title: How to compile ffmpeg to get only mp3 and mp4 support
body: <p>I'm building Electron app and I use ffmpeg to convert m4a or webm files to mp3, and also to merge video only mp4 with m4a audio file to mp4.</p>
  
  <p>I am able to achieve this using [media-autobuild-suite] (<a href="https://github.com/jb-alvarado/media-autobuild_suite" rel="noreferrer">https://github.com/jb-alvarado/media-autobuild_suite</a>), using light build option, but the size of static files is arround 20mb and I'would like to shrink it a little bit more. I've compiled ffmpeg and ffprobe with this configuration.</p>
  
  <pre><code>--disable-libaom
  --disable-version3
  # Full
  --disable-chromaprint
  --disable-cuda-sdk
  --disable-decklink
  --disable-frei0r
  --disable-libbs2b
  --disable-libcaca
  --disable-libcdio
  --disable-libfdk-aac
  --disable-libflite
  --disable-libfribidi
  --disable-libgme
  --disable-libgsm
  --disable-libilbc
  --disable-libkvazaar
  --disable-libmodplug
  --disable-libnpp
  --disable-libopenh264
  --disable-libopenmpt
  --disable-librtmp
  --disable-librubberband
  --disable-libssh
  --disable-libtesseract
  --disable-libxavs
  --disable-libzmq
  --disable-libzvbi
  --disable-opencl
  --disable-opengl
  --disable-libvmaf
  --disable-libcodec2
  --disable-libsrt
  --disable-ladspa
  --disable-ffplay
  #--enable-vapoursynth
  #--enable-liblensfun
  --disable-libndi_newtek
  
  --enable-demuxer=mp3
  --enable-demuxer=mov
  --enable-demuxer=opus
  
  --enable-parser=ac3
  --enable-parser=mpegaudio
  --enable-parser=h264
  --enable-parser=opus
  
  --enable-protocol=file
  --enable-protocol=pipe
  
  --enable-decoder=mp3
  --enable-decoder=mp4
  --enable-decoder=opus
  
  --enable-encoder=mp3
  --enable-encoder=mp4
  --enable-encoder=opus
  </code></pre>
  
  <p>With this configuration I'm getting ffmpeg static file arround 2mb and ffprobe static file arround 2mb but with this error. </p>
  
  <pre><code>C:\Users\Admin\Desktop\ffmpeg compilations\2mb\local64&gt;ffmpeg -i simple.m4a simple.mp3 
  ffmpeg version N-93147-g9326117bf6 Copyright (c) 2000-2019 the FFmpeg developers built with gcc 8.2.1 (Rev1, Built by MSYS2 project) 20181214
  configuration:  .... //here comes configuration as described above
  libavutil      56. 26.100 / 56. 26.100
  libavcodec     58. 47.102 / 58. 47.102
  libavformat    58. 26.101 / 58. 26.101
  libavdevice    58.  6.101 / 58.  6.101
  libavfilter     7. 48.100 /  7. 48.100
  libswscale      5.  4.100 /  5.  4.100
  libswresample   3.  4.100 /  3.  4.100
  libpostproc    55.  4.100 / 55.  4.100
  Guessed Channel Layout for Input Stream #0.0 : stereo
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'simple.m4a':
  Metadata:
    major_brand     : dash
    minor_version   : 0
    compatible_brands: iso6mp41
    creation_time   : 2018-10-31T19:47:32.000000Z
  Duration: 00:02:38.92, start: 0.000000, bitrate: 127 kb/s
  Stream #0:0(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, 7 kb/s (default)
  Metadata:
    creation_time   : 2018-10-31T19:47:32.000000Z
    handler_name    : SoundHandler
  [NULL @ 0000000000486200] Unable to find a suitable output format for 'simple.mp3' 
  simple.mp3: Invalid argument
  </code></pre>
  
  <p>Any ideas what else should I include into this static file?</p>