In Broadcast - July 2012 - 46
WWW.INBROADCAST.COM | ISSUE 10 - JULY 2012
The Reality Of Everywhere Media
We anticipate a world ﬁve years hence that will be overwhelmed with streamed video, delivered any time, interactive, in high quality and on every device we own (including spectacles and sunglasses thanks to Google’s Project Glass). This is no pipe dream. There are few mobile phones and tablet computers that do not ship with the technology to watch, create and deliver video – one to one and globally. Most DVD players and TV sets are now connected IPTV devices. Cars are multimedia hubs. Underground stations and airlines are rigging for high speed connectivity. 46
As Internet Protocol-based video and media on-demand usage takes over, Kieron Seth investigates ongoing developments in the world of multimedia
Adaptive Bitrate Workﬂow from Digital Rapids
This has all been a long time coming. Back in the mid 1990’s IT manufacturers such as Hewlett Packard spent days and thousands of pounds creating two-minute product trailers in 300 x 200 15fps windows, uploaded to their website and pioneering news aggregators such as Newsdesk International. These movies were ready for slow download to PCs that were barely able to handle this experiment in multimedia. Obviously the 15 years that followed have rendered this situation ancient history. Tracking the development of streamed media serves to outline where many of the hurdles still exist.
The primary technical issues related to streaming were having enough CPU grunt and bus bandwidth to support the required data rates. Computers were optimised for Microsoft Ofﬁce 95 not H.264 decoding. Dial up connections and internet speeds of under 50Kb/s were slowly superceded by broadband links but the earliest requirement was for the data rate to exceed a pitiful 256Kb/s. It was only in 2010 that the US Federal Communications Commission (FCC) deﬁned “Basic Broadband” as data transmission speeds of at least 4Mb/s downstream and 1Mb/s upstream. Sadly even today, parts of Western Europe still cannot match these criteria.
Consumer connection bottlenecks aside, the process of creating,
encoding and delivering mass multimedia to any signiﬁcant degree was limited by production costs in the pre-digital era. The arrival of DV in the late 90’s gave birth to low-cost home, college, corporate, independent and community studios. This coincided with the advent of Apple’s Quicktime 4, new versions of Microsoft Windows Media and Real Media formats; the result was a rush to embed players on websites. Mass-experience online video was born and took off quickly, particularly in the adult industry. Paysites, video hosting services, and peer-to-peer ﬁle sharing services all prospered. There was no turning back. During the last decade, the streamed video experience has become far more televisual and has spread from the computer screen to every other monitor we own. Landmarks included the development of H.264 in 2003, the overwhelming cross-platform success of Adobe Flash as a video player, the dramatic power increase in encoding technology, the fall in storage costs and the gradual development of network speeds.
The industry is now at a stage where live TV is streamed at near broadcast quality. The BBC’s iPlayer, for example, has been an extraordinary success. A cross-platform, Flash video-based streaming system, it delivers live and on-demand TV to computers, mobiles and connected set top boxes, games consoles and digital media receivers. Streaming at 1.5Mb/s, the viewing
experience is acceptable enough to have generated a big audience. July 2011 saw BBC iPlayer receive 153 million requests for TV and radio programmes in total. Superior quality (720p or higher) services are available with bitrates of 3.2Mb/s. In order to ensure that viewers always receive the best quality media their connection can support, modern servers can monitor network speeds and seamlessly vary the quality of the video being served to the viewer. Known as adaptive bitrate, it is supported by Adobe, Microsoft, Apple and other vendors in their streaming technology. Popular platforms such as Flash Media Server and the Wowza Media Server 3 both employ the strategy. Wowza’s Transcoder AddOn provides the ability to decode the video and audio of an incoming live stream and re-encode it to suit the desired playback device or devices. These new renditions are accurately key frame aligned for adaptive bitrate delivery. Integrated into such products as Digital Rapids’ StreamZ Live family of live encoders and transcoders, adaptive technology enables broadcasters to output a single source into multiple formats, multiple resolutions and bitrates simultaneously. Impressively, iPhones and web feeds can be satisﬁed with a single unit.
While quality variability is an acceptable compromise for viewing
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BBC iPlayer - A public service success story