Java tutorial
//package com.java2s; import java.nio.ByteBuffer; public class Main { public static byte[] addHeader(byte[] data) { byte[] h264 = new byte[data.length + 4]; for (int i = 0; i < data.length; i++) { h264[i + 4] = data[i]; } byte[] lens = ByteBuffer.allocate(4).putInt(data.length).array(); h264[0] = lens[0]; h264[1] = lens[1]; h264[2] = lens[2]; h264[3] = lens[3]; return h264; } }