libavutil      51. 37.100 / 51. 37.100
  libavcodec     54.  0.102 / 54.  0.102
  libavformat    54.  0.100 / 54.  0.100
  libavdevice    53.  4.100 / 53.  4.100
  libavfilter     2. 61.100 /  2. 61.100
  libswscale      2.  1.100 /  2.  1.100
  libswresample   0.  6.100 /  0.  6.100
  libpostproc    52.  0.100 / 52.  0.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'smurfs.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    creation_time   : 1970-01-01 00:00:00
    encoder         : Lavf53.9.0
  Duration: 01:42:43.17, start: 0.000000, bitrate: 5079 kb/s
    Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1280x720, 4577 kb/s, 23.98 fps, 47.92 tbr, 2500k tbn, 47.95 tbc
    Metadata:
      creation_time   : 1970-01-01 00:00:00
      handler_name    : VideoHandler
    Stream #0:1(eng): Audio: aac (mp4a / 0x6134706D), 48000 Hz, 5.1, s16, 495 kb/s
    Metadata:
      creation_time   : 1970-01-01 00:00:00
      handler_name    :
Incompatible sample format 's16' for codec 'ac3', auto-selecting format 'flt'
[ac3 @ 0x1705880] channel_layout not specified
[ac3 @ 0x1705880] No channel layout specified. The encoder will guess the layout, but it might be incorrect.
[ac3 @ 0x1705880] invalid bit rate
Output #0, mp4, to 'smurfstest.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    creation_time   : 1970-01-01 00:00:00
    encoder         : Lavf53.9.0
    Stream #0:0(eng): Video: h264, yuv420p, 1280x720, q=2-31, 4577 kb/s, 23.98 fps, 90k tbn, 2500k tbc
    Metadata:
      creation_time   : 1970-01-01 00:00:00
      handler_name    : VideoHandler
    Stream #0:1(eng): Audio: ac3, 48000 Hz, 5.1(side), flt, 0 kb/s
    Metadata:
      creation_time   : 1970-01-01 00:00:00
      handler_name    :
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #0:1 -> #0:1 (aac -> ac3)
Error while opening encoder for output stream #0:1 - maybe incorrect parameters such as bit_rate, rate, width or height