StreamNet™ Digital Media and
System Design Reference Guide
Table of Contents
Introduction ....................................................................................................3
Common AV Signals and Inter faces .............................................................5
What is StreamNet? ....................................................................................17
StreamNet Audio Technology .....................................................................24
Digital File Security and (DRM) ...................................................................26
HDCP Quick FAQ .........................................................................................31
Public Performance Rights ..........................................................................35
Designing a StreamNet System, introduction to required devices ...........41
Designing a StreamNet System, example configurations .........................47
StreamNet Products ....................................................................................50
AVoIP Video Encoder Feature Comparison Matrix .....................................55
View Decoder Comparison Chart ...............................................................57
Motion XT Use Chart ...................................................................................57
Encoders vs. Decoders Compatibility Matrices .........................................58
Example StreamNet System Design ...........................................................63
StreamNet FAQ ............................................................................................64
Solving Digital Media Related AV Problems ...............................................69
Glossary .......................................................................................................78
pg 2StreamNet Digital Media and System Design Reference Guide
The purpose of this reference guide is to provide valuable information on digital media
technologies for the AV dealer seeking to better understand how to make the transition
from analog based media formats and transports, to digital. Though comprehensive in
nature we recommend further study if the concepts and terms covered are new. ClearOne’s
StreamNet solutions are highly capable and scalable, allowing traditional system design
concepts to be challenged by offering more flexibility, higher quality and in many cases
costs savings.
Introduction
pg 3 StreamNet Digital Media and System Design Reference Guide
Introduction
We believe AV systems should no longer be analog.
+ Sources are digital. This doesn’t mean a modern audio video source won’t have
analog connectors. But since the program material is rendered digitally, it no longer
makes sense to convert the pristine quality of a digital file back to analog. Hence the
longer an AV systems designer is able to keep the digital signal intact, the better the
sound and picture quality will be.
+
Displays are digital. With the advent of digital fixed pixel displays and projectors,
the highest quality picture is possible when the content stream remains digital and is
not converted to analog. Though a reasonable quality picture is possible to achieve
with analog equipment, there are resolution and cabling limitations, which can greatly
degrade the end result.
+
Greater signal lengths without loss or degradation with digital. By transmitting
digital signals over Internet Protocol (IP) rather than analog or RF based distribution
methods, signal distances of several miles may be achieved with virtually no image
degradation or signal loss. This compared to mere hundreds of feet with analog where
image degradation can suddenly become a significant issue.
+
Mass exposure to HD and 3D program material has greatly raised consumer
expectation for AV system performance.
increasing sound and picture quality in nearly every arena. HDTV products and
program material is highly penetrated in the home. OEM automobile sound systems
are at the highest performance level they have ever been. Which along with ever
improving retail, and commercial AV system quality, means the average consumer has
a reasonably good understand of what constitutes good audio and video performance.
+
Wireless technologies improve installation flexibility. With new state of the art
wireless systems, the digital signal remains intact from the source to the transmitter to
the receiver to the speaker or display. This means AV systems designers have choices
in infrastructure that can lower or reduce the high cost of cabling or installation difficulty
when designing high performance audio video systems.
+
Cost benefits compared with extensive cabling costs and labor for large
installations.
type. However with IP based AV systems, a single Category 5 cable may carry the
load of several dozen audio channels along with multiple video streams and all control
signals. This reduces not only cable cost but also installation labor.
With analog systems, generally a single cable may only carry one signal
Consumers are presented with ever
pg 4StreamNet Digital Media and System Design Reference Guide
Common AV Signals and Interfaces
It is important to note that there is a difference between a file format and a codec. The job
of a digital codec is to perform the encoding and decoding of the raw audio data. While the
data itself is stored with a specific audio format in a file. Although most audio file formats
support a single type of audio data that is created with an audio coder, a multimedia
container format such as MKV or AVI may support multiple types of audio and video data.
Interfaces on the other hand commonly define a physical connectivity standard by which
various signals may be interconnected. Following are a few of the most common interface
types found in audio, video, network and control systems.
Digital Audio
AES/EBU - The digital audio standard frequently called AES/
EBU is officially known as AES3 and is used for carrying digital
audio signals between various devices. Several different
physical connectors are defined as part of the overall group of
standards such as IEC 60958 Type I Balanced – 3-conductor,
110-ohm twisted pair cabling with an XLR connector, used in
professional installations (AES3 standard). The IEC 60958 Type
II Unbalanced – 2-conductor, 75-ohm coaxial cable with an
RCA connector is often used in consumer audio applications.
Finally, IEC 60958 Type II Optical – optical fiber, usually plastic
but occasionally glass, with an F05 connector, may also be
found in consumer audio applications.
Toslink Optical
S/PDIF - A related system to AES/EBU, S/PDIF was developed
as a consumer version using connectors more commonly
found in the consumer market such as RCA connectors in
the case of 2-conductor 75-ohm coaxial cable. S/PDIF also
supports optical fiber termination and is found widely in
consumer applications.
pg 5 StreamNet Digital Media and System Design Reference Guide
XLR
RCA
Common AV Signals and Interfaces
Digital Video
HDMI – High-Definition Multimedia Interface (HDMI) technology
is a global standard for connecting high-definition products.
With HDMI’s uncompressed all-digital interface the viewer
receives both dazzling quality and ease of use. Well over 1,000
manufacturers incorporate HDMI connectivity into a growing
list of consumer products from HDTVs, Blu-ray Disc Players,
Gaming systems, Digital video cameras, Mobile devices and
more.
HDMI
The flexibility of HDMI is in the single cable capable to transmit digital video, digital audio,
and control data through a high-speed link.
DVI
HDMI offers
twice the bandwidth needed to transmit an uncompressed 1080p signal. This enables
better looking movies, faster game play, richer audio, 3D movies and gaming. Additional
benefits include higher resolution support beyond 1080p such as 1440p or Quad HD, faster
refresh rates like 120Hz or beyond and deep color, taking the HDTV display palette from
millions to trillions of colors. It should also be noted that HDMI specifies a robust digital
rights management scheme (DRM) known as HDCP. For this reason premium content
owners allow full HD output typically over HDMI only and not analog interfaces such as
component video.
Multimedia Interface (HDMI) standard in digital mode (DVI-D), and VGA in analog mode
(DVI-A) some devices will display a digital signal originating from a DVI connector but
terminating to an HDMI port. However, care must be taken in mixing and matching the
standards as certain data types and signals are not fully supported by DVI, but may be
supported by HDMI.
enormous bandwidth capacity of up to 10.2 gigabits per second, more than
DVI - The Digital Visual Interface (DVI) is a video interface
standard designed to provide high quality direct digital
connection of source devices to digital display devices such
as flat panel LCD computer displays and digital projectors.
DVI was developed by an industry consortium, the Digital
Display Working Group (DDWG) to replace the “legacy
analog technology” VGA connector standard and is designed
for carrying uncompressed digital video data to a display.
Because it is partially compatible with the High-Definition
pg 6StreamNet Digital Media and System Design Reference Guide
Common AV Signals and Interfaces
DisplayPort - DisplayPort is a digital display interface standard
put forth by the Video Electronics Standards Association (VESA)
which defines a digital audio and video interconnect scheme
intended primarily for use between a computer and its display.
DisplayPort is designed to replace digital (DVI) and analog
component video (VGA) connectors in computer monitors and
video cards. As well as replace internal digital LVDS links in
computer monitor panels and TV panels. Though DisplayPort
can provide the same functionality as HDMI it is not expected to
displace HDMI in high-definition consumer electronics devices.
DisplayPort includes optional DPCP (DisplayPort Content Protection) which is licensed from
Philips and uses 128-bit AES encryption. It also features full authentication and session key
establishment along with an independent revocation system, something that is considered
essential by premium content owners such as Hollywood studios. Later versions of
DisplayPort beginning with version 1.1 added support for the industry-standard 56-bit HDCP
(High-bandwidth Digital Content Protection) revision 1.3
DisplayPort
pg 7 StreamNet Digital Media and System Design Reference Guide
Common AV Signals and Interfaces
Network
Ethernet - Modern Ethernet networks are now able to easily
carry data and StreamNet signals simultaneously without
difficulty. This fact reduces cost for the AV systems designer
choosing IP audio / video systems as separate networks and
cabling no longer need to be installed.
Ethernet defines wiring and signaling standards for the Physical
Layer of the OSI networking model as well as a common
RG45 Ethernet
procedures at the lower part of the Data Link Layer. Evolutions include higher bandwidth
support, improved media access control methods, and changes to the physical medium
which has caused Ethernet to evolve into a complex networking technology. Ethernet
stations communicate by sending each other data packets, blocks of data that are
individually sent and delivered. As with other IEEE 802 LANs, each Ethernet station is given
a 48-bit MAC address. MAC addresses are used to specify both the destination and the
source of each data packet. Despite the significant changes in Ethernet over the years, all
generations of Ethernet (excluding early experimental versions) use the same frame formats
(and hence the same interface for higher layers), allowing them to be readily interconnected.
addressing format, and a variety of Medium Access Control
Ethernet network interconnection options:
pg 8StreamNet Digital Media and System Design Reference Guide
Common AV Signals and Interfaces
Category 5 / 6 Cable
Category 5 (Cat 5) cable for use in networks is tested for reliable transfer of signal
frequencies up to 100 MHz. Category 5 cable is terminated in either the T568A
scheme or the T568B scheme. Canada and Australia use the T568A standard,
and the U.S. commonly uses T568B scheme. Both schemes work equally well and
may be mixed in an installation so long as the same scheme is used on both ends
of the cable. An interesting fact regarding Category 5 network cable termination
is that 8P8C modular connectors are used but are often incorrectly referred to as
“RJ-45”. Of the four pairs of wire found in a Category 5 cable, each has differing
precise number of twists based on prime numbers so as to minimize crosstalk and
improve signal integrity. The pairs are made from 24 gauge (AWG) copper wires
within the Cat 5 cable standard. Although, cable assemblies containing 4 pairs are
common, Category 5 is not limited to 4 pairs. In fact backbone applications may
use up to 100 pairs.
12345
T568A
678
A newer cable standard known as Category 6 (Cat 6), is the cable standard
for Gigabit Ethernet and is backward compatible with the Category 5/5e and
Category 3 cable standards. Compared with Cat 5 and Cat 5e, Cat 6 features
more stringent specifications for crosstalk and system noise reduction. Category
6 provides performance of up to 250 MHz and is suitable for 10BASE-T, 100BASE-
TX (Fast Ethernet), 1000BASE-T/1000BASE-TX (Gigabit Ethernet) and 10GBASE-T
(10-Gigabit Ethernet).
12345
T568B
678
pg 9 StreamNet Digital Media and System Design Reference Guide
Common AV Signals and Interfaces
HTTP
FTP
TLS/SSL
Application Layer
TCP
UPD
Transport Layer
ICMP
IGMP
Internet Layer
ISDN
Ethernet
Link Layer
Internet Protocol Suite Layers
SMTP
POP
IMAP
REQUEST
IP
ANSWER
DSL
computer and facilitates the interconnection of networks. This layer establishes the Internet
and contains primarily the Internet Protocol, which defines the fundamental addressing
namespaces. Internet Protocol Version 4 (IPv4) and Internet Protocol Version 6 (IPv6) are
used to identify and locate hosts on the network. Direct host-to-host communications are
handled in the Transport Layer which provides a general framework to transmit data between
hosts using protocols like the Transmission Control Protocol. The highest-level Application
Layer contains all protocols defined specifically for the functioning of the vast array of data
communications services. This layer handles application-based interactions on a process-
to-process level between Internet hosts that are communicating.
TCP/IP – The Internet Protocol Suite is a set of communications
protocols used for the Internet. It is also known as TCP/IP named
from two of the most important protocols contained in it, the
Transmission Control Protocol (TCP) and the Internet Protocol
(IP). Modern IP networking represents a synthesis of several
developments which evolved in the 1960s, 1970s, and emerged
during the 1980s, together with the advent of the World Wide Web
in the early 1990s.
The Internet Protocol Suite consists of four layers from the lowest
to the highest layer these are the Link Layer, the Internet Layer,
the Transport Layer, and the Application Layer. Each layer defines
the operational scope or reach of the protocols and are reflected
loosely in the layer names. Each layer has functionality which
solves a set of problems relevant to its scope.
The Link Layer contains communication technologies for the local
network where the host is connected to directly. The Internet Layer
describes communication methods between multiple links of a
pg 10StreamNet Digital Media and System Design Reference Guide
Common AV Signals and Interfaces
MoCA (Multimedia over Coax Alliance)
Using Coaxial cable, MoCA is the only home entertainment networking standard in use
by cable, satellite and IPTV operators and equipment providers. The current MoCA
specification can support multiple streams of HD video, delivering up to 175 Mbps
throughputs while offering unparalleled user experience via parameterized quality of service
(PQoS). Though primarily implemented for transportation of digital entertainment files,
MoCA fully supports Ethernet and thus is an excellent way to transfer data of any type with
no limitations. MoCA is a popular solution in any installation where coaxial cable may be
already installed thus negating the need to pull new wire. For AV installers working with
residential projects we recommend MoCA as a cost effective way to distribute StreamNet
and Ethernet signals. The Multimedia over Coax Alliance (MoCA®) features more than 80
certified products and is the universal standard for home entertainment networking. For
information on MoCA and compatible products visit: http://www.mocalliance.org/
HomePlug AV (Powerline Alliance)
The purpose of HomePlug AV (HPAV) is to provide high-quality, multi-stream, entertainment
data transfer using Ethernet standards over existing AC wiring. HPAV employs advanced
PHY and MAC technologies to provide a 200 Mbps class powerline network for video,
audio and data. The Medium Access Control Layer is designed to be highly efficient with
AC line cycle synchronization and Quality of Service (QoS) guarantees. HomePlug AV also
provides advanced capabilities consistent with new networking standards. HPAV offers tight
security based on 128-bit AES and the design allows a station to participate in multiple AV
networks. HPAV is backward compatible with HomePlug 1.0 and aims to be the network of
choice for the distribution of data and multi-stream entertainment including HDTV, SDTV, and
audiophile quality audio throughout the home. It is designed to provide the best connectivity
at the highest QoS of the home networking technologies competing for these applications.
HomePlug AV enables all devices with a power plug to have network access through HPAV.
For information on HomePlug and compatible products visit: www.homeplug.org
pg 11 StreamNet Digital Media and System Design Reference Guide
Common AV Signals and Interfaces
Audio Video Bridging (AVB)
ClearOne is a proud member of the AVnu Alliance, an industry forum dedicated to the
advancement of professional-quality audio video transport by promoting the adoption of
the IEEE 802.1 Audio Video Bridging (AVB), and the related IEEE 1722 and IEEE 1733,
standards over various networking link-layers.
An “Audio Video Bridging” network is one that implements a set of protocols being
developed by the IEEE 802.1 Audio/Video Bridging Task Group. The four primary differences
between the Audio Video Bridging (AVB) architecture and existing 802 architectures are as
follows:
1. Precise synchronization of audio and video signals as required by high quality AV
systems.
2. Traffic shaping for media streams to ensure ultra low latency and signal integrity.
3. Admission controls.
4. Identification of non-participating devices.
Key to AVB is the fact that it has been specifically designed for AV use and addresses the
unique requirements of distributing an audio and video signal in a high quality manner over
a standard switch Ethernet network.
To understand why AVB is special, lets look at the requirements for A/V streaming.
First, it must be possible to synchronize multiple streams so they are rendered correctly in
time with respect to each other. This might be to ensure lip sync or to keep multiple digital
speakers in phase, or it could be to maintain tight time sync of 40 or more microphone
channels feeding a live mixing desk in a live sound or studio environment. Regardless of the
application, what this means is A/V streams must be synchronized to within approximately
one microsecond. Something that is impossible for a standard switched network to achieve
using regular 802 architecture.
Furthermore, applications must be able to receive a high level of confidence that the network
resources needed are available and will remain available as long as the application needs
them.
This is sometimes referred to as a “reservation”, or “admission control”. The intent is for an
application to notify the network of the requirements for a stream ahead of time, and have
the network lock down the resources needed for that stream and, if they are not available, to
notify the application so the stream may be stopped or an error message delivered.
pg 12StreamNet Digital Media and System Design Reference Guide
Common AV Signals and Interfaces
Although delay through a network may on the average be very low, there is little effort made
to limit that delay in a traditional IT network. Since there is no concept of “time” in an IT
network, there is nothing in the network infrastructure itself that can aid in synchronization.
Additionally, the network itself does not prevent network congestion, so data can be lost if
buffers are inadequate or link bandwidth insufficient for the offered traffic.
IT networks count on higher level protocols to handle congestion such as TCP which works
by throttling transmission and retransmitting dropped packets. This is adequate when long
delays are acceptable, but will not work where low deterministic delays are required.
The typical way these last two problems are handled today is with buffering, but excessive
buffering can cause delays that are annoying in the consumer environment and completely
unacceptable in a professional application.
One way to allow existing IT-oriented networks to be used for A/V streams is to “manage” the
network at a higher layer or to impose strictly defined, inflexible configurations. For example,
in the professional market, there are a few systems in place that can provide adequate
delays and guaranteed bandwidth, but they require a single proprietary solution, and need
to be reconfigured every time a new device is added. CobraNet is an example of this kind of
architecture.
pg 13 StreamNet Digital Media and System Design Reference Guide
Common AV Signals and Interfaces
How AVB came to exist.
An effort was started within the IEEE 802.3 (Ethernet) working group to define a “Residential
Ethernet” which would directly address the challenges of A/V streaming. However this work
quickly moved over to the IEEE 802.1 working group. In particular, the group wanted to
ensure the technology was scalable from consumer applications in the home and car, all the
way up to high professional standards.
As explained previously, there is nothing more important than time synchronization when
distributing audio and video signals. To achieve this AVB devices periodically exchange
timing information. This precise synchronization has two purposes:
1. To allow synchronization of multiple streams.
2. To provide a common time base for sampling and receiving data streams at a source
device, and presenting those streams at the destination device with the same relative
timing.
The protocol used for maintaining timing synchronization is specified in IEEE 802.1AS, which
is a tightly constrained subset of another IEEE standard (IEEE 1588), with extensions to
support IEEE 802.11 and also generic “coordinated shared networks” (examples include
some wireless, coaxial cable, and power line technologies).
pg 14StreamNet Digital Media and System Design Reference Guide
Common AV Signals and Interfaces
How audio and video signals stay in sync with AVB.
An 802.1AS network timing domain is formed when all devices follow the requirements of
the 802.1AS standard and communicate with each other using the IEEE 802.1AS protocol.
Within the timing domain there is a single device that provides a master timing signal called
the “Grand Master Clock”. All other devices synchronize their clocks with this master.
The device acting as Grand Master may be auto selected or specifically assigned. Example:
If the network is used in a professional environment that needs “house clock” for audio, or
“genlock” for video. Or if a specific timing hierarchy is needed for other reasons.
AVB devices typically exchange capability information after physical link establishment. If
peer devices on a link are network synchronization capable they will start to exchange clock
synchronization frames. If not, then an AVB timing domain boundary is determined.
Traffic shaping is yet another way AVB ensures tight timing and synchronization of signals
is achieved. Traffic shaping is the process of smoothing out the traffic for a stream so the
packets making up the stream are evenly distributed in time. If traffic shaping is not done
at sources and bridges, then the packets tend to “bunch-up” into bursts of traffic that may
overwhelm buffers in subsequent bridges, switches or other network infrastructure devices.
The AVB architecture implements traffic shaping using existing 802.1Q forwarding and
priority mechanisms and also defines a particular relationship between priority tags and
frame forwarding behavior at endpoints and bridges.
The vision of AVB is to realize a standard that will allow “no-compromise” streaming of
AV signals over modern networks. Since the same could be said of StreamNet products,
you may look to ClearOne to take a leadership position with respect to implementing AVB
support across our line.
pg 15 StreamNet Digital Media and System Design Reference Guide
Common AV Signals and Interfaces
Control
IR – Infrared Control (IR) is the most ubiquitous control method and format. Though every
manufacturer uses a slightly different standard, IR is so ubiquitous that near Universal
Remote Controls are available to operate nearly any consumer electronics device known.
IP – Internet Protocol is the preferred way to control any device as it eliminates issues with
IR interference and limited command sets. Using IP some manufacturers define a great
number of parameters that are not typically available on an IR remote.
Serial – Serial control otherwise known as RS-232 is the most common and widely used
standard for control of modern systems, after IR. Advantages of RS-232 include its wide
support and inclusion in many products. However, with RS-232, cable distance limitations
and the aging protocol are just a few of the reasons it is being rapidly replaced by IP which
offers much greater flexibility, reduced cabling and infrastructure requirements, and overall
greater reliability.
®
CEC – Consumer Electronics Control (CEC) provides for integrated, “one-touch”
commands across multiple linked components. When enabled CEC allows system-wide
behaviors such as one-touch play or one-touch record, where pressing a single button
launches a series of coordinated commands greatly streamlining the user experience. CEC
is enabled courtesy of HDMI because of the “smart” two-way connection protocols, which
allow devices to communicate and interact with each other using EDID information and
other mechanisms. Devices connected with HDMI have the ability to scan the other devices
capabilities to automatically configure certain settings. Though few consumer electronics
devices today take advantage of CEC, it is a capability all audio video professionals should
be aware of if and when it begins to show up in devices.
pg 16StreamNet Digital Media and System Design Reference Guide
What is StreamNet?
By utilizing standardized Ethernet TCP/IP protocols to distribute audio and video streams
over LANs, StreamNet offers a scalable system enabling virtually unlimited zones, and
sources. Using standard TCP/IP, StreamNet has the most advanced integration capabilities
available in distributed audio and video. With StreamNet, seamless communication with
other systems such as lighting
control systems, automation
systems, and security systems
is easily achieved. StreamNet’s
open architecture allows those
systems to feed information for
display and control in real-time,
eliminating need for keypads
to control each subsystem, or
intensive programming required
by integrated all-in-one control
solutions. In addition to selecting
sources from the TouchLinX
keypads, users can browse digital
media metadata via a color LCD or
any web enabled device.
pg 17 StreamNet Digital Media and System Design Reference Guide
What is StreamNet?
StreamNet is a family of products designed to distribute digital entertainment using standard
networking technology which by embracing open standards, has allowed ClearOne to
develop a system that leverages the reliability, expandability and cost-effectiveness of
traditional computer networking solutions. StreamNet provides the following advantages
over traditional distributed audio systems:
+ Unparalleled Scalability: 1,800,000 sources may be distributed to up to 1,800,000 zones
+ Compatible with both digital and analog sources and displays
+ High quality audio and video playback capabilities, supports high bit-rate codecs
+ Little to no programming required, since the system is IP-based, it requires little to no
programming
+ Easy to install and control with a rich user experience including animated screens
pg 18StreamNet Digital Media and System Design Reference Guide
What is StreamNet?
Because StreamNet was designed for real world applications, it does not require a
dedicated network. Instead, AV devices peacefully coexist with data services or other
applications on the same network. In order to place content on the
network, StreamNet multi-media encoders convert audio, video
and control signals into streaming data which is transmitted
across any Ethernet based network using Internet Protocol
(IP). For playback, StreamNet multi-media decoders convert
the IP stream back into audio, video and control signals for
playback on display devices and audio systems.
Furthermore with StreamNet, you may mix and match sources,
such as Blu-ray players, digital media players, satellite and cable boxes,
video cameras or computers, allowing virtually any audio, video or data source to be used
with a StreamNet solution. Additional capabilities of StreamNet include an interactive
network technology where audio channels are sent back over the network such as to
contact a help-desk or security office while simultaneously allowing the overhead speaker
system to play the audio track for the video display. StreamNet also provides GPIO at the
network edge, or in other words on the endpoints. This allows dealers to perform complex
room automation without any additional boxes, wiring or power supplies.
Existing Ethernet
IP Network
pg 19 StreamNet Digital Media and System Design Reference Guide
What is StreamNet?
Why TCP/IP for Distributed Video?
NetStreams’ vision for distributed video is one that consistently distributes high definition
video (up to 1080p) in an all digital format using TCP/IP on any standard switched Ethernet
RF (the old way)
max resolution 480 lines
IP
network. This is the backbone of StreamNet. By distributing
video over TCP/IP, drastic improvements in flexibility, scalability,
and price / performance are achieved over traditional video
distribution methods. In addition, the incorporation of a distributed
architecture and distributed intelligence allows for flexibility and
easy expansion, since A/V sources may still be located at the head
end (like RF and Baseband systems), OR located anywhere on the
network.
Since TCP/IP was primarily developed for data transmission
across a network, ClearOne had to solve fundamental challenges
with using the protocol to distribute video. For example Network
bandwidth is a constraint to quality as packets may be lost if the
network is not managed correctly. Additionally synchronization
of signal distribution is essential and backwards / forwards
compatibility with legacy and newer sources always presents
issues.
full 1080P HD resolution
Only ClearOne has been able to solve all of these issues and
distribute the highest quality (1080p), uncompressed video,
point to point, and point to multipoint over TCP/IP on an Ethernet
network. NetStreams’ IP-Based system is the most advanced and
expandable distributed video system ever built.
pg 20StreamNet Digital Media and System Design Reference Guide
What is StreamNet?
Advantages of StreamNet IP-Based video distribution:
1. StreamNet delivers the highest quality uncompressed video over TCP/IP on a network
to multiple displays. With StreamNet, NetStreams is the first to deliver uncompressed
video over TCP/IP as most digital solutions for distributing
video employ artifact introducing compression prior to
distribution, due to bandwidth issues.
2. StreamNet can distribute multiple resolution formats of high
definition and standard definition video signals.
3. StreamNet technology insures precise synchronization
of audio and video signals for point to point, and point
to multi-point distribution, delivering the highest quality
audio and video performance with the lowest latency,
allowing audio and video signals to be delivered and
played back simultaneously at all display locations
without perceptible dissonance. Additionally, audio and
video signals distributed to multiple display locations
are fully synchronized across the network using TCP/IP
and eliminating lip sync problems. In addition signals are
automatically synchronized over the entire network for
point to multipoint distribution, with a total latency of just 30
milliseconds.
StreamNet’s suite of communication capabilities enables
easy system configuration and concrete network reliability.
StreamNet incorporates a suite of communications
conventions which reduce system configuration time and increases overall network
reliability. StreamNet services are known as Service Discovery, Message Routing, and
Status reporting.
Service Discovery - Every feature or function of the StreamNet IP-Based Multi-Zone
Audio and Control system is provided by a “service.” There are many types of services
– audio renderers, audio sources, general purpose inputs and outputs (GPIO), user
interface, media server proxy, to name a few. These services ‘advertise’ their existence
to the network, broadcasting their name, type, IP-Address(es) and other important
information. When StreamNet-enabled devices are plugged into the network, they
immediately advertise their capabilities in effect auto discovering and configuring,
reducing the need to program the entire system from scratch.
pg 21 StreamNet Digital Media and System Design Reference Guide
What is StreamNet?
Message Routing - ASCII messages provide the primary method of control and status
reporting for StreamNet. Every service has a name and optionally belongs to a zone
and / or some number of “groups”. Messages may be addressed to the service name,
room name or group name. Messages may be sent multicast (UDP) or unicast (UDP
or TCP) to any or all StreamNet-enabled devices. If required, StreamNet devices will
forward messages to ensure delivery to the service(s) addressed.
Status Reporting - StreamNet services output unsolicited reports of their state and
changes in state. Reports are in a flexible format that resembles XML. Each report
is a list of “variable=value” pairs. Status reports may be sent unicast or multicast.
In addition, a TCP client may “register” for status from one or more services and the
StreamNet device will aggregate the reports onto the one TCP connection.
4. StreamNet PerfectPixel technology faithfully replicates video over the network to ensure
the highest quality is achieved regardless of distance from the video source. Packet
loss can always occur when distributing a video signal (even a compressed one) over
an Ethernet network which may cause the picture to appear blotchy, color shifted, or
chunks of the picture to be missing all together. PerfectPixel technology solves this
issue with both compressed and uncompressed signals over the network and is a
combination of ClearOne’s proprietary algorithms for packet delivery optimization and
error concealment algorithm, insuring reliable delivery of video data and eliminating
dropped content across the network. The result is pixel-for-pixel, high definition video
distribution with consistency of high quality images across the network, regardless of
distance.
5. StreamNet can also distribute and deliver bit-for-bit, high performance audio including
the use of Dolby Digital® and DTS® multi channel formats for decoding by a Display,
A/V Receiver or surround sound processor.
pg 22StreamNet Digital Media and System Design Reference Guide
What is StreamNet?
6. TCP/IP, the language of the internet, was developed to support an almost infinite
number of nodes. NetStreams’ StreamNet offers support for a nearly unlimited number
of sources and zones, on any packet switched network. StreamNet incorporates a
state-of-the-art network architecture in which each product on the network has its own
IP address and network intelligence, eliminating the need for costly matrix switches
and central controllers. In addition, audio and video streams are multicast to provide
scalability. StreamNet technology is incorporated in the ClearOne MediaLinX products
and automatically converts audio and video in real time so it may be streamed using
TCP/IP for playback.
7. The StreamNet IP-Based distributed video system is future upgradeable. ClearOne has
insured the firmware in all new distributed video products (just as the audio products)
is upgradeable so additional features and CODECs may be added without costly
hardware upgrades.
8. StreamNet is easy to install and setup. Because StreamNet is completely IP-Based, it
does not require complex Matrix switches or external control systems with the massive
custom programming. Sources and displays are automatically discovered over the
network and a variety of easy to use graphical user interface skins are available, which
means programming time may be reduced by as much as 80% over a traditional video
distribution system.
Encoders
Decoders
Ethernet Switch
pg 23 StreamNet Digital Media and System Design Reference Guide
StreamNet Audio Technology
Automatic Synchronization of Streams (Time Sync)
A fundamental problem with using TCP/IP to distribute digital audio to multiple zones in a
home or commercial environment is synchronization of playback. Without synchronization,
audio can sputter, cut out, or have strong echo effects from zone to zone, sometimes
playing several seconds apart.
Simply incorporating a buffer to attempt to synchronize the audio is not enough. ClearOne’s
StreamNet technology provides the solution by removing the effect of network delays. This
is achieved by StreamNet assigning a “master” which is dynamically chosen to serve as the
time reference, thereby allowing all devices to share the same concept of time and stay fully
synchronized.
The sample rate is synchronized using a VCXO for low jitter. As a result, the maximum delay
between any two speakers is reduced to just 1 millisecond which is considerably below the
audible threshold. StreamNet allows audio in all zones to be synchronized when playing the
same source throughout the system, solving the problem of distributing audio over TCP/IP
packet-switched streams.
pg 24StreamNet Digital Media and System Design Reference Guide
StreamNet Audio Technology
StreamNet is compatible with traditional audio sources because MediaLinX automatically
converts audio in real time so it may be streamed over TCP/IP for playback in any zone
including IR commands packetized for easy control of the source.
Internet Protocol (IP-Based) enables pristine audio to be delivered digitally using state-of-
the-art meshed network architecture in which each product on the network has its own IP
address and network intelligence, eliminating the need for costly matrix switches and central
controllers. In addition, audio streams are multicast to provide scalability. With StreamNet
there is virtually no limit to the number of sources or zones you can have in the system, so
no matter the size or scale of your project, ClearOne’s StreamNet system will deliver the
performance you require.
Choose Between Uncompressed, Full Bandwidth Audio and MP3. The StreamNet
Multi-Zone Audio / Video and Control system can handle a wide range of audio sources
simultaneously, from uncompressed, full bandwidth audio to MP3 songs compressed at any
sample rate.
StreamNet enables a pure digital signal all the way to the speakers. Digital provides the
highest quality audio since it represents a perfect copy of the original studio recording.
However, at the amplifier, the digital signal is converted to analog so it can be heard. A
fundamental principle in audio is the longer the speaker wire, the more compromised the
audio signal becomes, as losses can occur due to speaker wire resistance (regardless
of the gauge). Besides losses due to cable resistance, longer cables begin to exhibit a
significant reactive component of capacitance and inductance regardless of the wire gauge.
When an AV professional designs a multi-zone audio system with long cable lengths, the
signal quality is compromised even more. Using StreamNet it is now possible to maintain
the quality of the signal by allowing the power amplifiers to be located at the speaker or in
close proximity significantly reducing the length of the speaker wire required and keeping
the signal in the digital domain for as long as possible.
pg 25 StreamNet Digital Media and System Design Reference Guide
Digital File Security and DRM
Defining DRM
DRM stands for Digital Rights Management and refers to a collection of systems used to
protect electronic media such as music, movies, images or any digital content where the
publisher wishes to ensure their data “bits” are not available to be freely swapped or shared
without proper compensation. DRM systems can vary widely but most frequently include
two primary pieces, encryption and access control.
Encryption as the name implies is designed to limit the free exchange of content so it cannot
be played outside the intended ecosystem, whereas access control is intended to limit the
number of plays or authorized devices available for playback. For example, Apple iTunes
uses a DRM system to limit the number of Apple devices iTunes files may be played on.
Digital Rights Management (DRM) is important to publishers of electronic media to ensure
they receive the appropriate revenue. By controlling the trading, protection, and access to
digital media, DRM helps publishers limit the illegal propagation of copyrighted works and
maximize revenue in the case of premium “paid” content.
The history of DRM technologies extends well before digital or electronic media existed
where copyright holders, content producers, or other financially or artistically interested
parties had certain business and legal objections to copying technologies. As early as
the player piano rolls in the 20th century copying technology represented a disruptive
technology to the live player who suddenly was no longer needed for the piano to be played.
Thus debates about the need for DRM are really not all that new. In fact we can thank a
successful outcome from the famous Sony “Betamax case” in the U.S. as paving the way for
the video tape recorder being made available for mass consumer use. Copying technology
in any form has and always will represent disruptive technology.
The advent of digital media and their associated conversion technologies, especially those
that usable on mass-market general-purpose personal computers, has vastly increased the
concerns of copyright-dependent individuals and organizations, especially within the movie
business. For this reason it is incumbent that all audio video professionals have some
understanding of DRM technologies as they can play a key role in a systems design, or in
certain equipment and cabling choices that otherwise would not be a factor.
Though certain copy protection schemes exist for analog, such as Macrovision, because
digital media files may be duplicated an unlimited number of times, with no degradation in
quality, DRM technologies are used by publishers to enforce access policies that not only
disallow copyright infringements, but also prevent lawful fair use of copyrighted works.
pg 26StreamNet Digital Media and System Design Reference Guide