помогите сконверитровать xVid в mp4

  built on Apr 13 2012 10:52:01 with gcc 4.4.5
  configuration: --disable-vaapi
  libavutil      51. 46.100 / 51. 46.100
  libavcodec     54. 14.101 / 54. 14.101
  libavformat    54.  3.100 / 54.  3.100
  libavdevice    53.  4.100 / 53.  4.100
  libavfilter     2. 69.101 /  2. 69.101
  libswscale      2.  1.100 /  2.  1.100
  libswresample   0. 11.100 /  0. 11.100
Input #0, avi, from '/home/user1/Downloads/file.avi':
  Metadata:
    encoder         : VirtualDubMod 1.5.10.2 (build 2540/release)
  Duration: 03:06:49.96, start: 0.000000, bitrate: 1115 kb/s
    Stream #0:0: Video: mpeg4 (Advanced Simple Profile) (XVID / 0x44495658), yuv420p, 704x304 [SAR 1:1 DAR 44:19], 25 tbr, 25 tbn, 25 tbc
    Stream #0:1: Audio: ac3 ([0] [0][0] / 0x2000), 48000 Hz, stereo, s16, 192 kb/s

[NULL @ 0xa553540] Codec is experimental but experimental codecs are not enabled, see -strict -2
Output #0, mp4, to '/home/user1/output.mp4':
  Metadata:
    encoder         : VirtualDubMod 1.5.10.2 (build 2540/release)
    Stream #0:0: Video: mpeg4, yuv420p, 704x304 [SAR 1:1 DAR 44:19], q=2-31, 200 kb/s, 90k tbn, 25 tbc
    Stream #0:1: Audio: none, 48000 Hz, stereo, flt, 128 kb/s
Stream mapping:
  Stream #0:0 -> #0:0 (mpeg4 -> mpeg4)
  Stream #0:1 -> #0:1 (ac3 -> aac)
Error while opening encoder for output stream #0:1 - maybe incorrect parameters such as bit_rate, rate, width or height