Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;

import android.graphics.ImageFormat;

import android.util.Log;

public class Main {
    public static byte[] swapColors(byte[] data, int w, int h, int pictureFormat) {
        switch (pictureFormat) {
        case ImageFormat.YV12:
            return swapYUV420Planar(data);
        case ImageFormat.NV21:
            return swapYUV420SemiPlanar(data, w, h);
        default:
            Log.w("Util", "No color format to swap");
        }
        return data;
    }

    /**
     * Performs in place Cb and Cr swapping for a YUV 4:2:0 Planar frame <br>
     * The frame could be formatted as :
     * <ul>
     * <li>YUV420p, that is [Y1Y2Y3Y4....][U1U2...][V1V2...]</li> or
     * <li>YV12, that is [Y1Y2Y3Y4....][V1V2...][U1U2...]</li>
     * </ul>
     * Whatever will be the input format, the function converts it in the other format
     * @param frame the YUV420p frame
     * @return
     */
    public static byte[] swapYUV420Planar(byte[] frame) {
        int p = frame.length * 2 / 3; //<-- this is equals to width*height
        int idx = p;
        int Clen = p / 4; //<-- that is, (width/2*height/2)
        for (int i = 0; i < Clen; i++) {
            int uIdx = idx + i;
            int vIdx = idx + i + Clen;
            byte U = frame[uIdx];
            byte V = frame[vIdx];
            byte tmp = U;
            frame[uIdx] = V;
            frame[vIdx] = tmp;
        }
        return frame;
    }

    /**
     * Performs in place Cb and Cr swapping for a YUV 4:2:0 SemiPlanar frame <br>
     * The frame could be formatted as :
     * <ul>
     * <li>NV12, that is [Y1Y2Y3Y4....][U1V1U2V2...]</li> or
     * <li>NV21, that is [Y1Y2Y3Y4....][V1U1V2U2...]</li>
     * </ul>
     * Whatever will be the input format, the function converts it in the other format
     * @param frame the YUV420sp frame
     * @return
     */
    public static byte[] swapYUV420SemiPlanar(byte[] frame, int width, int height) {
        int p = frame.length * 2 / 3; //<-- this is equals to width*height
        int idx = p;
        int Clen = p / 2; //<-- that is, (width*height/2)
        for (int i = 0; i < Clen; i += 2) {
            int uIdx = idx + i;
            int vIdx = idx + i + 1;
            byte U = frame[uIdx];
            byte V = frame[vIdx];
            byte tmp = U;
            frame[uIdx] = V;
            frame[vIdx] = tmp;
        }
        return frame;
    }
}