Inconsistent Size

[sepehr]

i had an avi file on my hdd ,i changed the format to the mpg2 and every thing was fine now my problem is this:
the file on the hhd  has the size about 1.8 but when i want to write to DvD it indicates that it's 4.9 Gb!!!!!Why is that? :-?
(i tested my burning Program on other files and it worked fine)

any ideas that what's going up?

[Backdated]

It's because it was compressed as an AVI and you have just decompressed it.

[sepehr]

u mean when i want to write it ,i decompress it? i didn't unless it's done automatically done by the burning program!
would be decompressed when and Avi file is changed to mpg2?
i had converted the file before,i mean i was trying to burn a file that it's extension was .mpg alredy not avi and it was about 1.8 Gb
and in the burning program it indicates 4.8 gb !!! what should i do?