The file in question probably has the audio embedded in the video track -- you can do that with mpeg's. The fix: transcode the file to something that actually has a separate audio track, which is what AE expects to see.
Dear Dave ,
Thank you for you answer , now i wanna know why can't a proffessional program not
do that , while now I found out windows moviemaker can do it ?!!?
Can't answer that one! I don't work for Adobe. I guess it's because the file you're trying to work with is in a consumer delivery format intended just for playback and not professional format intended for production.
Also, After Effects is a graphics and compositing program, not an audio program. The audio features in After Effects are minimal and intended only for use of reference audio.
I must bring to light ONE of AE's positive qualities when dealing with audio.
Its reverb effect is EXTREMELY easy to tweak, and works great! I really like it.
thank you for your reaction
I know it's a graphics program , but why if you can import mpg , but only without sound -
almost all work/hobby/interest start in the beginning with simple camera's - and if you like to use old movies in your new work it should be possible -
I don't think Adobe have to pay more for license for the sound with mpg .
greetz , Jos
MPG's can be encoded in many different ways and your computer can be set up in an infinite number of ways. I've used MPG files in AE with no problem as have thousands of other people. If you've installed something like the K-Lite codec pack, that alone can really mess up professional video applications such as After Effects. If that particular MPG has the audio stream embedded in the video stream instead of as a separate one, as Dave mentions, AE can't read it. We don't have enough information to know much.
Does Premiere read it okay? If so, do as has already been suggested and transcode it to a proper intermediate codec.