Media translation: Audio, Video, Img, IFrame, staticFile

Asset paths

Remotion's staticFile("x.png") resolves to the project's public/ directory. HF uses relative paths from the composition's index.html, conventionally assets/:

<Img src={staticFile("logo.png")} />

<img src="assets/logo.png" />

When translating, copy the asset from remotion-src/public/x to hf-src/assets/x. Multiple files can be batched with a setup script; see T2's setup.sh for an example pattern.

<Audio>

<Audio src={staticFile("music.wav")} volume={0.5} />

<audio
  data-start="0"
  data-duration="6"
  data-track-index="2"
  data-volume="0.5"
  src="assets/music.wav"
></audio>

data-start and data-duration are required — the runtime needs them to schedule the audio. Default to the composition's full duration if Remotion didn't specify trim.

Volume ramps

<Audio src={staticFile("music.wav")} volume={(f) => interpolate(f, [0, 30], [0, 1])} />

Volume ramps become a data-automation volume lane on the <audio> (form in /media-use → references/mixing.md); data-volume is the static baseline.

Trim / playbackRate

<Audio src={staticFile("music.wav")} startFrom={60} endAt={180} playbackRate={1.5} />

<audio
  data-start="0"
  data-duration="<resolved from trim>"
  data-trim-start="2"
  data-trim-end="6"
  data-playback-rate="1.5"
  src="assets/music.wav"
></audio>

startFrom / endAt are frame indexes; convert to seconds.

<Video> and <OffthreadVideo>

<Video src={staticFile("intro.mp4")} playsInline />
<OffthreadVideo src={staticFile("intro.mp4")} />

<!-- intro.mp4 has an audio stream -->
<video
  playsinline
  data-has-audio="true"
  data-start="0"
  data-duration="5"
  data-track-index="0"
  src="assets/intro.mp4"
></video>

<!-- intro.mp4 is silent (or the Remotion element is muted) -->
<video
  playsinline
  muted
  data-start="0"
  data-duration="5"
  data-track-index="0"
  src="assets/intro.mp4"
></video>

<OffthreadVideo> is a Remotion-specific optimization for headless rendering. HF runs in headless Chrome already, so the off-thread variant collapses to a regular <video>.

playsinline is required for the runtime to autoplay (browser policy); always emit it. Check the source file for an audio stream first: ffprobe -v error -select_streams a -show_entries stream=codec_type -of csv=p=0 <file> (non-empty output means it has audio). Remotion <Video> maps to <video playsinline> + data-has-audio="true" only when the file has an audio stream and the Remotion source does not set muted or volume={0}; otherwise emit muted. Silent b-roll with data-has-audio="true" aborts the render (ASSET_MEDIA_TYPE_MISMATCH).

<Img>

<Img src={staticFile("logo.png")} style={{ width: 200, height: 200 }} />

<img src="assets/logo.png" style="width: 200px; height: 200px;" />

Width/height get rounded to integer px. If the original style has animated dimensions, the GSAP tween animates them — see timing.md.

<IFrame>

<IFrame src="https://example.com" />

<iframe src="https://example.com"></iframe>

When HF detects a nested iframe in a composition, it auto-falls back to screenshot mode rather than the deterministic BeginFrame mode. This costs render performance but produces visibly-correct output. See hyperframes-vs-remotion.mdx for details.

delayRender() / continueRender()

const handle = delayRender();
useEffect(() => {
  loadAsset().then(() => continueRender(handle));
}, []);

Drop. HF waits on asset readiness via the Frame Adapter pattern — images, videos, fonts, and Lottie animations all signal load completion natively. There's nothing to do at the application level.

When the asset isn't a file

If Remotion's media source is a Buffer, dataURL, or URL.createObjectURL, the asset doesn't exist on disk and can't be copied via setup.sh. Two options:

1. Materialize the asset at translation time — write the buffer to a file in hf-src/assets/.
2. Embed as a data URL directly in the HTML (src="data:image/png;base64,...") for small assets (< 100 KB).

For audio/video Buffers, option 1 is preferred — base64-encoded media bloats the HTML and slows the renderer.