I see another post where the admin requested to try the command from a test.php file. I got this message:

MEncoder 1.0rc1-4.1.2 (C) 2000-2006 MPlayer TeamCPU: Intel(R) Xeon(R) CPU
E5420 @ 2.50GHz (Family: 6, Model: 23, Stepping: 6)
CPUflags: Type: 6 MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 1 SSE2: 1
Compiled for x86 CPU with extensions: MMX MMX2 SSE SSE2
success: format: 0 data: 0x0 - 0x2d7f6aASF file format detected.
VIDEO: [WMV3] 720x480 24bpp 29.970 fps 0.0 kbps ( 0.0 kbyte/s)
[V] filefmt:6 fourcc:0x33564D57 size:720x480 fps:29.97 ftime:=0.0334
================================================== ========================
Opening audio decoder: [ffmpeg] FFmpeg/libavcodec audio decoders
AUDIO: 48000 Hz, 2 ch, s16le, 96.0 kbit/6.25% (ratio: 12000->192000)
Selected audio codec: [ffwmav2] afm: ffmpeg (DivX audio v2 (FFmpeg))========================================= =================================
Exiting...