audio: [4][0][0][0] / 0x0004, 5512 Hz, 1 channels
  </code></pre>