settings are needed for different content types,
and optimal bit savings can only be achieved
by encoding multiple times and producing a
range of versions.
Introduced in April by AWS Elemental,
Quality-Defined Variable Bitrate control
(QVBR) is a video compression technique
that is designed to deliver constant video
quality and waste zero bits in the process
by automatically adjusting bitrates in real
time. When video quality requirements are
high, but bandwidth budget is low, QVBR
addresses both issues.
QVBR-equipped encoders automatically adjust quantization
to different content types to maintain a consistent viewing
experience based on a target quality level. QVBR operates on an
individual frame basis and is built on statistics developed for
perceptual encoding such as adaptive quantization (AQ), rate
control (RC) and mode decision (MD). MD is the codec algorithm
that chooses block sizes, skip mode, whether to use intra/inter/
skip mode, motion vectors, and more.
QVBR also eliminates the guesswork and frustration of
managing the “bits budget:” Simply set it and forget it. When
video scenes are more complex, QVBR spends bits to maintain
the desired video quality level. When video quality level is
reached, QVBR will not use additional bits unnecessarily.
In the process, QVBR can realize bitrate reduction, which
can amount to significant savings in content delivery network
(CDN) egress and storage costs. QVBR puts an end to video
quality inequalities: It supports both AVC and HEVC, viewing
audiences enjoy a consistent experience and an optimal level of
video quality, and content providers enjoy the most cost-efficient
method of delivering that experience.
QVBR is available today for AWS Elemental appliance-based
encoding solutions, and is offered with no additional license fees.
To learn more, visit http://go2sm.com/whatisqvbr or watch an
informational webcast at http://go2sm.com/introqvbr.
ABOUT AWS ELEMENTAL
AWS Elemental, an Amazon Web Services company, combines
deep video expertise with the power of the AWS cloud. Solutions
from AWS Elemental allow broadcast TV and multiscreen video
to be customized, originated and monetized at global scale. This
gives customers the ability to quickly, easily and economically
scale and optimize video operations and the freedom to focus on
what matters: transforming ideas into compelling content that
Figure 3. QVBR automatically adjusts encoding bitrate to different content and scenes. Bits are saved when target quality is reached.
• Less CDN egress and less storage, offering
10% to 50% reductions depending on video content
• Improves video quality consistency —
Maintain uniformity across all content, and use
a higher peak bitrate only for complex scenes
• Easy operation — No more content-based bitrates.
Instead, set a fixed video quality level and a max bitrate.
The encoder does the rest
• Achieves the same level of encoding density,
with no drop in performance
• Works with both one-pass encoding for live video
(or faster-turn VOD encoding), or two-pass encoding
for additional processing
• How QVBR Makes Managing Video Quality Easy
• Adapts frame by frame to maintain video quality
• Useful for both live and VOD workflows in a variety
• AWS Elemental develops its own encoding algorithms,
and QVBR is integrated with no secondary processes
to run and no additional license fees
• Generate consistently high video quality, save space
to reduce transfer and storage costs, and simple to
configure no matter what the source content type