JsonCutDocs
Projects & Schema

Audio, voice and captions

Mix footage, music and narration, then add editable word-timed caption layers.

Video projects can mix multiple video and audio layers. Captions use ordinary text styling plus explicit word timing, so Studio can change the transcript, typography and active-word behavior after creation.

Rendered output

Street question reel

A vertical social format combining real footage, paced captions and independently timed graphic layers.

Video1080 × 192011 secondsEditable V2 source

Audio layer

<audio id="voice" data-jc-clip data-jc-kind="audio" data-jc-name="Voiceover"
  data-jc-start="0.4" data-jc-duration="8.2" data-jc-track="6"
  data-jc-media-start="0" data-jc-playback-rate="1" data-jc-volume="1"
  data-jc-fade-in="0.12" data-jc-fade-out="0.35"
  data-jc-normalize-audio="true"
  src="jsoncut-media://media_voice"></audio>

Audio supports source trim, speed, volume, mute, loop, fades, normalization, ducking and persistent volume keyframes. Multiple audible layers are mixed in the export.

Caption layer

<div id="captions" data-jc-clip data-jc-kind="caption" data-jc-name="Captions"
  data-jc-start="0" data-jc-duration="8" data-jc-track="8"
  data-jc-caption-display="active-word"
  data-jc-caption-words-per-page="4"
  data-jc-caption-active-color="#111111"
  data-jc-caption-active-background="#ff9418"
  data-jc-caption-inactive-color="#ffffff"
  data-jc-caption-word-animation="pop"
  data-jc-caption-words="[{&quot;id&quot;:&quot;w1&quot;,&quot;text&quot;:&quot;Build&quot;,&quot;start&quot;:0,&quot;end&quot;:0.42}]">
</div>

Display modes are static, typewriter, word-by-word and active-word. Typography, background, border, radius and shadow remain ordinary text styling and can be applied consistently to the whole caption track in Studio.

Audio property guide

AttributeDefaultPurpose
data-jc-media-start0Source in-point
data-jc-playback-rate1Playback speed
data-jc-volume1Base clip volume
data-jc-fade-in, data-jc-fade-out0Edge fades in seconds
data-jc-normalize-audiofalseEnables stored normalization gain
data-jc-normalization-gain1Gain used when normalization is enabled
data-jc-ducking1Volume factor while another audible track is active
data-jc-muted, data-jc-loopfalsePlayback flags

A volume animation track adds time-varying automation. Keep values between zero and one.

Caption timing

Caption words contain stable IDs, text and start/end seconds. wordsPerPage is an integer from 1 through 12. Word animation is none, pop or rise.

Studio can turn a transcript into readable cues and can import timed JSON, WebVTT, SRT-like timing and ASS dialogue. After transcription, review wording and timing before treating the caption track as final.

Voiceover and generated sound

Voiceover, music and sound effects generated in Studio are saved as ordinary project audio media. Their generation settings are not embedded as hidden render behavior; the accepted audio file and editable layer are what the final project uses.