Android OpenGLES绘制yuv420纹理

1. 把shader代码写入raw里面

vertex_shader.glsl

attribute vec4 av_Position;//顶点位置
attribute vec2 af_Position;//纹理位置
varying vec2 v_texPo;//纹理位置  与fragment_shader交互
void main() {
    v_texPo = af_Position;
    gl_Position = av_Position;
}

fragment_shader.glsl

precision mediump float;//精度 为float
varying vec2 v_texPo;//纹理位置  接收于vertex_shader
uniform sampler2D sampler_y;//纹理y
uniform sampler2D sampler_u;//纹理u
uniform sampler2D sampler_v;//纹理v

void main() {
    //yuv420->rgb
    float y,u,v;
    y = texture2D(sampler_y,v_texPo).r;
    u = texture2D(sampler_u,v_texPo).r- 0.5;
    v = texture2D(sampler_v,v_texPo).r- 0.5;
    vec3 rgb;
    rgb.r = y + 1.403 * v;
    rgb.g = y - 0.344 * u - 0.714 * v;
    rgb.b = y + 1.770 * u;

    gl_FragColor=vec4(rgb,1);
}

因为OpenGLES需要用rgb来加载显示，这里就需要将yuv转rgb，这里放在OpenGL里面转换，OpenGL里面使用GPU,提高性能。

2. 数据写入

YUV420Texture.java

import android.content.Context;
import android.opengl.GLES20;


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

public class YUV420Texture {

    private Context context;

    //顶点坐标
    static float vertexData[] = {   // in counterclockwise order:
            -1f, -1f, 0.0f, // bottom left
            1f, -1f, 0.0f, // bottom right
            -1f, 1f, 0.0f, // top left
            1f, 1f, 0.0f,  // top right
    };

    //纹理坐标
    static float textureData[] = {   // in counterclockwise order:
            0f, 1f, 0.0f, // bottom left
            1f, 1f, 0.0f, // bottom right
            0f, 0f, 0.0f, // top left
            1f, 0f, 0.0f,  // top right
    };

    //每一次取点的时候取几个点
    static final int COORDS_PER_VERTEX = 3;

    private final int vertexCount = vertexData.length / COORDS_PER_VERTEX;
    //每一次取的总的点 大小
    private final int vertexStride = COORDS_PER_VERTEX * 4; // 4 bytes per vertex

    //位置
    private FloatBuffer vertexBuffer;
    //纹理
    private FloatBuffer textureBuffer;

    private int program;

    //顶点位置
    private int avPosition;
    //纹理位置
    private int afPosition;

    //shader  yuv变量
    private int sampler_y;
    private int sampler_u;
    private int sampler_v;
    private int[] textureId_yuv;


    //YUV数据
    private int width_yuv;
    private int height_yuv;
    private ByteBuffer y;
    private ByteBuffer u;
    private ByteBuffer v;


    public YUV420Texture(Context context) {
        this.context = context;

        vertexBuffer = ByteBuffer.allocateDirect(vertexData.length * 4)
                .order(ByteOrder.nativeOrder())
                .asFloatBuffer()
                .put(vertexData);
        vertexBuffer.position(0);

        textureBuffer = ByteBuffer.allocateDirect(textureData.length * 4)
                .order(ByteOrder.nativeOrder())
                .asFloatBuffer()
                .put(textureData);
        textureBuffer.position(0);
    }

    public void initYUV() {
        String vertexSource = ShaderUtil.readRawTxt(context, R.raw.vertex_shader);
        String fragmentSource = ShaderUtil.readRawTxt(context, R.raw.fragment_shader);
        program = ShaderUtil.createProgram(vertexSource, fragmentSource);
        if (program > 0) {
            //获取顶点坐标字段
            avPosition = GLES20.glGetAttribLocation(program, "av_Position");
            //获取纹理坐标字段
            afPosition = GLES20.glGetAttribLocation(program, "af_Position");
            //获取yuv字段
            sampler_y = GLES20.glGetUniformLocation(program, "sampler_y");
            sampler_u = GLES20.glGetUniformLocation(program, "sampler_u");
            sampler_v = GLES20.glGetUniformLocation(program, "sampler_v");

            textureId_yuv = new int[3];
            //创建3个纹理
            GLES20.glGenTextures(3, textureId_yuv, 0);

            //绑定纹理
            for (int id : textureId_yuv) {
                GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, id);
                //环绕（超出纹理坐标范围）  （s==x t==y GL_REPEAT 重复）
                GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_S, GLES20.GL_REPEAT);
                GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_T, GLES20.GL_REPEAT);
                //过滤（纹理像素映射到坐标点）  （缩小、放大：GL_LINEAR线性）
                GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_LINEAR);
                GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR);
            }

        }

    }

    public void setYUVData(int width, int height, byte[] y, byte[] u, byte[] v) {
        this.width_yuv = width;
        this.height_yuv = height;
        this.y = ByteBuffer.wrap(y);
        this.u = ByteBuffer.wrap(u);
        this.v = ByteBuffer.wrap(v);
    }

    public void draw() {
        if (width_yuv > 0 && height_yuv > 0 && y != null && u != null && v != null) {
            GLES20.glUseProgram(program);
            GLES20.glEnableVertexAttribArray(avPosition);
            GLES20.glVertexAttribPointer(avPosition, COORDS_PER_VERTEX, GLES20.GL_FLOAT, false, vertexStride, vertexBuffer);

            GLES20.glEnableVertexAttribArray(afPosition);
            GLES20.glVertexAttribPointer(afPosition, COORDS_PER_VERTEX, GLES20.GL_FLOAT, false, vertexStride, textureBuffer);

            //激活纹理0来绑定y数据
            GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
            GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureId_yuv[0]);
            //glTexImage2D (int target,
            //                int level,
            //                int internalformat,
            //                int width,
            //                int height,
            //                int border,
            //                int format,
            //                int type,
            //                Buffer pixels)
            GLES20.glTexImage2D(GLES20.GL_TEXTURE_2D, 0, GLES20.GL_LUMINANCE, width_yuv, height_yuv, 0, GLES20.GL_LUMINANCE, GLES20.GL_UNSIGNED_BYTE, y);

            //激活纹理1来绑定u数据
            GLES20.glActiveTexture(GLES20.GL_TEXTURE1);
            GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureId_yuv[1]);
            GLES20.glTexImage2D(GLES20.GL_TEXTURE_2D, 0, GLES20.GL_LUMINANCE, width_yuv / 2, height_yuv / 2, 0, GLES20.GL_LUMINANCE, GLES20.GL_UNSIGNED_BYTE, u);

            //激活纹理2来绑定u数据
            GLES20.glActiveTexture(GLES20.GL_TEXTURE2);
            GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureId_yuv[2]);
            GLES20.glTexImage2D(GLES20.GL_TEXTURE_2D, 0, GLES20.GL_LUMINANCE, width_yuv / 2, height_yuv / 2, 0, GLES20.GL_LUMINANCE, GLES20.GL_UNSIGNED_BYTE, v);

            //给fragment_shader里面yuv变量设置值   0 1 2 标识纹理x
            GLES20.glUniform1i(sampler_y, 0);
            GLES20.glUniform1i(sampler_u, 1);
            GLES20.glUniform1i(sampler_v, 2);

            //绘制
            GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, vertexCount);

            y.clear();
            u.clear();
            v.clear();
            y = null;
            u = null;
            v = null;
            GLES20.glDisableVertexAttribArray(afPosition);
            GLES20.glDisableVertexAttribArray(avPosition);

        }
    }
}

ShaderUtil.java

import android.content.Context;
import android.opengl.GLES20;
import android.util.Log;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;

public class ShaderUtil {
    private static final String TAG = "ShaderUtil";


    public static String readRawTxt(Context context, int rawId) {
        InputStream inputStream = context.getResources().openRawResource(rawId);
        BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
        StringBuffer sb = new StringBuffer();
        String line;
        try {
            while ((line = reader.readLine()) != null) {
                sb.append(line).append("\n");
            }
            reader.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return sb.toString();
    }

    public static int loadShader(int shaderType, String source) {
        // create a vertex shader type (GLES20.GL_VERTEX_SHADER)
        // or a fragment shader type (GLES20.GL_FRAGMENT_SHADER)
        int shader = GLES20.glCreateShader(shaderType);
        if (shader != 0) {
            //添加代码到shader
            GLES20.glShaderSource(shader, source);
            //编译shader
            GLES20.glCompileShader(shader);
            int[] compile = new int[1];
            //检测是否编译成功
            GLES20.glGetShaderiv(shader, GLES20.GL_COMPILE_STATUS, compile, 0);
            if (compile[0] != GLES20.GL_TRUE) {
                Log.d(TAG, "shader compile error");
                GLES20.glDeleteShader(shader);
                shader = 0;
            }
        }
        return shader;
    }

    public static int createProgram(String vertexSource, String fragmentSource) {
        //获取vertex shader
        int vertexShader = loadShader(GLES20.GL_VERTEX_SHADER, vertexSource);
        if (vertexShader == 0) {
            return 0;
        }
        //获取fragment shader
        int fragmentShader = loadShader(GLES20.GL_FRAGMENT_SHADER, fragmentSource);
        if (fragmentShader == 0) {
            return 0;
        }
        //创建一个空的渲染程序
        int program = GLES20.glCreateProgram();
        if (program != 0) {
            //添加vertexShader到渲染程序
            GLES20.glAttachShader(program, vertexShader);
            //添加fragmentShader到渲染程序
            GLES20.glAttachShader(program, fragmentShader);
            //关联为可执行渲染程序
            GLES20.glLinkProgram(program);
            int[] linsStatus = new int[1];
            //检测是否关联成功
            GLES20.glGetProgramiv(program, GLES20.GL_LINK_STATUS, linsStatus, 0);
            if (linsStatus[0] != GLES20.GL_TRUE) {
                Log.d(TAG, "link program error");
                GLES20.glDeleteProgram(program);
                program = 0;
            }
        }
        return program;

    }

}

3. Render书写
   MyRender.java

import android.content.Context;
import android.opengl.GLES20;
import android.opengl.GLSurfaceView;

import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.opengles.GL10;

public class MyRender implements GLSurfaceView.Renderer {

    private Context context;

    private YUV420Texture yuv420Texture;

    public MyRender(Context context) {
        this.context = context;
    }

    @Override
    public void onSurfaceCreated(GL10 gl, EGLConfig config) {
        yuv420Texture = new YUV420Texture(context);
        yuv420Texture.initYUV();
    }


    @Override
    public void onSurfaceChanged(GL10 gl, int width, int height) {
        //宽高
        GLES20.glViewport(0, 0, width, height);
    }

    @Override
    public void onDrawFrame(GL10 gl) {
        //清空颜色
        GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
        //设置背景颜色
//        GLES20.glClearColor(1.0f, 1.0f, 1.0f, 1.0f);

        yuv420Texture.draw();
    }

    public void setYuvData(int width, int height, byte[] y, byte[] u, byte[] v) {
        if (yuv420Texture != null) {
            yuv420Texture.setYUVData(width, height, y, u, v);
        }
    }
}

4. GLSurfaceView引用Renderer

MyGLSurfaceView.java

import android.content.Context;
import android.opengl.GLSurfaceView;
import android.util.AttributeSet;

public class MyGLSurfaceView extends GLSurfaceView {

    private MyRender myRender;

    public MyGLSurfaceView(Context context) {
        this(context, null);
    }

    public MyGLSurfaceView(Context context, AttributeSet attrs) {
        super(context, attrs);
        setEGLContextClientVersion(2);
        myRender = new MyRender(context);
        setRenderer(myRender);
        //mode=GLSurfaceView.RENDERMODE_WHEN_DIRTY之后  调用requestRender()触发Render的onDrawFrame函数
        //mode=GLSurfaceView.RENDERMODE_CONTINUOUSLY之后  自动调用onDrawFrame  60fps左右
        setRenderMode(GLSurfaceView.RENDERMODE_WHEN_DIRTY);
    }

    public void setYUVData(int width, int height, byte[] y, byte[] u, byte[] v) {
        if (myRender != null) {
            myRender.setYuvData(width, height, y, u, v);
            requestRender();
        }
    }
}