<?xml version="1.0" encoding="utf-8"?>
<PRONOM-Report xmlns="http://pronom.nationalarchives.gov.uk">
  <report_format_detail>
    <FileFormat>
      <FormatID>2277</FormatID>
      <FormatName>Web Video Text Tracks (WebVTT) Format</FormatName>
      <FormatVersion>
      </FormatVersion>
      <FormatAliases>
      </FormatAliases>
      <FormatFamilies>
      </FormatFamilies>
      <FormatTypes>Text (Structured)</FormatTypes>
      <FormatDisclosure>
      </FormatDisclosure>
      <FormatDescription>WebVTT files are used for captioning or subtitling video content. It is a standard created by the World Wide Web Consortium (W3C) for displaying timed text, and is linked to the HTML5 &lt;track&gt; element. The primary purpose of WebVTT files is to add text overlays to a video. Each time interval is specified in the format (HH:)mm:ss.xxx --&gt; (HH:)mm:ss:xxx e.g. 00:00.000 --&gt; 00:02.310 or 01:00:05.000 --&gt; 01:00:07.000. The (HH:) is optional, but if included must have a minimum of 2 digits representing the hour (more than 2 digits may be used), and where both the minute (mm) and second (ss) parts must be between 00 and 59 inclusive.</FormatDescription>
      <BinaryFileFormat>
      </BinaryFileFormat>
      <ByteOrders>
      </ByteOrders>
      <ReleaseDate>
      </ReleaseDate>
      <WithdrawnDate>
      </WithdrawnDate>
      <ProvenanceSourceID>249</ProvenanceSourceID>
      <ProvenanceName>LIBNOVA / LIBNOVA</ProvenanceName>
      <ProvenanceSourceDate>16 Nov 2020</ProvenanceSourceDate>
      <ProvenanceDescription>
      </ProvenanceDescription>
      <LastUpdatedDate>13 Mar 2023</LastUpdatedDate>
      <FormatNote>https://www.w3.org/TR/webvtt1/
https://developer.mozilla.org/en-US/docs/Web/API/WebVTT_API 
https://www.iana.org/assignments/media-types/text/vtt</FormatNote>
      <FormatRisk>
      </FormatRisk>
      <TechnicalEnvironment>
      </TechnicalEnvironment>
      <FileFormatIdentifier>
        <Identifier>fmt/1454</Identifier>
        <IdentifierType>PUID</IdentifierType>
      </FileFormatIdentifier>
      <FileFormatIdentifier>
        <Identifier>text/vtt</Identifier>
        <IdentifierType>MIME</IdentifierType>
      </FileFormatIdentifier>
      <Developers>
        <DeveloperID>200</DeveloperID>
        <DeveloperName>W3C</DeveloperName>
        <OrganisationName>W3C</OrganisationName>
        <DeveloperCompoundName>W3C / W3C</DeveloperCompoundName>
      </Developers>
      <Support>
        <SupportID>200</SupportID>
        <SupportName>W3C</SupportName>
        <OrganisationName>W3C</OrganisationName>
        <SupportCompoundName>W3C / W3C</SupportCompoundName>
      </Support>
      <ExternalSignature>
        <ExternalSignatureID>2675</ExternalSignatureID>
        <Signature>vtt</Signature>
        <SignatureType>File extension</SignatureType>
      </ExternalSignature>
      <InternalSignature>
        <SignatureID>1819</SignatureID>
        <SignatureName>Web Video Text Tracks (WebVTT)</SignatureName>
        <SignatureNote>Absolute from beginning of file, offset 0-4, magic bytes: WEBVTT {10-40}  then a time stamp in the format xx:xx.xxx followed by --&gt; {0-5} followed by xx:xx.xxx (where x is a number).</SignatureNote>
        <ByteSequence>
          <ByteSequenceID>2110</ByteSequenceID>
          <PositionType>Absolute from BOF</PositionType>
          <Offset>0</Offset>
          <MaxOffset>4</MaxOffset>
          <IndirectOffsetLocation>
          </IndirectOffsetLocation>
          <IndirectOffsetLength>
          </IndirectOffsetLength>
          <Endianness>
          </Endianness>
          <ByteSequenceValue>574542565454{5-400}[30:35][30:39]3A[30:35][30:39]2E[30:39][30:39][30:39]202D2D3E20{0-5}[30:35][30:39]3A[30:35][30:39]2E[30:39][30:39][30:39]</ByteSequenceValue>
        </ByteSequence>
      </InternalSignature>
    </FileFormat>
    <SearchCriteria>Criteria</SearchCriteria>
  </report_format_detail>
</PRONOM-Report>
