Bandwidth for Live Streaming - VLOG #029 HD

VLOG #029- Available bandwidth can make or break your next live event. Years ago back in the time of SD (320x240) you could use flash to encode and stream at roughly 500 Kbps (That’s half a MBit). If you are just starting to learn about bandwidth and video storage (MegaBytes are used for files saved to a hard drive MegaBits are used for streaming data on the internet). In my opinion streaming in SD is not acceptable and we have to understand the bandwidth needed to stream in high definition. The minimum you want to live stream an event in would be 1280x720 which is technically considered High Definition. So before we talk about adaptive bit-rate distribution and bandwidth calculations let’s answer an important question. Should you be streaming in 720p or 1080p? 720 vs 1080 First of all let’s look at the quality of this video clip in 720p. Then let’s look at it in 1080p. The quality is better but only if you are watching it on 1080p display. If your viewers are using mobile devices it may not matter but most new mobile devices are capable of viewing content in at least 1080p quality. So the debate about 720p vs 1080p has been going on for quite a long time. I like to stream in 1080p because it give my audience the choice to view the stream quality in 1080p or scale down to lower qualities. I also like 1080p for cataloging and archiving our videos in a quality that takes full advantage High Definition displays. Adaptive Bit Rates Today most CDNs are providing something called adaptive bit-rate streaming which essentially takes the best quality stream you send and breaks it down into smaller resolutions for viewers. CDNs such as YouTube and Facebook will use Adaptive Bitrate Streaming to optimize the video quality your viewers receive based on their available bandwidth. This further supports the need to stream in the highest quality possible to allow the CDN to make the best choices for your viewers. Some CDN’s also call this process “Live Cloud Encoding”. Calculating Bandwidth First of all most CDNs recommend having an additional 30% of available bandwidth to sustain solid transfer throughout your event. So if your stream will require 3-6 Mbps in 1080p you should plan to have 8-10 Mbps of outbound bandwidth available. So how can you calculate your available bandwidth? I found that the most popular tools on the Internet such as SpeedTest.net and ookla are presenting the best possible scenario for available bandwidth. This is because these tools were originally designed for lobbying and helping to report bandwidth access for remote areas. For example if I run speedtest.net I get 67 Mbps Download and 82 Mbps Upload. This report would give me a false sense of speed because it is reporting best case scenarios for an average user in my local area and does not take into consideration the bandwidth that is currently being used on my network. So PTZOPTICS has actually created our own tool that reaches out to a server hosted by GoDaddy in Scottsdale,