[XviD-devel] find a problem

[???]

dear all:
  I use version of libxvidcore 1.0.1  to compress raw yuv test_sequence bridge-far.cif,and find some pink line and pink region are so abvious in condition of bitrate 393216 and h.263 quant,but I find even with 900k bitrate or mpeg4 quant things is also exits,but quality is good a little.I think lower bitrate even worse.but the other test sequence does not have this circumstance.Who can explain this condition? doesn't it block effect? I think it is block effect and should eliminate it.
thanks
xiongshu deng