Hdcd

Audio Single output Transform

Apply High Definition Compatible Digital (HDCD) decoding.

FFmpeg filter: hdcd — 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   = $audio->addFilter(new Hdcd(…));
$result = $node->outputs()[0];

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

$result = $audio->apply(new Hdcd(…));

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
disable_autoconvert	bool	true	—	Disable any format conversion or resampling in the filter graph.
process_stereo	bool	true	—	Process stereo channels together. Only apply target_gain when both channels match.
cdt_ms	int	2000	100–60000	Code detect timer period in ms.
force_pe	bool	false	—	Always extend peaks above -3dBFS even when PE is not signaled.
analyze_mode	HdcdAnalyzeMode	off	off, lle, pe, cdt, tgm	Replace audio with solid tone and signal some processing aspect in the amplitude.
bits_per_sample	HdcdBitsPerSample	16	16, 20, 24	Valid bits per sample (location of the true LSB).

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