ffmpeg -i input.mp4 -target ntsc-dvd output.mpg
ffmpeg version 0.8.9-6:0.8.9-1, Copyright (c) 2000-2013 the Libav developers
  built on Nov  3 2013 02:10:51 with gcc 4.7.2
*** THIS PROGRAM IS DEPRECATED ***
This program is only provided for compatibility and will be removed in a future release. Please use avconv instead.

Seems stream 0 codec frame rate differs from container frame rate: 47.95 (5994/125) -> 23.98 (24000/1001)
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 1
    compatible_brands: isomavc1
    creation_time   : 2013-07-03 14:08:03
  Duration: 01:53:43.90, start: 0.000000, bitrate: 2079 kb/s
    Stream #0.0(und): Video: h264 (High), yuv420p, 1920x816, 1979 kb/s, 23.98 fps, 23.98 tbr, 24k tbn, 47.95 tbc
    Metadata:
      creation_time   : 2013-07-03 14:08:03
    Stream #0.1(eng): Audio: aac, 48000 Hz, stereo, s16, 95 kb/s
    Metadata:
      creation_time   : 2013-07-03 14:08:10
[buffer @ 0x9dfdc80] w:1920 h:816 pixfmt:yuv420p
[scale @ 0x9df8640] w:1920 h:816 fmt:yuv420p -> w:720 h:480 fmt:yuv420p flags:0x4
Incompatible sample format 's16' for codec 'ac3', auto-selecting format 'flt'
Output #0, dvd, to 'output.mpg':
  Metadata:
    major_brand     : isom
    minor_version   : 1
    compatible_brands: isomavc1
    creation_time   : 2013-07-03 14:08:03
    encoder         : Lavf53.21.1
    Stream #0.0(und): Video: mpeg2video, yuv420p, 720x480, q=2-31, 6000 kb/s, 90k tbn, 29.97 tbc
    Metadata:
      creation_time   : 2013-07-03 14:08:03
    Stream #0.1(eng): Audio: ac3, 48000 Hz, stereo, flt, 448 kb/s
    Metadata:
      creation_time   : 2013-07-03 14:08:10
Stream mapping:
  Stream #0.0 -> #0.0
  Stream #0.1 -> #0.1
Press ctrl-c to stop encoding
Input stream #0.1 frame changed from rate:48000 fmt:s16 ch:2 to rate:48000 fmt:flt ch:2
frame=  518 fps= 63 q=2.0 size=    9100kB time=17.25 bitrate=4321.4kbits/s dup=105 drop=0