Optimize Audio Diarization Reliability, Speaker Sequencing & Waveform Analysis
Description
This merge request introduces major improvements to the audio processing and speaker diarization pipeline by enhancing long-audio reliability, implementing consistent speaker sequencing, and replacing traditional spectrogram analysis with waveform-based audio visualization. The update improves backend stability for compressed audio formats, enhances transcript readability, and introduces a cleaner audio waveform representation aligned with modern audio processing standards.
1. Enhanced Speaker Diarization Stability
Implemented a robust fallback mechanism to improve diarization reliability for long-duration compressed audio files such as:
- MP3
- M4A
- WhatsApp audio recordings
Improvements
- Detects Pyannote chunk/sample mismatch failures
- Automatically normalizes problematic audio into WAV format
- Retries diarization on normalized audio
- Cleans temporary files after processing
Benefits
- Improved handling of long audio uploads
- Reduced decoder-related diarization failures
- Increased backend processing stability
2. Sequential Speaker Ordering
Implemented normalized sequential speaker indexing to maintain consistent transcript structure.
Improvements
- Standardized speaker labels
- Sequential ordering of detected speakers
- Improved transcript readability and UI consistency
Example
Before:
Speaker_5
Speaker_2
Speaker_7
After:
Speaker_1
Speaker_2
Speaker_3
3. Transition from Spectrogram to Waveform Visualization
Replaced spectrogram-based analysis with waveform-based audio visualization.
Previous Implementation
The earlier implementation used STFT-based spectrogram analysis, which represented:
- frequency distribution
- intensity heatmaps
- frequency-domain visualization
While technically useful for signal analysis, the visualization was not intuitive for standard audio representation.
New Implementation
The system now generates waveform-based amplitude visualization by directly plotting raw audio samples over time.
Benefits
- Cleaner and more user-friendly audio representation
- Visualization similar to professional audio tools
- Improved frontend integration support
- Better representation of audio amplitude over time
Technical Enhancements
- Improved audio preprocessing workflows
- Better exception handling for long-duration files
- Added fallback recovery mechanisms
- Refactored waveform generation service
- Removed legacy spectrogram implementation
- Improved maintainability of audio analysis modules
Validation
The implementation was validated against:
- long-duration audio uploads
- compressed audio formats
- waveform rendering workflows
- speaker sequencing consistency
- fallback retry execution scenarios No breaking changes were introduced to existing functionality.
Outcome
This enhancement significantly improves:
- audio processing reliability
- diarization stability
- transcript consistency
- waveform visualization quality
- backend maintainability and scalability The backend is now more stable and production-ready for handling real-world audio processing workloads.