Topics for discussion at the CTA Fall Forum Workshop 2023

[ablasgen]

WAVE is holding a workshop on Monday, October 2 from 9 am-12 pm PT to cover some of the decision points which require a deeper discussion than the regular TF/group meetings.

Use this issue tracker to contribute discussion items. These will be collated by the TWG Chair before the meeting and converted in to a presentation deck to drive the agenda for the day.

For each item, please suggest a title, and provide some background text as well as the decision to make or call-to-action. Also state which TF or group you feel the work falls under.

[jpiesing]

I would like to discuss a proposal for the priorities for whatever CTA funding is available for 2024 DPCTF testing. In descending priority order ..

1. Maintenance of existing test cases, test runner, test content, test streams and OF
2. Usability improvements for the above.
3. Landing what exists today or what will exist before the end of 2023 but is not included in the first release (audio, HEVC SD, some HEVC HD and perhaps even HEVC HDR)
4. Integration and testing of WAVE DPCTF compatible test content contributed by media profile proponents e.g. Fraunhofer creating the HTML+JS+media combinations, running it on devices, reporting bugs, iterating
5. Commercial DRM
6. Any additional MSE/HTML dependencies for JavaScript subtitle/caption renderers. I hear second-hand information that JavaScript subtitle/caption renderers may have further dependencies on the browser than just 'currentTime' which is all we test today. If these can be identified then we should consider testing them. For example, I have seen mentions that the web browser support for WebVTT captions may be used but only for timing and not for rendering. We don't have any tests for this because it's previously been out of scope.

[jpiesing]

I volunteer @louaybassbouss to present the DPCTF test suite release plan presented in the testing meeting on September 26th.

[jpiesing]

Can we discuss the approach to take on thresholds in the DPCTF test suite (and sometimes in the spec).

• The maximum permitted startup delay is set to 120ms in the spec with a note that "NOTE: This constraint is defined as a first approach, but may be refined after running some initial tests.". Initial feedback from Fraunhofer testing 10 TV sets shows that somewhere between 600ms and 1s would cover most TVs most of the time but something like 1.7/1.8s would be needed for all devices to pass all tests. https://github.com/cta-wave/dpctf-tests/issues/116
• We currently have a 20ms tolerance on the duration of a piece of CMAF content. Given the potential inaccuracies introduced during the measurement process, this is very demanding. See https://github.com/cta-wave/dpctf-tests/issues/118.

[krasimirkolarov]

Can we discuss the refreshed Internet Streaming Video Technologies Survey and plan to finalize it at the meeting.

[krasimirkolarov]

It will be good to discuss how to promote the WAVE Streaming Technologies report (CMAF-IF related activity).

[JohnRiv]

Topic: Media application development

As @wilaw captured in the IBC-Adjacent WAVE Meeting topics, the following proposal came out of the HTML5 vs native streaming survey discussion at W3C TPAC's MEIG meeting:

1. Develop a performance based test suite for HTML5 media development on TVs (based on the Streaming Media Test Suite)
2. Develop a program to create and maintain definitions of acceptable performance thresholds under this test suite.
3. Work with W3C to add new APIs that are needed (such as a standard way to launch web URLs and web apps)
4. Create a group of content distributors who commit to only offering their content if this performance threshold is met on a TV.
5. Grow this group until it presents the majority of brands distributing TV content, at which point TV manufacturers can enforce that it is the only app environment they will support and they can cease supporting custom app environments.

This topic was discussed at both the IBC-Adjacent WAVE Meeting and the September 27th HATF meeting, with next steps coming out of both of those meetings (see meeting notes for both for details).

For discussion at Fall Forum, would like to

1. See if there are any updates from the IBC-Adjacent WAVE Meeting next steps
2. Discuss softening part 5 from the above proposal (this was suggested at the most recent HATF Meeting)
3. Determine which content providers and testing providers would potentially be interested in this
4. Discuss if this open action item is still relevant: "The HATF will develop a mapping of the APIs used in the DPCTF device testing to HTML5 methods as a potential step towards a portable test infrastructure."

If it's easier, some/all of those 4 items can be broken up into separate discussion topics.

[jpiesing]

3 CSTF topics originally from DPCTF have got lost in the wider discussion and may be useful to discuss.

• Is non-square pixel content relevant to test (see https://standards.cta.tech/apps/org/workgroup/cstf/message.php/202307/msg00005.html )?
• How is portrait content originated from cellphones handled? Is it distributed as-is in portrait format? Is this relevant to test?
• What spatial resolutions are useful to test for HEVC? For AVC, we test a lot of spatial resolutions - perhaps too many. For HEVC it is suggested to reduce the spatial resolutions tested to 2. Is this going too far in the other direction?