Sound bridge

사운드 브리지

Music, ambience, or an effect crosses a picture cut and links two shots into one flow.

Also known as: audio bridgesound overlap
···
html
<div class="stage bridge-demo">
  <div class="monitor">
    <div class="shot dawn"><i class="sun"></i><i class="ridge"></i><span>SHOT A · DAWN</span></div>
    <div class="shot dusk"><i class="sun"></i><i class="ridge"></i><span>SHOT B · DUSK</span></div>
    <div class="bridge-label">ONE SOUND · TWO SHOTS</div>
  </div>
  <div class="timeline">
    <div class="track-row"><b>PICTURE</b><div class="lane"><i class="clip video-a">A · DAWN</i><i class="clip video-b">B · DUSK</i><i class="cut"></i><i class="playhead"></i></div></div>
    <div class="track-row"><b>AUDIO</b><div class="lane"><i class="clip bridge waveform">MUSIC / AMBIENCE</i><i class="cut"></i><i class="playhead"></i></div></div>
    <div class="track-row"><b>ROOM TONE</b><div class="lane"><i class="clip tone-a">A</i><i class="clip tone-b">B</i><i class="cut"></i><i class="playhead"></i></div></div>
    <div class="note"><i></i> THE BRIDGE TRACK CROSSES THE PICTURE CUT</div>
  </div>
</div>
css
.bridge-demo{position:absolute;inset:0;overflow:hidden;background:var(--bg)}
.monitor{position:absolute;inset:5% 6% 55%;overflow:hidden;border:1px solid var(--line);background:var(--surface)}
.shot{position:absolute;inset:0;overflow:hidden;color:#fff;font:700 clamp(8px,1vw,12px) ui-monospace,monospace;letter-spacing:.08em}
.dawn{background:linear-gradient(180deg,#d4a76e 0 50%,#647d70 50%);animation:dawn-shot 4s steps(1,end) infinite}
.dusk{background:linear-gradient(180deg,#36475b 0 50%,#282f3a 50%);opacity:0;animation:dusk-shot 4s steps(1,end) infinite}
.sun{position:absolute;left:23%;top:20%;width:17%;aspect-ratio:1;border-radius:50%;background:#ffe2a2;box-shadow:0 0 0 10px #ffe2a226}
.dusk .sun{left:68%;top:28%;background:#c5d2db;box-shadow:0 0 0 8px #c5d2db20}
.ridge{position:absolute;left:-5%;right:-5%;bottom:-20%;height:55%;border-radius:48% 48% 0 0;background:#34483f;transform:rotate(-3deg)}
.dusk .ridge{background:#171f2a;transform:rotate(4deg)}
.shot span{position:absolute;left:10px;bottom:8px;text-shadow:0 1px 4px #000}
.bridge-label{position:absolute;right:8px;top:8px;padding:4px 6px;border:1px solid var(--line);background:var(--surface);color:var(--fg);font:700 clamp(7px,.9vw,11px) ui-monospace,monospace;letter-spacing:.06em}
.timeline{position:absolute;left:6%;right:6%;top:49%;bottom:6%;display:grid;grid-template-rows:repeat(3,minmax(0,1fr)) auto;gap:4px}
.track-row{display:grid;grid-template-columns:clamp(50px,8vw,96px) 1fr;gap:6px;align-items:stretch;min-height:0}
.track-row>b{display:flex;align-items:center;color:var(--muted);font:700 clamp(7px,1vw,11px) ui-monospace,monospace;letter-spacing:.05em}
.lane{position:relative;overflow:visible;min-width:0;border-bottom:1px solid var(--line)}
.clip{position:absolute;top:0;bottom:0;display:flex;align-items:center;overflow:hidden;padding:0 5px;white-space:nowrap;color:var(--fg);font:700 clamp(7px,1vw,12px) ui-monospace,monospace;letter-spacing:.025em}
.video-a{left:0;width:42%;border:1px solid var(--line);background:var(--surface)}
.video-b{left:42%;width:58%;border:1px solid var(--line);background:var(--surface)}
.bridge{left:21%;width:56%;border:1px solid var(--accent);background:var(--surface)}
.waveform:after{content:"";position:absolute;inset:27% 4px;background:repeating-linear-gradient(90deg,transparent 0 4px,currentColor 4px 5px,transparent 5px 8px);opacity:.36;pointer-events:none;color:var(--accent)}
.tone-a{left:0;width:42%;border:1px solid var(--line);background:var(--surface);opacity:.62}
.tone-b{left:42%;width:58%;border:1px solid var(--line);background:var(--surface);opacity:.62}
.cut{position:absolute;z-index:2;left:42%;top:-2px;bottom:-2px;width:1px;background:var(--fg);opacity:.72}
.playhead{position:absolute;z-index:3;top:-3px;bottom:-3px;left:0;width:2px;background:var(--accent);animation:playhead 4s linear infinite}
.note{display:flex;align-items:center;gap:6px;color:var(--muted);font:700 clamp(7px,1vw,11px) ui-monospace,monospace;letter-spacing:.035em}
.note i{width:7px;aspect-ratio:1;border-radius:50%;background:var(--accent);animation:blink 4s linear infinite}
@keyframes dawn-shot{0%,41.9%{opacity:1}42%,100%{opacity:0}}
@keyframes dusk-shot{0%,41.9%{opacity:0}42%,100%{opacity:1}}
@keyframes playhead{from{left:0}to{left:100%}}
@keyframes blink{0%,18%,78%,100%{opacity:.35}24%,74%{opacity:1}}

Music or ambience begins in one shot and carries across the cut into the next. The picture changes, but the unbroken sound makes the two moments feel connected.

Extend the audio clip across the boundary between the two video shots. Add volume keyframes before and after the cut if the sound needs a gentle entrance or exit.

A sound bridge is the broad idea of connecting shots with sound; J-cuts and L-cuts describe which shot’s sound leads or lingers. Carrying every sound can blur the sense of place, so choose what should cross and what should stop at the edit.

When to use

Use it to smooth a change of time or place, or to foreshadow the next shot with sound. Often one music or ambience layer is enough.

Open as page ↗

Suggest an entry

Tell us about a film term or effect that’s missing. We review each suggestion.