Livepeer Wowza Module

How it works

Start

• Input stream to be transcoded arrives in Wowza.
• LivepeerWowza creates a stream, sending a request to the API containing its bitrate ladder and transcoding configuration: POST https://livepeer.live/api/stream. Recieves back a Stream ID, e.g. 7abb1446-aca2-4220-b9f0-c7ac35cdcbee.

Wowza --> Livepeer loop

• LivepeerWowza requests a broadcaster from https://livepeer.live/api/broadcaster. This endpoint and others are running on Cloudflare Workers with geolocation logic to send them to the nearest Livepeer production cluster. It recieves back a broadcaster address, e.g. https://aks-default-16253462-vmss000002.livepeer.live.
• LivepeerWowza starts segmenting the input stream into MPEG-TS segments and uploading them to the broadcaster, e.g. PUT https://aks-default-16253462-vmss000002.livepeer.live/live/7abb1446-aca2-4220-b9f0-c7ac35cdcbee/1.ts.
• If there is a problem with the upload, LivepeerWowza requests another stream from https://livepeer.live/api/broadcaster and retries.

Livepeer --> Wowza loop

• Based on the transcoding configuration, LivepeerWowza determines the URL of the HLS playlist for each transcoded rendition. Stream Files are created for each one, at URLs like https://livepeer.live/stream/7abb1446-aca2-4220-b9f0-c7ac35cdcbee/P144p30fps16x9.m3u8.
• These playlists are running on Cloudlfare Workers that are aware of all the broadcasters and amalgamate the m3u8 playlists to include all available segments. It then serves out media playlists that include the full broadcaster URLs of the segments,such as:

#EXTM3U
#EXT-X-VERSION:3
#EXT-X-MEDIA-SEQUENCE:232212
#EXT-X-TARGETDURATION:2
#EXTINF:1.667,
https://aks-default-16253462-vmss000002.livepeer.live/live/7abb1446-aca2-4220-b9f0-c7ac35cdcbee/1.ts
#EXTINF:1.666,
https://aks-default-16253462-vmss000001.livepeer.live/live/7abb1446-aca2-4220-b9f0-c7ac35cdcbee/2.ts
#EXTINF:2.000,
https://aks-default-16253462-vmss000000.livepeer.live/live/7abb1446-aca2-4220-b9f0-c7ac35cdcbee/3.ts

• (Note that the broadcaster servers can change from segment to segment, providing one coherent stream even if LivepeerWowza switches broadcasters.)
• These HLS streams are stitched back together and are accessible for any functions of Wowza.