H.264
H.264 standard compresses a digital video file so that it only uses
half the space of MPEG-2 (the DVD standard), to deliver the same
quality video. This means you can enjoy stunning HD video the way
it was meant to be seen without sacrificing speed or performance.
Video for DivX Plus is based on the H.264 standard, a state-of-the-art
digital format for efficiently encoding high definition video. Why is
H.264 so great? To make a long story short, H.264 encompasses a
collection of powerful features that enable the delivery of high-quality
video at very low data rates. Using DivX Plus Software you can create,
enjoy and share stunning HD video in the same ways that you can
with standard definition DivX video. This includes creating personal
libraries on your hard drive, burning files to disc or transferring them
via USB drives to your DivX Plus devices, or even serving them to
visitors on your web page using the DivX Plus Web Player.
The H.264 standard supports the notion that different categories of
decoder device may have individual requirements and capabilities.
For example, compared to a desktop computer, mobile devices may
have lower display resolution, less internal memory and processing
power, and a desire to maintain battery life. By selecting the H.264
bitstream features used during content creation, we can significantly
influence the playback requirements. DivX Plus HD represents a carefully
selected balance of features developed in collaboration with our
manufacturing partners that enable both strong compression and
interoperability across a huge range of device categories including
DVD players, Blu-ray players, digital TVs, set-top boxes and more.
An H.264 encoder reduces the amount of information required AAC:
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
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.
DivX 10
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DivX, LLC
User Guide
