mudler/LocalAI · error

error: transcription failed\n

Error message

error: transcription failed\n

What it means

transcribe() failed: crispasr_session_transcribe_lang() returned NULL after the session accepted parameters (translate flag, freed previous result). A NULL result means the transcription run itself errored — decode failure, invalid language string, or an internal session state problem. The shim returns 1 and leaves g_result NULL.

Source

Thrown at backend/go/crispasr/cpp/crispasr_shim.cpp:262

  }

  // Reset stale abort flag from any prior cancelled call. set_abort remains
  // best-effort: the session transcribe call is blocking and exposes no abort
  // hook, so a mid-decode abort cannot interrupt it.
  g_abort.store(0, std::memory_order_relaxed);

  crispasr_session_set_translate(g_session, translate ? 1 : 0);

  if (g_result) {
    crispasr_session_result_free(g_result);
    g_result = nullptr;
  }

  const char *language = (lang && *lang) ? lang : nullptr;
  g_result = crispasr_session_transcribe_lang(g_session, pcmf32, (int)pcmf32_len,
                                              language);
  if (!g_result) {
    fprintf(stderr, "error: transcription failed\n");
    return 1;
  }

  *segs_out_len = crispasr_session_result_n_segments(g_result);
  return 0;
}

const char *get_segment_text(int i) {
  if (!g_result) {
    return "";
  }
  return crispasr_session_result_segment_text(g_result, i);
}

int64_t get_segment_t0(int i) {
  if (!g_result) {
    return 0;
  }

View on GitHub (pinned to 44413a9d06)

Solutions

1. Pass a known language code (e.g., "en") or NULL for auto-detect — never an unrecognized string.
2. Check pcmf32_len > 0 and the PCM is valid 16 kHz float mono as whisper expects.
3. Inspect ggml logs immediately before the error for the decoding failure reason.
4. If the session is suspect, reload the model (load_model) to get a fresh session.

Example fix

// before: empty string is not auto-detect
transcribe(pcm, n, "", 0);
// after: NULL selects auto-detection in the shim
code := (*C.char)(unsafe.Pointer(nil));
if lang != "" { code = C.CString(lang); defer C.free(unsafe.Pointer(code)) }
transcribe(pcm, n, code, 0);

if len(pcm) == 0 { return nil, errors.New("empty audio") }
if lang != "" && !knownLanguages()[lang] { lang = "" } // fall back to auto-detect

When it happens

Trigger: transcribe(pcm, len, lang, translate) with an unsupported lang code, pcm length of zero or exceeding the session's limit, corrupted session state after a prior failed run, or backend compute errors during decoding.

Common situations: Passing an empty-string or invalid language identifier instead of NULL; feeding an audio buffer that is empty because upstream resampling failed; GPU backend faults mid-decode; repeatedly reusing a session after an OOM event.

Related errors

• error: failed to open CrispASR session for model\n
• Web Audio API not available
• error: Failed to init model as VAD\n
• error: failed to detect speech\n

AI-assisted analysis of mudler/LocalAI@44413a9d06 (2026-08-15). Data as JSON: /api/errors/cf96f9a23c6813b3. Report an issue: GitHub.