I met a problem.
The rate of width and height of my camera sampling is 4/3.so i set previewsize = 320*240;
when it render with vertical srceen(screen size=272*480), it seems that a horizontal preview display in vertical srceen.
when it render with horizontal srceen(screen size=480*272),problem remains.this time it looks like a verticalpreview display in horizontal srceen.
I think there is somesthing wrong with registerbuffer() .
Now there are no further idea!