Video Background

In prpr, you can play a video in the background, but the audio will not be played. However, since most videos have a large file size and the upload limit for prpr charts is 10MB, charts that have large BGA may not be uploaded. If you need to have a video background, it is recommended that the video background is used for small animations and compressed (including but not limited to removing audio).

Format

You need to add a videos field in the extra.json file, whose content is an array of Video.

Video

The format for a single Video is as shown below:

{
	"path": "bga.mp4",
	"time": [0, 0, 1],
	"scale": "cropCenter",
	"alpha": 1.0,
	"dim": 0.3
}

The path field is mandatory to be filled in, and it should point to the file path of the video, the other four fields are optional.

time indicates the start time of the video in terms of beat numbers.

scale indicates how the video is scaled. When making a chart, you need to consider how the chart will look at different aspect ratios. For this purpose, the scale field has 3 options available:

• cropCenter (default): Scales up the video uniformly until it fills the screen.
• inside: Scales down the video uniformly, ensures that the entire video is shown within the screen.
• fit: Forcefully stretch the video to the entire screen.

alpha 和 dim 分别代表视频的不透明度（若透明，则会显示下方的曲绘）和昏暗程度，他们都是 动画变量。