• Ronald S. Bultje's avatar
    vp10: allow MV refs to point outside visible image. · dea99899
    Ronald S. Bultje authored
    In VP9, the ref MV had to point to a block that itself fully resided
    within the visible image, i.e. all borders of the image had to be
    within the visible borders of the coded frame. This is somewhat
    illogical, and had obscure side effects, e.g. clamping of fairly
    reasonable motion vectors such as 0,0 were clipped to negative values
    if the block was overhanging on frame edges (such as the last rows
    on 1080p content), which makes no sense whatsoever.
    Instead, relax clamping constraints such that the ref MVs are allowed
    to point to blocks exactly outside the visible edges in both Y as well
    as UV planes, including the 8tap filter edges (that's why the offset is
    8 pixels + block size).
    See issue 1037.
    Change-Id: I2683eb2a18b24955e4dcce36c2940aa2ba3a1061