1-pass VBR, 2-pass CBR and 2-pass VBR Compression with Real Media, QuickTime and Windows Media
When it comes to real-time streaming videos and using Windows Media, Real Video or QuickTime there are differences between 1-pass VBR compression, 2-pass CBR compression and 2-pass VBR compression within each architecture. CBR stands for Constant Bit Rate and VBR stands for Variable Bit Rate.
If your're looking to do real-time streaming using Windows Media you should select 2-pass CBR. In Real Media choose 2-pass VBR for real-time streams and for QuickTime choose 1-pass VBR. Even though each of these methods of compression generally has a specific meaning, there is no uniform agreement on how each method should operate within each proprietary streaming architecture. Content encoded with each of these compression methods listed (1-pass VBR for QuickTime, 2-pass CBR for Windows Media and 2-pass VBR for Real Media) can go on a streaming server as longer as you are using for example 2-pass VBR for Real Media content. Don't try encoding with 2-pass VBR using QuickTime for real-time streaming because your videos won't stream properly. 2-pass VBR encoding for QuickTime would only be good for downloadable streaming videos.
The fact that each proprietary format has different ways that it utilzes 1-pass VBR, 2-pass CBR and 2-pass VBR is a downfall because it makes it confusing for those encoding content. It would be nice if the organizations which created each format made the compression methods consistent across each format.
