| name | hyperframes-media |
| description | Audio and media assets for HyperFrames compositions, produced by one shared audio engine (`scripts/audio.mjs`) — multi-provider TTS (HeyGen / ElevenLabs / Kokoro local), background music + sound effects (HeyGen audio-library retrieval by default, with local Lyria / MusicGen BGM generation and a bundled SFX library as the no-credential fallback), Whisper transcription, background removal, and caption authoring. Use for voiceover / TTS, BGM, SFX / sound effects, transcription, captions / subtitles / lyrics / karaoke / per-word styling, voice + provider selection, and music-mood prompting. |
HyperFrames Media
Create the audio and media assets a composition needs — voiceover (TTS), background music + sound effects, transcription, captions, background removal — then consume and animate that data in HTML. For placing assets into compositions, see hyperframes-core.
The audio engine — one source for TTS · BGM · SFX
Workflows do NOT hand-roll audio or vendor a copy. There is one engine — scripts/audio.mjs — that takes a neutral audio_request.json and writes audio_meta.json (plus assets under assets/voice|bgm|sfx):
node <MEDIA_DIR>/scripts/audio.mjs --request ./audio_request.json --hyperframes . --out ./audio_meta.json
All three capabilities degrade on ONE switch — whether a HeyGen credential is present (resolved from $HEYGEN_API_KEY / $HYPERFRAMES_API_KEY / ~/.heygen, not the CLI):
| Capability | HeyGen credential present | absent |
|---|
| TTS | HeyGen Starfish REST (native word timestamps) | → ElevenLabs → Kokoro (chain transcribe for words) |
| BGM | HeyGen music retrieval | Lyria → MusicGen local generation (detached) |
| SFX | HeyGen sound-effects retrieval (min_score 0.4) | bundled 21-file library (assets/sfx/) |
- Request (
audio_request.json): { provider?, lang?, speed?, lines: [{ id, text, sfx?: [names] }], bgm: { mode?, query?, prompt? } }. id joins each line back to the caller's model (a frame number, a scene id, …). bgm.mode = retrieve | generate | none; omit for auto (retrieve when credentialed, else generate). An explicit retrieve is strict — it skips rather than starting a detached generate (for callers with no wait-bgm step).
- Output (
audio_meta.json, id-keyed): { tts_provider, voice_id, bgm, bgm_pending, …, voices: [{ id, path, duration_s, words }], sfx: [{ id, name, file, source, offset_s, duration_s, volume }], total_duration_s }.
--only tts,bgm,sfx runs a subset and merges into an existing --out (e.g. TTS+BGM early, SFX once cues exist).
- BGM generate is spawned detached (
bgm_pending: true) — run scripts/wait-bgm.mjs before assembling.
scripts/heygen-tts.mjs is a single-shot CLI over the same code (one text → wav + words) for when you just need HeyGen TTS without a request file.
Full flag list + the audio_meta.json schema live in the header of scripts/audio.mjs. The references below cover the provider details and edge cases behind each capability.
Provider chains (the detail behind the engine)
TTS — first available provider wins (the engine, or npx hyperframes tts "..."):
| Order | Provider | Detected when | Word timestamps |
|---|
| 1 | HeyGen (Starfish) | $HEYGEN_API_KEY / hyperframes auth login | Yes, native — pass --words narration.words.json to capture |
| 2 | ElevenLabs | $ELEVENLABS_API_KEY set | No — chain transcribe after |
| 3 | Kokoro-82M (local, 54 voices) | always (no key required) | No — chain transcribe after |
The published hyperframes tts CLI is often the local-only build (its --help says "Kokoro-82M", no --provider/--words) and silently falls back to Kokoro even with $HEYGEN_API_KEY set. That is why the engine's HeyGen path is the self-contained scripts/heygen-tts.mjs (REST), NOT the CLI; the CLI is used only for the Kokoro path. See references/tts.md.
BGM & SFX — by default retrieved from the HeyGen audio library (/v3/audio/sounds), same credential as HeyGen TTS, with the no-credential fallback from the switch above:
| Asset | HeyGen type | Lands in | Fallback (no credential) |
|---|
| BGM | music | assets/bgm/track.mp3 (retrieve) · track.wav (generate) | Lyria / MusicGen generation |
| SFX | sound_effects (min_score 0.4) | assets/sfx/<slug>.mp3 | bundled 21-file library (assets/sfx/* + manifest.json) |
See references/bgm.md and references/sfx.md.
Routing
| Task | Read |
|---|
The audio engine — request/meta schema, --only, the switch | scripts/audio.mjs (header comment) |
npx hyperframes tts / heygen-tts.mjs — providers, voices, words | references/tts.md |
| BGM — HeyGen retrieval + local Lyria / MusicGen generation | references/bgm.md |
| SFX — HeyGen retrieval (min_score 0.4) + bundled local library | references/sfx.md |
npx hyperframes transcribe — Whisper, model rules, output shape | references/transcribe.md |
npx hyperframes remove-background — transparent cutouts | references/remove-background.md |
| TTS → transcription → captions (no recorded voiceover) | references/tts-to-captions.md |
| Caption authoring — style detection, layout, word grouping, exit | references/captions/authoring.md |
| Transcript handling — input formats, quality gates, cleanup, APIs | references/captions/transcript-handling.md |
| Caption motion — karaoke, marker effects, audio-reactive | references/captions/motion.md |
| Model caches, system dependencies, troubleshooting | references/requirements.md |
Non-negotiable rules
- One engine, no vendored copies. Produce audio via
scripts/audio.mjs (or heygen-tts.mjs for one-shot HeyGen TTS). Don't re-implement TTS/BGM/SFX inside a workflow — write an audio_request.json adapter and call the engine.
- "HeyGen available" = a resolvable credential, not the CLI. The whole switch keys off
heygenCredential(); the published hyperframes tts may be Kokoro-only, and there is no hyperframes bgm / hyperframes sfx command at all.
- Voice IDs are provider-specific.
am_michael is Kokoro-only; HeyGen UUIDs don't work on Kokoro. If you pass --voice, also pin --provider to avoid silent provider drift when the user's env changes.
- Always pass
--model to transcribe. The CLI default small.en silently translates non-English audio. See references/transcribe.md → "Language Rule".
- HeyGen returns word timestamps; ElevenLabs / Kokoro do not. The engine chains
transcribe automatically for the latter two; standalone, pass --words to HeyGen or run transcribe against the audio file.
- Captions consume the flat word-array format with
{ id, text, start, end }. See references/transcribe.md → "Output Shape".
remove-background --background-output is hole-cut, not inpainted. For "scene without the person", a different tool is needed. See references/remove-background.md → "When NOT the right tool".
- BGM/SFX default to HeyGen retrieval; the no-credential fallback is generation (BGM) or the bundled library (SFX).
/audio/sounds ranks by a text query — name effects concretely (glass shatter, not dramatic sound); a no-match skips, never blocks the render. SFX sit at volume ~0.35 under voice + BGM. See references/sfx.md / references/bgm.md.