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Android使用Opengl錄像時(shí)添加水印

更新時(shí)間：2020年04月05日 09:33:16 作者：feng海濤

這篇文章主要為大家詳細(xì)介紹了Android使用Opengl錄像時(shí)添加水印，文中示例代碼介紹的非常詳細(xì)，具有一定的參考價(jià)值，感興趣的小伙伴們可以參考一下

最近需要開發(fā)一個(gè)類似行車記錄儀的app，其中需要給錄制的視頻添加動(dòng)態(tài)水印。我使用的是OpenGL開發(fā)的，剛開始實(shí)現(xiàn)的是靜態(tài)水印，后面才實(shí)現(xiàn)的動(dòng)態(tài)水印。

先上效果圖，左下角的是靜態(tài)水印，中間偏下的是時(shí)間水?。▌?dòng)態(tài)水?。?/p>

一、靜態(tài)水印

實(shí)現(xiàn)原理：錄像時(shí)是通過OpenGL把圖像渲染到GLSurfaceView上的，通俗的講，就是把圖片畫到一塊畫布上，然后展示出來。添加圖片水印，就是把水印圖片跟錄制的圖像一起畫到畫布上。

這是加載紋理跟陰影的Java類

package com.audiovideo.camera.blog;


import android.opengl.GLES20;


/**
 * Created by fenghaitao on 2019/9/12.
 */

public class WaterSignSProgram{

  private static int programId;
  private static final String VERTEX_SHADER =
          "uniform mat4 uMVPMatrix;\n" +
          "attribute vec4 aPosition;\n" +
          "attribute vec4 aTextureCoord;\n" +
          "varying vec2 vTextureCoord;\n" +
          "void main() {\n" +
          "  gl_Position = uMVPMatrix * aPosition;\n" +
          "  vTextureCoord = aTextureCoord.xy;\n" +
          "}\n";

  private static final String FRAGMENT_SHADER =
          "precision mediump float;\n" +
          "varying vec2 vTextureCoord;\n" +
          "uniform sampler2D sTexture;\n" +
          "void main() {\n" +
          "  gl_FragColor = texture2D(sTexture, vTextureCoord);\n" +
          "}\n";

  public WaterSignSProgram() {
    programId = loadShader(VERTEX_SHADER, FRAGMENT_SHADER);

    uMVPMatrixLoc = GLES20.glGetUniformLocation(programId, "uMVPMatrix");
    checkLocation(uMVPMatrixLoc, "uMVPMatrix");
    aPositionLoc = GLES20.glGetAttribLocation(programId, "aPosition");
    checkLocation(aPositionLoc, "aPosition");
    aTextureCoordLoc = GLES20.glGetAttribLocation(programId, "aTextureCoord");
    checkLocation(aTextureCoordLoc, "aTextureCoord");
    sTextureLoc = GLES20.glGetUniformLocation(programId, "sTexture");
    checkLocation(sTextureLoc, "sTexture");
  }

  public int uMVPMatrixLoc;
  public int aPositionLoc;
  public int aTextureCoordLoc;
  public int sTextureLoc;

  public static void checkLocation(int location, String label) {
    if (location < 0) {
      throw new RuntimeException("Unable to locate '" + label + "' in program");
    }
  }

/**
 * 加載編譯連接陰影
 * @param vss source of vertex shader
 * @param fss source of fragment shader
 * @return
 */
public static int loadShader(final String vss, final String fss) {
  Log.v(TAG, "loadShader:");
  int vs = GLES20.glCreateShader(GLES20.GL_VERTEX_SHADER);
  GLES20.glShaderSource(vs, vss);
  GLES20.glCompileShader(vs);
  final int[] compiled = new int[1];
  GLES20.glGetShaderiv(vs, GLES20.GL_COMPILE_STATUS, compiled, 0);
  if (compiled[0] == 0) {
   Log.e(TAG, "Failed to compile vertex shader:"
      + GLES20.glGetShaderInfoLog(vs));
   GLES20.glDeleteShader(vs);
   vs = 0;
  }

  int fs = GLES20.glCreateShader(GLES20.GL_FRAGMENT_SHADER);
  GLES20.glShaderSource(fs, fss);
  GLES20.glCompileShader(fs);
  GLES20.glGetShaderiv(fs, GLES20.GL_COMPILE_STATUS, compiled, 0);
  if (compiled[0] == 0) {
   Log.w(TAG, "Failed to compile fragment shader:"
     + GLES20.glGetShaderInfoLog(fs));
   GLES20.glDeleteShader(fs);
   fs = 0;
  }

  final int program = GLES20.glCreateProgram();
  GLES20.glAttachShader(program, vs);
  GLES20.glAttachShader(program, fs);
  GLES20.glLinkProgram(program);

  return program;
}

  /**
   * terminatinng, this should be called in GL context
   */
  public static void release() {
    if (programId >= 0)
      GLES20.glDeleteProgram(programId);
    programId = -1;
  }
}

package com.audiovideo.camera.blog;

import android.opengl.GLES20;
import android.opengl.Matrix;

import com.audiovideo.camera.glutils.GLDrawer2D;
import com.audiovideo.camera.utils.LogUtil;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;


這是畫水印的Java類
/**
 * Created by fenghaitao on 2019/9/12.
 */

public class WaterSignature {

  private static final String VERTEX_SHADER =
      "uniform mat4 uMVPMatrix;\n" +
          "attribute vec4 aPosition;\n" +
          "attribute vec4 aTextureCoord;\n" +
          "varying vec2 vTextureCoord;\n" +
          "void main() {\n" +
          "  gl_Position = uMVPMatrix * aPosition;\n" +
          "  vTextureCoord = aTextureCoord.xy;\n" +
          "}\n";

  private static final String FRAGMENT_SHADER =
      "precision mediump float;\n" +
          "varying vec2 vTextureCoord;\n" +
          "uniform sampler2D sTexture;\n" +
          "void main() {\n" +
          "  gl_FragColor = texture2D(sTexture, vTextureCoord);\n" +
          "}\n";

  public static final int SIZE_OF_FLOAT = 4;
  /**
   * 一個(gè)“完整”的正方形，從兩維延伸到-1到1。
   * 當(dāng) 模型/視圖/投影矩陣是都為單位矩陣的時(shí)候，這將完全覆蓋視口。
   * 紋理坐標(biāo)相對(duì)于矩形是y反的。
   * (This seems to work out right with external textures from SurfaceTexture.)
   */
  private static final float FULL_RECTANGLE_COORDS[] = {
      -1.0f, -1.0f,  // 0 bottom left
      1.0f, -1.0f,  // 1 bottom right
      -1.0f, 1.0f,  // 2 top left
      1.0f, 1.0f,  // 3 top right
  };
  private static final float FULL_RECTANGLE_TEX_COORDS[] = {
      0.0f, 1.0f,   //0 bottom left   //0.0f, 0.0f, // 0 bottom left
      1.0f, 1.0f,   //1 bottom right  //1.0f, 0.0f, // 1 bottom right
      0.0f, 0.0f,   //2 top left    //0.0f, 1.0f, // 2 top left
      1.0f, 0.0f,   //3 top right    //1.0f, 1.0f, // 3 top right
  };

  private FloatBuffer mVertexArray;
  private FloatBuffer mTexCoordArray;
  private int mCoordsPerVertex;
  private int mCoordsPerTexture;
  private int mVertexCount;
  private int mVertexStride;
  private int mTexCoordStride;
  private int hProgram;

  public float[] mProjectionMatrix = new float[16];// 投影矩陣
  public float[] mViewMatrix = new float[16]; // 攝像機(jī)位置朝向9參數(shù)矩陣
  public float[] mModelMatrix = new float[16];// 模型變換矩陣
  public float[] mMVPMatrix = new float[16];// 獲取具體物體的總變換矩陣
  private float[] getFinalMatrix() {
    Matrix.multiplyMM(mMVPMatrix, 0, mViewMatrix, 0, mModelMatrix, 0);
    Matrix.multiplyMM(mMVPMatrix, 0, mProjectionMatrix, 0, mMVPMatrix, 0);
    return mMVPMatrix;
  }

  public WaterSignature() {
    mVertexArray = createFloatBuffer(FULL_RECTANGLE_COORDS);
    mTexCoordArray = createFloatBuffer(FULL_RECTANGLE_TEX_COORDS);
    mCoordsPerVertex = 2;
    mCoordsPerTexture = 2;
    mVertexCount = FULL_RECTANGLE_COORDS.length / mCoordsPerVertex; // 4
    mTexCoordStride = 2 * SIZE_OF_FLOAT;
    mVertexStride = 2 * SIZE_OF_FLOAT;

    Matrix.setIdentityM(mProjectionMatrix, 0);
    Matrix.setIdentityM(mViewMatrix, 0);
    Matrix.setIdentityM(mModelMatrix, 0);
    Matrix.setIdentityM(mMVPMatrix, 0);
    hProgram = GLDrawer2D.loadShader(VERTEX_SHADER, FRAGMENT_SHADER);
    GLES20.glUseProgram(hProgram);
  }

  private FloatBuffer createFloatBuffer(float[] coords) {
    ByteBuffer bb = ByteBuffer.allocateDirect(coords.length * SIZE_OF_FLOAT);
    bb.order(ByteOrder.nativeOrder());
    FloatBuffer fb = bb.asFloatBuffer();
    fb.put(coords);
    fb.position(0);
    return fb;
  }

  private WaterSignSProgram mProgram;

  public void setShaderProgram(WaterSignSProgram mProgram) {
    this.mProgram = mProgram;
  }

  public void drawFrame(int mTextureId) {
    GLES20.glUseProgram(hProgram);
    // 設(shè)置紋理
    GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
    GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mTextureId);
    GLES20.glUniform1i(mProgram.sTextureLoc, 0);
    GlUtil.checkGlError("GL_TEXTURE_2D sTexture");
    // 設(shè)置 model / view / projection 矩陣
    GLES20.glUniformMatrix4fv(mProgram.uMVPMatrixLoc, 1, false, getFinalMatrix(), 0);
    GlUtil.checkGlError("glUniformMatrix4fv uMVPMatrixLoc");
    // 使用簡(jiǎn)單的VAO 設(shè)置頂點(diǎn)坐標(biāo)數(shù)據(jù)
    GLES20.glEnableVertexAttribArray(mProgram.aPositionLoc);
    GLES20.glVertexAttribPointer(mProgram.aPositionLoc, mCoordsPerVertex,
        GLES20.GL_FLOAT, false, mVertexStride, mVertexArray);
    GlUtil.checkGlError("VAO aPositionLoc");
    // 使用簡(jiǎn)單的VAO 設(shè)置紋理坐標(biāo)數(shù)據(jù)
    GLES20.glEnableVertexAttribArray(mProgram.aTextureCoordLoc);
    GLES20.glVertexAttribPointer(mProgram.aTextureCoordLoc, mCoordsPerTexture,
        GLES20.GL_FLOAT, false, mTexCoordStride, mTexCoordArray);
    GlUtil.checkGlError("VAO aTextureCoordLoc");
    // GL_TRIANGLE_STRIP三角形帶，這就為啥只需要指出4個(gè)坐標(biāo)點(diǎn)，就能畫出兩個(gè)三角形了。
    GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, mVertexCount);
    // Done -- 解綁~
    GLES20.glDisableVertexAttribArray(mProgram.aPositionLoc);
    GLES20.glDisableVertexAttribArray(mProgram.aTextureCoordLoc);
    GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, 0);
    GLES20.glUseProgram(0);
  }

  /**
   * terminatinng, this should be called in GL context
   */
  public void release() {
    if (hProgram >= 0)
      GLES20.glDeleteProgram(hProgram);
    hProgram = -1;
  }

  /**
   * 刪除texture
   */
  public static void deleteTex(final int hTex) {
    LogUtil.v("WaterSignature", "deleteTex:");
    final int[] tex = new int[] {hTex};
    GLES20.glDeleteTextures(1, tex, 0);
  }

}

沒時(shí)間了。先寫到這，后面是調(diào)用，遲點(diǎn)再寫。

下面是如何把水印繪制到畫布上：

1、在SurfaceTexture的onSurfaceCreated方法中初始化并設(shè)置陰影；

@Override
   public void onSurfaceCreated(final GL10 unused, final EGLConfig config) {
     LogUtil.v(TAG, "onSurfaceCreated:");
     // This renderer required OES_EGL_image_external extension
     final String extensions = GLES20.glGetString(GLES20.GL_EXTENSIONS);  // API >= 8
   // 使用黃色清除界面
     GLES20.glClearColor(1.0f, 1.0f, 0.0f, 1.0f);
     //設(shè)置水印
      if (mWaterSign == null) {
        mWaterSign = new WaterSignature();
      }
      //設(shè)置陰影
     mWaterSign.setShaderProgram(new WaterSignSProgram());
    mSignTexId = loadTexture(MyApplication.getContext(), R.mipmap.watermark);
   }

這里是生成mSignTexId 的方法，把該圖像與紋理id綁定并返回：

public static int loadTexture(Context context, int resourceId) {
  final int[] textureObjectIds = new int[1];
  GLES20.glGenTextures(1, textureObjectIds, 0);
  if(textureObjectIds[0] == 0){
    Log.e(TAG,"Could not generate a new OpenGL texture object!");
    return 0;
  }
  final BitmapFactory.Options options = new BitmapFactory.Options();
  options.inScaled = false;  //指定需要的是原始數(shù)據(jù)，非壓縮數(shù)據(jù)
  final Bitmap bitmap = BitmapFactory.decodeResource(context.getResources(), resourceId, options);
  if(bitmap == null){
    Log.e(TAG, "Resource ID "+resourceId + "could not be decode");
    GLES20.glDeleteTextures(1, textureObjectIds, 0);
    return 0;
  }
  //告訴OpenGL后面紋理調(diào)用應(yīng)該是應(yīng)用于哪個(gè)紋理對(duì)象
  GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureObjectIds[0]);
  //設(shè)置縮小的時(shí)候（GL_TEXTURE_MIN_FILTER）使用mipmap三線程過濾
  GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_LINEAR_MIPMAP_LINEAR);
  //設(shè)置放大的時(shí)候（GL_TEXTURE_MAG_FILTER）使用雙線程過濾
  GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR);
  //Android設(shè)備y坐標(biāo)是反向的，正常圖顯示到設(shè)備上是水平顛倒的，解決方案就是設(shè)置紋理包裝，紋理T坐標(biāo)（y）設(shè)置鏡面重復(fù)
  //ball讀取紋理的時(shí)候 t范圍坐標(biāo)取正常值+1
  //GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_T, GLES20.GL_MIRRORED_REPEAT);
  GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, bitmap, 0);
  bitmap.recycle();
  //快速生成mipmap貼圖
  GLES20.glGenerateMipmap(GLES20.GL_TEXTURE_2D);
  //解除紋理操作的綁定
  GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, 0);
  return textureObjectIds[0];
}

2、在繪制方法onDrawFrame中繪制畫面的同時(shí)把水印繪制進(jìn)去；

/**
    * 繪圖到glsurface
    * 我們將rendermode設(shè)置為glsurfaceview.rendermode_when_dirty，
    * 僅當(dāng)調(diào)用requestrender時(shí)調(diào)用此方法（=需要更新紋理時(shí)）
    * 如果不在臟時(shí)設(shè)置rendermode，則此方法的最大調(diào)用速度為60fps。
    */
   @Override
   public void onDrawFrame(final GL10 unused) {
     GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
     GLES20.glEnable(GLES20.GL_BLEND);
     //開啟GL的混合模式，即圖像疊加
     GLES20.glBlendFunc(GLES20.GL_ONE, GLES20.GL_ONE_MINUS_SRC_ALPHA)；
     /**
     *中間這里是你繪制的預(yù)覽畫面
     */
   //畫水印（非動(dòng)態(tài)）
    GLES20.glViewport(20, 20, 288, 120);
   mWaterSign.drawFrame(mSignTexId);
    }

這里最重要的是要開啟GL的混合模式，即圖像疊加，不然你繪制的水印會(huì)覆蓋原先的預(yù)覽畫面

//開啟GL的混合模式，即圖像疊加
GLES20.glBlendFunc(GLES20.GL_ONE, GLES20.GL_ONE_MINUS_SRC_ALPHA)；

以上就是本文的全部?jī)?nèi)容，希望對(duì)大家的學(xué)習(xí)有所幫助，也希望大家多多支持腳本之家。

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Android使用Opengl錄像時(shí)添加水印

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