Readeia608

Video Single output Transform

Read EIA-608 Closed Caption codes from input video and write them to frame metadata.

FFmpeg filter: readeia608 — the official reference.

Add it to a graph. The explicit form works for every filter — bind it to its input and read the result from outputs():

$node   = $video->addFilter(new Readeia608(…));
$result = $node->outputs()[0];

Shorthand. Single-output filters can skip the node — apply() returns the result stream directly:

$result = $video->apply(new Readeia608(…));

When to use it

TODO — when this filter shines: what it’s the right tool for, what to reach for instead when it isn’t, and how it composes with neighbouring filters.

How to use it

TODO — prose: how the filter actually works and what its key parameters mean (the explanation FFmpeg’s terse option help omits).

Examples

TODO — runnable PHP, with the equivalent ffmpeg CLI alongside.

Gotchas

TODO

See also

TODO

Parameters

Parameter	Type	Default	Range / values	Description
scan_min	int	0	≥ 0	set from which line to scan for codes
scan_max	int	29	≥ 0	set to which line to scan for codes
spw	float	0.27	0.1–0.7	set ratio of width reserved for sync code detection
chp	bool	false	—	check and apply parity bit
lp	bool	true	—	lowpass line prior to processing

---

Maps to FFmpeg’s readeia608 filter. Verified against ffmpeg n7.1.1.