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Media captions support for accessibility

See original GitHub issue

Description

Reference: https://captionmax.com/common-subtitle-prerecorded-closed-caption-file-types/

Accessibility bug: 28383785

Open Issues

iOS Sidecar support?
Android sidecar support?
WPF sidecar support?
UWP sidecar support?
JS sidecar support?
What about per-language captions?

Requirements

If a video is encoded with closed captions they should be automatically supported on each platform (if the media mimeType is supported)
If the video file does not have captions, one or more “sidecar” caption formats can be provided, which will be passed along to the Renderer/Native Platform Media player as appropriate.

Schema

Media

One new property on Media

Property	Type	Required	Description
captions	`CaptionSource[]`	No	Array of “sidecar” close caption sources that will be passed to the underlying platform.

CaptionSource

New type called CaptionSource

Property	Type	Required	Description
mimeType	`string`	Yes	Mime type of associated closed captions (e.g. “scc”).
url	`uri`	Yes	URL to closed captions file.
label	`label`	Yes	Label to display for this caption track.

Examples

{
	"$schema": "http://adaptivecards.io/schemas/adaptive-card.json",
	"type": "AdaptiveCard",
	"version": "1.1",
	"fallbackText": "This card requires Media to be viewed. Ask your platform to update to Adaptive Cards v1.1 for this and more!",
	"body": [
		{
			"type": "Media",
			"poster": "https://adaptivecards.io/content/poster-video.png",
			"altText": "Adaptive Cards overview video",
			"sources": [
				{
					"mimeType": "video/mp4",
					"url": "https://adaptivecardsblob.blob.core.windows.net/assets/AdaptiveCardsOverviewVideo.mp4"
				}
			],
			"captionSources": [
				{
					"mimeType": "vtt",
					"label": "English (vtt)",
					"url": "https://gist.githubusercontent.com/PankajBhojwani/d11855a1e0c0b1f70a0e64f81a1fb696/raw/46fa93da5c3703d03843d59cedd8b5f10aa3747b/test.vtt"
				}
			]
		}
	],
	"actions": [
		{
			"type": "Action.OpenUrl",
			"title": "Learn more",
			"url": "https://adaptivecards.io"
		}
	]
}

Issue Analytics

State:
Created 3 years ago
Comments:5 (4 by maintainers)

Top GitHub Comments

1reaction

PankajBhojwanicommented, Apr 5, 2022

Updated the schema here to include label and also updated the example json

0reactions

beervoleycommented, Apr 5, 2022

@PankajBhojwani could you please edit the schema here to support language as well?😃

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