DivX5.1

This version includes all the playback and encoding functionality necessary to watch and create DivX videos. And what's more, it's completely free for download! Find out what your friends have been talking about.
New:
Added a new high-quality psychovisual mode that includes the following features:
Texture cortex masking and rate distortion algorithm
Hybrid mode (with texture cortex masking)
Speed optimization
Chroma operation (this option is not enabled by default for performance reasons; to enable it, create an empty file in C: called "DivxPvShapingChroma.txt" for "fast" mode and "DivxPvSimpleChroma.txt" for slow mode; testing shows only 1-2% gains in JND tests)
The decoder has been rearchitected and is now 10 to 30% faster on all CPU platforms.
The decoder now supports automatic post-processing during video playback.
Added new features to the rate control modes of the encoder, including:
A complexity vector log file
An API that allows real-time control of rate control
An API that allows forced I-frame insertion
Improved:
Redesigned encoder GUI. The new GUI is more accessible and simplifies overall usage.
DivX 3 compatibility. (There were no problems detected on any of the more than 60 hours of test content.)
Performance of Nth Pass strategy planning performance.
Fixed:
A bug that caused the quantizer to overshoot the bitrate following a transition to a complex scene.
A bug that limited the interframe change in quantizer to the ideal quantizer or plus or minus 2.
A bug in RGB32 to YUV conversion on Pentium 4 machines.
A minor bug that affected multiple CPU configuration.
A bug with the rate control video buffer verifier (VBV) that would enforce a "3 sec" max bitrate. Several bugs that affected Nth Pass encoding strategy planning.
A bug that caused a different number of frames to be reported between different passes in VirtualDub.
A bug that caused motion vector (MV) reuse to be non-functional.
A bug that caused problems when MV reuse and psychovisual mode were used together.
Several bugs with the installer.
A bug that caused a crash when setting crop/resize values.