Android使用Opengl錄像時(shí)添加水印
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)間水印(動(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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