Function Introduction

Video-on-demand websites or applications typically provide the ability to drag videos, allowing users to freely navigate through the video player's progress bar. With CDN acceleration, you can configure video dragging functionality to support users' video dragging requests.

When a user drags a video on a VOD website, a request is sent to the server in the format like: http://www.example.com/a.mp4?start=5. If the CDN node has enabled video dragging functionality, it will return the audio and video data files from the nearest keyframe after the 5th second to the end of the video file.

Applicable Scenarios

Video-on-demand websites requiring support for flv or mp4 video dragging functionality.

Additional Considerations

Source videos must contain meta information and keyframes; otherwise, the video dragging functionality is ineffective, and the original file is returned.
If the starting parameter in the video dragging request is out of bounds, for example, if the start parameter corresponds to a byte position beyond the file size, a default 4xx status code is returned.
If the ending parameter in the video dragging request is out of bounds, mp4 time dragging and flv time dragging default to returning content from the starting parameter to the end of the file, while flv byte dragging defaults to returning 416.
Support for mp4 files with the moov header at the end for video dragging.
Before enabling video dragging, ensure that the source station supports range requests and can return a 206 status code and the corresponding range of files.

Instructions for Use

This functionality is not currently available for self-service configuration by customers. If you need to use it, please contact our customer support team via hotline (852)31000000 or email global.noc@chinatelecomglobal.com for manual operation.

Please provide the following information:

Video File Format	Dragging Parameters	URL Example
mp4	1. Support for time dragging; please specify the specific starting and ending parameters; the default starting and ending parameters are start and end, respectively, in seconds. 2. Please specify whether dragging searches for the nearest keyframe forward or backward by default; for example, start=5 defaults to returning the audio and video content closest to the keyframe after the 5th second.	http://www.example.com/a.mp4?start=5 indicates returning audio and video content starting from the 5th second of the a.mp4 file.
flv	1. Support for byte or time dragging; please specify whether it is by byte or by time dragging. 2. Please specify the starting and ending parameters, where the starting parameter is mandatory; the default byte dragging starting and ending parameters are begin and stop, respectively, with the range being left-closed and right-open (adjustable to left-closed and right-closed as needed, please specify if adjustment is required); the default time dragging starting and ending parameters are start and end, respectively, with the range being left-closed and right-closed. 3. When time dragging, if the user request carries both time dragging parameters and a range request header, support for ignoring the range header or taking a relative range within the time dragging range is available, meaning first obtaining a new file based on the time dragging parameters (including meta header and dragging interval), and then taking the range on the new file; the default is to ignore the range header, please specify if a relative range within the time dragging range is required. 4. In addition to returning the corresponding audio and video for flv dragging requests, the flv media header is also returned by default; if you need to return the flv header + script tag (metadata) + the first video tag + the first audio tag, please specify selecting the meta header as the flv media header; if you need to return the flv header + the first video tag + the first audio tag, please specify selecting the media header as the flv media header.	1. Request URL: http://www.example.com/a.flv?start=5&end=15, if it is time dragging, it returns the flv media header plus the content from the 5th second to the 15th second of the a.flv file. 2. Request URL: http://www.example.com/a.flv?begin=100&stop=1000, if it is byte dragging, it returns the flv media header plus the content from the 100th byte to the 999th byte of the a.flv file.

Content Delivery Network

Video dragging