HyperFrames Media Preprocessing Three CLI commands that produce assets for compositions: tts (speech), transcribe (timestamps), and remove-background (transparent video). Each downloads a model on first run and caches it under ~/.cache/hyperframes/ . Drop the output into the project, then reference it from the composition HTML — see the hyperframes skill for the audio/video element conventions. Text-to-Speech ( tts ) Generate speech audio locally with Kokoro-82M. No API key. npx hyperframes tts "Text here" --voice af_nova --output narration.wav npx hyperframes tts script.txt --voice bf_emma --output narration.wav npx hyperframes tts --list

all 54 voices

Voice Selection Match voice to content. Default is af_heart . Content type Voice Why Product demo af_heart / af_nova Warm, professional Tutorial / how-to am_adam / bf_emma Neutral, easy to follow Marketing / promo af_sky / am_michael Energetic or authoritative Documentation bf_emma / bm_george Clear British English, formal Casual / social af_heart / af_sky Approachable, natural Multilingual Voice IDs encode language in the first letter: a =American English, b =British English, e =Spanish, f =French, h =Hindi, i =Italian, j =Japanese, p =Brazilian Portuguese, z =Mandarin. The CLI auto-detects the phonemizer locale from the prefix — no --lang needed when the voice matches the text. npx hyperframes tts "La reunión empieza a las nueve" --voice ef_dora --output es.wav npx hyperframes tts "今日はいい天気ですね" --voice jf_alpha --output ja.wav Use --lang only to override auto-detection (stylized accents). Valid codes: en-us , en-gb , es , fr-fr , hi , it , pt-br , ja , zh . Non-English phonemization requires espeak-ng system-wide ( brew install espeak-ng / apt-get install espeak-ng ). Speed 0.7-0.8 — tutorial, complex content, accessibility 1.0 — natural pace (default) 1.1-1.2 — intros, transitions, upbeat content 1.5+ — rarely appropriate; test carefully Long Scripts For more than a few paragraphs, write to a .txt file and pass the path. Inputs over ~5 minutes of speech may benefit from splitting into segments. Requirements Python 3.8+ with kokoro-onnx and soundfile ( pip install kokoro-onnx soundfile ). Model downloads on first use (~311 MB + ~27 MB voices, cached in ~/.cache/hyperframes/tts/ ). Transcription ( transcribe ) Produce a normalized transcript.json with word-level timestamps. npx hyperframes transcribe audio.mp3 npx hyperframes transcribe video.mp4 --model small --language es npx hyperframes transcribe subtitles.srt

import existing

npx hyperframes transcribe subtitles.vtt npx hyperframes transcribe openai-response.json Language Rule (Non-Negotiable) Never use .en models unless the user explicitly states the audio is English. .en models ( small.en , medium.en ) translate non-English audio into English instead of transcribing it. This silently destroys the original language. Language known and non-English → --model small --language (no .en suffix) Language known and English → --model small.en Language unknown → --model small (no .en , no --language ) — whisper auto-detects Default model is small , not small.en . Model Sizes Model Size Speed When to use tiny 75 MB Fastest Quick previews, testing pipeline base 142 MB Fast Short clips, clear audio small 466 MB Moderate Default — most content medium 1.5 GB Slow Important content, noisy audio, music large-v3 3.1 GB Slowest Production quality Music with vocals: start at medium minimum; produced tracks often need manual SRT/VTT import. For caption-quality checks (mandatory after every transcription), the cleaning JS, retry rules, and the OpenAI/Groq API import path, see hyperframes/references/transcript-guide.md . Output Shape Compositions consume a flat array of word objects. The id field ( w0 , w1 , ...) is added during normalization for stable references in caption overrides; it's optional for backwards compatibility. [ { "id" : "w0" , "text" : "Hello" , "start" : 0.0 , "end" : 0.5 } , { "id" : "w1" , "text" : "world." , "start" : 0.6 , "end" : 1.2 } ] Background Removal ( remove-background ) Remove the background from a video or image so it can sit as a transparent overlay in a composition (e.g. an avatar floating on a background plate). npx hyperframes remove-background avatar.mp4 -o transparent.webm