HlsIFrameVariant class

Represents an HLS I-frame-only variant stream declared using #EXT-X-I-FRAME-STREAM-INF in a master playlist.

I-frame variants contain only IDR / keyframes and are primarily used for:

  • Video scrubbing / trick play
  • Thumbnail previews
  • Fast seeking without decoding full segments

These playlists are never used for normal playback.

HLS example (raw)

#EXT-X-I-FRAME-STREAM-INF:
  BANDWIDTH=86000,
  URI="iframes_1080p.m3u8",
  CODECS="avc1.640028",
  RESOLUTION=1920x1080

Parsed result

HlsIFrameVariant(
  uri: Uri.parse('iframes_1080p.m3u8'),
  bandwidth: 86000,
  codecs: 'avc1.640028',
  width: 1920,
  height: 1080,
)

Notes

  • BANDWIDTH is required by the HLS specification.
  • URI points to a media playlist containing only I-frame segments.
  • CODECS is strongly recommended and usually matches the main video codec.
  • RESOLUTION is optional but commonly present.
  • Audio, subtitles, and captions are not allowed for I-frame variants.

Relevant spec

  • RFC 8216 (HLS) – #EXT-X-I-FRAME-STREAM-INF

Common real-world quirks

  • Some packagers omit RESOLUTION entirely.
  • CODECS may include multiple codecs (comma-separated).
  • Players may ignore I-frame variants if they don’t match a video rendition.
  • #EXT-X-STREAM-INF (normal video variants)
  • #EXT-X-MEDIA (audio/subtitles)

Constructors

HlsIFrameVariant({required Uri uri, required int bandwidth, int? averageBandwidth, String? codecs, int? width, int? height, String? videoRange})
const

Properties

averageBandwidth → int?
Average segment bandwidth in bits per second.
final
bandwidth → int
Peak segment bandwidth in bits per second.
final
codecs → String?
Codec string as defined by RFC 6381.
final
hashCode → int
The hash code for this object.
no setteroverride
height → int?
Video height extracted from the RESOLUTION attribute.
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
uri → Uri
URI of the I-frame-only media playlist.
final
videoRange → String?
Video range (HDR/SDR) from VIDEO-RANGE attribute.
final
width → int?
Video width extracted from the RESOLUTION attribute.
final

Methods

copyWith({Uri? uri, int? bandwidth, int? averageBandwidth, String? codecs, int? width, int? height, String? videoRange}) → HlsIFrameVariant
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toString() → String
A string representation of this object.
override

Operators

operator ==(covariant HlsIFrameVariant other) → bool
The equality operator.
override