Using the mciSendString command I am able to play avi, mpeg, mp3, etc. but I am unable to play mp4. Here in this web-site it says I can play any videos provided that I have the correct codecs. I am able to play mp4 using my other media players (eg. vlc player). How can I play mp4 videos or how can I make the MCI device auto detect the necessary driver type and play the videos ?
VLC embeds its MPEG-4 parser and codecs within the applciation and does not share it with the system. You need "true" codecs which register with Windows and extend standard API with support for MPEG-4. If you don't feel like looking for specific codec to install, perhaps the easiest would be to install a codec pack such as K-Lite.