* fix(cli): serve project media with HTTP Range so validate reads WAV duration
The local static server used by validate/snapshot/layout answered every
asset request with a plain 200 and no Accept-Ranges header. Chromium treats
such resources as non-seekable, and for WAV that makes the media element
report `.duration` as Infinity no matter how long it buffers (readyState
reaches HAVE_ENOUGH_DATA but duration never resolves). The duration audit in
validate then emitted a spurious "Could not read the duration of N media
element(s) within the validate timeout" warning for a perfectly valid local
WAV, and a longer --timeout never helped because the value is never going to
arrive. MP3/MP4 carry duration in their container metadata so they were
unaffected.
Serve files with Range support (206 + Content-Range, plus Accept-Ranges on
the full 200) so the element is seekable. WAV duration now resolves, the
false warning is gone, and the genuine "media shorter than its slot" check
works for WAV for the first time.
* perf(cli): stream Range responses instead of buffering the whole file
serveFileWithRange read the entire asset with readFileSync and then sliced
it, so a 1KB Range of a 50MB MP4 still allocated the full 50MB per request.
Switch to statSync for the total size and createReadStream(filePath, { start,
end }) piped to the response, reading only the requested window. Behavior is
unchanged: 206 + Content-Range + Content-Length for a satisfiable range, 416
for an unsatisfiable one, Accept-Ranges advertised on every response, and a
plain 200 full-body stream when there is no Range header. writeHead is
deferred to the stream's open event so a failed open still answers 500, and
the fd closes on end/error. This benefits MP4 seek too, not just WAV duration.
Extend staticProjectServer.test.ts with an 8MB-file case that pulls a 4-byte
slice from deep inside and asserts the streamed bytes, Content-Range, and
Content-Length are correct.
hyperframes
CLI for creating, previewing, and rendering HTML video compositions.
Install
npm install -g hyperframes
Or use directly with npx:
npx hyperframes <command>
Requirements: Node.js >= 22, FFmpeg
Commands
init
Scaffold a new Hyperframes project from a template:
npx hyperframes init my-video
cd my-video
preview
Start the live preview studio in your browser:
npx hyperframes preview
# Studio running at http://localhost:3002
npx hyperframes preview --port 4567
render
Render a composition to MP4:
npx hyperframes render ./my-composition.html -o output.mp4
lint
Validate your Hyperframes HTML:
npx hyperframes lint ./my-composition
npx hyperframes lint ./my-composition --json # JSON output for CI/tooling
npx hyperframes lint ./my-composition --verbose # Include info-level findings
By default only errors and warnings are shown. Use --verbose to also display informational findings (e.g., external script dependency notices). Use --json for machine-readable output with errorCount, warningCount, infoCount, and a findings array.
compositions
List compositions found in the current project:
npx hyperframes compositions
benchmark
Run rendering benchmarks:
npx hyperframes benchmark ./my-composition.html
doctor
Check your environment for required dependencies (Chrome, FFmpeg, Node.js):
npx hyperframes doctor
browser
Manage the bundled Chrome/Chromium installation:
npx hyperframes browser
info
Print version and environment info:
npx hyperframes info
docs
Open the documentation in your browser:
npx hyperframes docs
upgrade
Check for updates and show upgrade instructions:
npx hyperframes upgrade
npx hyperframes upgrade --check --json # machine-readable for agents
Documentation
Full documentation: hyperframes.heygen.com/packages/cli
Related packages
@hyperframes/core— types, parsers, frame adapters@hyperframes/engine— rendering engine@hyperframes/producer— render pipeline@hyperframes/studio— composition editor UI