Progressive Download Versus Streaming
Tech Talk
Several clients have asked about the difference between steaming and progressive download delivery methods.
In practice, you will very rarely realize whether the content has been streamed or progressively downloaded, unless you look for some of the distinguishing features described below.
What is Progressive Download?
With progressive downloads, the video is actually downloaded to the viewer’s computer, and stored in a temporary directory. Content will start playing out as soon as it is available locally.
If viewers want to fast-forward or skip to another section, they will only be able to do so if that part of the video has already been delivered and stored on their machine. The video is delivered via the standard http protocol like any other webpage.
Progressive Download Characteristics
- Advancing is not possible unless it has been downloaded already
- Does not effectively utilize Brightcove’s dynamic delivery feature
- Less secure, content can be easily copied
- More bandwidth is used as all parts of the video are downloaded, not just the watched portions
- HTTP protocol in use
Progressive Download Benefits
You would think that streaming would be the obvious choice as it has certain advantages over progressive download. Having said that, in 2009, we have many customers who use progressive download. For example, one of our clients in Germany switched to progressive download because of the firewall restrictions on German cooperate networks.
Another reason for using progressive download, would be the use of the Brightcove sample to build an iPhone app, which works with progressive download.
What is Streaming Delivery?
Streaming video, on the other hand, is delivered via a streaming server without the file ever being downloaded to the viewer’s computer. As soon as the viewer presses play, the video will start to play.
Viewers can fast-forward or skip to other parts of the video immediately and the video will continue to play from that point onwards.
Streaming Delivery Characteristics
- Advancing video is possible
- Effectively utilizes Brightcove’s dynamic delivery feature
- Secures video content via temporary video link
- Allows you to serve more steams with less bandwidth
- Real Time Messaging Protocol (RTMP) in use
Streaming Delivery Benefits
One of the big positives of streaming media is that it only uses as much bandwidth as the viewer has watched, since only the portion of video viewed was delivered. Nothing is kept on the client side. Everything is on the server side and is being delivered via the Real Time Messaging Protocol (RTMP), which is a proprietary protocol developed by Adobe.
Brightcove Video Delivery Support
Brightcove supports both types of delivery methods, which is set on the account level. If switching from one type of delivery to the other, you will find that the videos already uploaded to Brightcove will remain in the original format.
