root@ip-10-0-0-196:/home/ubuntu/prav# ffmpeg -i BigBuckBunny.mp4 -i bigbuck.ass -map 0 -map 1 -vcodec libx264 -vprofile main -preset slow -b:v 1024k -maxrate 400k -bufsize 800k -vf scale=-1:480 -threads 0 -acodec libfaac bigbuckbunny_sub.mp4
ffmpeg version git-2012-09-26-299c0b3 Copyright (c) 2000-2012 the FFmpeg developers
  built on Sep 26 2012 09:07:15 with gcc 4.6.1 (Ubuntu/Linaro 4.6.1-9ubuntu3)
  configuration: --enable-gpl --enable-libfaac --enable-libass --enable-libfdk-aac --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-librtmp --enable-libtheora --enable-libvorbis --enable-libvpx --enable-x11grab --enable-libx264 --enable-nonfree --enable-version3
  libavutil      51. 73.101 / 51. 73.101
  libavcodec     54. 59.100 / 54. 59.100
  libavformat    54. 28.101 / 54. 28.101
  libavdevice    54.  2.101 / 54.  2.101
  libavfilter     3. 17.100 /  3. 17.100
  libswscale      2.  1.101 /  2.  1.101
  libswresample   0. 15.100 /  0. 15.100
  libpostproc    52.  0.100 / 52.  0.100
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x36eb260] multiple edit list entries, a/v desync might occur, patch welcome
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'BigBuckBunny.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: mp42isom
    creation_time   : 2012-09-24 08:04:09
    encoder         : mp4creator 1.6.1d
  Duration: 00:01:30.04, start: 0.000000, bitrate: 872 kb/s
    Stream #0:0(eng): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 1024x768 [SAR 1:1 DAR 4:3], 744 kb/s, 25 fps, 25 tbr, 90k tbn, 50 tbc
    Metadata:
      creation_time   : 2012-09-24 08:04:09
    Stream #0:1(eng): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, s16, 126 kb/s
    Metadata:
      creation_time   : 2012-09-24 08:04:09
[ass @ 0x36fbb60] Estimating duration from bitrate, this may be inaccurate
Input #1, ass, from 'bigbuck.ass':
  Duration: N/A, bitrate: N/A
    Stream #1:0: Subtitle: ssa
File 'bigbuckbunny_sub.mp4' already exists. Overwrite ? [y/N] y
Output #0, mp4, to 'bigbuckbunny_sub.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: mp42isom
    encoder         : mp4creator 1.6.1d
    Stream #0:0(eng): Video: none, yuv420p, 640x480 [SAR 1:1 DAR 4:3], q=-1--1, 90k tbn, 25 tbc
    Metadata:
      creation_time   : 2012-09-24 08:04:09
    Stream #0:1(eng): Audio: none, 44100 Hz, stereo, s16, 128 kb/s
    Metadata:
      creation_time   : 2012-09-24 08:04:09
    Stream #0:2: Subtitle: none
Stream mapping:
  Stream #0:0 -> #0:0 (h264 -> libx264)
  Stream #0:1 -> #0:1 (aac -> libfaac)
  Stream #1:0 -> #0:2 (ass -> ?)
Encoder (codec none) not found for output stream #0:2
root@ip-10-0-0-196:/home/ubuntu/prav#