Android OpenGLES渲染MediaCodec解码数据

1、OpenGL生成纹理
2、纹理绑定到SurfaceTexture上
3、用SurfaceTexture做参数创建Surface
4、MediaCodec解码的视频就往Surface发送，就显示出画面了

• Shader编写

vertex_shader.glsl

attribute vec4 av_Position;
attribute vec2 af_Position;
varying vec2 v_texPosition;
void main() {
    v_texPosition = af_Position;
    gl_Position = av_Position;
}

fragment_mediacodec.glsl

#extension GL_OES_EGL_image_external : require
precision mediump float;
varying vec2 v_texPosition;
//samplerExternalOES渲染视频
uniform samplerExternalOES sTexture;

void main() {
    gl_FragColor=texture2D(sTexture, v_texPosition);
}

VideoRender.java

import android.content.Context;
import android.graphics.SurfaceTexture;
import android.opengl.GLES11Ext;
import android.opengl.GLES20;
import android.opengl.GLSurfaceView;
import android.view.Surface;

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

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

public class VideoRender implements GLSurfaceView.Renderer, SurfaceTexture.OnFrameAvailableListener {

    private Context context;

    private final float[] vertexData = {
            -1f, -1f,
            1f, -1f,
            -1f, 1f,
            1f, 1f

    };

    private final float[] textureData = {
            0f, 1f,
            1f, 1f,
            0f, 0f,
            1f, 0f
    };

    private FloatBuffer vertexBuffer;
    private FloatBuffer textureBuffer;


    //mediacodec
    private int program_mediacodec;
    private int avPosition_mediacodec;
    private int afPosition_mediacodec;
    private int samplerOES_mediacodec;
    private int textureId_mediacodec;
    private SurfaceTexture surfaceTexture;
    private Surface surface;

    private OnSurfaceCreateListener onSurfaceCreateListener;
    private OnRenderListener onRenderListener;

    public VideoRender(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 setOnSurfaceCreateListener(OnSurfaceCreateListener onSurfaceCreateListener) {
        this.onSurfaceCreateListener = onSurfaceCreateListener;
    }

    public void setOnRenderListener(OnRenderListener onRenderListener) {
        this.onRenderListener = onRenderListener;
    }

    @Override
    public void onSurfaceCreated(GL10 gl, EGLConfig config) {
        initRenderMediacodec();
    }

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

    @Override
    public void onDrawFrame(GL10 gl) {
        GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
        GLES20.glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
        renderMediacodec();
        GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4);
    }

    @Override
    public void onFrameAvailable(SurfaceTexture surfaceTexture) {
        if (onRenderListener != null) {
            ////将onFrameAvailable函数回掉到GLSurfaceView调用requestRender()触发onDrawFrame()
            onRenderListener.onRender();
        }
    }

    private void initRenderMediacodec() {
        String vertexSource = ShaderUtil.readRawTxt(context, R.raw.vertex_shader);
        String fragmentSource = ShaderUtil.readRawTxt(context, R.raw.fragment_mediacodec);
        program_mediacodec = ShaderUtil.createProgram(vertexSource, fragmentSource);

        avPosition_mediacodec = GLES20.glGetAttribLocation(program_mediacodec, "av_Position");
        afPosition_mediacodec = GLES20.glGetAttribLocation(program_mediacodec, "af_Position");
        samplerOES_mediacodec = GLES20.glGetUniformLocation(program_mediacodec, "sTexture");

        int[] textureids = new int[1];
        GLES20.glGenTextures(1, textureids, 0);
        textureId_mediacodec = textureids[0];
            
        GLES20.glTexParameteri(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_WRAP_S, GLES20.GL_REPEAT);
        GLES20.glTexParameteri(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_WRAP_T, GLES20.GL_REPEAT);
        GLES20.glTexParameteri(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_LINEAR);
        GLES20.glTexParameteri(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR);

        surfaceTexture = new SurfaceTexture(textureId_mediacodec);
        surface = new Surface(surfaceTexture);
        surfaceTexture.setOnFrameAvailableListener(this);

        if (onSurfaceCreateListener != null) {
            //将Surface回掉出去给MediaCodec绑定渲染
            onSurfaceCreateListener.onSurfaceCreate(surface);
        }
    }

    private void renderMediacodec() {
        surfaceTexture.updateTexImage();
        GLES20.glUseProgram(program_mediacodec);

        GLES20.glEnableVertexAttribArray(avPosition_mediacodec);
        GLES20.glVertexAttribPointer(avPosition_mediacodec, 2, GLES20.GL_FLOAT, false, 8, vertexBuffer);

        GLES20.glEnableVertexAttribArray(afPosition_mediacodec);
        GLES20.glVertexAttribPointer(afPosition_mediacodec, 2, GLES20.GL_FLOAT, false, 8, textureBuffer);

        GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
        GLES20.glBindTexture(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, textureId_mediacodec);
        GLES20.glUniform1i(samplerOES_mediacodec, 0);
    }


    public interface OnSurfaceCreateListener {
        void onSurfaceCreate(Surface surface);
    }

    public interface OnRenderListener {
        void onRender();
    }
}

VideoGLSurfaceView.java

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

public class VideoGLSurfaceView extends GLSurfaceView {

    private VideoRender render;

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

    public VideoGLSurfaceView(Context context, AttributeSet attrs) {
        super(context, attrs);
        setEGLContextClientVersion(2);
        render = new VideoRender(context);
        setRenderer(render);
        setRenderMode(GLSurfaceView.RENDERMODE_WHEN_DIRTY);

        render.setOnRenderListener(new VideoRender.OnRenderListener() {
            @Override
            public void onRender() {
                requestRender();
            }
        });
    }

    public VideoRender getWlRender() {
        return render;
    }
}