User guide

DivX Plus Player for Windows
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DivX, LLC User Guide
AAC:
An H.264 encoder reduces the amount of information required
to reproduce the input video by exploiting redundancy in the
pictures it’s encoding, both spatially (within the same picture)
and temporally (between pictures). Temporally, an encoder
processes each frame, subdividing the picture into a grid of
blocks and searching previous or future frames for each block
for matching texture, a technique known as motion estimation.
Once a suitable match is found, a decoder can later reproduce
the texture of that block using only a vector pointing to the
matching reference texture along with a little information to
correct any small texture differences. Spatially, where motion
estimation fails to find suitable matches, an encoder can use
the texture of nearby blocks within the same frame to predict
the block texture and store only the difference between the
prediction and the actual block texture. This is more efficient
than storing the complete texture directly but still more
costly than motion estimation. H.264 encoders act as “lossy”
compressors; their goal is not to reproduce the original picture
exactly but instead to choose the optimal means to reduce the
data rate while preserving visual quality as best as possible.
With suitable settings differences can be unperceivable even
when compression over raw input approaches 100:1.
The H.264 standard offers substantial performance
improvements over its predecessors. For example, a DVD can
hold one two-hour movie compressed using MPEG-2 encoding
(typical for DVD video) but four hours of video using an H.264
codec. H.264 encoding used by DivX Plus is even more efficient
than the popular DivX 6 codec, which is based on the MPEG-4
ASP standard, H.264’s predecessor.
To learn more about H.264, visit our website.
Advanced Audio Coding (AAC) is the preferred audio format
for high definition videos and is a substantial improvement on
the well-known MP3 format. AAC has become the standard
for high-quality digital audio and DivX Plus video supports
AAC audio tracks with 5.1 channel surround sound to deliver a
cinematic experience with your home theater setup.
Given the same file size, AAC audio tracks can achieve better
sound quality than MP3 audio tracks so you can achieve
matching quality while reducing the data rate and audio stream
in your DivX Plus file. This will take up less space than before,
making for smaller files or the option to encode video with
higher quality. Where storage or bandwidth is constrained,
AAC’s High Efficiency modes provide technologies like spectral
band replication that allows you to come close to CD-quality
sound at roughly half the data rate that MP3 would require.
AAC audio is much more efficient to decode than other
audio formats, which means that it leaves more CPU power
to make sure your video plays smooth and stutter-free. The
AAC standard is the perfect complement to the H.264 video
technology that powers DivX Plus Software, providing high
definition audio to match the HD video on your computer, in
your living room or on the go.