What drains the Sansa e280's battery more, mpg playback in Rockbox or mov in OF?

[cocopugg]

I love the mpeg playback feature of Rockbox! You can really compress some video files to 1/3 the size of the mov files created by the Sansa media convertor. My question is which player would drain the battery more quickly, a large mov file played with the Sansa's original firmware, or the smaller mpeg file played with the Rockbox mpeg player? Thanks.

[Febs]

This seems like the type of thing that you could bench test fairly easily yourself.