Watch any YouTube video in your language—live. Play TV captures speech, transcribes it, translates it, and streams back a natural voice‑over directly into the same player. First words arrive in ~0.9–1.3 s; a refined, corrected dub locks in by ~5–6 s.
Ready-made Solution
Sub‑second feel • RTF < 1 across languages
Modular ASR → NMT → TTS (or speech‑to‑speech)
Scales from 1 speaker to thousands of concurrent listeners
Multi‑region WebRTC/WebSocket streaming built for hostile networks
Designed for quick implementation with REST/gRPC/WebRTC SDKs
Language barriers with brand names, jargon, and dialects across thousands of pairs.
Fast speech, accents, code-switching, and overlapping speakers challenge accuracy.
Tight latency budget for a believable “live” feel (sub-second to first words).
Prosody and volume drift — keeping emotion without sounding robotic.
Thousands of language pairs with domain‑specific terms and proper names.
Tight latency budget for a believable “live” experience.
Mixed audio (music, SFX) masking speech; variable recording quality.
Fluctuating network conditions and jitter in the browser.
Consistent prosody and volume while preserving the video’s mood.
Compliance & privacy expectations for enterprise rollouts.
What Users Get
Play TV is a drop-in, low-latency dubbing layer that makes any video feel native
Instant dub: First words in ~0.9 s; refined line lands ~5–6 s later.
Audio mixer: Original track ducked −12…−18 dB with an adjustable slider.
Multilingual: Choose target language; optional parallel tracks + captions.
On-video captions: HTML/WebVTT overlay with karaoke-style word highlighting.
Hotkeys & presets: Quick language switch, “Pause dubbing,” profiles for Interview / Lecture / Stream.
Start: Click Dub this video on YouTube.
Select: Pick language (and voice), optionally enable captions.
Tune: Choose Speed or Quality mode; apply a preset (Interview / Lecture / Stream).
Mix: Adjust original-audio level with the ducking slider.
Control: Use hotkeys to pause/resume dubbing or switch languages on the fly.
Live experience: Sub-second perceived latency that feels conversational.
Accuracy under pressure: Keeps domain terms right during fast speech and code-switching.
Operational simplicity: Plug-in SDKs/extension—no backend surgery.
Audience scale: Thousands of concurrent listeners per session, multi-region.
Post-event assets: Clean audio + VTT/SRT delivered automatically.
Architecture Overview
Event Backbone: NATS / Kafka event bus decouples ASR → MT → TTS services with backpressure and idempotent job retries, preventing stalls during viral video spikes.
Elastic Compute Pools: Independent autoscaling for ASR / MT / TTS (CPU / GPU) based on queue depth and latency SLOs. Traffic-aware routing maintains sub-second 'first words' under surge.
Real-time Pipeline: YouTube audio captured, transcribed with ~0.9s first words, translated via RAG term banks, and synthesized with natural voice-over streamed back to player.
Regional Edge Delivery: Multi-region PoPs route users to nearest region for lower latency. Live streams use priority lanes with regional failover for uninterrupted sessions.
Audio Mixing & Control: Original track ducked -12…-18 dB with adjustable slider. Hotkeys for pause / resume dubbing, language switching, and preset modes (Interview / Lecture / Stream).
Challenges
Start TTS from ASR partials while safely reconciling later corrections without audible jumps.
Robust VAD + adaptive thresholds to detect speech onset/offset amid music and crowd noise.
SSML‑driven rate/pitch/emphasis to avoid robotic delivery; energy normalization across segments.
Custom glossaries and per‑channel dictionaries applied in ASR, MT, and TTS.
Value
Play TV uses RAG term banks + glossaries to deliver domain-true, real-time translation
ASR keeps recognition errors low on our benchmarks
Separates speakers correctly in group videos
MT delivers high-quality translations by standard metrics.
Voices sound human and pleasant
Benchmarks
Play TV scales globally with autoscaling + priority lanes for a consistent sub-second feel
Play TV runs ASR → MT → TTS through a NATS / Kafka event bus that decouples services, applies backpressure, and retries idempotent jobs — so spikes from popular videos don’t stall the dub
Independent autoscaling pools for ASR / MT / TTS (CPU / GPU) expand on queue depth and latency SLOs. A traffic-aware router picks the optimal model pool per language and load, keeping sub-second “first words” under surge.
Real-time QoS guardrails with automatic scaling and performance tracking
Multi-region PoPs route users to the nearest region for lower round-trip time; live streams ride priority lanes to protect real-time feel. Regional failover keeps sessions going if a zone degrades
Uptime across regions with active-active failover
Median RTT to nearest PoP via geo-routing
Autoscaling convergence from a 2× traffic spike
Application
Lectures, interviews, research talks.
Automatic dubbing for new markets (higher retention & watch time).
Training videos and leadership messages for local teams.
Dubbing + captions for non‑native and hard‑of‑hearing users.
Skim long videos with translated audio without losing tone.
Reviews, guides, live event streams in local language.
Delivery Crew
High-performing developers for growing companies
Renata Sarvary
Sales Manager
Start an instant or scheduled call with real-time translation, for 1–50 or thousands in Conference Mode
Talk to an ExpertData Protection
Private by design: encrypted in transit & at rest, minimal retention, isolated tenants, and compliance-ready
TLS 1.3 for all traffic; KMS-managed AES-256 encryption for caches and config stores. Optional mTLS between services and HSTS at the edge
Process only what’s needed for dubbing; strict retention windows; ephemeral, rotated tokens. Optional on-device / edge path for sensitive use cases
Per-tenant buckets, queues, and keys; scoped API tokens and RBAC. Tamper-evident audit logs with SIEM export for enterprise
GDPR-aligned with DPA/SCCs; HIPAA with BAA on request; SOC 2–aligned SDLC and vendor review. Data residency options (EU/US) and RTBF/SAR flows
Competitive Ability
Any (incl. non‑native) video becomes understandable and emotionally faithful with latency close to live interpreting
MVP 1 ships for YouTube; next up: multi‑platform, duplex, and on‑device
YouTube tab
Audio capture and voice detection → VAD (speech start)
ASR partials
Speech recognition and real-time transcription
MT partials
Machine translation pipeline
Audio Output
TTS streaming → Mixer (duck/original) → Output to player overlay
Sub-second starts: P95 first words ≤ 0.9 s; RTF < 1 under surge
At scale: 3,000+ concurrent listeners per session with priority lanes for live
Autoscaled pipeline: Per-stage GPU / CPU pools with traffic-aware routing
Fast path: < 200ms median RTT to nearest PoP; caches skip repeated segments
ASR: Low WER / CER, multi-speaker diarization, auto-punctuation
MT: High BLEU / COMET with RAG-guided glossaries for domain terms
TTS: High MOS / CMOS, SSML emphasis, stable prosody
Fidelity: Robust to code-switching/accents; preserves names and jargon
Live stream: Real-time dub with optional on-video captions
Captions:WebVTT during playback; SRT generated automatically after
Exports: Clean mixed track + transcripts saved per session (e.g., S3)
Ops: Shareable links, audit logs, and per-tenant isolation for enterprise
Order Fulfillment Process
Our strategic development phases from MVP to advanced real-time capabilities
YouTube + core languages / voices
Other platforms (e.g., Twitch / Vimeo), improved mixer & AEC
JS SDK & API, brand voices, glossary management
Two‑way mode for streams, on‑device TTS
Results you can measure: speed, uptime, scale
Streaming TTS starts ~0.9s after speech onset; a refined, corrected line lands ~5–6s in
Quick language switch, “pause dubbing,” presets for Interview / Lecture / Stream
Pick the target language; optional parallel tracks and captions
HTML / WebVTT overlay with karaoke‑style highlighting
Toggle Speed ↔ Quality; aggressive “live” mode for streams
Tools We Used
Project Estimator
The estimated time to launch the product
Clear vision of functionality you need
15% discount on your first sprint
Frequently Asked Questions
Find answers to your common concerns
RAG Glossaries & custom dictionaries across ASR/MT/TTS
Encrypted transport, minimal logging, optional on‑device path; per‑tenant isolation for enterprise
Use the Speed mode for lower latency; expect more frequent micro‑corrections
MVP1 targets YouTube; connectors for Twitch/Vimeo/custom players are on the roadmap
Later ASR/MT refinements overwrite early takes with smooth cross‑fades
About Plavno
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Senior engineers + proven AI components to accelerate time-to-value.
From MVPs to enterprise platforms at global scale.
From extension UX to GPU pipelines and global scale.
Testimonials
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Commercial Director, RNDpoint
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Product Manager, T-Rize Group
“We are very satisfied with their excellent work”
Michael Bychenok
CEO, MediaCube
“They have a clear understanding of what the end user needs.”
Helen Lonskaya
Head of Growth, Codabrasoft LLC
“The app was delivered on time without any serious issues.”
Mitya Smusin
Founder, 24hour.dev
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