Transcription Debugger

This skill diagnoses the transcription issues that have caused silent failures in v1.0.87-94.

When This Skill Activates

• "Transcription not working", "no text appears", "whisper not responding"
• "AudioFileReady not firing", "event handler issues"
• Whisper process errors or timeouts
• Users reporting recording works but no text output

Diagnostic Flow

Step 1: Check Build Configuration

Debug vs Release Mode

// Check: ErrorLogger.cs
#if DEBUG
    Console.WriteLine("DEBUG MODE - Full logging enabled");
#else
    // PROBLEM: v1.0.94 bug - logging was suppressed here!
#endif

Critical: Ensure logging works in Release builds!

Step 2: Verify Event Chain

Expected Flow:

User Press Hotkey
    ↓
AudioRecorder.StartRecording()
    ↓
AudioRecorder.StopRecording()
    ↓
AudioFileReady event fires ← COMMON FAILURE POINT
    ↓
PersistentWhisperService.TranscribeAsync()
    ↓
TranscriptionCompleted event fires
    ↓
TextInjector.InjectText()

Check Event Subscription:

// MainWindow.xaml.cs - Verify this exists:
_audioRecorder.AudioFileReady += OnAudioFileReady;

// Common issue: Event not subscribed or handler missing
private async void OnAudioFileReady(object sender, AudioFileReadyEventArgs e)
{
    // v1.0.87 bug: This wasn't being called
    ErrorLogger.Log($"AudioFileReady fired: {e.FilePath}");
}

Step 3: Test Whisper Directly

Manual Whisper Test:

# Create test audio file
echo "Test audio" > test.txt

# Run whisper directly
./VoiceLite/whisper/whisper.exe \
  -m VoiceLite/whisper/ggml-tiny.bin \
  -f test_audio.wav \
  --no-timestamps \
  --language en \
  --temperature 0.2 \
  --beam-size 1

# Expected: Text output within 2 seconds

Step 4: Check Process Lifecycle

Whisper Process Issues:

// PersistentWhisperService.cs
// Check timeout calculation
var timeout = (int)(audioLength * 3000); // Should be 2-3x audio length

// Verify process disposal
finally
{
    process?.Dispose(); // Must dispose to prevent zombies
}

// Check for hanging processes
tasklist | findstr whisper.exe

Step 5: Verify Model & Files

Required Files:

# Model file exists and correct size
test -f "VoiceLite/whisper/ggml-tiny.bin" || echo "Model missing!"
stat -c%s "VoiceLite/whisper/ggml-tiny.bin" # Should be 44048314 bytes

# Whisper executable present
test -f "VoiceLite/whisper/whisper.exe" || echo "Whisper missing!"

# Check permissions
ls -la VoiceLite/whisper/

Common Issues & Fixes

Issue 1: Silent Failure (No Error, No Text)

v1.0.87-90 Bug: AudioFileReady event not firing

Fix:

// Ensure event is raised after file write
_audioRecorder.AudioFileReady += OnAudioFileReady; // Subscribe
await File.WriteAllBytesAsync(path, audioData);
AudioFileReady?.Invoke(this, new AudioFileReadyEventArgs(path)); // Raise

Issue 2: Logging Suppressed in Release

v1.0.94 Bug: #if !DEBUG blocks around logging

Fix:

// Remove conditional compilation from logging
- #if DEBUG
    ErrorLogger.Log("Important diagnostic info");
- #endif
+ ErrorLogger.Log("Important diagnostic info"); // Always log

Issue 3: Whisper Process Hangs

Symptom: Transcription never completes

Diagnostics:

# Check for zombie processes
tasklist | findstr whisper.exe

# Kill if needed
taskkill /F /IM whisper.exe

Fix:

// Add proper timeout handling
if (!process.WaitForExit(timeout))
{
    ErrorLogger.Log($"Whisper timeout after {timeout}ms");
    process.Kill();
    throw new TimeoutException();
}

Issue 4: Wrong Audio Format

Symptom: Garbled or empty transcription

Check:

// AudioRecorder.cs - Must be 16kHz, 16-bit, mono
_waveIn = new WaveInEvent
{
    WaveFormat = new WaveFormat(16000, 16, 1), // Critical!
};

Testing Checklist

1. Record 5-second test audio
2. Verify WAV file created in temp directory
3. Check AudioFileReady event fires
4. Confirm whisper.exe launches
5. Verify transcription completes < 3 seconds
6. Check text appears in target application

Historical Context

v1.0.87-90: AudioFileReady event wasn't firing due to missing event raise v1.0.94: Logging was disabled in Release builds with #if !DEBUG v1.0.95-96: Model file missing from installer (different issue)

Critical Log Patterns

Search VoiceLite logs for diagnostic info:

# Log location
$log_file = "$env:LOCALAPPDATA\VoiceLite\logs\voicelite.log"

# Check if AudioFileReady is firing
grep "AudioFileReady fired" $log_file

# Check whisper process launch
grep "Starting whisper process" $log_file | tail -5

# Check for timeout errors
grep "Whisper timeout" $log_file

# Check for event subscription
grep "Event subscribed: AudioFileReady" $log_file

# Check transcription completion
grep "Transcription completed" $log_file | tail -5

Test Audio Phrases

Use these phrases to test accuracy (expect 95%+ correct):

Technical Terms:

• "npm install react useState useEffect"
• "git commit minus m add new feature"
• "dotnet build configuration release"

Common Dictation:

• "Hello world this is a test recording"
• "The quick brown fox jumps over the lazy dog"

Expected: All technical terms captured correctly