A Closer Look at Streaming Servers
Nov 16, 2012 12:05 PM, By Jan Ozer
Understanding the options
Your client has decided to stream live or on-demand video and to run a streaming server. Remember, of course, that you don’t actually need a traditional streaming server for progressive download, or for HTTP-based adaptive streaming technologies such as Apple HTTP Live Streaming (HLS) or Microsoft Smooth Streaming. However, streaming servers are necessary if the client wants to protect their streams with encryption, deliver via peer-to-peer or multicast, or serve multiple targets such as Flash and iOS with the same stream or streams.
For these applications, there are four basic choices: the Adobe Flash Media Server line of products, Microsoft’s IIS Media Services, RealNetworks’ Helix Server line of products, and Wowza Media Server. There’s also an open-source streaming server called Red5 that uses some secure protocols to deliver to Flash, but it doesn’t currently convert streams for delivery to iOS or support any adaptive streaming technology. This would eliminate it from contention for most streaming producers.
How to choose between the candidates? The obvious first question is whether it can deliver video to the platforms that you’re targeting using the technologies and protocols that you want to use. A quick review of the origins of each server will shed some light here.
NASA’s Jet Propulsion Lab streamed the historic landing of Mars rover Curiosity using the Adobe Flash Media Server 4.5.
Adobe Media Server Family
In May 2012, Adobe announced Adobe Media Server 5 and Adobe Access 4, with Linux and Amazon Web Services versions available in June 2012. There are four software versions and the product is also available on Amazon Web Services. Like its predecessor, Adobe Flash Access 3.0, Adobe Access 4 enables providers to securely deliver and monetize content to a range of computers, mobile devices, and set-top boxes with other players.
The four software versions vary as follows. The Starter version is free, but maxes out at 10 simultaneous RTMP connections, and limited durations for IP multicast, HTTP based Dynamic Streaming (HDS), HTTP Live Streaming to iOS devices (HLS), IP multicast, RTMFP unicast, and RTMFP P2P. You can also experiment with higher-level video streaming and content protection functionality, as well as implement closed captions, which all versions support. Overall, however, this version is good for evaluation and debugging, but not real day-to-day operation.
The Adobe Media Server 5 Standard version ($995) offers unlimited RTMP, HDS, and HLS streaming, but no IP multicast, RTMFP unicast and RTMFP P2P, or the two-way webcam/audio support needed for videoconferencing. You also can’t access multicast fusion for Flash or application-level multicast, or protected HDS or HLS. This should suffice for many externally focused streamers, but not for enterprise clients or those who require content protection.
The Adobe Media Server 5 Professional ($4,500) offers unlimited RTMP, HDS, HLS, and IP multicast streaming, but limits RTMFP unicast and RTMFP P2P streams to 500 users. However, you also get full access to multicast fusion and application-level multicast, streaming splitting and multicast ingest and recording, protected HDS and HLS, and realtime encryption for multicast and P2P. Bi-direction audio/video capture capabilities enable video chat, videoconferencing, and similar apps.
The most capable version, the Adobe Media Server 5 Extended edition, includes unlimited access to all the features available in other versions, but you have to call for pricing. The version on Amazon Web Service offers most but not all of the features of the installed versions of the server, including transmuxing for HDS and HLS, protected HLS and HDS, peer-to-peer delivery and application-level multicast. Beyond a $5 one-time charge for setup, and recurring monthly charges of $5, you also pay according to the number of simultaneous connections and a fee for data transfer. Check the Adobe website for more details about features and versions. Although the Adobe family of servers can securely deliver to a range of desktop, set-top box, and mobile players, if your client plans to deliver video to either Microsoft’s Silverlight player or the older RealPlayer, or to IPTV platforms, you’ll have to use a different server.
A Closer Look at Streaming Servers
Nov 16, 2012 12:05 PM, By Jan Ozer
Understanding the options
Olympic video delivered to the iPad via Microsoft’s cloud-based Windows Azure Media Services.
Microsoft IIS Media Services 4
Microsoft’s Internet Information Services (IIS) for Windows Server is a general-purpose web server with extensions such as IIS Media Services for video delivery functions, including Smooth Streaming and throttled progressive downloads of common media formats. Recognizing that most video producers must reach both a desktop platform and iOS devices with live and on-demand adaptive streaming, Microsoft added transmuxing capabilities to IIS Media Services 4. Specifically, IIS Media Services 4 can transmux incoming Smooth Streaming fragments into Apple iOS-compatible streams with AES-128 encryption, if desired. The server can also configure an HTML5 page for use in playing the streams in Apple Safari.
If you’ve already purchased Windows Server, the Smooth Streaming functionality is free, though obviously it’s of little use if you need to reach desktop platforms other than Silverlight or other Smooth Streaming-compatible players.
Microsoft recently released a preview release of the cloud-based Windows Azure Media Services that was used to deliver video from the London Olympics to a range of players, including Silverlight, iOS, Android, and Flash, the last via a custom software development kit produced by a Microsoft partner.
RealNetworks’ Helix Universal Server
RealNetworks was the first major streaming-related brand, though it fell from prominence in the early ‘00s. Since then, the company has retooled its Helix Media Server into a general purpose platform that provides legacy support for existing RealNetworks and Windows Media shops, plus transmuxing of H.264/AAC content for delivery to Flash, QuickTime, Silverlight, Blackberry, Symbian, and iOS devices. Helix Media Server also supports HTTP Live streaming to iOS devices and QuickTime X.
RealNetworks offers Helix in three configurations: Helix Server Standard, which supports a handful of clients and formats, including Flash Dynamic Streaming; Helix Universal Media Server, which adds non-adaptive Windows Media, 3GPP, and Apple iOS delivery; and the Helix Universal Media Server for Mobile, which adds adaptive bitrate streaming to iOS and 3GPP devices. Helix Server Standard costs $999, and the company doesn’t publish prices for the two more highly featured servers. As with Microsoft and Adobe, Helix supports multiple target platforms by transmuxing an incoming stream, and in the case of iOS devices, using AES-128 encryption, if desired.
However, RealNetworks doesn’t support Flash encryption via RTMPE and RTMPTE, doesn’t support applications like Flash-based video chat, and can’t distribute video to the Flash Player using multicast or peer-to-peer. If legacy support for RealNetworks files is a priority, Helix is your natural choice. Beyond this, RealNetworks offers very broad support for a range of devices in both single- and adaptive-bitrate streams.
Wowza media server powers Justin.tv.
Wowza Media Server 3
Wowza Media Systems is the company that pioneered the transmux process, which the company implemented as its H.264 everywhere features in Wowza Media Server 2. Wowza currently offers a traditional perpetual license for $995, or you can license a single instance for a month for $55, or for a day for $5, which is ideal for live events.
Wowza was initially designed as a low cost alternative for Flash streaming, so it provides very broad-based Flash distribution and supports most, if not all, of the protocols supported by Adobe’s own server family. However, while Wowza can provide some of the interactivity features enabled by Adobe’s Flash Media Interactive Server, the server can’t push multicast streams to the Flash Player or implement peer-to-peer delivery to the Flash Player within the enterprise. Fortunately, for enterprise live streaming, Wowza delivers live streams using both standard HTTP caching infrastructures for unicast streams to most any player and canonical RTP multicast for delivery to Silverlight players.
In addition to Flash, Wowza can also transmux an incoming stream for distribution to iOS (with AES-128 encryption), Smooth Streaming players such as Silverlight and QuickTime/3GPP, and is the only server that can distribute H.264-encoded packets in an MPEG-2 Transport stream for playback on IPTV devices.
At press time, Wowza announced Wowza Media Server 3.5, which includes on-the-fly encryption for live and on-demand content and several additional forms of security. Also new is closed captioning support, with the ability to transmux captions as necessary for each target platform, and integration with the Silverlight Multicast Player, enabling multicast streaming of MPEG-TS files to any Silverlight desktops.
A Closer Look at Streaming Servers
Nov 16, 2012 12:05 PM, By Jan Ozer
Understanding the options
Other Basics
Beyond reaching your target viewers, you should also consider the source of your stream. For example, if you’ll be transmuxing an MPEG-2 transport stream from a satellite or similar source, it’s best if your server can simply input the live stream. Wowza Media Server can, while the other servers will require additional hardware, software, or both.
While it’s not unusual to purchase a separate standalone computer to host a streaming server, you should also check operating system support early in the purchasing process. Microsoft’s Windows-only IIS is the most limited, while the Adobe family of servers supports both Windows Server 2008 and Red Hat Enterprise Linux. RealNetwork’s Helix runs on Windows and Red Hat Linux, plus Oracle Solaris, while Wowza runs on Windows, Linux, Solaris, Unix, and Mac OS X. If Infrastructure-as-a-service cloud-based operation is the goal, you can directly license all streaming servers except Helix on the Amazon EC2 cloud platform. With Helix, you would have to create your own Cloud platform on EC2 using one of the compatible operating systems and install the product separately. Microsoft and Wowza will also support Platform-as-a-Service streaming from the newly announced Windows Azure Media Services, if your client prefers the Microsoft cloud platform.
Other Features
Beyond basics, there are a few other features worth considering when choosing a streaming server. In this regard, Wowza has done the best job differentiating its product from the other offerings.
Specifically, with Wowza Media Server 3.0, Wowza debuted a plug-in architecture that allows the company to enhance the base product offering with several very useful enhancements, most notably, the Wowza Transcoder and nDVR AddOns. The Wowza Transcoder AddOn allows the server to accept an incoming stream in MPEG-2 or H.264 format and re-encode the stream for single or adaptive delivery.
In a broadcast environment, the Transcoder could input an MPEG-2 encoded stream from a satellite or similar source, and transcode the stream to H.264 for delivery to Flash, iOS, or any other of the supported target platforms. In a live production, the Transcoder could input a single, high-quality H.264 stream and produce multiple output streams for adaptive streaming to any of the supported target platforms. This latter application is exceptionally useful in many live event scenarios, where outbound bandwidth is a significant limitation and onsite encoding costs are a constant concern. For example, for an event shot and distributed in HD, producing the necessary adaptive streams might require multiple encoders and 5Mbps to 7Mbps outbound bandwidth. With the Transcoder plug-in, a single encoder could produce a compact 720p stream that might require 2.5Mbps to 3Mbps outbound bandwidth.
Once the stream gets to the server, the Transcoder plug-in creates the adaptive streams in realtime, avoiding the outbound bandwidth logjam and reducing onsite encoding costs. Single license pricing for the Transcoder AddOn is $1,495 for a perpetual license, $30 per channel for a monthly license, and $3 per channel for a daily license.
The other noteworthy Wowza plug-in is the Wowza nDVR AddOn, which is currently in beta. While most streaming servers offer some DVR functionality, typically you have to configure the DVR differently for each target platform. In contrast, Wowza nDVR creates a single content cache that’s accessed by clients viewing via Flash HTTP Dynamic Streaming, Microsoft Smooth Streaming, and Apple HLS clients. This reduces the on-server cache and setup complexity. Single license pricing for the nDVR AddOn is $495 for a perpetual license, $20 for a monthly license, and $2 for a daily license.
Overall, Adobe’s unique strengths lie in the ability to efficiently distribute video within an enterprise, as well as comprehensive support for all Adobe protocols and DRM technologies, with its newest server offering significant protection for iOS delivery as well. Microsoft’s IIS server is an inexpensive mechanism for adding iOS clients to an existing Silverlight distribution system, but can only publish progressive download files to Flash clients. RealNetworks’ Helix Server offers very good format support, but it doesn’t support all major adaptive bitrate streaming protocols or Flash interactivity, which could be limiting. Finally, Wowza Media Server is a cost effective and very broad-based multi-client distribution solution with a flexible plug-in architecture that enables and simplifies many user and business scenarios.
