Multi-View Signaling

[technogeek00]

Use Case Description

Content providers desiring to serve content with multi-view encoded bitstreams need to appropriately package these bitstreams and signal them within the manifest response.

Working Notes

• Primarily raised around Multi-View HEVC
• HLS signaling details
  • REQ-VIDEO-LAYOUT attribute with value CH-STEREO signals stereo availability in the bitstream
  • Intermix of stereoscopic and monoscopic requires both CH-MONO and CH-STEREO in REQ-VIDEO-LAYOUT
• Apple device constraints (Stereo Video 16 and Additional stereo video specifications), notables
  • vexu atom/box requirements
  • Parallax metadata for captioning
  • Multi-channel audio suggestion
  • Stereo video is only carried in MV-HEVC
  • Further Apple Stereo Video Profile guidelines
• DASH Signaling details
  • DASH bindings defined in 23009-1 5.8.5.6
  • Prior deployment work from 3GPP on both frame-packed stereoscopic (7.3.5) and multiview stereoscopic (7.3.4) in 3GPP TS 26.247
  • Role descriptor utilized to signify eye alignment, needs further investigation

Open Questions

• Should this be generic multi-view or specifically stereoscopic constrained?

Scoring

To be filled out post CMAF work completion

Question	Answer
Does the feature relate to an industry streaming use-case?	Yes/No
- What is the commonality of this case?	Uncommon/Common/Very Common
- Is this an established or emerging practice?	Declining/Established/Emerging
Does this feature have related mechanisms in both DASH and HLS?	Yes/No
- What is the maturity of support in both specifications?	HLS - Immature/Mature, DASH - Immature/Mature
- What is the maturity of implementation support for both specifications?	HLS - Immature/Mature, DASH - Immature/Mature
- Are there known interoperability issues between specs?	Yes/No/Potentially
- Has anyone implemented this interoperably?	Yes/No/Potentially
- Are there features missing in a specification with open proposals for it?	HSL - Yes/No, DASH - Yes/No
Has the industry defined defacto mechanisms not present in both DASH and/or HLS?	Unknown/Spec Invalid/Industry Desire
- Why was functionality defined outside of the main specifications?	??
- Has the functionality been standardized elsewhere (DASH-IF, CTA, SVA)?	Yes/No
- Is the functionality proprietary or openly developed?	Proprietary/Open
- Could the functionality be incorporated into specifications with evangelism?	Yes/No

[technogeek00]

2024/08/14

• CMAF working on binding profile for MV-HEVC based on HLS enablements that have been done
• DASH signaling binding would come after this
• Interop group will wait on more formal CMAF work completion before evaluating here
• If there is feedback on structure or expectations we can provide those to MPEG