Should I have to get Xv to overlay?

 
    Hi,

    I have a question about Xv and overlay.
    I tried S3 Trio 3D/2X (rev.2) for xawtv 3.61 running on Redhat 7.1 (2.4.2-2) successfully.
    But xawtv reported that X Server(XFree86-SVGA-3.3.6) do not support XVideo Extension.
    and xawtv-3.61/src/xvideo   too.

    If xawtv is overlaying without XVideo, what is used for overlay?
    DRI?

    Thanks in advance.