convert video to mobile phone formats

Hi,
    if ur mobile phone is supporting video formats.then u can convert the video to the mobile phone video formats.For this Conversion, if we use any freeware, they will watermark the video with their company name, logo or with URL.
 So How can we convert the video to mobile phone video format without any watermark;

 just download "ffmpeg for windows".

This Zip file will have ffmpeg.exe.

Using this ffmpeg we can convert any type of video to the Mobile phone video format;
just run the ffmpeg with the following arguments :

 ffmpeg -i "D:\Source.avi"  -f 3gp -vcodec mpeg4  -s 176x144 -acodec libfaac -ar 8000 -ac 1 -ab 12.2k "D:\Output.3gp"

"D:\source.avi" may be any type of video file avi, wmv or any type.