海康IPC接入TRTC时，从海康中获取的数据显示时色差不正确

2021/1

记录海康IPC接入TRTC时的历史日志

从海康sdk接口获取数据，进行解码

java 复制代码

org.MediaPlayer.PlayM4.Player.T_YV12;
    private void setDecodeCB() {
        Player.getInstance().setDecodeCB(m_iPort, (nPort, data, nDataLen, nWidth, nHeight, nFrameTime, nDataType, arg7) -> {
                if (nDataType == T_YV12 ) {
                    byte[] i420bytes = swapYV12toI420(data, nWidth, nHeight);
                    callback.afterCall(context, i420bytes.length, i420bytes, nWidth, nHeight, nFrameTime);
                }
        });
    }

解码后如下展示的时候，出现图片偏差

java 复制代码

    byte[] nv12bytes = RSNV12ToBitmap.getInstance(context).swapI420toNV12(data, nWidth, nHeight);//额外转换 3ms
    Bitmap buffBitmap = RSNV12ToBitmap.getInstance(context).nv12ToBitmap(nv12bytes, nWidth, nHeight);//20毫秒

可能是android.renderscript.ScriptIntrinsicYuvToRGB接受的YUV是nv21而不是nv12

java 复制代码

    byte[] nv21bytes = RSNV12ToBitmap.getInstance(context).swapI420toNV21(data, nWidth, nHeight);//额外转换 3ms
    Bitmap buffBitmap = RSNV12ToBitmap.getInstance(context).nv21ToBitmap(nv21bytes, nWidth, nHeight);//20毫秒

图像格式转换函数

java 复制代码

package com.sunshine.mhs.pension.doctormodule.trct.ipc.util;

/**
 * 作者：Administrator on 2020/3/26
 * 邮箱：[email protected]
 */

import android.content.Context;
import android.graphics.Bitmap;
import android.renderscript.Allocation;
import android.renderscript.Element;
import android.renderscript.RenderScript;
import android.renderscript.ScriptIntrinsicYuvToRGB;
import android.renderscript.Type;

public class RSNV21ToBitmap {
    private static RSNV21ToBitmap instance;
    private RenderScript rs;
    private ScriptIntrinsicYuvToRGB yuvToRgbIntrinsic;
    private byte[] nv21bytes;

    private RSNV21ToBitmap(Context context) {
        nv21bytes = null;
        rs = RenderScript.create(context);
        yuvToRgbIntrinsic = ScriptIntrinsicYuvToRGB.create(rs, Element.U8_4(rs));
    }
    public static RSNV21ToBitmap getInstance(Context context) {
        if (instance == null) {
            instance = new RSNV21ToBitmap( context);
        }
        return instance;
    }
    public static void destory() {
         if (instance != null) {
            instance.yuvToRgbIntrinsic.destroy();
            instance.rs.destroy();
            instance = null;
        }
    }

    public Bitmap nv21ToBitmap(byte[] nv21, int width, int height) {
        if (nv21 == null) return null;

        Type.Builder yuvType, rgbaType;
        Allocation in, out;
        yuvType = new Type.Builder(rs, Element.U8(rs)).setX(nv21.length);
        in = Allocation.createTyped(rs, yuvType.create(), Allocation.USAGE_SCRIPT);
        rgbaType = new Type.Builder(rs, Element.RGBA_8888(rs)).setX(width).setY(height);
        out = Allocation.createTyped(rs, rgbaType.create(), Allocation.USAGE_SCRIPT);

        Bitmap bmpout = null;
        try {
            in.copyFrom(nv21);
            yuvToRgbIntrinsic.setInput(in);
            yuvToRgbIntrinsic.forEach(out);
            bmpout = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
            out.copyTo(bmpout);

        } catch (Exception e) {
            e.printStackTrace();
        }
        return bmpout;
    }

    public byte[] swapI420toNV21(byte[] I420bytes, int width, int height) {
        if (null == nv21bytes) {
            nv21bytes = new byte[I420bytes.length];
        }
        if (I420bytes.length != nv21bytes.length)
            return null;
        int nLenY = width * height;
        int nLenU = nLenY / 4;
        System.arraycopy(I420bytes, 0, nv21bytes, 0, nLenY);
        for (int i = 0; i < nLenU; i++) {
            nv21bytes[nLenY + 2 * i + 1] = I420bytes[nLenY + i];//先v后U
            nv21bytes[nLenY + 2 * i] = I420bytes[nLenY + nLenU + i];
        }
        return nv21bytes;
    }

}