Multimedia

Multimedia

Multimedia 101

Implementing a streaming protocol created for your business needs allows you to communicate more effectively and increase profits.  At ABT Internet, we understand the importance of utilizing the most efficient streaming media for our clients to ensure they are at the forefront of marketing, selling and supporting their products and services through live broadcasts, video, internal communications and training.

As the Multimedia industry has grown exponentially, it has become a powerful vehicle, not only for entertainment purposes, but as a way to achieve mass communication while maintaining security, content and controlling viewership.   

At ABT Internet, we provide streaming that can be broadcast live or through video. In live streaming, we broadcast the media live over the internet, utilizing a camera for the media, an encoder to digitize the content, a media publisher and a content delivery network to distribute and deliver the content. The audience can then view the media live. HTML5 and iPad have accelerated the demand for understanding and creating the underlying technology of digital video. Putting aside codecs (H264 & VP8) which handles compression, the following methods and their acronyms outline the various video streaming methods, they are:  Real Time Streaming Protocol (RTSP) for entertainment purposes, SD (Static Domain for cooki-less server), Content Delivery Network (CDN) for distributing traffic to a multitude of servers, and HTTP Live Streaming (HLS) implemented  by Apple Inc., as part of their QuickTime X and iPhone software systems.

The following is a discussion about the pros and cons, of the technologies that support Progressive Download, RTMP/RTSP Streaming, and Adaptive HTTP video streaming methods.

Progressive Download

Progressive Download is the simplest and easiest mode to deploy on a server. It is also the most common delivery method (YouTube is using Progressive Download). and the easiest to implement: just upload a video to your web-server and point your player to the URL. The reset is done by the browser.  When the user hits play, the player starts downloading the file. As soon as the player has enough data it will play the video immediately. As the player plays the video it will continue to download the video file, continuing to download until it has received the whole file.  Progressive Download is supported by HTML5, Flash browsers, iPad, iPhone and Android.

On the server side, all web and ftp hosts including Content Delivery Network (CDN) also support progressive download.  In most cases (Flash needs a small server module), it is possible to seek in a player to a not-yet-downloaded part of the video. At that point, the player re-downloads the video, starting at the seek offset instead of at the beginning. We call that feature pseudo-streaming.

The main downside of Progressive Download is over utilization of bandwidth.  Bandwidth is wasted on data downloaded but not watched. Consider watching a twenty minutes video, then leave the page after having watched only two minutes of the video, your browser has already downloaded the entire twenty minutes video.

This means that the Host site has transferred nine times as much data as the user actually watched - This becomes an expensive ordeal on a large scale.

Another downside is the inability to change the quality of the video after download starts; the video quality is locked. It becomes an issue when you watch video on an iPad while your connection may switch from WIFI to 3G. The video will then stutter as the download speeds are lower on 3G v. WiFi.  In summary, Progressive Download works best for short videos (a few minutes).

Live streaming is not possible with progressive download as there's no downloadable file.

RTSP/RTMP Streaming

RTMP (Real Time Messaging Protocol)/RTSP (Real Time Streaming Protocol) Streaming is popularly used by professional media companies like Netflix and Hulu. RTMP/RTSP Streaming utilize special web-servers that only deliver the portion of a video the user is currently watching. There is no data downloaded in advance and data viewed is immediately discarded. The preferred solution is RTMP (Real Time Messaging Protocol); Flash streaming protocol. It is supported by servers such as RED5, FMS and Wowza and most CDNs.  Android does support RTSP. At this time RTSP is not widely supported by servers and CDNs.

This lack of support for RTSP at the server side, is the biggest drawback. Most Web hosting companies do not want to maintain expensive, dedicated servers to stream their videos.   Also, the RTMP and RTSP protocols are often blocked by the companies' firewalls.

The RTSP lets you change video quality at mid-stream; allowing for optimum playback quality in full-screen.  However, if the connection speed drops below the minimum bandwidth needed for the video, playback will be continuously interrupted.  To summarize, RTMP/RTSP Streaming works great even for long videos or live video. however, it needs a special server to support the protocol requirements, which makes it less accessible and costly.

Please note: ABT does host videos using the RTSP protocol.

Adaptive HTTP

Adaptive HTTP Streaming, is a hybrid of the Progressive Download and RTMP/RTSP Streaming. It utilizes the best of the two worlds of RTSP (Live streaming, bandwidth efficiency, quality switching) and Progressive Download (simple server needed).

Adaptive HTTP Streaming stores your videos on the server in smaller chunks of data of a few seconds each. The player then put these chunks of data together into a continuous stream. Adaptive HTTP Streaming is supported by both Flash and the iPad/iPhone. Android  and HTML5.  They are supported by web hosters and CDNs alike.

Although Adaptive HTTP Streaming eliminates many of the shortcomings of RTMP/RTSP Streaming and Progressive Download, it still has issues of its own, the biggest being standardization or the lack of standardization. Because it is a new technology, there is no single, widely used implementation. Apple, Adobe and Microsoft are now helping to come with a unique standard as each has its own version.  The most popular is Apple's HTTP Live Streaming (HLS), which is supported by the iPad/iPhone and Android, while Adobe and Microsoft have competing offerings (Zeri & Smooth). The DASH is offered by the MPEG consortium.  They all require your files to be converted from a regular MP4 into a specific fragmented format. Apple, Microsoft and Adobe each supply a tool for this, but support for these formats doesn't exist in regular video editors and transcoding tools (yet).

In summary, Adaptive HTTP Streaming will likely become the single video streaming method over time.    Utilizing the right streaming protocol for your business can translate into a more efficient method to increase profits by communicating more effectively.

How your internet connection affects your viewing, and why type and size matters

When watching a video or live broadcast, the browser needs to be able to receive all video data in a rate which is equal to or higher than the streaming speed. A raw video file as AVI will need an enormous bandwidth; in other words you need to have a high speed internet that will be equal to or greater than the streaming rate of an AVI file. To achieve a decent quality, while keeping the bandwidth relatively low, a video and audio compression is used. For instance, with video compression (H264) and audio compression (CODEC) we can stream a nice quality video in a 320 by 240 pixels window with a 29 frames per seconds. To watch this video live, a user will need a bandwidth of about 350 bps (bits per seconds), which is about half the speed of a DSL line from Verizon or any competitive company can provide. Please note: When your bandwidth (Internet Speed) is lower than the streaming rate of the required bandwidth, your browser will buffer the data and play the movie in delayed time.

When a compression is deployed, the following table should reflect file size and bit rate needed to stream a desired size window.

Video file format:

mov extension
These file types are based on the Quicktime (QT) system. Its designed initially for the Mac platform but is now usable via a plugin and helper application on most other operating systems. You can load the standard Quicktime player™ from Apple for free as well as get access to a host of resources. QT has some great compression schemes which often make QT files smaller without loss of quality.

It can also be streamed

mpeg extension
This format takes its name from the developing group (motion Pictures Expert Group). Remains an important web video file type due to the range of compression that can be applied. Unlike avi and Quicktime not developed for a particular operating system
http://www.mpeg.org/ can provide more info


wmv extension
Windows Media Video.
Part of Microsoft's windows media format, a comparatively new all singing and dancing media format but as you can guess has Microsoft's resources behind it. It benefits from jumps in compression technology and has the weight of Microsoft behind it. WMV files can be downloaded or streamed. Microsoft have tons of resources at:http://www.microsoft.com/windows/windowsmedia/default.asp many of which are free to download.
.wmv files can also be streamed
rm extension
RealVideo® files.
These are the archetypical streamed video files. Good examples can be seen in action on the BBC news site at http://news.bbc.co.uk/). One of the first and still most popular streamed media format. The basic player can still be downloaded for free at http://www.real.com/. You can also use the files as non streamed format, but they are not so well designed for that

But for more details about creating .rm files visit the Real networks site athttp://www.realnetworks.com/ they have a host of free resources.

flv extension
The FLV file type is primarily associated with 'Flash' by Adobe Systems Incorporated.

Adobe Flash, initially known as Shockwave Flash and popularly called simply Flash, refers to both the Adobe Flash Player and to the Adobe Flash Professional multimedia authoring program.

The Flash Player, developed and distributed by Adobe Systems (which acquired Macromedia in a merger that was finalized in December 2005), is a client application available in most common Web browsers.

Among other uses, if you obtain a video from YouTube it will likely have the .FLV file extension and be a Flash Video File.