glam/schemas/20251121/linkml/modules/classes/VideoSubtitle.yaml
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refactor(schema): centralize 1515 inline slot definitions per Rule 48
- Remove inline slot definitions from 144 class files
- Create 7 new centralized slot files in modules/slots/:
  - custodian_type_broader.yaml
  - custodian_type_narrower.yaml
  - custodian_type_related.yaml
  - definition.yaml
  - finding_aid_access_restriction.yaml
  - finding_aid_description.yaml
  - finding_aid_temporal_coverage.yaml
- Add centralize_inline_slots.py automation script
- Update manifest with new timestamp

Rule 48: Class files must NOT define inline slots - all slots
must be imported from modules/slots/ directory.

Note: Pre-existing IdentifierFormat duplicate class definition
(in Standard.yaml and IdentifierFormat.yaml) not addressed in
this commit - requires separate schema refactor.
2026-01-11 22:02:14 +01:00

730 lines
17 KiB
YAML

id: https://nde.nl/ontology/hc/class/VideoSubtitle
name: video_subtitle_class
title: Video Subtitle Class
imports:
- linkml:types
- ./VideoTranscript
- ./VideoTimeSegment
- ../slots/has_average_entry_duration_seconds
- ../slots/default_position
- ../slots/entry_count
- ../slots/includes_music_description
- ../slots/includes_sound_description
- ../slots/includes_speaker_identification
- ../slots/is_auto_generated
- ../slots/is_closed_caption
- ../slots/is_sdh
- ../slots/raw_subtitle_content
- ../slots/specificity_annotation
- ../slots/subtitle_format
- ../slots/template_specificity
- ../slots/track_id
- ../slots/track_name
- ./SpecificityAnnotation
- ./TemplateSpecificityScores
prefixes:
linkml: https://w3id.org/linkml/
hc: https://nde.nl/ontology/hc/
schema: http://schema.org/
dcterms: http://purl.org/dc/terms/
prov: http://www.w3.org/ns/prov#
crm: http://www.cidoc-crm.org/cidoc-crm/
skos: http://www.w3.org/2004/02/skos/core#
ma: http://www.w3.org/ns/ma-ont#
default_prefix: hc
classes:
VideoSubtitle:
is_a: VideoTranscript
class_uri: hc:VideoSubtitle
abstract: false
description: 'Time-coded caption/subtitle content for video.
**DEFINITION**:
VideoSubtitle represents caption/subtitle tracks that provide time-coded
text synchronized with video playback. It extends VideoTranscript because
subtitles contain complete transcription PLUS temporal synchronization.
**INHERITANCE FROM VideoTranscript**:
VideoSubtitle inherits all transcript capabilities:
- `full_text`: Complete subtitle text concatenated
- `segments`: Time-coded entries (REQUIRED for subtitles)
- `includes_timestamps`: Always true for subtitles
- `content_language`: Language of subtitle text
- All provenance from VideoTextContent
And adds subtitle-specific properties:
- `subtitle_format`: SRT, VTT, TTML, SBV, ASS
- `is_closed_caption`: CC vs regular subtitles
- `is_sdh`: Subtitles for Deaf/Hard-of-Hearing
- `includes_sound_descriptions`: Non-speech audio descriptions
**SCHEMA.ORG ALIGNMENT**:
Maps to `schema:caption` property:
> "For downloadable machine formats (closed caption, subtitles etc.)
> use the MediaObject.encodingFormat property."
**SUBTITLE vs CAPTION vs TRANSCRIPT**:
| Type | Time-coded | Purpose | Audience |
|------|------------|---------|----------|
| Transcript | Optional | Reading, search | Everyone |
| Subtitle | Required | Language translation | Hearing viewers |
| Caption (CC) | Required | Accessibility | Deaf/HoH viewers |
| SDH | Required | Full accessibility | Deaf viewers, noisy environments |
**SDH (Subtitles for Deaf/Hard-of-Hearing)**:
SDH differs from regular subtitles by including:
- Speaker identification: "(John) Hello"
- Sound effects: "[door slams]", "[music playing]"
- Music descriptions: "♪ upbeat jazz ♪"
- Emotional cues: "[laughing]", "[whispering]"
**SUBTITLE FORMATS**:
| Format | Extension | Features | Use Case |
|--------|-----------|----------|----------|
| SRT | .srt | Simple, universal | Most video players |
| VTT | .vtt | W3C standard, styling | HTML5 video, web |
| TTML | .ttml/.dfxp | XML, rich styling | Broadcast, streaming |
| SBV | .sbv | YouTube native | YouTube uploads |
| ASS | .ass | Advanced styling | Anime, complex layouts |
**SRT FORMAT EXAMPLE**:
```
1
00:00:00,000 --> 00:00:03,500
Welcome to the Rijksmuseum.
2
00:00:03,500 --> 00:00:08,200
Today we''ll explore the Night Watch gallery.
```
**VTT FORMAT EXAMPLE**:
```
WEBVTT
00:00:00.000 --> 00:00:03.500
Welcome to the Rijksmuseum.
00:00:03.500 --> 00:00:08.200
Today we''ll explore the Night Watch gallery.
```
**HERITAGE INSTITUTION CONTEXT**:
Subtitles are critical for heritage video accessibility:
1. **Accessibility Compliance**: WCAG 2.1, Section 508
2. **Multilingual Access**: Translate for international audiences
3. **Silent Viewing**: Social media, public displays, quiet spaces
4. **Search Discovery**: Subtitle text is indexed by platforms
5. **Preservation**: Text outlasts video format obsolescence
**YOUTUBE API INTEGRATION**:
Subtitle tracks from YouTube API populate:
- `subtitle_format`: Typically VTT or SRT
- `generation_method`: PLATFORM_PROVIDED or ASR_AUTOMATIC
- `content_language`: From track language code
- `is_auto_generated`: YouTube auto-caption flag
**SEGMENTS ARE REQUIRED**:
Unlike VideoTranscript where segments are optional, VideoSubtitle
REQUIRES the `segments` slot to be populated with VideoTimeSegment
entries that include start_seconds, end_seconds, and segment_text.
'
exact_mappings:
- schema:caption
close_mappings:
- ma:CaptioningFormat
related_mappings:
- schema:transcript
slots:
- has_average_entry_duration_seconds
- default_position
- entry_count
- includes_music_description
- includes_sound_description
- includes_speaker_identification
- is_auto_generated
- is_closed_caption
- is_sdh
- raw_subtitle_content
- specificity_annotation
- subtitle_format
- template_specificity
- track_id
- track_name
slot_usage:
has_or_had_segment:
required: true
description: 'Time-coded subtitle entries as VideoTimeSegment objects.
**REQUIRED for VideoSubtitle** (optional in parent VideoTranscript).
Each segment represents one caption display unit:
- start_seconds: When caption appears
- end_seconds: When caption disappears
- segment_text: Caption text content
- segment_index: Order in subtitle track
- confidence: For auto-generated captions
Segments are ordered by start_seconds for proper playback.
'
includes_timestamp:
ifabsent: 'true'
description: 'Whether subtitle includes time markers.
**Always true for VideoSubtitle** - time-coding is definitional.
'
subtitle_format:
slot_uri: dcterms:format
description: 'Subtitle file format.
Dublin Core: format for resource format.
Specifies the encoding format of the subtitle content.
Affects parsing and rendering capabilities.
'
range: SubtitleFormatEnum
required: true
examples:
- value: VTT
description: WebVTT format (W3C standard)
- value: SRT
description: SubRip format (most common)
raw_subtitle_content:
slot_uri: hc:rawSubtitleContent
description: 'Original subtitle file content as raw string.
Preserves the complete subtitle file in its native format.
Useful for:
- Format conversion
- Re-parsing with different tools
- Archive preservation
May be large - consider storing separately for large files.
'
range: string
required: false
examples:
- value: 'WEBVTT
00:00:00.000 --> 00:00:03.500
Welcome to the museum.
'
description: Complete VTT file content
is_closed_caption:
slot_uri: hc:isClosedCaption
description: 'Whether this is a closed caption track (CC).
Closed captions differ from subtitles:
- **CC (true)**: Designed for Deaf/HoH, includes non-speech audio
- **Subtitles (false)**: Translation of dialogue only
CC typically includes [MUSIC], [APPLAUSE], speaker ID, etc.
'
range: boolean
required: false
ifabsent: 'false'
examples:
- value: true
description: This is a closed caption track
is_sdh:
slot_uri: hc:isSDH
description: 'Whether these are Subtitles for Deaf/Hard-of-Hearing (SDH).
SDH combines subtitle translation with CC-style annotations:
- Dialogue translation (like subtitles)
- Sound descriptions (like CC)
- Speaker identification
Typically marked "[SDH]" on streaming platforms.
'
range: boolean
required: false
ifabsent: 'false'
examples:
- value: true
description: SDH subtitle track
includes_sound_description:
slot_uri: hc:includesSoundDescriptions
description: 'Whether subtitle includes non-speech sound descriptions.
Examples of sound descriptions:
- [door slams]
- [phone ringing]
- [thunder]
- [footsteps approaching]
Characteristic of CC and SDH tracks.
'
range: boolean
required: false
ifabsent: 'false'
examples:
- value: true
description: Contains sound effect descriptions
includes_music_description:
slot_uri: hc:includesMusicDescriptions
description: 'Whether subtitle includes music/song descriptions.
Examples:
- ♪ upbeat jazz playing ♪
- [classical music]
- ♪ singing in Dutch ♪
- [somber orchestral music]
Important for heritage content with significant musical elements.
'
range: boolean
required: false
ifabsent: 'false'
examples:
- value: true
description: Contains music descriptions
includes_speaker_identification:
slot_uri: hc:includesSpeakerIdentification
description: 'Whether subtitle identifies speakers.
Speaker identification patterns:
- (John): Hello there.
- NARRATOR: Welcome to the museum.
- [Curator] This painting dates from 1642.
Different from transcript speaker_id which is per-segment;
this indicates whether the TEXT CONTENT includes labels.
'
range: boolean
required: false
ifabsent: 'false'
examples:
- value: true
description: Subtitle text includes speaker labels
is_auto_generated:
slot_uri: hc:isAutoGenerated
description: 'Whether subtitle was auto-generated by the platform.
Distinct from generation_method (inherited from VideoTextContent):
- `is_auto_generated`: Platform flag (YouTube, Vimeo)
- `generation_method`: How WE know it was generated
Auto-generated captions typically have lower accuracy.
'
range: boolean
required: false
ifabsent: 'false'
examples:
- value: true
description: YouTube auto-generated caption
track_name:
slot_uri: schema:name
description: 'Human-readable name of the subtitle track.
Schema.org: name for track label.
Examples from YouTube:
- "English"
- "English (auto-generated)"
- "Dutch - Nederlands"
- "English (United Kingdom)"
'
range: string
required: false
examples:
- value: English (auto-generated)
description: YouTube auto-caption track name
track_id:
slot_uri: dcterms:identifier
description: 'Platform-specific identifier for this subtitle track.
Dublin Core: identifier for unique ID.
Used to fetch/update specific tracks via API.
'
range: string
required: false
examples:
- value: en.3OWxR1w4QfE
description: YouTube caption track ID
default_position:
slot_uri: hc:defaultPosition
description: "Default display position for captions.\n\nFor formats that support positioning (VTT, TTML, ASS):\n-\
\ BOTTOM: Default, below video content\n- TOP: Above video content \n- MIDDLE: Center of video\n\nMay be overridden\
\ per-segment in advanced formats.\n"
range: SubtitlePositionEnum
required: false
ifabsent: string(BOTTOM)
examples:
- value: BOTTOM
description: Standard bottom caption position
entry_count:
slot_uri: hc:entryCount
description: 'Number of subtitle entries (caption cues).
Equals length of segments array.
Useful for content sizing without loading full segments.
'
range: integer
required: false
minimum_value: 0
examples:
- value: 127
description: 127 caption cues in this track
has_average_entry_duration_seconds:
slot_uri: hc:averageEntryDuration
description: 'Average duration of subtitle entries in seconds.
Typical ranges:
- 2-4 seconds: Normal speech rate
- < 2 seconds: Rapid dialogue
- > 5 seconds: Slow narration or long displays
Useful for quality assessment - very short or long entries
may indicate timing issues.
'
range: float
required: false
minimum_value: 0.0
examples:
- value: 3.2
description: Average 3.2 seconds per caption
specificity_annotation:
range: SpecificityAnnotation
inlined: true
template_specificity:
range: TemplateSpecificityScores
inlined: true
rules:
- postconditions:
description: 'segments must be populated for VideoSubtitle.
This is enforced by making segments required in slot_usage.
'
comments:
- Time-coded caption/subtitle content
- Extends VideoTranscript - subtitles ARE transcripts plus time codes
- 'Supports multiple formats: SRT, VTT, TTML, SBV, ASS'
- 'Accessibility metadata: CC, SDH, sound/music descriptions'
- Critical for heritage video accessibility compliance
see_also:
- https://schema.org/caption
- https://www.w3.org/TR/webvtt1/
- https://developer.mozilla.org/en-US/docs/Web/API/WebVTT_API
- https://www.3playmedia.com/learn/popular-topics/closed-captioning/
enums:
SubtitleFormatEnum:
description: 'Subtitle/caption file formats.
Each format has different capabilities for timing precision,
styling, positioning, and metadata.
'
permissible_values:
SRT:
description: 'SubRip subtitle format (.srt).
Most widely supported format.
Simple: sequence number, timecode, text.
No styling or positioning support.
'
VTT:
description: 'WebVTT format (.vtt).
W3C standard for HTML5 video.
Supports styling (CSS), positioning, cue settings.
Recommended for web delivery.
'
TTML:
description: 'Timed Text Markup Language (.ttml/.dfxp/.xml).
W3C XML-based standard.
Rich styling, regions, timing.
Used in broadcast and streaming (Netflix, Amazon).
'
SBV:
description: 'YouTube SubViewer format (.sbv).
Simple format similar to SRT.
Native YouTube caption format.
'
ASS:
description: 'Advanced SubStation Alpha (.ass).
Advanced styling, positioning, effects.
Popular for anime subtitles.
Includes SSA (.ssa) as predecessor.
'
STL:
description: 'EBU STL format (.stl).
European Broadcasting Union standard.
Used in broadcast television.
Binary format with teletext compatibility.
'
CAP:
description: 'Scenarist Closed Caption (.scc/.cap).
Used for broadcast closed captioning.
CEA-608/CEA-708 compliant.
'
SAMI:
description: 'Synchronized Accessible Media Interchange (.smi/.sami).
Microsoft format for Windows Media.
HTML-like markup with timing.
'
LRC:
description: 'LRC lyrics format (.lrc).
Simple format for song lyrics.
Line-by-line timing, no duration.
'
JSON:
description: 'JSON-based subtitle format.
Used by some APIs (YouTube transcript API).
Structure varies by source.
'
UNKNOWN:
description: 'Unknown or unrecognized format.
May require manual parsing or conversion.
'
SubtitlePositionEnum:
description: 'Default caption display position on video.
May be overridden by format-specific positioning (VTT, TTML, ASS).
'
permissible_values:
BOTTOM:
description: 'Bottom of video frame (standard position).
Most common for subtitles and captions.
Typically in lower 10-15% of frame.
'
TOP:
description: 'Top of video frame.
Used when bottom is occluded.
Common for some broadcast formats.
'
MIDDLE:
description: 'Center of video frame.
Rarely used except for specific effects.
'
LEFT:
description: 'Left side of frame (vertical text).
Rare, used for specific languages/effects.
'
RIGHT:
description: 'Right side of frame (vertical text).
Rare, used for specific languages/effects.
'