In the SDk framework, there are two coordinate systems: Meishe SDK coordinate system and view coordinate system. Meishe SDK coordinate system is the timeline coordinate system, which is the coordinate system used to create the timeline in the SDK and add assets. When editing a video, timeline coordinate system is used to set the corresponding coordinates which add the captions, stickers, video effects and Transform 2D,etc. The effect of "Transform 2D" can scale, rotate and translation in the coordinate system. Before recording or editing a video, users need to set image's width and height in certain aspect ratio. The origin of the timeline coordinate is located at the center of the rectangle frame which constructed by the preset width and height. The positive direction of X-axis is right and the positive direction of Y-axis is up. Take a video of 1280 * 720 resolution as an example, which is shown below:

The view coordinate system is the coordinate system used by the control of live window to play the video. When playing and previewing a video, users can set the fill mode of the Live Window. And if users need to convert the corresponding timeline coordinates into view coordinates. Specific API are available for the convertion. For more details, please refer to: NvsLiveWindow The origin of view coordinate system is located in the upper left corner of the live window, with the X axis right and the Y axis down. The view coordinate system is shown as below: