Streaming Video

6
Jul/091

Streaming is the ability to use content without (down)loading it in whole first. This is very important for web video since a user would usually want to watch the video online instead of downloading it first. When it comes to web video on a technical level streaming is achieved in two main ways:

Streaming network protocols – this is the low level concept it involves sending(or broadcasting) packets over an IP network. A media server is required for this process and a player compliant with that server’s protocol. This method is also referred as “true streaming” or “live streaming” when it is used with a real time feed. Examples of this concept are Macromedia(now under Adobe) Flash Media server and it’s RTMP protocol and Helix Server(Real Media) with the RTSP.
File container formats – Some video container formats are designed to be like a stream of packets and can be used in a streaming context. This is also called “Progressive Download” a regular HTTP web server is used for the process. Examples of file formats used for streaming include: .flv(Flash Video), .wmv(Windows Media Video) and many others popular formats.

There is also a hack to progressive download called PHP Streaming. This hack concept solves(sort of) some of the limitations of progressive download namely: random access capability.

All of the above streaming concepts have been used in large scale projects. Progressive download is probably the easiest to scale and most widely used to date.

In the sense of video hosting there are three main ways to do it:

Video Sharing services – these services allow you to publish your video content and share it with other people on the web, usually through the attached portal of the service. The most popular video sharing service to date is YouTube.com though there are many others worth mentioning. This type of video hosting is usually free, but has some limitations. One of the main benefits of video sharing services is that you may be able to reach a huge audience through their attached portal.
Video Hosting services – these services allow you to upload your videos and then use their facilities in order to reach your own audience, usually through your own website or email campaigns. These are paid services and provide some capabilities that you can’t receive with Video Sharing services like: branding capabilities, allowance of large videos, pay-per-view to name a few.
Self Hosting – this is when you put your video on your own server/network. It is usually related to uploading videos to your web hosting and using a player to embed them in your pages. This is practical for small profile sites, intranet use or testing.

The different streaming concepts have different capabilities and are sweetable for different scenarios. Here are some basic scenarios:

Live feeds can only work with true/live streaming through a media server.
On regular web hosting you can only use progressive download.
True streaming is sweetable for longer videos over 10 minutes in length.
Progressive download can deliver better video quality within the same bandwidth. Due to the fact that variable bitrate(VBR) can be used
True streaming requires buffering and is generally slower to start playing.
True streaming usually has built in Digital Rights Management(DRM) capability.