A live video stream refers to sending online video and audio signals real time to any number of viewers. No matter what the live content is – sporting events, local interest stories, government-mandated open meetings, specialized business opportunities, or training sessions – there is a local or global audience for it. With streaming technology, viewers can watch and listen to media while it is being sent to their browser, instead of waiting for it to download completely and then play it.

Harnessing the power of streaming technology can take your business to the highest levels. But first you need to understand why streaming media is a compelling way to capture your audience and the technologies behind it.

Streaming media types

Streamed content can be in 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 media to reach out to home-based viewers. And, a lot of less well-known applications exist for video streaming, including traffic cameras and surveillance in high-crime areas.

A number of applications use the streaming technology. 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; viewers watch the event from start to finish as it is happening. When streamed content is delivered as continuous news, sports or entertainment to Internet-connected viewers, it is often called Internet TV. Those tend to be channels, rather than events (viewers can tune in anytime), much like a broadcast television channel.

Another variant, IPTV, is associated generally with delivering premium movie content to viewers on demand, usually to home televisions. This type tends to be one-to-one streams from a stored media library to individual viewers.

Main workflow processes

Media files can be quite large. For example, five minutes of uncompressed video requires almost one Gigabyte of space. To prepare audio and video for streaming, the media needs to be compressed to make the file size smaller. When a viewer requests the file, the video server sends a compressed file in a steady stream. A streaming media player (such as the free Windows Media Player) on the viewer’s computer or mobile device decompresses the file to play automatically in real time. The viewer can jump to any location in the video or audio presentation. Streaming media generally tries keep pace with the viewer’s connection speed to reduce interruptions and stalling. Regardless of the final use of the video, this process can be divided into three main workflow processes:

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

• Typically the captured video is saved as a file and processed and/or authored into its final form for delivery

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

• Multiple source content is to be digitized and saved

• Requires a scheduler to automate capture sessions

• Can be single or multiple sources
• Live event at a specific time
• Can be a remote or local capture
• Final content is delivered in real time to viewers

ViewCast Osprey® cards have application in all three categories. With Osprey video capture cards, you can pull video directly into your computer to broadcast live, or to create a streaming media file directly from your video camera.

ViewCast Niagara® series encoders are designed primarily for the third category - live video capture, processing and delivery. The Niagara streaming appliances have been designed from the ground up to provide a highly reliable, preconfigured, plug-and-play solution that enables users to quickly and easily transform and deliver premium quality standard- or high-definition video to IP and mobile networks.

• Broadband Internet makes possible a massive new audience that broadcasters, news services and other multimedia content providers can reach.
• The audience is already poised to receive voice, data and video content on their cell phones, PDAs and notebook computers.
• Mass media via the Internet is a new source of advertising revenue.
• ViewCast empowers you to successfully stream your content to the perfect audience.
• Streaming powerfully influences your key audience's buying decisions.
• Streaming is extremely cost-effective.
• Streaming greatly appeals to the Internet-savvy generation.

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

Before you can design a suitable solution, you need to understand a little about the equipment needed to accept live video at its source and deliver it where you want.

TV-quality video contains a large amount of brightness and color information as well as picture detail … too much to go down a small IP pipe like the Internet. It needs to be converted to a form suitable for the Internet or a 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, 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.

This illustration 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.

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.

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.

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.

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.

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.

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

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.