Video Sharing Website Part 1 : Introduction to Video Streaming

Posted on | June 30, 2009 | 1 Comment

This series of blog post will talk about how to setup a Video Sharing Website.

Definition to various methods of video downloads and video format

Streaming
HTTP Download
HTTP Streaming – A combination of Streaming and HTTP Download

Streaming

Use of Video Stream Application servers. Examples of Video Stream Application servers include: Video Desk, Adobe Flash Media Server. To use a Streaming Application Server, you need to have a dedicated server with dedicated bandwidth. Such setups are expensive and can run up to a few thousand dollars per month. This is not for the average user. But more suited for the needs of content delivery network. Like news streaming, on demand TV or Movies. Requires a lot of specialized server setup and maintenance knowledge.

HTTP Download

The usual way files are downloaded completely before you can view them. Longer waiting time. This method would require user to have the plugin that supports the playback installed.

HTTP Streaming

A flash player will play part of the video when it is downloaded. With this method, you can fast forward to any segment you want to watch before the video is downloaded fully. The player will send a request to the server for the seeked segment of the video and the start playing from there. This is call pseudo streaming.

This streaming setup uses three components:

A Flash Player
A server side script for the transcoding of uploaded video to different formats, and the pseudo streaming of the video
An FLV video

The server side script needs to take care of bandwidth throttling, securing the video to prevent leeching, detection of bandwidth to if variable bandwidth video is supported. This will be covered in further posts.

Video Formats Suitable for Online Stream

FLV (H.263/MP3) – 320px in width
MP4 (H.264/AAC) – 320px in width ~500kbps
A TV conversion (720px wide, H.264/AAC, ~1000kbps)
An HD conversion (1280px wide, H.264/AAC, ~2000kbps)

Higher bitrates or bigger file size will result in longer transcoding time. Since this is the case, the transcoding process has to be ‘behind the scenes’ to avoid letting users wait for a long time. The FLV version is the most commonly used format.