* 1080HD encoding mode

     DivX Codec now includes a 1080HD encoding mode allowing
     you to create full size 1920 x 1080 resolution video in
     high quality DivX format. Videos encoded using this new
     setting are suitable for playback on fast desktop
     computers and are more likely to play on future
     hardware devices than videos encoded using
     unconstrained mode, and unlike unconstrained mode,
     1080HD encoding will be available for free in the
     DivX Community Codec. Both 1080i and 1080p encoding is
     supported.

   * Fast 1st pass rate control mode

     When you need to produce a video that has to hit a
     target file size, multipass (e.g. 2-pass) encoding is
     the way to go for maximum quality consistency, but
     have you ever wondered which settings can you safely
     tweak to make a multipass encoding run faster without
     introducing serious quality problems? Now the DivX 6.4
     codec can take care of this for you.

     By selecting the new "Multipass, 1st pass (fast)"
     rate-control option the encoder will automagically
     adjust your settings during the first pass to maximize
     the encoding rate, so there is no need to manually
     change all the settings in the configuration window
     for every single pass. Even better than this, we've
     included new optimizations for the fast 1st pass that
     can reduce even the default "Balanced" mode encoding by
     up to 35% on a single core PC! Much larger reductions
     can be seen for higher quality modes.

   * High efficiency resize filters

     We have enhanced the resize filters in the DivX 6.4
     codec such that they improve the overall
     quality/compression of the encoder. The new resize
     filters reduce encoding rate by approximately 10% over
     the 6.2.5 codec, but with typical 1:1 aspect correction
     achieve the same video quality with 15-20% less bitrate
     (measured using the "lanczos4" filter).
    
   * Improved support for interlaced video

     New colorspace transforms designed to prevent displaced
     chroma for interlaced content improve video quality
     over previous releases. The quality of the built-in
     de-interlace preprocessing has also been improved.

   * Adaptive noise reduction

     The 6.4 codec introduces a new option for noise
     reduction. Changing the noise reduction option to
     "Auto-Detect" will cause the preprocessor to adjust the
     noise reduction level as necessary to reduce grain and
     low-light noise from the picture without significantly
     degrading the video. This setting is particularly
     useful when the noise level various throughout the clip
     - a common trait for DV cameras in indoor or low-light
     conditions.