Streaming Videoconferences

Soh Hock HengNational University of Singapore

Doug Pearson

Internet2 Commons Site Coordinator TrainingDecember 3, 2003National University of Singapore

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Streaming

Streaming is the one-way delivery of digital content from a streaming server to a streaming client in a continuous, paced, and controlled flow.

Streaming alleviates the need to download an entire media clip as a file.• Live events don’t exist as a file yet!• Allows playing to start before download is completed• Protects copyright

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Streaming a Videoconference

Streaming a videoconference makes it possible for any number of people to view a conference – either live or recorded for on-demand access.

Viewers use desktop computers with standard media players such as Real, Windows Media, or QuickTime.

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What Kinds of Things Can You Do?

Key individuals participate interactively by videoconference; a larger audience views the live stream.

Save the proceedings of a meeting. Make a class or lecture available on-

demand for student review. In fact, maybe all you want to do is stream

an event – you don’t need to videoconference. You have a videoconferencing appliance in the room, and…

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Interactive for Live Events

Streaming is a one-way delivery of media.

Participants in a live, streaming event can participate interactively by:• E-mail to a conference facilitator• On-line chat

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Four Methods to Stream a Videoconference

All-in-one box solutions

Combination of videoconferencing terminal and standard streaming encoder

Videoconferencing appliances with built-in H.26x/G.7xx multicast streaming

Application service providers

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All-In-One Box

As either an• H.323 terminal and a streaming server, or • H.323 MCU and streaming server.

These devices• Take the H.26x video and G.7xx audio out of an H.323 envelope and stuff into the envelope of a common streaming format such as Real, Windows Media, or QuickTime, and

• Serve the unicast or multicast stream.• Can store the stream for VOD.

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All-In-One Box

Examples:• STARBAK Torrent CE• FVC Conference Server with Streaming Support• Virtual Rooms Videoconference Service (VRVS)

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Combo Terminal and Encoder

Two standard devices…• H.323 videoconference terminal• Streaming encoder

Are interconnected• A/V out of H.323 terminal into A/V input of encoder

Encoder can be just about anything• Real, Windows Media, QuickTime; or MPEG-1,-2,-4; unicast or multicast

Video can be recorded and stored for VOD

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Terminals with Built-In

Some high-end terminals such as • Polycom FX• Tandberg 880

Can multicast the H.26x/G.7xx audio and video in standard streaming envelopes (QT, etc.).

No ability to record for VOD.

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Application Service Providers

Many videoconference bridging service providers also provide a streaming option.

The technology that an ASP will employ will either be an All-In-One Box or a Combination Terminal and Encoder

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Pros and Cons

Video and audio quality• CON: Both All-In-One Box and Terminals with Built-In repackage H.26x and G.7xx video and audio.

– H.26x & G.7xx are not optimized for streaming. The video quality is more susceptible to degradation due to network congestion than made-for-streaming formats such as Real and Windows Media encoders.

– H.26x doesn’t provide dynamic bandwidth adjusting capability like Real SureStream and Windows Intelligent Streaming.

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Just because…

You’re getting a Real, QT, or WM stream out of an All-in-One Box, doesn’t mean optimized-for-streaming encoders are being used!

All-In-One Box and Terminals with Built-In DO NOT use the Real or WM encoders. They stuff H.26x and G.7xx encoded video and audio into Real, WM, or QT envelopes.

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Pros and Cons

Video and audio quality• PRO: Solution Combo Terminal and Encoder uses optimized-for-streaming encoding formats.

– H.26x & G.7xx from the videoconference are decoded to baseband video and audio and re-encoded in an optimized-for-streaming format.

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Pros and Cons

Networking• CON: Terminals with Built-In require IP multicast.

– Multicast is sparsely supported in the commercial Internet.

– Multicast support in university and commercial intranets is varied and typically not robust.

– Internet2 supports multicast.– Terminals with Built-In are only feasible if your audience

is on multicast-enabled networks.

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Pros and Cons

Networking• PRO: All-in-One Box and Combo Terminals and Encoders support IP unicast and multicast transmissions.

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Pros and Cons

Operations and Management• CON: Combo Terminal and Encoder can be complex to manage

– Have to schedule and manage the encoder. Videoconference scheduling systems don’t support viewing the pair of devices as a single logical device.

Features• CON: Terminals with Built-In don’t have the ability to record a videoconference.

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  All-In-One Combo Built-In

Initial set upmoderate to

complexcomplex simple

Management & operation

moderate complex simple

Networktransmission

unicast ormulticast

unicast ormulticast

requiresIP multicast

Transmission speed

fixed to speed of

conference

flexible modem to broadband

fixed to speed of

conference

Perf under net congestion

fair to poor good fair to poor

Record for VOD yes yesonly w/ extra

special tech

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  All-In-OneCombo Term

& EncoderBuilt-In

Cost to support a small number of concurrent conferences

high moderate low

Cost to support a large number of concurrent conferences

moderate highmoderate-to-

low

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Internet2 CommonsVC Streaming Service

Utilizes STARBAK Torrent CE all-in-one box

Available to any Internet2 Commons member who requests a conference

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Internet2 Commons VC Streaming Service

Simple web interface• Video uses QuickTime, Windows Media Player, or

RealOne

Can add slides and chat, if you want them

Stream has about a 1 to 1 ½ second delay over the actual videoconference• Comparatively speaking, a very short amount of time

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Internet2 Commons VC Streaming Service

If you request that the Commons record your conference, you will need to store the stream on your own server.

Can be played back in QuickTime or Real.

When filling out the conference request form, select streaming.

You will need to describe the anticipated audience.