Jpeg vs bitmap import

[cyberdread]

I import graphics files I make into flash. I used to save these image files as JPEG before importing.
I then thought hey, why not use bitmaps... becuase the quality is better and the exported movie size shouldnt be bigger becuase flash renders its own image out from the imported file right?
So I did a test: 2 files, same picture, same attributes, 1 bitmap+ 1 jpeg.
I imported the jpeg, placed image from the library onto the movie scene, export the movie. do exactly the same with the bitmap.
I expected to see both movies the same size as i thought flash renders its own image out from the imported graphics, or maybe even the bitmap import movie bigger becuase the quality of the image was better so the image rendered out might be higher quality and bigger. But i didnt expect to find the jpeg as bigger in size?
i did the same test with another picture and the movie with jpeg imported is always bigger. but being jpeg is worse quality then the bitmap one.
Am i missing something here? im pretty confused.
someone please enlighten me.
thankyou

 

[suppau]

Jpeg or BMP imported into flash will not do any different. Check your publish settings. There should be a quality settings. One you set that, the file size for bmp or jpeg in flash will be quite the same.