



vCon                                                    T. McCarthy-Howe
Internet-Draft                                                    VCONIC
Intended status: Standards Track                       25 September 2025
Expires: 29 March 2026


               vCon World Transcription Format Extension
                    draft-howe-vcon-wtf-extension-00

Abstract

   This document defines the World Transcription Format (WTF) extension
   for Virtualized Conversations (vCon).  The WTF extension provides a
   standardized method for representing speech-to-text transcription
   data from multiple providers within vCon containers.  This extension
   enables consistent transcription storage, analysis, and
   interoperability across different transcription services while
   preserving provider-specific features through extensible fields.

   The WTF extension is designed as a Compatible Extension that
   introduces transcription attachments without altering existing vCon
   semantics, ensuring backward compatibility with existing vCon
   implementations.

About This Document

   This note is to be removed before publishing as an RFC.

   The latest revision of this draft can be found at https://vcon-
   dev.github.io/draft-howe-vcon-wtf-extension/draft-howe-vcon-wtf-
   extension-00.html.  Status information for this document may be found
   at https://datatracker.ietf.org/doc/draft-howe-vcon-wtf-extension/.

   Discussion of this document takes place on the vCon Working Group
   mailing list (mailto:vcon@ietf.org), which is archived at
   https://mailarchive.ietf.org/arch/browse/vcon/.  Subscribe at
   https://www.ietf.org/mailman/listinfo/vcon/.

   Source for this draft and an issue tracker can be found at
   https://github.com/vcon-dev/draft-howe-vcon-wtf-extension.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.






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Table of Contents

   1.  Requirements Language . . . . . . . . . . . . . . . . . . . .   3
   2.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Conventions and Definitions . . . . . . . . . . . . . . . . .   4
     3.1.  Core Terms  . . . . . . . . . . . . . . . . . . . . . . .   4
   4.  World Transcription Format Overview . . . . . . . . . . . . .   5
     4.1.  Design Principles . . . . . . . . . . . . . . . . . . . .   5
     4.2.  Core Structure  . . . . . . . . . . . . . . . . . . . . .   5
   5.  vCon WTF Extension Definition . . . . . . . . . . . . . . . .   6
     5.1.  Extension Classification  . . . . . . . . . . . . . . . .   6
     5.2.  Extension Registration  . . . . . . . . . . . . . . . . .   6
     5.3.  Extension Usage . . . . . . . . . . . . . . . . . . . . .   6
   6.  WTF Attachment Structure  . . . . . . . . . . . . . . . . . .   7
     6.1.  Attachment Container  . . . . . . . . . . . . . . . . . .   7
     6.2.  WTF Body Structure  . . . . . . . . . . . . . . . . . . .   8
       6.2.1.  Required Fields . . . . . . . . . . . . . . . . . . .   8
       6.2.2.  Optional Fields . . . . . . . . . . . . . . . . . . .   9
   7.  Provider Integration Guidelines . . . . . . . . . . . . . . .  11
     7.1.  Supported Providers . . . . . . . . . . . . . . . . . . .  11
     7.2.  Conversion Requirements . . . . . . . . . . . . . . . . .  11
     7.3.  Provider-Specific Mappings  . . . . . . . . . . . . . . .  11



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       7.3.1.  Whisper Integration . . . . . . . . . . . . . . . . .  11
       7.3.2.  Deepgram Integration  . . . . . . . . . . . . . . . .  12
   8.  Quality and Confidence Metrics  . . . . . . . . . . . . . . .  12
     8.1.  Confidence Score Normalization  . . . . . . . . . . . . .  12
     8.2.  Quality Metrics . . . . . . . . . . . . . . . . . . . . .  13
   9.  Security Considerations . . . . . . . . . . . . . . . . . . .  13
     9.1.  Data Privacy  . . . . . . . . . . . . . . . . . . . . . .  13
     9.2.  Provider-Specific Security  . . . . . . . . . . . . . . .  13
     9.3.  Integrity Protection  . . . . . . . . . . . . . . . . . .  14
     9.4.  Temporal Validation . . . . . . . . . . . . . . . . . . .  14
   10. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  14
     10.1.  vCon Extensions Names Registry . . . . . . . . . . . . .  14
     10.2.  WTF Attachment Type Values Registry  . . . . . . . . . .  14
     10.3.  WTF Provider Registry  . . . . . . . . . . . . . . . . .  15
   11. Examples  . . . . . . . . . . . . . . . . . . . . . . . . . .  15
     11.1.  Basic Two-Party Call Transcription . . . . . . . . . . .  15
     11.2.  Multi-Provider Transcription Comparison  . . . . . . . .  18
   12. References  . . . . . . . . . . . . . . . . . . . . . . . . .  20
     12.1.  Normative References . . . . . . . . . . . . . . . . . .  20
     12.2.  Informative References . . . . . . . . . . . . . . . . .  20
   Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .  21
   Trademark Notice  . . . . . . . . . . . . . . . . . . . . . . . .  21
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .  21

1.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 RFC2119 [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

2.  Introduction

   Virtualized Conversations (vCon) [I-D.draft-ietf-vcon-core-00]
   provide a standardized container format for conversation data,
   enabling interoperability across different communication platforms
   and modalities.  As speech-to-text technology becomes increasingly
   important for conversation analysis, compliance, and accessibility,
   there is a growing need for standardized transcription representation
   within vCon containers.

   Current transcription services each use proprietary formats, making
   it difficult to:

   *  Switch between transcription providers without data conversion

   *  Perform comparative analysis across different providers



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   *  Maintain consistent data processing pipelines

   *  Preserve transcription metadata during system migrations

   *  Ensure long-term accessibility and archival compliance

   This document defines the World Transcription Format (WTF) extension
   for vCon, which addresses these challenges by providing:

   *  A unified schema for transcription data from any speech-to-text
      provider

   *  Hierarchical organization from words to segments to complete
      transcripts

   *  Extensible fields for provider-specific features

   *  Built-in quality metrics and confidence scoring

   *  Support for real-time and batch transcription workflows

   *  Consistent export capabilities to standard subtitle and caption
      formats

   The WTF extension enables organizations to standardize their
   transcription workflows while maintaining the flexibility to use
   multiple providers and preserve provider-specific enhancements.

3.  Conventions and Definitions

3.1.  Core Terms

   *World Transcription Format (WTF)*: A standardized JSON schema for
   representing speech-to-text transcription data from any provider in a
   consistent, interoperable format.

   *Transcription Provider*: A service or system that converts audio or
   video content to text, such as Whisper(TM), Deepgram(TM),
   AssemblyAI(TM), Google Cloud Speech-to-Text(TM), Amazon
   Transcribe(TM), or Azure Speech Services(TM).

   *WTF Attachment*: A vCon attachment with type "wtf_transcription"
   that contains structured transcription information in World
   Transcription Format.

   *Segment*: A logical chunk of transcribed content, typically
   representing sentence or phrase boundaries with associated timing
   information.



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   *Speaker Diarization*: The process of partitioning an audio stream
   into homogeneous segments according to the speaker identity, enabling
   "who spoke when" analysis.

   *Compatible Extension*: A vCon extension that introduces additional
   data without altering the meaning or structure of existing elements,
   as defined in [I-D.draft-ietf-vcon-core-00].

4.  World Transcription Format Overview

   The World Transcription Format uses a hierarchical JSON structure
   designed to capture transcription data at multiple levels of
   granularity while maintaining consistency across different providers.

4.1.  Design Principles

   *Completeness*: WTF captures all essential transcription data
   including text, timing, confidence scores, and speaker information.

   *Consistency*: Provides uniform structure regardless of the
   underlying transcription provider.

   *Extensibility*: Supports provider-specific features through
   structured extension fields.

   *Validation*: Includes built-in data integrity checking and quality
   metrics.

   *Hierarchical Organization*: Natural progression from words to
   segments to complete transcripts.

4.2.  Core Structure

   WTF uses a hierarchical JSON structure with three required sections
   and multiple optional enrichment layers:

   {
     "transcript": { /* Required: Core transcript information */ },
     "segments": [ /* Required: Time-aligned text segments */ ],
     "metadata": { /* Required: Processing metadata */ },
     "words": [ /* Optional: Word-level details */ ],
     "speakers": { /* Optional: Speaker diarization */ },
     "alternatives": [ /* Optional: Alternative transcriptions */ },
     "enrichments": { /* Optional: Analysis features */ },
     "extensions": { /* Optional: Provider-specific data */ },
     "quality": { /* Optional: Quality metrics */ },
     "streaming": { /* Optional: Streaming information */ }
   }



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5.  vCon WTF Extension Definition

5.1.  Extension Classification

   The WTF extension is a *Compatible Extension* as defined in
   Section 2.5 of [I-D.draft-ietf-vcon-core-00].  This extension:

   *  Introduces transcription data without altering existing vCon
      semantics

   *  Can be safely ignored by implementations that don't support
      transcription processing

   *  Does not require listing in the must_support parameter

   *  Maintains backward compatibility with existing vCon
      implementations

5.2.  Extension Registration

   This document defines the "wtf_transcription" extension token for
   registration in the vCon Extensions Names Registry:

   *  *Extension Name*: wtf_transcription

   *  *Extension Description*: World Transcription Format for
      standardized speech-to-text representation with multi-provider
      support

   *  *Change Controller*: IESG

   *  *Specification Document*: This document

5.3.  Extension Usage

   vCon instances that include WTF transcription attachments SHOULD
   include "wtf_transcription" in the extensions array:














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   {
     "uuid": "01234567-89ab-cdef-0123-456789abcdef",
     "extensions": ["wtf_transcription"],
     "created_at": "2025-01-02T12:00:00Z",
     "parties": [...],
     "dialog": [...],
     "attachments": [
       {
         "type": "wtf_transcription",
         "start": "2025-01-02T12:15:30Z",
         "party": 0,
         "dialog": 0,
         "encoding": "json",
         "body": {
           // WTF transcription data structure defined below
         }
       }
     ]
   }

6.  WTF Attachment Structure

6.1.  Attachment Container

   Transcription information MUST be included as vCon attachments using
   the standard attachment object structure defined in Section 4.4 of
   [I-D.draft-ietf-vcon-core-00].

   The WTF transcription attachment MUST include:

   *  *type*: MUST be set to "wtf_transcription"

   *  *encoding*: MUST be set to "json" for structured transcription
      data

   *  *body*: MUST contain the WTF transcription data structure as
      defined below

   The WTF transcription attachment SHOULD include:

   *  *start*: ISO 8601 timestamp when transcription was created

   *  *party*: Index of the party in the vCon parties array (for single-
      speaker transcription)

   *  *dialog*: Index of the associated dialog in the vCon dialog array





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6.2.  WTF Body Structure

   The body field of the WTF transcription attachment MUST contain a
   JSON object with the following structure:

6.2.1.  Required Fields

6.2.1.1.  Transcript Object

   "transcript": {
     "text": "string",       // Complete transcription text
     "language": "string",   // BCP-47 language code (e.g., "en-US")
     "duration": "number",   // Total audio duration in seconds
     "confidence": "number"  // Overall confidence score \[0.0-1.0\]
   }

   The transcript object provides the high-level summary of the entire
   transcription:

   *  *text*: The complete, concatenated transcription text

   *  *language*: MUST use BCP-47 format [BCP47] (examples: "en-US",
      "es-MX", "fr-CA")

   *  *duration*: Floating-point seconds, MUST be >= 0

   *  *confidence*: Normalized to [0, 1] range regardless of provider
      scale

6.2.1.2.  Segments Array

"segments": [
  {
    "id": "integer",              // Sequential segment identifier
    "start": "number",            // Start time in seconds
    "end": "number",              // End time in seconds
    "text": "string",             // Segment text content
    "confidence": "number",       // Segment-level confidence \[0.0-1.0\]
    "speaker": "integer|string",  // Optional: Speaker identifier
    "words": ["integer"]          // Optional: Array of word indices
  }
]

   Segments represent logical chunks of transcribed content, typically
   sentence or phrase boundaries:

   *  *id*: MUST be unique within the document, typically sequential




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   *  *start*/*end*: Floating-point seconds, where end > start

   *  *text*: SHOULD be trimmed of leading/trailing whitespace

   *  *speaker*: Can be integer (0, 1, 2) or string ("Speaker A")

   *  *words*: References indices in the words array

6.2.1.3.  Metadata Object

"metadata": {
  "created_at": "string",        // ISO 8601 timestamp
  "processed_at": "string",      // ISO 8601 timestamp
  "provider": "string",          // Provider name (lowercase)
  "model": "string",             // Model/version identifier
  "processing_time": "number",   // Optional: Processing duration in seconds
  "audio": {
    "duration": "number",        // Source audio duration in seconds
    "sample_rate": "integer",    // Optional: Sample rate in Hz
    "channels": "integer",       // Optional: Number of channels
    "format": "string",          // Optional: Audio format
    "bitrate": "integer"         // Optional: Bitrate in kbps
  },
  "options": "object"            // Provider-specific options used
}

   The metadata object captures processing and source information:

   *  *created_at*/*processed_at*: MUST use ISO 8601 format

   *  *provider*: Lowercase identifier for supported providers

   *  *model*: Provider's model identifier (e.g., "whisper-large-v3",
      "nova-2")

   *  *options*: Preserves provider-specific configuration

6.2.2.  Optional Fields

6.2.2.1.  Words Array











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  "words": [
    {
      "id": "integer",              // Sequential word identifier
      "start": "number",            // Word start time in seconds
      "end": "number",              // Word end time in seconds
      "text": "string",             // Word text
      "confidence": "number",       // Word-level confidence \[0.0-1.0\]
      "speaker": "integer|string",  // Optional: Speaker identifier
      "is_punctuation": "boolean"   // Optional: Punctuation marker
    }
  ]

6.2.2.2.  Speakers Object

"speakers": {
  "speaker_id": {
    "id": "integer|string",       // Speaker identifier
    "label": "string",            // Human-readable speaker name
    "segments": ["integer"],      // Array of segment IDs for this speaker
    "total_time": "number",       // Total speaking time in seconds
    "confidence": "number"        // Diarization confidence \[0.0-1.0\]
  }
}

6.2.2.3.  Quality Object

   "quality": {
     "audio_quality": "string",      // high, medium, low
     "background_noise": "number",   // Noise level \[0.0-1.0\]
     "multiple_speakers": "boolean",
     "overlapping_speech": "boolean",
     "silence_ratio": "number",      // Percentage of silence
     "average_confidence": "number",
     "low_confidence_words": "integer",
     "processing_warnings": ["string"]
   }

6.2.2.4.  Extensions Object

   "extensions": {
     "provider_name": {
       // Provider-specific fields preserved during conversion
     }
   }







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7.  Provider Integration Guidelines

7.1.  Supported Providers

   The WTF extension supports integration with major transcription
   providers:

   *  *Whisper(TM)*: OpenAI's open-source speech recognition system

   *  *Deepgram(TM)*: Real-time speech-to-text API

   *  *AssemblyAI(TM)*: AI-powered transcription and audio intelligence

   *  *Google Cloud Speech-to-Text(TM)*: Google's speech recognition
      service

   *  *Amazon Transcribe(TM)*: AWS speech-to-text service

   *  *Azure Speech Services(TM)*: Microsoft's speech recognition
      platform

   *  *Rev.ai(TM)*: Automated and human transcription services

   *  *Speechmatics(TM)*: Real-time and batch speech recognition

   *  *Wav2Vec2(TM)*: Facebook's self-supervised speech recognition
      model

   *  *Parakeet(TM)*: NVIDIA's speech recognition toolkit

7.2.  Conversion Requirements

   When converting from provider-specific formats to WTF:

   1.  *Normalize confidence scores* to [0.0, 1.0] range

   2.  *Convert timestamps* to floating-point seconds

   3.  *Standardize language codes* to BCP-47 format

   4.  *Preserve provider-specific features* in extensions field

   5.  *Validate output* against WTF schema requirements

7.3.  Provider-Specific Mappings

7.3.1.  Whisper Integration




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   {
     "extensions": {
       "whisper": {
         "tokens": ["array of token IDs"],
         "temperature": "number",
         "compression_ratio": "number",
         "avg_logprob": "number",
         "no_speech_prob": "number"
       }
     }
   }

7.3.2.  Deepgram Integration

   {
     "extensions": {
       "deepgram": {
         "utterances": ["array of utterance objects"],
         "paragraphs": ["array of paragraph objects"],
         "search_terms": ["array of detected search terms"]
       }
     }
   }

8.  Quality and Confidence Metrics

8.1.  Confidence Score Normalization

   All confidence scores MUST be normalized to the [0.0, 1.0] range:

   *  *1.0*: Highest confidence (perfect recognition)

   *  *0.9-1.0*: High confidence

   *  *0.7-0.9*: Medium confidence

   *  *0.5-0.7*: Low confidence

   *  *0.0-0.5*: Very low confidence

   Provider-specific scales are converted during import:

   *  Percentage (0-100) -> divide by 100

   *  Log probability -> exponential transformation

   *  Custom scales -> linear normalization




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8.2.  Quality Metrics

   The quality object provides assessment metrics:

   *  *audio_quality*: Categorical assessment (high/medium/low)

   *  *background_noise*: Noise level [0.0-1.0]

   *  *multiple_speakers*: Boolean indicator of multi-speaker content

   *  *overlapping_speech*: Boolean indicator of speaker overlap

   *  *silence_ratio*: Percentage of audio that is silence

   *  *average_confidence*: Mean confidence across all words/segments

   *  *low_confidence_words*: Count of words below 0.5 confidence

   *  *processing_warnings*: Array of processing issues or notices

9.  Security Considerations

9.1.  Data Privacy

   Transcription data often contains sensitive personal information.
   Implementations SHOULD:

   *  Apply appropriate access controls to WTF transcription attachments

   *  Consider encryption requirements for transcription data at rest
      and in transit

   *  Implement data retention policies consistent with privacy
      regulations

   *  Provide mechanisms for transcription data redaction or
      anonymization

9.2.  Provider-Specific Security

   When integrating with external transcription providers:

   *  Validate provider credentials and API security

   *  Implement secure communication channels (TLS 1.2 or higher)

   *  Consider data residency requirements for audio processing




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   *  Audit provider data handling practices and compliance
      certifications

9.3.  Integrity Protection

   WTF transcription attachments SHOULD be integrity protected using
   vCon signing mechanisms as defined in [I-D.draft-ietf-vcon-core-00]
   to prevent unauthorized modification of transcription data.

9.4.  Temporal Validation

   Implementations SHOULD validate that transcription timestamps are
   consistent with the associated dialog timing information to detect
   potential tampering or synchronization issues.

10.  IANA Considerations

10.1.  vCon Extensions Names Registry

   This document requests IANA to register the following extension in
   the vCon Extensions Names Registry established by
   [I-D.draft-ietf-vcon-core-00]:

   *  *Extension Name*: wtf_transcription

   *  *Extension Description*: World Transcription Format for
      standardized speech-to-text representation with multi-provider
      support

   *  *Change Controller*: IESG

   *  *Specification Document*: This document

10.2.  WTF Attachment Type Values Registry

   This document requests IANA to establish a new registry for WTF
   attachment type values with the following initial registration:

   *  *Type Value*: wtf_transcription

   *  *Description*: Structured transcription records using World
      Transcription Format

   *  *Change Controller*: IESG

   *  *Specification Document*: This document Registration Template:
      *Type Value*: The string value used as the attachment type
      identifier *Description*: Brief description of the attachment type



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      and its purpose *Change Controller*: For Standards Track RFCs,
      list "IESG".  For others, give the name of the responsible party.
      *Specification Document(s)*: Reference to defining documents with
      URIs where available

10.3.  WTF Provider Registry

   This document requests IANA to establish a new registry for WTF
   transcription providers with initial registrations for supported
   providers:

   *  *Provider Name*: whisper

   *  *Description*: OpenAI Whisper(TM) speech recognition system

   *  *Change Controller*: IESG

   *  *Specification Document*: This document (Additional provider
      registrations would be added for each supported provider)

11.  Examples

11.1.  Basic Two-Party Call Transcription

{
  "uuid": "01928e10-193e-8231-b9a2-279e0d16bc46",
  "vcon": "0.0.2",
  "extensions": ["wtf_transcription"],
  "created_at": "2025-01-02T12:00:00Z",
  "parties": [
    {
      "tel": "+1-555-123-4567",
      "name": "Alice"
    },
    {
      "tel": "+1-555-987-6543",
      "name": "Bob"
    }
  ],
  "dialog": [
    {
      "type": "recording",
      "start": "2025-01-02T12:15:30Z",
      "duration": 65.2,
      "parties": [0, 1],
      "mediatype": "audio/wav",
      "filename": "call-recording.wav"
    }



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  ],
  "attachments": [
    {
      "type": "wtf_transcription",
      "start": "2025-01-02T12:16:35Z",
      "dialog": 0,
      "encoding": "json",
      "body": {
        "transcript": {
          "text": "Hello, this is Alice from customer service. " +
                  "How can I help you today? Hi Alice, I'm having " +
                  "trouble with my account. Can you help me reset " +
                  "my password?",
          "language": "en-US",
          "duration": 65.2,
          "confidence": 0.92
        },
        "segments": [
          {
            "id": 0,
            "start": 0.5,
            "end": 4.8,
            "text": "Hello, this is Alice from customer service. " +
                    "How can I help you today?",
            "confidence": 0.95,
            "speaker": 0,
            "words": [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14]
          },
          {
            "id": 1,
            "start": 5.2,
            "end": 9.1,
            "text": "Hi Alice, I'm having trouble with my account. " +
                    "Can you help me reset my password?",
            "confidence": 0.88,
            "speaker": 1,
            "words": [16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29,
                      30, 31]
          }
        ],
        "words": [
          {
            "id": 0,
            "start": 0.5,
            "end": 0.8,
            "text": "Hello",
            "confidence": 0.98,
            "speaker": 0,



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            "is_punctuation": false
          },
          {
            "id": 1,
            "start": 0.9,
            "end": 1.1,
            "text": ",",
            "confidence": 0.95,
            "speaker": 0,
            "is_punctuation": true
          }
          // Additional words...
        ],
        "speakers": {
          "0": {
            "id": 0,
            "label": "Alice (Customer Service)",
            "segments": [0],
            "total_time": 4.3,
            "confidence": 0.95
          },
          "1": {
            "id": 1,
            "label": "Bob (Customer)",
            "segments": [1],
            "total_time": 3.9,
            "confidence": 0.88
          }
        },
        "metadata": {
          "created_at": "2025-01-02T12:15:30Z",
          "processed_at": "2025-01-02T12:16:35Z",
          "provider": "deepgram",
          "model": "nova-2",
          "processing_time": 12.5,
          "audio": {
            "duration": 65.2,
            "sample_rate": 8000,
            "channels": 1,
            "format": "wav",
            "bitrate": 128
          },
          "options": {
            "punctuate": true,
            "diarize": true,
            "language": "en"
          }
        },



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        "quality": {
          "audio_quality": "high",
          "background_noise": 0.1,
          "multiple_speakers": true,
          "overlapping_speech": false,
          "silence_ratio": 0.15,
          "average_confidence": 0.92,
          "low_confidence_words": 0,
          "processing_warnings": []
        },
        "extensions": {
          "deepgram": {
            "utterances": [
              {
                "start": 0.5,
                "end": 4.8,
                "confidence": 0.95,
                "channel": 0,
                "transcript": "Hello, this is Alice from customer service. " +
                              "How can I help you today?"
              }
            ]
          }
        }
      }
    }
  ]
}

11.2.  Multi-Provider Transcription Comparison

   {
     "attachments": [
       {
         "type": "wtf_transcription",
         "dialog": 0,
         "encoding": "json",
         "body": {
           "transcript": {
             "text": "The quick brown fox jumps over the lazy dog.",
             "language": "en-US",
             "duration": 3.5,
             "confidence": 0.96
           },
           "segments": [
             {
               "id": 0,
               "start": 0.0,



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               "end": 3.5,
               "text": "The quick brown fox jumps over the lazy dog.",
               "confidence": 0.96,
               "speaker": 0
             }
           ],
           "metadata": {
             "created_at": "2025-01-02T12:00:00Z",
             "processed_at": "2025-01-02T12:00:15Z",
             "provider": "whisper",
             "model": "whisper-large-v3",
             "processing_time": 15.2
           },
           "extensions": {
             "whisper": {
               "temperature": 0.0,
               "compression_ratio": 2.1,
               "avg_logprob": -0.25,
               "no_speech_prob": 0.01
             }
           }
         }
       },
       {
         "type": "wtf_transcription",
         "dialog": 0,
         "encoding": "json",
         "body": {
           "transcript": {
             "text": "The quick brown fox jumps over the lazy dog.",
             "language": "en-US",
             "duration": 3.5,
             "confidence": 0.94
           },
           "segments": [
             {
               "id": 0,
               "start": 0.0,
               "end": 3.5,
               "text": "The quick brown fox jumps over the lazy dog.",
               "confidence": 0.94,
               "speaker": 0
             }
           ],
           "metadata": {
             "created_at": "2025-01-02T12:00:00Z",
             "processed_at": "2025-01-02T12:00:08Z",
             "provider": "deepgram",



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             "model": "nova-2",
             "processing_time": 8.1
           },
           "extensions": {
             "deepgram": {
               "model_info": {
                 "name": "nova-2",
                 "version": "2024-01-09",
                 "uuid": "4d892fb6-7cc1-4e7a-a1b3-1c2e3f4a5b6c"
               }
             }
           }
         }
       }
     ]
   }

12.  References

12.1.  Normative References

   [I-D.draft-ietf-vcon-core-00]
              Petrie, D., "Virtualized Conversation (vCon) Container",
              Work in Progress, Internet-Draft, draft-ietf-vcon-core-00,
              March 2025, <I-D.draft-ietf-vcon-core-00>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/rfc/rfc2119>.

   [RFC3339]  Klyne, G., "Date and Time on the Internet: Timestamps",
              July 2002, <https://www.rfc-editor.org/rfc/rfc3339.html>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.

   [RFC8949]  Bormann, C., "Concise Binary Object Representation
              (CBOR)", December 2020,
              <https://www.rfc-editor.org/rfc/rfc8949.html>.

12.2.  Informative References

   [BCP47]    Phillips, A., "Tags for Identifying Languages", September
              2009, <https://www.rfc-editor.org/rfc/rfc5646.html>.





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   [I-D.draft-ietf-vcon-overview]
              McCarthy-Howe, T., "The vCon - Conversation Data Container
              - Overview", Work in Progress, Internet-Draft, draft-ietf-
              vcon-overview-00, July 2025, <I-D.draft-ietf-vcon-
              overview-00>.

   [WHISPER]  Radford, A., Kim, J. W., Xu, T., Brockman, G., McLeavey,
              C., and I. Sutskever, "Whisper: Robust Speech Recognition
              via Large-Scale Weak Supervision", September 2022,
              <https://openai.com/research/whisper>.

Acknowledgements

   *  Appreciation to the transcription provider community for their
      input on standardization requirements.

   *  Thanks to the vCon working group for their feedback and guidance
      on extension design patterns.

Trademark Notice

   All trademarks mentioned in this document are the property of their
   respective owners.  The use of these trademarks does not imply
   endorsement by the IETF or the authors of this document.  The
   following trademarks are referenced:

   *  Whisper(TM) is a trademark of OpenAI, Inc.

   *  Deepgram(TM) is a trademark of Deepgram, Inc.

   *  AssemblyAI(TM) is a trademark of AssemblyAI, Inc.

   *  Google Cloud Speech-to-Text(TM) is a trademark of Google LLC.

   *  Amazon Transcribe(TM) is a trademark of Amazon.com, Inc.

   *  Azure Speech Services(TM) is a trademark of Microsoft Corporation.

   *  Rev.ai(TM) is a trademark of Rev.com, Inc.

   *  Speechmatics(TM) is a trademark of Speechmatics Limited.

   *  Wav2Vec2(TM) is a trademark of Meta Platforms, Inc.

   *  Parakeet(TM) is a trademark of NVIDIA Corporation.

Author's Address




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   Thomas McCarthy-Howe
   VCONIC
   Email: ghostofbasho@gmail.com
















































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