Live Caption Pro
https://www.livecaption.proCaptions, translation and an interpreter over your calls – on your own machine.
Live Caption Pro transcribes, translates and speaks the translation locally – even in the speaker's own voice. The internet is needed once, to download the models.
Incoming
What the other party says, you read as captions and as a translation – and, if you want, you hear it too, in the speaker's cloned voice or a built-in one.
Outgoing
What you say, the other party hears in their own language, in your voice – through a virtual microphone in the call application.
Batch, from the command line
Subtitle a whole folder of videos to SRT, or translate subtitle files – with the same local models, without the caption window.
- Live Caption Pro – the caption window on your machine
- AccountServer (port 8100) – the account service: users, roles, API keys, audit log and usage metering
- TranslatorServer (port 8080) – the translator: translates each sentence with TranslateGemma
- VoiceServer (port 8090) – the voice service: speaks the translation, optionally in the speaker's cloned voice
- CaptionServer (port 5111) – the caption server: splits the audio into sentences and transcribes it (Whisper)
Measured, not promised
| What we measured | Result | Under what conditions |
|---|---|---|
| First translated word | 62 ms | TranslateGemma 12b Q8, 20 sentences; the whole sentence in 270 ms, 19 of 20 flawless. For comparison, the cloud model gpt-4o-mini took 1106 ms to the first word. |
| Transcribing 6.3 s of speech | 108 ms | Whisper large-v3-turbo on the GPU, through the caption server. |
| Sentence end to the interpreter's first sound – in-process voice | 0.99 s | Median of the 24 spoken sentences (13 of 37 skipped under load); 95th percentile 5.56 s. Piper voice, no GPU needed for the voice. |
| Sentence end to the interpreter's first sound – cloned voice | 2.93 s | Median of the 22 spoken sentences (16 of 38 skipped under load); 95th percentile 6.86 s. XTTS-v2 in the voice service. |
| Video memory for the three engines together | 22.3 GB | Measured on one machine with the largest translator model. On a 20 GB card the translator runs as 12b Q4_K_M (measured 7.5 GB), on a 32 GB card as 12b Q8_0. |
Measured on the developer's machine; other machines give other numbers. Conditions and the full table on the website.
Requirements
The caption window runs on Windows x64 (Windows 11 or 10) and on Macs with Apple silicon (macOS 14.2 or later). On Windows the services are fast with an NVIDIA graphics card, on a Mac with the Metal acceleration and unified memory of Apple silicon; without a graphics card the caption server and the translator run on the CPU, more slowly. The services do not run on an Intel-based Mac. The first installation needs the internet for the tools and the models; after that everything runs locally.
The voice service's current engine, XTTS-v2, is under a non-commercial licence; it is being replaced before commercial release. The licensing page says exactly what this covers.
Access
Commercial software; access on request, licensed by quote. Details, guides and the contact form: https://www.livecaption.pro