YYEVA-DataConstruct.md

YYEVA-docs

Introduction

• The Json data loaded by YYEVA is compressed by zlib and then converted to base64.
• The converted data is written in the Metadata section of MP4.

Format specification

{
	"descript": {                          //Description of the video
		"width": 1808,                     //width of the video
		"height": 1008,                    //height of the video
		"isEffect": 1,                     //Whether it is a dynamic element video
		"version": 1,                      //version of plug-in
		"rgbFrame": [0, 0, 900, 1000],     //Position info of rgb
		"alphaFrame": [900, 0, 450, 500]   //Position info of alpha area
	},
	"effect": [
         {  //Mask description information for dynamic elements ： text type
		"effectWidth": 700,        //width of the dynamic element
		"effectHeight": 1049,      //height of the dynamic element
		"effectId": 1,             //index id of the dynamic element
		"effectTag": "nickName",   //tag of the dynamic element of the key for logic code using.
		"effectType": "txt",       //dynamic element type, txt and img
        "fontColor":"#ffffff",     //It only exists when it is of txt type. If it is not specified on the design side, the default value is specified by the rendering side
        "fontSize":13,             //It only exists when it is of txt type. If it is not specified on the design side, the default value is specified by the rendering side
	},{  //Mask description information for dynamic elements    ： image type
        "effectWidth": 300,  //same as above
        "effectHeight": 400,//same as above
        "effectId": 2,       //same as above
        "effectTag": "user_avatar",   //same as above
        "effectType": "img",  //same as above
        "scaleMode":"aspectFill",  //It only exists when it is of img type. If it is not specified on the design side, the default value is specified by the rendering side
    }...],
	"datas": [{                                      //potion infomation of dynamic element each frame
		"frameIndex": 0,                             //index of frame
		"data": [{       
			"renderFrame": [x1, y1, w1, h1],         //postion of canvas
			"effectId": 1,                           //id of dynamic element
			"outputFrame": [x1`, y1`, w1`, h1`]      //position of video
		}，{       
            "renderFrame": [x2, y2, w2, h2],         //same as above
            "effectId": 2,                           //same as above
            "outputFrame": [x2`, y2`, w2`, h2`]      //same as above
         } ... ]
}

Field overview

The json contains 3 layers: descript/effect/datas

1. descript: general information describing the resource
2. effect: describe all mask related information under this resource
3. datas: description The position information of the mask for each frame

Detail

descript

General information describing the resource

1. width,height: width or height of the video
2. isEffect: Whether it is a dynamic element video
3. version": version of plug-in
4. rgbFrame": Position info of rgb
5. alphaFrame": position info of alpha area

effect

Describe all mask related information under this resource. For each mask, an element will be saved in this field to describe the type-related information of the mask.

At present, masks are divided into two types: image text, which can be judged according to effectType.

1. Basic Property

   • effectWidth: width of the dynamic element
   • effectHeight: height of the dynamic element
   • effectId: index id of the dynamic element
   • effectTag: tag of the dynamic element of the key for logic code using.
   • effectType: dynamic element type, txt and img

2. Unique properties

   • text type (effectType == txt)

     fontColor: when it is text, it indicates the text color that needs to be specified when rendering on the client side. fontSize: when it is text, it means the text size that needs to be specified when rendering on the client side.

   • image type (ffectType == img) saleMode: the stretching method when the image is adapted to the display area of ​​the client. There are three types of values.

     1. scaleFill: Don't keep image aspect ratio, surfacing background area, default mode
     2. aspectFit: Maintain the aspect ratio of the image and scale the image to the smallest size that will completely cover the background positioning area
     3. aspectFill: Maintains the aspect ratio of the image and scales the image to the largest size that will fit in the background positioning area

datas

The position information of the mask for each frame

For each mask element of each frame, there will be a data segment to describe how the mask element should be displayed in this frame.

• frameIndex: index of frame
• data: all mask information of current frame
• effectId: Indicates which mask the data belongs to, and corresponds to the effectId under the effect. The corresponding mask information can be indexed under the effect.
• outputFrame: Indicates the position information of the mask in the output video area.
• renderFrame: Indicates the position of the mask on the rendering canvas.