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Supported Features

Browsers

Any browser that supports MSE (media source extensions). See https://caniuse.com/#feat=mediasource

Note that browsers with native HLS support may play content with the native player, unless the overrideNative option is used. Some notable browsers with native HLS players are:

  • Safari (macOS and iOS)
  • Chrome Android
  • Firefox Android

However, due to the limited features offered by some of the native players, the only browser on which VHS defaults to using the native player is Safari (macOS and iOS).

Streaming Formats and Media Types

Streaming Formats

VHS aims to be mostly streaming format agnostic. So long as the manifest can be parsed to a common JSON representation, VHS should be able to play it. However, due to some large differences between the major streaming formats (HLS and DASH), some format specific code is included in VHS. If you have another format you would like supported, please reach out to us (e.g., file an issue).

  • HLS (HTTP Live Streaming)
  • MPEG-DASH (Dynamic Adaptive Streaming over HTTP)

Media Container Formats

  • TS (MPEG Transport Stream)
  • MP4 (MPEG-4 Part 14: MP4, M4A, M4V, M4S, MPA), ISOBMFF
  • AAC (Advanced Audio Coding)

Codecs

If the content is packaged in an MP4 container, then any codec supported by the browser is supported. If the content is packaged in a TS container, then the codec must be supported by the transmuxer. The following codecs are supported by the transmuxer:

  • AVC (Advanced Video Coding, h.264)
  • AVC1 (Advnced Video Coding, h.265)
  • HE-AAC (High Efficiency Advanced Audio Coding, mp4a.40.5)
  • LC-AAC (Low Complexity Advanced Audio Coding, mp4a.40.2)

General Notable Features

The following is a list of some, but not all, common streaming features supported by VHS. It is meant to highlight some common use cases (and provide for easy searching), but is not meant serve as an exhaustive list.

  • VOD (video on demand)
  • LIVE
  • Multiple audio tracks
  • Timed ID3 Metadata is automatically translated into HTML5 metedata text tracks
  • Cross-domain credentials support with CORS
  • Any browser supported resolution (e.g., 4k)
  • Any browser supported framerate (e.g., 60fps)
  • DRM via videojs-contrib-eme
  • Audio only (non DASH)
  • Video only (non DASH)
  • In-manifest WebVTT subtitles are automatically translated into standard HTML5 subtitle tracks
  • AES-128 segment encryption

Notable Missing Features

Note that the following features have not yet been implemented or may work but are not currently suppported in browsers that do not rely on the native player. For browsers that use the native player (e.g., Safari for HLS), please refer to their documentation.

Container Formats

Codecs

If the content is packaged within an MP4 container and the browser supports the codec, it will play. However, the following are some codecs that are not routinely tested, or are not supported when packaged within TS.

HLS Missing Features

Note: features for low latency HLS in the 2nd edition of HTTP Live Streaming are on the roadmap, but not currently available.

VHS strives to support all of the features in the HLS specification, however, some have not yet been implemented. VHS currently supports everything in the HLS specification v7, revision 23, except the following:

In the event of encoding changes within a playlist (see https://tools.ietf.org/html/draft-pantos-http-live-streaming-23#section-6.3.3), the behavior will depend on the browser.

DASH Missing Features

DASH support is more recent than HLS support in VHS, however, VHS strives to achieve as complete compatibility as possible with the DASH spec. The following are some notable features in the DASH specification that are not yet implemented in VHS:

Note that many of the following are parsed by mpd-parser but are either not yet used, or simply take on their default values (in the case where they have valid defaults).

  • Audio and video only streams
  • Audio rendition switching
    • Each video rendition is paired with an audio rendition for the duration of playback.
  • MPD
    • @id
    • @profiles
    • @availabilityStartTime
    • @availabilityEndTime
    • @minBufferTime
    • @maxSegmentDuration
    • @maxSubsegmentDuration
    • ProgramInformation
    • Metrics
  • Period
    • @xlink:href
    • @xlink:actuate
    • @id
    • @duration
      • Normally used for determing the PeriodStart of the next period, VHS instead relies on segment durations to determine timing of each segment and timeline
    • @bitstreamSwitching
    • Subset
  • AdaptationSet
    • @xlink:href
    • @xlink:actuate
    • @id
    • @group
    • @par (picture aspect ratio)
    • @minBandwidth
    • @maxBandwidth
    • @minWidth
    • @maxWidth
    • @minHeight
    • @maxHeight
    • @minFrameRate
    • @maxFrameRate
    • @segmentAlignment
    • @bitstreamSwitching
    • @subsegmentAlignment
    • @subsegmentStartsWithSAP
    • Accessibility
    • Rating
    • Viewpoint
    • ContentComponent
  • Representation
    • @id (used for SegmentTemplate but not exposed otherwise)
    • @qualityRanking
    • @dependencyId (dependent representation)
    • @mediaStreamStructureId
    • SubRepresentation
  • CommonAttributesElements (for AdaptationSet, Representation and SubRepresentation elements)
    • @profiles
    • @sar
    • @frameRate
    • @audioSamplingRate
    • @segmentProfiles
    • @maximumSAPPeriod
    • @startWithSAP
    • @maxPlayoutRate
    • @codingDependency
    • @scanType
    • FramePacking
    • AudioChannelConfiguration
  • SegmentBase
    • @presentationTimeOffset
    • @indexRangeExact
    • RepresentationIndex
  • MultipleSegmentBaseInformation elements
  • SegmentList
    • @xlink:href
    • @xlink:actuate
    • MultipleSegmentBaseInformation
    • SegmentURL
      • @index
      • @indexRange
  • SegmentTemplate
    • MultipleSegmentBaseInformation
    • @index
    • @bitstreamSwitching
  • BaseURL
    • @serviceLocation
  • Template-based Segment URL construction
  • ContentComponent elements
    • Right now manifests are assumed to have a single content component, with the properties described directly on the AdaptationSet element
  • SubRepresentation elements
  • Subset elements
  • Early Available Periods (may work, but has not been tested)
  • Access to subsegments via a subsegment index ('ssix')
  • The @profiles attribute is ignored (best support for all profiles is attempted, without consideration of the specific profile). For descriptions on profiles, see section 8 of the DASH spec.
  • Construction of byte range URLs via a BaseURL byteRange template (Annex E.2)
  • Multiperiod content where the representation sets are not the same across periods
  • In the event that an S element has a t attribute that is greater than what is expected, it is not treated as a discontinuity, but instead retains its segment value, and may result in a gap in the content