Video miners in the Livepeer network provide video transcoding services (and in the future other video infrastructure services as well) that allow developers to build scalable video applications and are compensated with Livepeer token (LPT) and Ether (ETH). While the term "miner" was popularized in the context of Proof-of-Work (PoW) blockchains such as Bitcoin where it referred to participants that used computational power to secure the blockchain, in the context of Livepeer, the term miner refers to participants that use computational power to provide video transcoding services in an open marketplace to developers.
Video miners can take on different roles in the network:
Orchestrators coordinate work on the network. They earn LPT rewards by staking their own LPT and attracting the stake of delegators by sharing earnings, and earn ETH fees by providing high quality transcoding service to broadcasters. The quality of transcoding service is influenced by a combination of factors including economic security (the stake of the orchestrator and its delegators which can be slashed if the work is performed incorrectly), geographic coverage and transcoding capacity (affected by bandwidth and computational capacity). Since a broadcaster selects orchestrators to send work to based on these factors, an orchestrator's earning potential depends on its ability to perform well in each of these areas.
Transcoders perform work on the network. They provide computational capacity to orchestrators with hardware resources. An orchestrator can also be a transcoder itself, but also has the option of outsourcing transcoding to one or many separate transcoders similar to how PoW mining pools outsource PoW hashing to one or many separate miners. Orchestrators that outsource transcoding to one or many separate transcoders are commonly referred to as transcoding pools.
Transcoding is the process of taking an input source video in one format and bitrate, and converting it to many output rendition videos with different formats and bitrates such that the video can be played on the majority of the devices in the world at any internet connection speed. Additional details on transcoding can be found in this blog post.
In the Livepeer network, broadcasters and video miners establish a price for transcoding on the open market. Once a broadcaster has selected one or many video miners to work with it will send segments of a video stream to the video miners with micropayments based on the agreed upon price. The video miners then return transcoded results for each segment to the broadcasters.