This topic describes the terms that are related to ApsaraVideo Player for web.


  • playAuth: the unique credential for video playback. A playback credential is associated with a specific user and cannot be shared among different users. Otherwise, video playback may fail. By default, a playback credential is valid for 100 seconds. For more information about how to obtain a playback credential, see GetVideoPlayAuth.
  • Resource Access Management (RAM) and Security Token Service (STS): the permission management systems of Alibaba Cloud. RAM is used to control account permissions. RAM enables you to create RAM users within the permissions of your Alibaba Cloud account. Different RAM users can be granted different permissions. STS is a security token management system that grants temporary access permissions. You can use STS to grant access permissions to temporary accounts. For more information, see Create a role and grant temporary access permissions to the role by using STS.
  • On-demand AccessKey ID, AccessKey secret, and security token: obtained by using STS API operations or SDKs after RAM authorization is enabled. They are used for video playback. For more information, see STS SDK Reference.
  • Hotlink protection: The referer in the request header is checked to determine whether a request is originated from an allowed site and whether the video can be played. You can set the referer in the ApsaraVideo VOD or Alibaba Cloud CDN console. For more information, see Hotlink protection.
  • Time-shifting live streaming: Time-shifting live streaming is based on the regular HTTP Live Streaming (HLS) technology. A live stream is divided into TS segments and the TS segments are distributed to users by using the HLS protocol. The .m3u8 playlist that is requested by users contains TS segment URLs that are constantly updated. For regular HLS streaming, TS segment URLs and corresponding TS files are not persistently stored. This causes a failure to trace the previous video content of the live streaming. For HLS streaming of which the time shifting feature is enabled, TS segment URLs and corresponding TS files are persistently stored in a database and an Object Storage Service (OSS) bucket for up to 15 days. This enables users to trace the video content from the start time of the live streaming to the current time. For more information, see Time-shifting live streaming.
  • Immersive mode: On an Android phone, a browser, such as WeChat, displays a video in full-screen mode. The browser hijacks the video and uses the default player to play the video. In this case, the DOM element is overwritten. No effective solution is provided to resolve this issue. However, browsers with the X5 kernel, such as QQ Browser and WeChat, provide some attributes to enable the immersive mode. This way, video playback is not hijacked and the DOM element is not overwritten. The immersive mode applies only to browsers with the X5 kernel in Android. An X5-kernel browser displays a pop-up playback screen in overwrite mode, with the Exit and Share buttons in the upper part and a black edge in the lower part. The layout is slightly different from the original screen. To tune the layout, you must subscribe to the x5requestFullScreen and x5cancelFullScreen events. For more information, see Immersive mode.