The height padding offset was computed from the beginning of the pixel buffer
and not the current position in the pixel buffer.

  PSNR | PSNR Cb | PSNR Cr | PSNR HVS |    SSIM | MS SSIM | CIEDE 2000
0.0000 | -0.0001 |  0.0002 |  -0.0000 | -0.0000 | -0.0000 |    -0.0002

Change-Id: Id20ec3a6395b11d0258ec1e100890fe4701b820c