Alibaba Cloud Content Delivery Network (CDN) provides the audio or video preview feature. This feature allows CDN nodes to return audio or video files of a specific length of time to clients. This topic describes how to configure the audio or video preview feature.

Background information

The audio or video preview feature allows a CDN node to return audio or video files of a specific length of time to clients.

This feature supports TS and MP3 files. If you want to allow users to preview FLV or MP4 files, enable the video seeking feature and set the end parameter. For more information, see Configure video seeking.


  1. Log on to the Alibaba Cloud CDN console.
  2. In the left-side navigation pane, click Domain Names.
  3. On the Domain Names page, find the domain name that you want to manage and click Manage in the Actions column of the domain name.
  4. In the management pane of the domain name, click Video.
  5. In the Audio/video Preview section, turn on Audio/video Preview.
  6. On the right side of Custom Preview Parameter, click Modify.
  7. Enter a parameter name in the Custom Preview Parameter field.

    Clients send requests that specify the length of time in seconds. For example, if Custom Preview Parameter is set to free_time and the field free_time=15 is included in a client request, Alibaba Cloud CDN returns 15 seconds of the requested file to the client.

    Note Custom Preview Parameter can be set to any value. If the specified length of time is greater than the total time of the file, the client previews the entire file. The value of the Custom Preview Parameter parameter may not be as accurate as expected. We recommend that you advise your users to specify a time period that is slightly longer than the expected one. For example, if a user wants to preview 13 seconds of an audio or video file, they can set the time period to 15 seconds in the request.
  8. Click OK.