One-page reference: the four-step pipeline (hear, ASR, MT, TTS); earbuds as an audio endpoint in front of that pipeline (on-device vs phone+cloud); cascade vs direct speech-to-speech trade-offs; why live translations rewrite themselves (word reorder, ear-voice span, wait-k, replace-until-final); the latency budget (~1 s machine + ~2-3 s deliberate wait; ITU-T G.114 150 ms / <800 ms feels live / AIIC 3-5 s ceiling); SFU-side per-listener-language fan-out (captions on RFC 8831 data channel, ducked audio on an injected RFC 6716 Opus track, VAD-gated); the per-language cost math ($21.60 for a 1-hour 3-language event); and a build-vs-buy checklist.
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The book · Volume 3 of 7
Video Streaming: A Complete Guide to Video Delivery: From ABR and CDNs to Players, WebRTC, DRM, and the Economics of Streaming
This real-time speech translation cheat sheet covers the hear-ASR-MT-TTS pipeline, earbuds as an audio endpoint, cascade versus direct speech-to-speech and why live translations rewrite themselves. Volume 3 covers the delivery side in depth: WebRTC and real-time media, SFU routing of audio tracks, players and QoE monitoring. Written by Nikolay Sapunov, CEO at Fora Soft.
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