ffmpeg terminates without any output

I am using ffmpeg to convert a video file to mp4. here is my code

    echo "converting ".basename($src)." --- to --- ".basename($dest).".mp4...<br />";
$command = FFMPEG.' -i ' . $src . ' -sameq -strict -2 -vcodec libx264 -ar 22050 -y ' . $dest.'.mp4 2>&1';   //
echo $command.'<br>';

exec($command,$output,$status);
echo '<pre>',join('<br>',$output),'</pre><br>';

if($status == 0) {              // Success
    echo 'Successfully converted to MP4!<br />';
} else {
    echo $status."<br>failed<br>";
} 

The code works fine on my localhost (Windows 7 + wamp).. But on live server , only $command is echoed.. and script is terminated. The output file is generated but it is only 4.5MB (it should be around 17 MB) and not complete... and sometime I get the following output..

    ffmpeg version 0.11.1 Copyright (c) 2000-2012 the FFmpeg developers  built on Sep 10 2012 00:38:24 with gcc 4.1.2 20080704 (Red Hat 4.1.2-52)  configuration: --prefix=/home/one01qsc/local --extra-cflags='-L/home/one01qsc/local/lib/ -I /home/one01qsc/local/include/' --extra-ldflags='-L/home/one01qsc/local/lib/ -Wl,-rpath,/home/one01qsc/local/lib/' --enable-libmp3lame --enable-libvorbis --enable-shared --disable-yasm --enable-libtheora --enable-libx264 --enable-gpl
  libavutil      51. 54.100 / 51. 54.100
  libavcodec     54. 23.100 / 54. 23.100
  libavformat    54.  6.100 / 54.  6.100
  libavdevice    54.  0.100 / 54.  0.100
  libavfilter     2. 77.100 /  2. 77.100
  libswscale      2.  1.100 /  2.  1.100
  libswresample   0. 15.100 /  0. 15.100
  libpostproc    52.  0.100 / 52.  0.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/home/one01qsc/public_html/temp/pending/1455-testing-mobidick.mov':
  Metadata:
    major_brand     : qt
    minor_version   : 537199360
    compatible_brands: qt
    creation_time   : 2012-09-08 16:00:41
  Duration: 00:00:23.13, start: 0.490000, bitrate: 6028 kb/s
    Stream #0:0: Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1920x1080, 5331 kb/s, 29.97 fps, 29.97 tbr, 60k tbn, 59.94 tbc
    Metadata:
      creation_time   : 2012-09-08 16:00:41
      handler_name    : Apple Alias Data Handler
    Stream #0:1: Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, s16, 192 kb/s
    Metadata:
      creation_time   : 2012-09-08 16:00:41
      handler_name    : Apple Alias Data Handler
[buffer @ 0x2405ce0] w:1920 h:1080 pixfmt:yuv420p tb:1/60000 sar:0/1 sws_param:flags=2
[buffersink @ 0x2429ec0] No opaque field provided
[aformat @ 0x23fa560] auto-inserting filter 'auto-inserted resampler 0' between the filter 'src' and the filter 'aformat'
[aresample @ 0x2402e60] chl:stereo fmt:s16 r:44100Hz -> chl:stereo fmt:flt r:22050Hz
[libx264 @ 0x24288e0] using cpu capabilities: none!
[libx264 @ 0x24288e0] profile High, level 4.0
[libx264 @ 0x24288e0] 264 - core 128 - H.264/MPEG-4 AVC codec - Copyleft 2003-2012 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=24 lookahead_threads=4 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to '/home/one01qsc/public_html/temp/1455-testing-mobidick.mp4':
  Metadata:
    major_brand     : qt
    minor_version   : 537199360
    compatible_brands: qt
    creation_time   : 2012-09-08 16:00:41
    encoder         : Lavf54.6.100
    Stream #0:0: Video: h264 (![0][0][0] / 0x0021), yuv420p, 1920x1080, q=-1--1, 30k tbn, 29.97 tbc
    Metadata:
      creation_time   : 2012-09-08 16:00:41
      handler_name    : Apple Alias Data Handler
    Stream #0:1: Audio: aac (@[0][0][0] / 0x0040), 22050 Hz, stereo, flt, 128 kb/s
    Metadata:
      creation_time   : 2012-09-08 16:00:41
      handler_name    : Apple Alias Data Handler
Stream mapping:
  Stream #0:0 -> #0:0 (h264 -> libx264)
  Stream #0:1 -> #0:1 (aac -> aac)
Press [q] to stop, [?] for help
frame=   18 fps=0.0 q=0.0 size=       0kB time=00:00:00.00 bitrate=   0.0kbits/s

the value printed for $status is 137 in this case.

Any help is really appreciated.