IntSize CCVideoLayerImpl::computeVisibleSize(const WebKit::WebVideoFrame& frame, unsigned plane)
{
int visibleWidth = videoFrameDimension(frame.width(), plane, frame.format());
int originalWidth = visibleWidth;
int visibleHeight = videoFrameDimension(frame.height(), plane, frame.format());
// When there are dead pixels at the edge of the texture, decrease
// the frame width by 1 to prevent the rightmost pixels from
// interpolating with the dead pixels.
if (hasPaddingBytes(frame, plane))
--visibleWidth;
// In YV12, every 2x2 square of Y values corresponds to one U and
// one V value. If we decrease the width of the UV plane, we must decrease the
// width of the Y texture by 2 for proper alignment. This must happen
// always, even if Y's texture does not have padding bytes.
if (plane == WebKit::WebVideoFrame::yPlane && frame.format() == WebKit::WebVideoFrame::FormatYV12) {
if (hasPaddingBytes(frame, WebKit::WebVideoFrame::uPlane))
visibleWidth = originalWidth - 2;
}
return IntSize(visibleWidth, visibleHeight);
}
static bool hasPaddingBytes(const WebKit::WebVideoFrame& frame, unsigned plane)
{
return frame.stride(plane) > videoFrameDimension(frame.width(), plane, frame.format());
}
