Adaptive Bitrate

Abstract #

Adaptive bitrate works by adjusting to each viewer’s network and serving adequately lower quality content to minimize loading and reloading times; read about it here https://en.wikipedia.org/wiki/adaptive_bitrate_streaming

Opportunity for WpStream clients #

– Use up less overall streaming bandwidth as some of your viewers will stream at a lower quality than the original

– Better perceived quality of service for some of your viewers; faster start time and fewer interruptions

– Feature has been used in production by multiple customers during closed beta, since May 2019, with consistently good results

Restrictions, shortcomings, notes #

– Feature requires individual whitelisting

– Feature can be enabled for particular channels (i.e. for initial testing) or for all of them

– Only functions with RTMP broadcasting (i.e. OBS, Wirecast, vMix, iOS and Android apps); browser broadcast will no longer be available once the feature is enabled for a specific channel

– Only available for horizontal, 16:9 video

– Fast, high, and stable upload capabilities to anywhere in the world (i.e. not just your city, country, or ISP) is required to broadcast; if your streams are interrupting right now, ABR will only make them worse

– A recommended encoding profile (i.e. for OBS etc) is to be used; during beta, we will not be able to offer support outside the margins of this profile

– The feature is still experimental and may not work under various unexpected circumstances

– We can only offer limited support related to the feature at this time

To apply for the feature, please provide the following information in an email to prerelease at wpstream.net

– Your WpStream account username

– Your website

– IDs of channels for which you would like the feature enabled (i.e list of channel IDs, or “ALL”)

– Please confirm you understand Web Broadcasting (i.e. broadcast from the browser) will no longer function after feature is enabled for specific channels

– Please confirm you understand this only works well within specified technical parameters

– Please confirm you understand that superior network capabilities are required on the broadcaster’s end for this to work well

Recommended settings for broadcasting #

Software: OBS Studio

Video:

Resolution: 480p or higher

Video aspect ratio: strictly 16:9 horizontal (854×480, 960×540, 1280×720 etc)

Video Bitrate: 1mbps or higher

Encoder: x264

Keyframe Interval: 5 seconds

Audio:

Sample rate: 48khz

Bitrate: 128kbps or higher

Codec: AAC