whisper-pwa

A SvelteKit PWA that transcribes YouTube videos and audio/video files using a local whisper-rtx2080 backend.

Features

• Web Share Target — share YouTube URLs, video or audio files directly from your phone or browser
• Smart audio preparation — multi-strategy FFmpeg pipeline (auto/standard/aggressive/none) before submission
• One job → one webhook — whisper-rtx2080 handles internal chunking; we receive a single webhook when done
• Live progress — SSE stream showing chunk N of M + percentage
• Post-processing — collapse repeats, n-gram deduplication to clean up hallucinations
• 4 output formats — SRT, plain TXT, Markdown (with timestamps), JSON
• Web Push notifications — get notified when the transcript is ready (works on mobile too)

Requirements

• Node.js 20+
• FFmpeg in $PATH
• yt-dlp in $PATH (for YouTube URLs)
• Docker + whisper-rtx2080 running (or reachable at WHISPER_URL)

Setup

1. Install dependencies

npm install

2. Generate VAPID keys (one-time)

npx web-push generate-vapid-keys

3. Create .env

cp .env.example .env
# Edit .env and fill in all values

Required env vars:

Variable	Example	Description
WHISPER_URL	http://localhost:8080	whisper-rtx2080 base URL
WEBHOOK_BASE_URL	http://192.168.1.x:3000	Reachable from inside Docker
OUTPUT_DIR	/home/user/transcripts	Where to write output files
VAPID_PUBLIC_KEY	BNxx...	From npx web-push generate-vapid-keys
VAPID_PRIVATE_KEY	xxxx	From npx web-push generate-vapid-keys
VAPID_SUBJECT	mailto:you@example.com	Contact for push service
DATA_DIR	/home/user/.whisper-pwa	SQLite DB + tmp audio (default: ~/.whisper-pwa)

Important

: WEBHOOK_BASE_URL must be the IP/hostname reachable from inside the whisper-rtx2080 Docker container (not localhost).

4. Build and run

npm run build
npm start

Visit http://localhost:3000.

5. For development

npm run dev

Audio preparation modes

Mode	Description
auto (default)	volumedetect → boost quiet audio + denoise + EBU R128 loudnorm
standard	Highpass 80Hz + lowpass 8kHz + EBU R128 loudnorm
aggressive	Standard + FFT denoiser (afftdn) + noise gate (agate)
none	Convert to 16kHz mono WAV only

All modes trim leading silence to prevent Whisper hallucinations at file start.

API

Endpoint	Method	Description
/api/jobs	POST	Create job ({ source, title, audioMode })
/api/jobs	GET	List recent jobs
/api/jobs/[id]	GET	Poll job status
/api/jobs/[id]	DELETE	Cancel job
/api/jobs/[id]/stream	GET (SSE)	Live progress stream
/api/jobs/[id]/download/[format]	GET	Download SRT/TXT/MD/JSON
/api/jobs/[id]/reprocess	POST	Re-run post-processing on stored segments
/api/webhook/[jobId]	POST	Whisper completion webhook (called by whisper-rtx2080)
/api/push	GET	Get VAPID public key
/api/push	POST	Register push subscription
/share	POST	Web Share Target entry point

whisper-rtx2080 internals

The backend handles all audio chunking internally (60s chunks with 30s snap window, silence-detected at −35dB). We submit one WAV file per job and receive one webhook when all chunks are transcribed.

SSE progress events from the backend include { percent, chunk, total } relayed live to the browser.