There are subtle artifacts at some small places in DivX 5.1-encoded movies with Qpel. It's OK with -vc divx4 (5.0.5), but not with libavcodec. It's not specific to MPlayer, the artifacts are there in other programs that use libavcodec, too - some waves/curves/archs that disappear with the next keyframe. In this sample, it's at the top center, above/around the woman's head, seconds 5-10 (disappearing -blink!- at frame no. 250) and 19-21. The same artifact at the same place appears also in XviD-encoded Qpel version. No -lavdopts from the MPlayer 1.0-pre2 man page help.