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Overview

The Callbacks interface allows you to monitor and respond to various stages of the transcription process. It extends preprocessing and splitting callbacks from ffmpeg-simplified, providing a complete view of the entire audio processing pipeline.

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Type definition

interface Callbacks extends PreprocessingCallbacks, SplitOnSilenceCallbacks {
    onTranscriptionFinished?: (transcripts: Segment[]) => Promise<void>;
    onTranscriptionProgress?: (chunkIndex: number) => void;
    onTranscriptionStarted?: (totalChunks: number) => Promise<void>;
}

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Properties

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Transcription callbacks

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onTranscriptionStarted
(totalChunks: number) => Promise<void>
Called just before the transcription process begins.Parameters:
  • totalChunks: Total number of chunks to be transcribed
Use this to initialize progress tracking or logging.
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onTranscriptionProgress
(chunkIndex: number) => void
Called when each individual chunk is transcribed.Parameters:
  • chunkIndex: Index of the current chunk being processed (0-based)
Use this to update progress indicators or track completion status.
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onTranscriptionFinished
(transcripts: Segment[]) => Promise<void>
Called when all transcription is complete.Parameters:
  • transcripts: Array of all transcribed segments
This callback is only called when ALL chunks transcribe successfully. If any chunk fails, this callback will not be invoked.

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Inherited callbacks

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Usage examples

import { transcribe } from 'tafrigh';

const transcript = await transcribe('audio.mp3', {
  callbacks: {
    onTranscriptionStarted: async (totalChunks) => {
      console.log(`Starting transcription of ${totalChunks} chunks`);
    },
    onTranscriptionProgress: (chunkIndex) => {
      console.log(`Completed chunk ${chunkIndex + 1}`);
    },
    onTranscriptionFinished: async (transcripts) => {
      console.log(`Done! ${transcripts.length} segments transcribed`);
    }
  }
});

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Error handling

When errors occur during transcription, the onTranscriptionFinished callback will not be called. Handle errors using try-catch: 
import { transcribe, TranscriptionError } from 'tafrigh';

try {
  const transcript = await transcribe('audio.mp3', {
    callbacks: {
      onTranscriptionFinished: async (transcripts) => {
        // This is only called on complete success
        console.log('Success!');
      }
    }
  });
} catch (error) {
  if (error instanceof TranscriptionError) {
    // Some chunks may have succeeded
    console.log(`Partial results: ${error.transcripts.length} segments`);
    console.log(`Failed chunks: ${error.failures.length}`);
  }
}

TranscribeOptions

Configuration options including callbacks

Segment

Type passed to onTranscriptionFinished

Progress callbacks guide

Complete guide to using callbacks

Error handling

Learn about error handling strategies

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