As of version 66 of Google Chrome onwards it will no longer automatically start playback of audio and video files when the playback volume is not muted.
This change was made to prevent autoplay on ad videos and other annoying web page elements. However, this has negative consequences for a number of perfectly valid applications of the autoplay feature, for instance in signage applications.
The new default behaviour of not auto playing a video with sound can be overridden at the startup of the Google Chrome browser with the command line options
--autoplay-policy=no-user-gesture-required
or
--no-user-gesture-required
The new default autoplay behaviour is also present in the Chrome browser on ChromeOS (currently in the beta channel). For Kiosk-apps running on ChromeOS there are no command line options, only configuration using the Manifest.json file.
Currently there is no option in the documentation of the Manifest.json format that allows changing the autoplay policy.
Is there any way to change the new Chrome default autoplay policy in Kiosk apps to allow autoplay of videos in an app on ChromeOS?
It turns out that the end user will have to enable automatic video playback manually, by:
- upon startup pressing Ctrl+Alt+S
- logging in
- opening a Chrome browser and typing:
chrome://flags/#autoplay-policy - changing the "Autoplay policy" from "Default" to "No user gesture is required"
- pressing "relaunch"
- rebooting the device
From now on autoplay works again in webview components used in your app.
See this comment thread about this topic by Google.
来源：https://stackoverflow.com/questions/49921453/how-to-allow-video-autoplay-in-a-google-chrome-kiosk-app-in-version-66-or-later