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Learn About Streaming

What is Live Streaming?

You have live content - sporting events, local interest stories, government-mandated open meetings, specialized business opportunities, or any number of possibilities. One thing is certain.  There is an audience for it - local or global. Connect to your audience with the media of the future.

So how do you harness the power of streaming technology to take your business to the highest levels? Let’s begin with an understanding of why streamed media is a compelling way to capture your audience, and then explore some of the technologies behind live streaming media.

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Reasons to reach your audience with streaming media.

Streamed content can be any of a variety of types - news and entertainment being perhaps the most familiar. But it can also be educational media, as in Distance Learning. For a large enterprise,  the video may be a corporate CEO presentation to global employees.

For governments, it may be streaming a city council meeting. Internet Radio is streaming without video. Ministries use streaming to reach out to home-based viewers.  And there are lots of less well-known applications for video streaming, including traffic cameras and surveillance in high-crime areas.

There are many applications for capturing video into the computer environment ranging from DVD authoring to live webcasting. Regardless of the final use of the video,  all can be categorized into three main workflow processes:

Single video/session capture (i.e. one-off file capture for non-real time delivery)

Batch video/session capture (i.e. archiving, scheduling and storage)

Live video capture, processing and delivery

ViewCast Osprey® cards have application in all three categories. ViewCast Niagara® series encoders are designed primarily for the third category - live video capture, processing and delivery.

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What Can Streaming Do for You?

All of these applications use essentially the same technologies to create, process, manage and deliver live video via a network. All require that the live media be captured continuously, frame-by-frame,  and made into a digital form in real time for real-time streaming delivery.

Streaming is a rather technical term, more a property of the delivery system than the media itself. The name is usually applied to video and/or audio distributed by a TCP/IP data network to media players on computers, mobile devices or set-top boxes for viewing on conventional TV sets. It is not limited to audio and video; it can include, for example, graphics from PowerPoint presentations.

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Streaming by any other name…

There are a number of applications which use the technology of streaming. When video, or a combination of video and graphics, is delivered over the Internet for a defined and somewhat closed audience, it is often called webcasting. These tend to be live events, viewed by the audience from start to finish as it is happening. When streamed content is delivered as continuous news, sports or entertainment to Internet-connected users, it is often called Internet TV. Those tend to be channels, rather than events (e.g., the viewers can “tune in” anytime), much like a broadcast television channel.

There is another variant called IPTV, generally associated with delivering premium movie content to users on demand, usually viewed on home televisions. These tend to be one-to-one streams from a stored media library to individual users.

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What Do I Need to Know about Video Streaming to Make it Work for Me?

The best place to start is to know a little about the equipment needed to accept live video at its source and deliver it where you want it. Here’s an overview of the technologies and components of live streaming video - from the video source, to the video processing needed for network delivery, to streaming video playback. This will help you understand some of the choices you’ll need to make when designing a suitable solution.

The illustration below details the whole streaming video path starting with a “live” video source, like a camera or video player, all the way through to the viewer.

The video source

Hey, wait a second… you just said ‘live video from a video player.’ I understand live video from a camera, but are we saying the video out of a video player is “live”? Yes, indeed…the video is being played out in real time, to be captured and processed for IP network delivery immediately as it is received as a continuous video (and audio) stream from the player.

So, when we say ‘live,’ that could be video from an as-it-is-happening live event, or it could be any video reproduced from any storage device which you intend to be viewed while it is being played from the device. We’ll continue to call this ‘live’ for purposes of illustration.

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Video Compression

TV-quality video contains a huge amount of brightness information, color information and picture detail… much too much to cram down a small IP pipe like the Internet. So it needs to be converted to a form suitable for Internet or private network delivery. The technical terms for this conversion are scaling and compression, which together reduce the amount of network resources needed to convey a reasonable facsimile of the original picture and sound.

The conversion process is the careful balance of several factors, including acceptable video quality, available network bandwidth, desired playback picture size and playback device capabilities. The device doing the compressing is called the Encoder, and in the figure below, the Encoder is shown as one of our ViewCast Niagara models - the Niagara Pro II. The Encoder accepts live video and audio and compresses them into a stream of data, delivered continuously by the Encoder’s TCP/IP network port.

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The Encoder and its Codecs

The little piece of wizardry inside the Encoder that is doing the compression is called a Codec, which is a short form of “COder-DECoder.” A little misnamed, since all we want to look at right now is the Coder part. All compression codecs invite you to specify the aforementioned factors of speed, size and quality in various ways, but all codecs are not created equal.

There has been considerable evolution in codec technology that improves picture quality for a given network quality and picture size. And there are popular codecs and less popular codecs, each promoted by their creators for picture quality, or suitability to an application, or for compatibility with specific viewing devices, or to be compatible with different international standards.

You may recognize some of these codecs by name: Microsoft Windows Media®, RealVideo®, MPEG 2, MPEG 4, H.264, Adobe® Flash® and Adobe Flash Live, the video parts of Microsoft Silverlight™, 3GPP for mobile phones, etc. You’ve probably encountered all of these as you watch video on the Internet.

Which means that unless you have one very specific application for streaming video, which in turn usually means an application to a closed audience where you can define what encoded format and what the playback experience will be, you’ll need an encoder that can handle all of the popular codecs, in any combination, often at the same time. Better yet, you need an encoder that makes it easy to control any or all via a single, common, easy-to-understand user experience.

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The Streaming Server

The Encoder creates the desired video and audio stream. The next steps take care of making the stream available in volume for the anticipated size of the audience, and giving the user some way to start the playback experience.

The device that accepts the stream from the Encoder (the Uplink Stream) and makes it available to a mass audience is called a Streaming Server. The Server runs special software that accepts uplink streams from an Encoder and manages connection requests from hundreds or thousands of viewers. The software these servers run come from a variety of sources, including Microsoft Windows Media Server, Real Network Helix Universal Server, and many others. Most can stream several different formats.

The server can be a single Server if the audience size is small, like a couple hundred viewers or so. This is often the case in Enterprise and Education applications; in these small environments you may wish to own your own media server and manage its operations.

But if your application requires a more global audience, the Server will in reality be a server farm, which is an array of servers that are interconnected and are often deployed in numbers around the globe. There are companies, such as Akamai and LimeLight, who own and maintain vast networks of such servers and make them available to you for a fee.

These companies call their server array a Content Delivery Network (CDN). The term has over time come to represent the service itself - you “hire” a CDN to deliver your content. Some CDN companies have online account signup so you can create an instant relationship and be streaming globally in mere minutes.

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How Viewers Find the Stream

So far, you are capturing and encoding live video and audio and creating a TCP/IP stream. You have signed up a CDN, and now you want your audience to view it. So, what’s next? You will need some way for your audience to know how, and where, to pick up your stream for viewing.

Here’s how that typically works: when you sign up with a streaming service provider (CDN), they will give you both a network address to send your Uplink video to (their server network’s input point), and a link to the server output. It’s that Output URL that’s important - it’s where you want your viewer to browse TO.

For browser-based users the publish link is usually contained in a Web site link (Step 2 in the diagram below); clicking on the link (Step 3) launches an appropriate video player (if one is installed on the viewer’s computer) and the playback experience begins.

For mobile devices and most TV-based playback applications, the link is contained in some sort of electronic program guide. The guide can be searchable and even schedule-able. When the link is selected, a suitable player is launched and the video appears on-screen. You can also send the links in e-mails or include them in electronic newsletters. The reader then simply clicks the link to watch the video on their computer or mobile device.

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Are We On the Air?

Almost. Once your viewers have an active URL, clicking on it will usually launch a compatible video player. But, as we noted earlier, not every playback device can play every type of video stream. Most players will invite the user to allow automatic installation of the components needed to view the stream type, but not always.

To ensure that anyone can view your stream, you may want to stream in more than one format at the same time. Niagara streaming encoders from ViewCast include everything you need to stream in multiple formats, simultaneously. In practice, each different stream from the Encoder would be fed to the Server or server array, and multiple URLs (one for each stream type) would be offered to the viewer. Then the viewer need only click on his or her preference to receive the proper stream.

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Simple Guide to Streaming Audio and Video Types

As noted above, the Encoder can create several different types of audio and video streams. Although all are a type of IP video format, each has certain properties that make it more attuned to a specific streaming video application.

The following chart lists all formats available on ViewCast Niagara encoders. All of these formats can be used for many different applications.

IP Video Compression for Streaming in Full Resolution & Lower
Windows Media Streaming Internet video and mobile devices
Windows Media VC-1 High-quality Internet video and video to set-top players
RealVideo/Helix Streaming Internet video and mobile devices
MPEG-4 Handheld devices and mobile phones
Adobe Flash Live Internet video for flash players
flash to File For VOD playback to selected media players that support flash encoding format, including the popular QuickTime and VLC players
Microsoft AVI Uncompressed video for later post-processing

To determine the data rate you will stream your content, you will need to determine the IP bandwidth to which your audience has access.

For example, if the access method uses an ISDN connection or less, then you would stream your video and/or audio at a low data rate such as QCIF at 56kbps. If the access is much greater like a cable modem or DSL connection, then you can provide a higher quality stream at full resolution at 2 Mbps.

All Niagara Encoders provide preconfigured encoding profiles for different bandwidth connections. The profiles loaded will depend upon how you configure your Niagara encoder on its initial startup.

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