What are the best ways to implement transcription in podcast apps?

[ShaneCorn]

I am starting this discussion for everyone who can answer my query.

[bianca_unifeye]

Hi @ShaneCorn, great question 👋

When you think about transcription for a podcast app with Databricks, it helps to break it down into a simple pattern:

1. Ingest & store the audio

2. Transcribe it with a speech model

3. Enrich the transcript (chapters, speakers, topics)

4. Expose everything for search & recommendations

Databricks works well here because you can run this end-to-end on one platform.

[nayan_wylde]

1. Use Speech-to-Text Models via MLflow

• Integrate open-source models like OpenAI Whisper, Hugging Face Wav2Vec2, or AssemblyAI API.
• Log the model in MLflow for versioning and reproducibility.
• Deploy as a Databricks Model Serving endpoint for real-time transcription.

2. Leverage Serverless Compute for Audio Processing

• Use Databricks Serverless Jobs or Delta Live Tables for batch transcription of podcast episodes.
• Store audio files in Unity Catalog-managed storage.
• Process audio in parallel using Spark UDFs or Pandas UDFs for distributed workloads.

3. Optimize with Delta Lake

• Store transcriptions in Delta tables for efficient querying and analytics.
• Add metadata like speaker info, timestamps, and confidence scores.
• Enable Unity Catalog governance for secure access control.

4. Integrate External APIs for Accuracy

• If you need high accuracy and language support, integrate APIs like:
• Azure Cognitive Services Speech-to-Text
• Google Cloud Speech
• AWS Transcribe

5. Enhance with NLP for Summarization & Search

After transcription, apply NLP models for:

• Summarization (using Hugging Face transformers)
• Keyword extraction
• Semantic search (via Databricks Vector Search)

6. Streaming for Live Podcasts

• Use Structured Streaming with Auto Loader to ingest audio chunks.
• Apply real-time transcription using a deployed MLflow model or external API.
• Output to Delta tables or publish to Kafka for downstream apps.

7. Cost & Performance Tips

• Use Spot instances or Photon runtime for compute efficiency.
• Compress audio before processing.
• Batch process episodes during off-peak hours.