Average bitrate
Average bitrate is the typical amount of data per second a viewer actually received during a view, weighted by how long each quality level played. Because adaptive streaming switches renditions as the network changes, this is the honest measure of the quality delivered, rather than the top quality on offer.
Why it matters
Average bitrate shows the quality viewers actually received, which can sit far below the top rendition a service pays to encode. It also drives delivery cost. Watching it by market and device shows where viewers are stuck on low quality and where top renditions are wasted.
How it works
- During a view, the player records which rendition is playing and for how long.
- Each rendition's bitrate is multiplied by the time it played.
- Those values are added and divided by total playing time to give the time-weighted average.
- Averages are compared across countries, devices and titles to see the quality really delivered.
What is a good bitrate for 1080p?
A good bitrate for 1080p streaming is roughly 4.5 to 8 Mbps, depending on codec and content. Apple's sample ladder lists 1080p H.264 variants at 6,000 and 7,800 kbit/s and HEVC variants at 4,500 and 5,800 kbit/s. Fast-moving content such as sports needs the higher end; newer codecs need less.
Average bitrate vs peak bitrate: what is the difference?
Average bitrate is the typical data rate across the whole view; peak bitrate is the highest rate reached at any moment. Peak matters for whether a network can handle the busiest scenes. Average matters for overall quality delivered and for cost, since total data delivered equals average bitrate multiplied by watch time.
Where it's used
OTT services and video platforms compare average bitrate across countries and devices to see where viewers are stuck on low renditions and where a higher rung would be wasted.
Where it usually goes wrong, and how FastPix handles it
Teams often quote the top rendition in their ladder as their quality, while many viewers spend most of each view on lower renditions.
Each view's average bitrate in FastPix Video Data is weighted by how long each rendition played. It can be broken down by country, device, connection type and title. Viewers stuck on low quality become visible, and so do top-quality pictures that rarely reach anyone.
By the numbers
- Apple's HLS authoring specification lists sample 1080p variants at 6,000 and 7,800 kbit/s for H.264, and 4,500 and 5,800 kbit/s for HEVC at 30 fps. (HLS Authoring Specification for Apple Devices)
