Quiet down ffmpeg logs

[markcerqueira]

For each .wav to .m4a conversion, ffmpeg outputs the a large chunk of log statements (see below). We don't need this much information. Configure/compile/run ffmpeg to log less.

ffmpeg version git-2017-01-14-3ac46a0 Copyright (c) 2000-2017 the FFmpeg developers
  built with gcc 4.9.2 (Debian 4.9.2-10)
  configuration: --enable-libfdk-aac
  libavutil      55. 43.100 / 55. 43.100
  libavcodec     57. 72.100 / 57. 72.100
  libavformat    57. 62.100 / 57. 62.100
  libavdevice    57.  2.100 / 57.  2.100
  libavfilter     6. 69.100 /  6. 69.100
  libswscale      4.  3.101 /  4.  3.101
  libswresample   2.  4.100 /  2.  4.100
Guessed Channel Layout for Input Stream #0.0 : stereo
Input #0, wav, from 'resources/57b1f2b4c994b66bf82d9f65308ffeafa5824b7e2469b7ecbffbdf99d6f7de57.wav':
  Duration: 00:00:30.00, bitrate: 1536 kb/s
    Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 48000 Hz, stereo, s16, 1536 kb/s
[libfdk_aac @ 0x2440ee0] Note, the VBR setting is unsupported and only works with some parameter combinations
Output #0, ipod, to 'resources/57b1f2b4c994b66bf82d9f65308ffeafa5824b7e2469b7ecbffbdf99d6f7de57.m4a':
  Metadata:
    encoder         : Lavf57.62.100
    Stream #0:0: Audio: aac (libfdk_aac) (mp4a / 0x6134706D), 48000 Hz, stereo, s16
    Metadata:
      encoder         : Lavc57.72.100 libfdk_aac
Stream mapping:
  Stream #0:0 -> #0:0 (pcm_s16le (native) -> aac (libfdk_aac))
Press [q] to stop, [?] for help
size=     226kB time=00:00:30.01 bitrate=  61.6kbits/s speed=60.5x
video:0kB audio:220kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 2.838930%
172.17.0.1 - - [19/Jan/2017:06:35:40 +0000] "POST /render/ HTTP/1.1" 200 231185 2.8421
[chuck](VM): sporking incoming shred: 2 (204f63b3af836d85201ff0587ce57f4a.ck)...
ffmpeg version git-2017-01-14-3ac46a0 Copyright (c) 2000-2017 the FFmpeg developers
  built with gcc 4.9.2 (Debian 4.9.2-10)
  configuration: --enable-libfdk-aac
  libavutil      55. 43.100 / 55. 43.100
  libavcodec     57. 72.100 / 57. 72.100
  libavformat    57. 62.100 / 57. 62.100
  libavdevice    57.  2.100 / 57.  2.100
  libavfilter     6. 69.100 /  6. 69.100
  libswscale      4.  3.101 /  4.  3.101
  libswresample   2.  4.100 /  2.  4.100
Guessed Channel Layout for Input Stream #0.0 : stereo
Input #0, wav, from 'resources/2d233ae623da0b06b943a132a811993b70a0956a0d7ea4b331324c555da3f3e9.wav':
  Duration: 00:00:20.00, bitrate: 1536 kb/s
    Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 48000 Hz, stereo, s16, 1536 kb/s
[libfdk_aac @ 0x3d17ee0] Note, the VBR setting is unsupported and only works with some parameter combinations
Output #0, ipod, to 'resources/2d233ae623da0b06b943a132a811993b70a0956a0d7ea4b331324c555da3f3e9.m4a':
  Metadata:
    encoder         : Lavf57.62.100
    Stream #0:0: Audio: aac (libfdk_aac) (mp4a / 0x6134706D), 48000 Hz, stereo, s16
    Metadata:
      encoder         : Lavc57.72.100 libfdk_aac
Stream mapping:
  Stream #0:0 -> #0:0 (pcm_s16le (native) -> aac (libfdk_aac))
Press [q] to stop, [?] for help
size=     140kB time=00:00:20.01 bitrate=  57.4kbits/s speed=74.2x
video:0kB audio:136kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 3.238465%