两张yuv图片进行竖屏、横屏拼接

本文是针对NV21格式图片进行横/竖屏拼图

NV21：YVU排列，vu交错排列，vu高度是y的一半，y占得字节数是width*height,剩下的字节数都是vu
为了更形象的展示，以4*4图片为例子：

image.png

竖屏拼图后是

image.png

横屏拼图后是

image.png

竖屏拼图

首先进行全部Y分量的交错填充，然后全部VU分量交错填充

横屏拼图

先是Y分量一行一行拼接，然后再vu一行一行拼接

具体代码如下：

private int width=640;
private int height=480;
private byte[] dataIr_y=new byte[width*height];
private byte[] dataRgb_y=new byte[width*height];
private byte[] dataIr_vu=new byte[width*height/2];
private byte[] dataRgb_vu=new byte[width*height/2];
private byte[] mergeData=new byte[width*height*3];
//竖屏拼接
private byte[] concat(byte[] data1, byte[] data2) {
        System.arraycopy(data1, 0, dataIr_y, 0, dataIr_y.length);
        System.arraycopy(data2, 0, dataRgb_y, 0, dataRgb_y.length);
        System.arraycopy(data1,dataIr_y.length,dataIr_vu,0,dataIr_vu.length);
        System.arraycopy(data2,dataRgb_y.length,dataRgb_vu,0,dataRgb_vu.length);
        //y拼接
        System.arraycopy(dataIr_y, 0, mergeData, 0, dataIr_y.length);
        System.arraycopy(dataRgb_y,0, mergeData, dataRgb_y.length, dataRgb_y.length);

        //vu拼接
        System.arraycopy(dataIr_vu, 0, mergeData, dataIr_y.length+dataRgb_y.length, dataIr_vu.length);
        System.arraycopy(dataRgb_vu, 0, mergeData, dataIr_y.length+data1.length, dataRgb_vu.length);
        return mergeData;
    }

//横屏拼图代码
private byte[] concat(byte[] data1, byte[] data2) {
    System.arraycopy(data1, 0, dataIr_y, 0, dataIr_y.length);
    System.arraycopy(data2, 0, dataRgb_y, 0, dataRgb_y.length);
    System.arraycopy(data1, dataIr_y.length, dataIr_vu, 0, data1.length - dataIr_y.length);
    System.arraycopy(data2, dataRgb_y.length, dataRgb_vu, 0, data2.length - dataRgb_y.length);
    //y分量一行一行拼接
    int y = 0;
    for (int i = 0; i < height; i++) {
        System.arraycopy(dataIr_y, width * i, mergeData, width * y, width);
        y++;
        System.arraycopy(dataRgb_y, width * i, mergeData, width * y, width);
        y++;
    }
    //vu分量一行一行拼接
    int z = 0;
    for (int i = 0; i < height / 2; i++) {
        System.arraycopy(dataIr_vu, width * i, mergeData, width * height * 2 + z * width, width);
        z++;
        System.arraycopy(dataRgb_vu, width * i, mergeData, width * height * 2 + z * width, width);
        z++;
    }
    return mergeData;
}