Setting the file. One moment.
Subchapter 18.9
references/mixing.mdMarkdown5 KBView on GitHub
Preview and render run the same Web Audio graph, so what plays while scrubbing is what renders. Everything lives in attributes on the <audio> or <video> element.
| Attribute | Meaning |
|---|---|
data-volume | Track gain, 1 = 0 dB |
data-fade-in, data-fade-out | Edge fades in seconds |
data-playback-rate | Constant speed, 0.1–10, pitch preserved; give a video and its paired audio the same value |
A crossfade is two clips on different tracks that overlap, each with a fade.
<audio
id="music"
data-automation='{"version":1,"lanes":[{"target":"volume","points":[{"t":0,"v":1},{"t":2.5,"v":0.35}]}]}'
…
></audio>target is volume, rate (a speed ramp, 0.1–10, overrides data-playback-rate) or fx.<nodeId>.<param>.t is seconds from the start of the clip, not of the composition. v is in the parameter’s unit: 0..1 for volume, dB for a gain, Hz for a frequency.volume lane multiplies data-volume in preview and render, so write the level in one of them: data-volume="0.5" under a lane at 0.5 plays at 0.25.t: 0.curve (-1..1) bends the segment leaving a point. 512 points per lane at most.volume with GSAP on a track that has a volume lane or a data-volume; lint flags both.{
"version": 1,
"nodes": [
{ "type": "highpass", "id": "n1", "label": "Remove rumble", "params": { "frequency": 80 } },
{
"type": "peaking",
"id": "n2",
"label": "Clarity",
"params": { "frequency": 3000, "gain": 2.5, "q": 1 }
},
{ "type": "limiter", "id": "n3", "params": { "limit": -1 } }
]
}".id is what automation targets (fx.n2.gain); give every node one, and a label when it does a named job. enabled: false bypasses a node.gain, highpass, lowpass, peaking, lowshelf, highshelf, compressor, limiter, gate, saturate, delay, reverb, chorus, phaser, bitcrush.compressor, limiter, gate and bitcrush can’t be automated; a lane on them does nothing. Automate a gain before them instead.fromCarve by hand.reverb and delay make the rendered track longer than its source; that is expected.| It sounds like | Reach for |
|---|---|
| Hum, rumble, handling noise | highpass at 80 Hz |
| Boomy, too close | peaking 200 Hz, −4 dB |
| Muffled | peaking 250 Hz, −3 dB |
| Words hard to make out | peaking 3 kHz, +2.5 dB, or duck the music |
| Harsh | peaking 3.2 kHz, −3 dB |
| Peaks clipping | limiter last in the chain |
Duck the bed with a volume lane on the music: full level before the voice, down to about 0.3–0.4 while anyone speaks (word timings from npx hyperframes transcribe or the voiceover give the times), back up after. Then carve the bed, which dips only the bands the voice uses: node <SKILL_DIR>/audio/scripts/carve.mjs --comp index.html (needs ffmpeg and @hyperframes/core in the project; --dry-run to see the plan). It is the same analysis as Studio’s carve panel. It reads only double-quoted attributes (JSON quotes as "), so write the bed’s chain and lanes that way or it overwrites them. Never put a carve on a voice track.
Give clips the same data-audio-group="<id>" to treat them as one group. An <hf-audio-group id="<id>"></hf-audio-group> element with that id (closed like that: /> does not close it) makes the group a submix bus with one data-fx-chain, one volume and one automation clock for every member. Keep one role per group: voiceover, music, sfx.