通过opengl es 2.0来实现yuv(NV21)的显示

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基本思路参考如下文章，用opengles2.0 来实现yuv（NV21）的显示。

http://blog.csdn.net/fu_shuwu/article/details/72972312

public static String  VERTEX_SHADER =

        "attribute vec4 vPosition;    \n"+

                "attribute vec2 a_texCoord;   \n"+

                "varying vec2 tc;             \n"+

                "void main()                  \n"+

                "{                            \n"+

                "   gl_Position = vPosition;  \n"+

                "   tc = a_texCoord;          \n"+

                "}                            \n";

public static String FRAG_SHADER =

        "precision mediump float;\n"+

                "varying  vec2 tc;                      \n"+

                "uniform sampler2D SamplerY;            \n"+

                "uniform sampler2D SamplerUV;            \n"+

                "const float PI = 3.14159265;           \n"+

                "const mat3 convertMat = mat3( 1.0, 1.0, 1.0, 0.0, -0.39465, 2.03211, 1.13983, -0.58060, 0.0 );\n"+

                "void main(void)                            \n"+

                "{                                          \n"+

                "vec3 yuv;                                  \n"+

                "yuv.x = texture2D(SamplerY, tc).r;         \n"+

                "yuv.z = texture2D(SamplerUV, tc).r - 0.5;   \n"+

                "yuv.y = texture2D(SamplerUV, tc).a - 0.5;   \n"+

                "vec3 color = convertMat * yuv;             \n"+

                "vec4 mainColor = vec4(color, 1.0);         \n"+

                "gl_FragColor =mainColor;                                       \n"+

                "}                                                              \n";

//设置opengl 渲染的坐标系统，从[-1，1]

public static float squareVertices[] = {  //rotate 90

        1.0f,  1.0f,//rt

        1.0f, -1.0f,//rb

        -1.0f,  1.0f,//lt

        -1.0f, -1.0f,//lb

};

//设置纹理基本坐标

public static float coordVertices[] = {

        0.0f, 0.0f,//lb

        1.0f, 0.0f,//rb

        0.0f,  1.0f,//lt

        1.0f,  1.0f,//rt

};

// 创建纹理

private void createTexture(int width, int height, int format, int[] textureId)

    //创建纹理

    GLES20.glGenTextures(1, textureId, 0);

    //绑定纹理

    GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureId[0]);

    //设置纹理属性

    GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_S, GLES20.GL_CLAMP_TO_EDGE);

    GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_T, GLES20.GL_CLAMP_TO_EDGE);

    GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_NEAREST);

    GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR);

    GLES20.glTexImage2D(GLES20.GL_TEXTURE_2D, 0, format, width, height, 0, format, GLES20.GL_UNSIGNED_BYTE, null);

//GLSurface Render 子类相关部分

private void InitShader()

    programHandleMain = util.createShaderProgram();

    if ( programHandleMain != -1 )

  //启动纹理

       GLES20.glEnable(GLES20.GL_TEXTURE_2D);

       GLES20.glActiveTexture(GLES20.GL_TEXTURE0);

       GLES20.glActiveTexture(GLES20.GL_TEXTURE1);

        // 获取VertexShader变量

        aPositionMain = getShaderHandle(programHandleMain, "vPosition");

        aTexCoordMain = getShaderHandle(programHandleMain, "a_texCoord");

        // 获取FrameShader变量

        uYTextureMain = getShaderHandle(programHandleMain, "SamplerY");

        uUVTextureMain = getShaderHandle(programHandleMain, "SamplerUV");

        // 使用滤镜着色器程序

        GLES20.glUseProgram(programHandleMain);

        //给变量赋值

        GLES20.glUniform1i(uYTextureMain, 0);

        GLES20.glUniform1i(uUVTextureMain, 1);

        GLES20.glEnableVertexAttribArray(aPositionMain);

        GLES20.glEnableVertexAttribArray(aTexCoordMain);

        // 设置Vertex Shader数据

        squareVertices.position(0);

        GLES20.glVertexAttribPointer(aPositionMain, 2, GLES20.GL_FLOAT, false, 0, squareVertices);

        coordVertices.position(0);

        GLES20.glVertexAttribPointer(aTexCoordMain, 2, GLES20.GL_FLOAT, false, 0, coordVertices);

        //创建yuv纹理

        createTexture(frameWidth, frameHeight, GLES20.GL_LUMINANCE, Ytexture);

        createTexture(frameWidth >> 1, frameHeight >> 1, GLES20.GL_LUMINANCE_ALPHA, UVtexture);

public void onDrawFrame(GL10 unused)

    // 重绘背景色

    GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);

    if ( yBuf != null )

//y

        GLES20.glActiveTexture(GLES20.GL_TEXTURE0);

        GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, Ytexture[0]);

        GLES20.glTexSubImage2D(GLES20.GL_TEXTURE_2D,

0,

0,

0,

                frameWidth,

                frameHeight,

                GLES20.GL_LUMINANCE,

                GLES20.GL_UNSIGNED_BYTE,

                yBuf);

        //uv

        GLES20.glActiveTexture(GLES20.GL_TEXTURE2);

        GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, UVtexture[0]);

        GLES20.glTexSubImage2D(GLES20.GL_TEXTURE_2D,

0,

0,

0,

                frameWidth >> 1,

                frameHeight >> 1,

                GLES20.GL_LUMINANCE_ALPHA,

                GLES20.GL_UNSIGNED_BYTE,

                uvBuf);

    //绘制

    GLES20.glViewport(0, 0, viewWidth, viewHeight);

    GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4);

public void onSurfaceCreated(GL10 unused, EGLConfig config)

    //设置背景的颜色为黑色

    GLES20.glClearColor(0.f, 0.f, 0.f, 1.0f);

    InitShader();

public void onSurfaceChanged(GL10 unused, int width, int height)

    viewWidth  = width;

    viewHeight = height;

    GLES20.glViewport(0, 0, viewWidth, viewHeight);

camera preview那边一旦有数据callback frame 来，设置这样一个回调接口。

public void onNewFrames(byte[] data, int length)

    if (  length != 0  )

        yBuf.clear();

        uvBuf.clear();

        copyYUV(data, length);;//填充camera preview数据到opengl        requestRender();//请求opengl 刷新屏幕一次

public void copyYUV(byte[] src,int ilen)

    int len =(ilen<<1)/3;

    yBuf.put(src,0,len).position(0);

    uvBuf.put(src,len,len>>1).position(0);

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