She is a life-enthusiast who is independent, persistent, enthusiastic, energetic, and interested in music, exercise, travel, dance, painting. Here’s what I wrote back in 2010 for an article entitled Adaptive Streaming in the Field for Streaming Media Magazine, which included input from MTV, Turner, NBC, Microsoft, Harvard, Indiana University, and other producers. A much better way is to convert AVI to iPhone supported format to solve the AVI playback problem. what you wrote above? H.264 IIS SmoothStreaming is CBR 1-pass only at the moment. VBR and CBR are most common video stream bitrate control technologies. ]]> A leading expert on H.264 encoding for live and on-demand production, and as contributing editor to Streaming Media Magazine, has tested most cloud, enterprise and desktop encoding tools, worked with most online video platforms (OVPs) and live streaming services, and many webcast platforms. Indiana University used constrained VBR, limiting the 1500Kbps stream to 2Mbps, the 750Kbps stream to 1Mbps, and the 250Kbps stream to 500Kbps (see Table 2). The course will be available in perpetuity and you can unsubscribe from the newsletter at anytime. get an idea of how well a particular encoding setting will play -- a few important scenes will do. VBR could work, but one has to be careful with setting average/peak/buffer values in order not to cause issues on playback.”. Alternatively, if we just want the best viewing experience for encodings of SD and HD TV-programs, whixh parameters should we choose? 4) VBR can reduce the total amount of disk storage space required for the encoded content. Click Buy, and either sign in or register as a new user. 2) When streaming VBR content, the end-users machine and nework connection may handle the average bitrate of the VBR content -- only to get overloaded during a "big action scene" were the VBR bitrate is peaked. 1080P. My questions could obviously be generalized to how to determine the optimal parameters for an encoding? So what is an appropriate bitrate setting for H.264 encoding? It is quite possible to a level that the machine and/or network connection can't sustain -- forcing the heuristics to switch to a lower bitrate. To this discussion I would add Apple’s dictate from Apple Tech Note TN2224 that states, “Bit Rate Variability – Should not exceed 10% of target bit rate.”. See the answers below. In practice, all live Olympic streams were CBR with a 5-second VBV buffer, while on-demand streams were VBR constrained to 10% over the target bitrate. http://en.wikipedia.org/wiki/Variable_bitrate. If you have the plan to encode or re-encode video into H.264 with, like say freeware HandBrake, one thing that you better pay close attention to is the bit rate settings, which, to some extent, decides your video visual quality. For Twitch, CBR makes capacity planning easier since it's just broadcasters * bitrate for total bandwidth requirements at any given moment. Variable bitrate (VBR) is a term used in telecommunications and computing that relates to the bitrate used in sound or video encoding. Which of the H.264 profiles would you select, Baseline, Main or High? This was certainly the view of Microsoft’s Zambelli (now with iStreamPlanet), who said, “The reason I prefer CBR for adaptive streaming is because it exhibits less oscillation in data rates, making fragment sizes more consistent and consequently making it easier for client heuristics to accurately estimate bandwidth. Is it correct that CUDA accelleration only applies to VBR? If you scan the white papers on the topic, most recommend using constant bit rate (CBR) encoding to simplify the stream selection process. Can you refer to a precise description of all these parameters defining an encoding, like e.g. My knee-jerk reaction here was to use constant bitrate encoding because the consistent stream should be easier to distribute, particularly in an adaptive setting where the viewer is often retrieving 2- or 3-second chunks of video at a time. Good info on the different H.264 profiles here: Strange -- Try applying one of the H.264 presets -- say "Encoding For Silverlight" -> "H.264" -> "Variable Bitrate" -> "H.264 HD 720P VBR" and then chech the Encode panel. I must say that as I use Expression Encoder 4 Pro (the licensed variant) the Encode tab's Video panel's Mode drop down only contains "CBR - 1 pass" for any of the Baseline, Main and High. Therefore, the high quality of video requires high network bandwidth. 2) When the content will be delived to the customer by downloading instead of streaming -- using VBR here similarly reduces the total number of bits than need to be downloaded. Deutsche Welle is exclusively CBR, while Harvard is CBR except for the highest quality stream. Depends -- In theory H.264 delivers the best PQ (percieved quality) at a particular bitrate.