Class: HLS::Manifest::Variant

Inherits:
Object
  • Object
show all
Defined in:
lib/hls/manifest.rb

Overview

A single rendition variant — its ordered list of segments and the ability to slice a duration window for previews.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(manifest:, variant_path:, items:) ⇒ Variant

Returns a new instance of Variant.



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# File 'lib/hls/manifest.rb', line 151

def initialize(manifest:, variant_path:, items:)
  @manifest = manifest
  @variant_path = variant_path
  @items = items
end

Instance Attribute Details

#items ⇒ Object (readonly)

Returns the value of attribute items.



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# File 'lib/hls/manifest.rb', line 149

def items
  @items
end

#manifest ⇒ Object (readonly)

Returns the value of attribute manifest.



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# File 'lib/hls/manifest.rb', line 149

def manifest
  @manifest
end

#variant_path ⇒ Object (readonly)

Returns the value of attribute variant_path.



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# File 'lib/hls/manifest.rb', line 149

def variant_path
  @variant_path
end

Instance Method Details

#[](range) ⇒ Object

Slice a duration window. The range is in seconds. Inclusive ranges round down, exclusive ranges round up. Useful for preview windows (e.g. ‘variant` for a 30-second teaser).

Raises:

  • (ArgumentError) 


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# File 'lib/hls/manifest.rb', line 167

def [](range)
  raise ArgumentError, "Only Range objects are supported" unless range.is_a?(Range)

  segment_count =
    if range.exclude_end?
      (range.end.to_f / manifest.segment_duration).ceil
    else
      (range.end.to_f / manifest.segment_duration).floor
    end

  Variant.new(manifest: manifest, variant_path: variant_path, items: items.take(segment_count))
end

#duration ⇒ Object

Duration in seconds. Approximate — uses segment_duration as a uniform per-segment value, which matches how ffmpeg writes VOD bundles. The last segment may be slightly shorter.



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# File 'lib/hls/manifest.rb', line 160

def duration
  items.count * manifest.segment_duration
end

#playlist ⇒ Object

The variant playlist with each segment rewritten to a pre-signed URL. Returns a fresh M3u8::Playlist; does not mutate ‘items`.



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# File 'lib/hls/manifest.rb', line 182

def playlist
  list = M3u8::Playlist.new
  list.items = items.map do |item|
    signed = item.clone
    signed.segment = manifest.presigned_url(variant_path, item.segment)
    signed
  end
  list
end