Why does corn video download video keep showing synthesis

So the downloaded video is in the fragment phenomenon, there will be a situation in the merger of the situation is very normal, but if you download the video in the network is weak, the downloaded video fragment in the merger of the video picture will be blurred as well as will damage the sound of the video. This is normal, but if you download a video under a weak network, the downloaded video clip will blur the video picture and damage the sound effect in the merge. On the official platform, it keeps showing that it is in the process of compositing. This is probably because the video you uploaded takes up too much memory, so it takes a certain amount of time to consolidate the videos and make them fit together smoothly to ensure the integrity of your video. So this time you just need to wait for him to upload.