Sorry to tell you that the video length in the cloud cannot be prolonged or shorten, and the length of the video uploaded to the cloud is 8 seconds. When the cloud finishes uploading the video of the first 8 seconds, it will upload the coming 8 seconds' video into another package. After the first 8 seconds' video has been uploaded, the 9th second might be lost, then the cloud will start to upload the 9-16th second's video.
We're sorry for the inconvenience caused and we are trying our best to prolong the length of the video uploaded to the cloud. Thanks for your understanding.