Transcripts

For Language Translation, the SDK always delivers two parallel streams of transcript events — one for the source language (what was spoken) and one for the target language (the translation). Both arrive as JSON strings through your TranscriptCallback.

Registering the callback

auto onTranscript = [](const std::string& json) {
    // parse and handle the JSON event (see schema below)
};

// Pass as the 4th argument to CreateAudioProcessor
auto p = sdk->CreateAudioProcessor(params, rc, onState, onTranscript);

Event types

`type` field	Contents
`"transcription"`	Speech recognised in the source language.
`"translation"`	Text translated into the target language.

JSON schema

{
  "type": "transcription",
  "transcription": {
    "lang": "en-US",
    "complete": [
      { "word": " hello", "start": 0.10, "end": 0.42, "probability": 0.99 }
    ],
    "partial": [
      { "word": " world", "start": 0.42, "end": 0.70, "probability": 0.88 }
    ],
    "utterance_idx": 0
  }
}

Field	Type	Description
`type`	string	`"transcription"` or `"translation"`
`lang`	string	BCP-47 language code for this event.
`complete`	array	Finalised words — will not change.
`partial`	array	In-progress words — may be revised in the next event.
`word`	string	Word text with a leading space. Concatenate to rebuild sentences.
`start` / `end`	float	Timing offsets in seconds from the start of the utterance.
`probability`	float (0–1)	Recognition confidence. Words below ~0.7 are lower-confidence.
`utterance_idx`	integer	Monotonically increasing counter that groups words into utterances.

Example: print finalised text

auto onTranscript = [](const std::string& jsonData) {
    try {
        auto root = nlohmann::json::parse(jsonData);
        std::string type = root.value("type", "");
        if (!root.contains(type)) return;

        const auto& body = root[type];
        std::string text;
        for (const auto& w : body.value("complete", nlohmann::json::array()))
            text += w.value("word", "");
        if (!text.empty())
            std::cout << "["
                      << (type == "translation" ? "TARGET" : "SOURCE")
                      << " " << body.value("lang", "") << "] " << text << "\n";
    } catch (const std::exception& e) {
        std::cerr << "parse error: " << e.what() << "\n";
    }
};

JSON library. nlohmann/json is used in examples for brevity. Any JSON library works. Always wrap parsing in try/catch.

Python SDK

C++ SDK

Registering the callback

Event types

JSON schema

Example: print finalised text

​Registering the callback

​Event types

​JSON schema

​Example: print finalised text

Registering the callback

Event types

JSON schema

Example: print finalised text