mpg video format in anime studio 9.5 how?

[aji]

I tried to import .mpg video format into anime studio 9.5 version.
But couldn,t. I tried with .mp4 format...it is okay. Is there problem with codecs?. Which codec i need to install ?
I s there any limit for the duration of video format..?
can i import one hour video. I cant go with experiments since my mechine has low resources..?
Please reply.
I express my gratitude in advance
aji