TV playout software. Installed, in a box, or in the cloud.

At 8:59:58 the software knows that the news ends in two seconds, that a five-second ident follows, and that the film after it starts on frame one at 9:00:05. It cues the file, crossfades, keeps the logo in the corner, fires an SCTE-35 cue thirty seconds before the first break, and does this again every few minutes until the schedule runs out, at which point it fills from the library rather than going to black. The job splits into four parts, and they stay the same however the software is bought.

What it is not is live-production software. A vision mixer or a desktop switcher takes cameras and sources and makes a programme; playout takes finished programmes and makes a channel. Many channels use both, and the seam between them is a live input the schedule switches to at the right time and back from when the show ends.

A playout server is a computer that does nothing else: storage fast enough to read two video files at once, a card that outputs SDI or a transport stream, and the headroom to decode, composite and encode without ever dropping a frame. The traditional build has two of them, a main and a backup, and a changeover switch between them, because a single server is a single point of failure for a channel that is expected to be on air every second of the year.

For a channel delivered over the internet, the server has not disappeared; it has moved. The cloud vendor runs it, sizes it per channel, watches it, and replaces it without a maintenance window. The parts you keep are the ones that matter to the channel, the schedule, the graphics, the cues, the guide, driven from a browser instead of a keyboard in a machine room. Where the server still earns its rack is a channel whose destination is a physical output: an SDI feed to a transmitter, a modulator, a headend that wants a card rather than a stream. Even then, a constant-bitrate SRT or RIST output from cloud playout feeds most of those from a small decoder at the far end, which is how the satellite migration and local cable setups run.

Installed software is priced as a licence per channel, perpetual or annual, and the licence is the smaller half of the bill. Add the server, the second server if the channel matters, the output card, the storage, a support contract, and the person who knows the kit. It is a capital project that pays off over years, which is fine for a broadcaster with a portfolio of channels and an engineering floor, and a heavy way to find out whether a new channel has an audience.

Cloud playout is a subscription per channel. The number to look for is what is included: some vendors publish a flat monthly price with delivery inside it; others publish a rate per streaming hour or per gigabyte delivered, which reads cheap until you multiply by the roughly 730 hours a linear channel runs each month. Our own plans are flat, $254 per channel per month billed yearly or $299 month to month, with graphics, the programme guide and unlimited delivery included, and no contract. Compare the whole bill, metered arithmetic included, against what a transponder or a rack costs.