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Thaumic Cast

Sound is late

The speakers always play a little behind your browser. A song never finds out. A film looks badly dubbed, and a game feels slow. This page says where the delay comes from and what to do about it.

For films: video sync

Section titled “For films: video sync”

Turn on Video sync in the extension’s Settings, under Finer points. It plays the page’s sound early by as much as the speakers play late, so the lips and the words arrive together. It works on many players, though not all, and needs a PCM cast. See Video sync.

Where the delay comes from

Section titled “Where the delay comes from”

Most of it is put there on purpose, as a cushion against cut-outs. For a PCM cast, the extension’s Settings, under Audio, adds the head start and smoothing together as Added delay.

Where Default What it is
Speaker head start (desktop app, Settings › Speakers) 500 ms Each speaker keeps that much in hand, to ride out Wi-Fi stalls.
Smoothing (extension, Settings › Audio › Advanced) 200 ms The app holds the audio that long, so pieces that arrive late can catch up.
Frame size (extension, Settings › Audio › Advanced) 10 ms How much audio goes in each message from the browser.
The speakers themselves Not set by Thaumic Cast Sonos adds a delay of its own on top.

Lowering the head start or smoothing lowers the delay, and raises the chance of cut-outs. Turn one down a step at a time, and stop when the sound starts to break up. Frame size is already at its smallest.

Delay that grows

Section titled “Delay that grows”

In Bespoke, When the connection falls behind decides what happens if your browser cannot send the audio as fast as it arrives. Let delay grow (up to a limit), the default, keeps every bit of the audio and plays it later. Skip ahead (brief gaps) keeps the delay short and lets you hear the gaps. Economical skips ahead too.

If the delay has crept up during a long cast, stop the cast and start it again.

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