全网首发：安卓GLSurfaceView绘制显示YUV(NV21)

　　前几天遇到一个问题：得到摄像头数据后，如何能够直接显示？

吾已解决。需要的朋友可下载吾开源项目：

https://github.com/quantum6?tab=repositories

• 最简单的办法，就是转换为RGB。这个有现在的代码，吾亦提供了一个：

https://blog.csdn.net/quantum7/article/details/105720150

　　性能较差。有的手机会特别慢。

• 不转换，直接显示。NATIVE方式。

网上有人提供了NATIVE方式。吾本来要试一下，一看要装CYGWIN，放弃。

• 使用GLSurfaceView。

为什么使用这个？因为在doubango中，就是这样做的。具体步骤：

1. 配置

在AndroidManifest.xml中增加一句：

1. 格式转换

NV21转换为YUV420SP。

https://quantum6.blog.csdn.net/article/details/105744636

1. 继承GlSurfaceView

package net.quantum6.kit;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
import java.nio.ShortBuffer;
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;

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

import android.content.Context;
import android.graphics.PixelFormat;
import android.opengl.GLES20;
import android.opengl.GLSurfaceView;
import android.util.Log;
import android.view.SurfaceHolder;


/**
 * OpenGL Surface view
 */
public class VideoRendererView extends GLSurfaceView implements GLSurfaceView.Renderer
{
    private final static String TAG = VideoRendererView.class.getCanonicalName();
    
	int mBufferWidthY, mBufferHeightY,  mBufferWidthUV, mBufferHeightUV;
	ByteBuffer mBuffer;
	int mBufferPositionY, mBufferPositionU, mBufferPositionV;
	
	private static final int FLOAT_SIZE_BYTES = 4;
	private static final int SHORT_SIZE_BYTES = 2;
    private static final int TRIANGLE_VERTICES_DATA_STRIDE_BYTES = 5 * FLOAT_SIZE_BYTES;
    private static final int TRIANGLE_VERTICES_DATA_POS_OFFSET   = 0;
    private static final int TRIANGLE_VERTICES_DATA_UV_OFFSET    = 3;
    private final float[] TRIANFLE_VERTICES_DATA = {
    		 1, -1, 0, 1, 1,
    	     1,  1, 0, 1, 0,
    	    -1,  1, 0, 0, 0,
    	    -1, -1, 0, 0, 1
    	 };
    private final short[] INDICES_DATA = {
    		0, 1, 2,
    	    2, 3, 0};

    private FloatBuffer mTriangleVertices;
    private ShortBuffer mIndices;

    private static final String VERTEX_SHADER_SOURCE =
        "attribute vec4 aPosition;\n" +
        "attribute vec2 aTextureCoord;\n" +
        "varying vec2 vTextureCoord;\n" +
        "void main() {\n" +
        "  gl_Position = aPosition;\n" +
        "  vTextureCoord = aTextureCoord;\n" +
        "}\n";

    private static final String FRAGMENT_SHADER_SOURCE = "precision mediump float;" +
    "varying vec2 vTextureCoord;" +
    "" +
    "uniform sampler2D SamplerY; " +
    "uniform sampler2D SamplerU;" +
    "uniform sampler2D SamplerV;" +
    "" +
    "const mat3 yuv2rgb = mat3(1, 0, 1.2802,1, -0.214821, -0.380589,1, 2.127982, 0);" +
    "" +
    "void main() {    " +
    "    vec3 yuv = vec3(1.1643 * (texture2D(SamplerY, vTextureCoord).r - 0.0625)," +
    "                    texture2D(SamplerU, vTextureCoord).r - 0.5," +
    "                    texture2D(SamplerV, vTextureCoord).r - 0.5);" +
    "    vec3 rgb = yuv * yuv2rgb;    " +
    "    gl_FragColor = vec4(rgb, 1.0);" +
    "} ";

    private int mProgram;
    private int maPositionHandle;
    private int maTextureHandle;
    private int muSamplerYHandle;
    private int muSamplerUHandle;
    private int muSamplerVHandle;
    private int[] mTextureY = new int[1];
    private int[] mTextureU = new int[1];
    private int[] mTextureV = new int[1];

    private boolean mSurfaceCreated;
    private boolean mSurfaceDestroyed;
    @SuppressWarnings("unused")
	private Context mContext;
    
    private int mViewWidth, mViewHeight, mViewX, mViewY;
    private boolean mFullScreenRequired;
	
	public VideoRendererView(Context context) {
		super(context);
        setEGLContextClientVersion(2);
		setEGLConfigChooser(8, 8, 8, 8, 16, 0);	
        setRenderer(this);
        getHolder().setFormat(PixelFormat.TRANSLUCENT);
        getHolder().setType(SurfaceHolder.SURFACE_TYPE_GPU);
        setRenderMode(GLSurfaceView.RENDERMODE_WHEN_DIRTY);
  
        mContext = context;
        
        mTriangleVertices = ByteBuffer.allocateDirect(TRIANFLE_VERTICES_DATA.length
                * FLOAT_SIZE_BYTES).order(ByteOrder.nativeOrder()).asFloatBuffer();
        mTriangleVertices.put(TRIANFLE_VERTICES_DATA).position(0);
        
        mIndices = ByteBuffer.allocateDirect(INDICES_DATA.length
                * SHORT_SIZE_BYTES).order(ByteOrder.nativeOrder()).asShortBuffer();
        mIndices.put(INDICES_DATA).position(0);
	}
	
    public void setParams(boolean fullScreenRequired, ByteBuffer buffer, int bufferWidth, int bufferHeight, int fps)
    {
        mFullScreenRequired = fullScreenRequired;

        setBuffer(buffer, bufferWidth, bufferHeight);
    }

	public void setBuffer(ByteBuffer buffer, int bufferWidth, int bufferHeight){
	    mValidDataList.clear();
	    mEmptyDataList.clear();
	    
		mBuffer          = buffer;
		mBufferWidthY    = bufferWidth;
		mBufferHeightY   = bufferHeight;
		
		mBufferWidthUV   = (mBufferWidthY >> 1);
		mBufferHeightUV  = (mBufferHeightY >> 1);
		
		mBufferPositionY = 0;
		mBufferPositionU = (mBufferWidthY * mBufferHeightY);
		mBufferPositionV = (mBufferPositionU + (mBufferWidthUV * mBufferHeightUV));
	}

	public boolean isReady(){
		return (mSurfaceCreated && !mSurfaceDestroyed);
	}
	
	public boolean isDestroyed(){
		return mSurfaceDestroyed;
	}
	
    @Override
	public void surfaceDestroyed(SurfaceHolder holder) {
    	mSurfaceCreated   = false;
    	mSurfaceDestroyed = true;
		super.surfaceDestroyed(holder);
	}

    @Override
	public void onDrawFrame(GL10 glUnused) {
    	GLES20.glViewport(mViewX, mViewY, mViewWidth, mViewHeight);
    	GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT | GLES20.GL_DEPTH_BUFFER_BIT);
        GLES20.glUseProgram(mProgram);
        checkGlError("glUseProgram");

        if (mValidDataList.size() < BUFFER_COUNT_MIN)
        {
            return;
        }
        if (mBuffer == null)
        {
            mBuffer = ByteBuffer.allocateDirect(mBufferWidthY*mBufferHeightY*3/2);
        }
        byte[] newData = mValidDataList.get(0);
        mBuffer.rewind();
        mBuffer.put(newData);
        
        if(mBuffer != null){
        	synchronized(this){        	    
		        GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
		        GLES20.glBindTexture(  GLES20.GL_TEXTURE_2D, mTextureY[0]);
		        GLES20.glTexImage2D(   GLES20.GL_TEXTURE_2D, 0, GLES20.GL_LUMINANCE, mBufferWidthY, mBufferHeightY, 0, GLES20.GL_LUMINANCE, GLES20.GL_UNSIGNED_BYTE, mBuffer.position(mBufferPositionY));
		        GLES20.glUniform1i(muSamplerYHandle, 0);
		        
		        GLES20.glActiveTexture(GLES20.GL_TEXTURE1);
		        GLES20.glBindTexture(  GLES20.GL_TEXTURE_2D, mTextureU[0]);
		        GLES20.glTexImage2D(   GLES20.GL_TEXTURE_2D, 0, GLES20.GL_LUMINANCE, mBufferWidthUV, mBufferHeightUV, 0, GLES20.GL_LUMINANCE, GLES20.GL_UNSIGNED_BYTE, mBuffer.position(mBufferPositionU));
		        GLES20.glUniform1i(muSamplerUHandle, 1);
		        
		        GLES20.glActiveTexture(GLES20.GL_TEXTURE2);
		        GLES20.glBindTexture(  GLES20.GL_TEXTURE_2D, mTextureV[0]);
		        GLES20.glTexImage2D(   GLES20.GL_TEXTURE_2D, 0, GLES20.GL_LUMINANCE, mBufferWidthUV, mBufferHeightUV, 0, GLES20.GL_LUMINANCE, GLES20.GL_UNSIGNED_BYTE, mBuffer.position(mBufferPositionV));
		        GLES20.glUniform1i(muSamplerVHandle, 2);
        	}
        }
        
	    GLES20.glDrawElements(GLES20.GL_TRIANGLES, INDICES_DATA.length, GLES20.GL_UNSIGNED_SHORT, mIndices);
	    
	    this.mEmptyDataList.add(newData);
    }

    public void onSurfaceChanged(GL10 glUnused, int width, int height) {
    	GLES20.glViewport(0, 0, width, height);
    	setViewport(width, height);
        // GLU.gluPerspective(glUnused, 45.0f, (float)width/(float)height, 0.1f, 100.0f);
    }

    public void onSurfaceCreated(GL10 glUnused, EGLConfig config) {
    	GLES20.glEnable( GLES20.GL_BLEND);
    	GLES20.glDisable(GLES20.GL_DEPTH_TEST);
    	GLES20.glDisable(GLES20.GL_DITHER);
    	GLES20.glDisable(GLES20.GL_STENCIL_TEST);
		GLES20.glDisable(GL10.GL_DITHER);
        
		String extensions = GLES20.glGetString(GL10.GL_EXTENSIONS);
		Log.d(TAG, "OpenGL extensions=" +extensions);

    	// Ignore the passed-in GL10 interface, and use the GLES20
        // class's static methods instead.
        mProgram = createProgram(VERTEX_SHADER_SOURCE, FRAGMENT_SHADER_SOURCE);
        if (mProgram == 0) {
            return;
        }
        maPositionHandle = GLES20.glGetAttribLocation(mProgram, "aPosition");
        checkGlError("glGetAttribLocation aPosition");
        if (maPositionHandle == -1) {
            throw new RuntimeException("Could not get attrib location for aPosition");
        }
        maTextureHandle = GLES20.glGetAttribLocation(mProgram, "aTextureCoord");
        checkGlError("glGetAttribLocation aTextureCoord");
        if (maTextureHandle == -1) {
            throw new RuntimeException("Could not get attrib location for aTextureCoord");
        }
        
        muSamplerYHandle = GLES20.glGetUniformLocation(mProgram, "SamplerY");
        if (muSamplerYHandle == -1) {
            throw new RuntimeException("Could not get uniform location for SamplerY");
        }
        muSamplerUHandle = GLES20.glGetUniformLocation(mProgram, "SamplerU");
        if (muSamplerUHandle == -1) {
            throw new RuntimeException("Could not get uniform location for SamplerU");
        }
        muSamplerVHandle = GLES20.glGetUniformLocation(mProgram, "SamplerV");
        if (muSamplerVHandle == -1) {
            throw new RuntimeException("Could not get uniform location for SamplerV");
        }
        
        mTriangleVertices.position(TRIANGLE_VERTICES_DATA_POS_OFFSET);
        GLES20.glVertexAttribPointer(maPositionHandle, 3, GLES20.GL_FLOAT, false, TRIANGLE_VERTICES_DATA_STRIDE_BYTES, mTriangleVertices);
        checkGlError("glVertexAttribPointer maPosition");
        
        mTriangleVertices.position(TRIANGLE_VERTICES_DATA_UV_OFFSET);
        GLES20.glEnableVertexAttribArray(maPositionHandle);
        checkGlError("glEnableVertexAttribArray maPositionHandle");
        GLES20.glVertexAttribPointer(maTextureHandle, 2, GLES20.GL_FLOAT, false, TRIANGLE_VERTICES_DATA_STRIDE_BYTES, mTriangleVertices);
        checkGlError("glVertexAttribPointer maTextureHandle");
        GLES20.glEnableVertexAttribArray(maTextureHandle);
        checkGlError("glEnableVertexAttribArray maTextureHandle");

        GLES20.glGenTextures(1, mTextureY, 0);
        GLES20.glBindTexture(  GLES20.GL_TEXTURE_2D, mTextureY[0]);
        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);
        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.glGenTextures(1, mTextureU, 0);
        GLES20.glBindTexture(  GLES20.GL_TEXTURE_2D, mTextureU[0]);
        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);
        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.glGenTextures(1, mTextureV, 0);
        GLES20.glBindTexture(  GLES20.GL_TEXTURE_2D, mTextureV[0]);
        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);
        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);
        
        mSurfaceCreated = true;
        
        setViewport(getWidth(), getHeight());
    }

    private int loadShader(int shaderType, String source) {
        int shader = GLES20.glCreateShader(shaderType);
        if (shader != 0) {
            GLES20.glShaderSource(shader, source);
            GLES20.glCompileShader(shader);
            int[] compiled = new int[1];
            GLES20.glGetShaderiv(shader, GLES20.GL_COMPILE_STATUS, compiled, 0);
            if (compiled[0] == 0) {
                Log.e(TAG, "Could not compile shader " + shaderType + ":");
                Log.e(TAG, GLES20.glGetShaderInfoLog(shader));
                GLES20.glDeleteShader(shader);
                shader = 0;
            }
        }
        return shader;
    }

    private int createProgram(String vertexSource, String fragmentSource) {
        int vertexShader = loadShader(GLES20.GL_VERTEX_SHADER, vertexSource);
        if (vertexShader == 0) {
            return 0;
        }

        int pixelShader = loadShader(GLES20.GL_FRAGMENT_SHADER, fragmentSource);
        if (pixelShader == 0) {
            return 0;
        }

        int program = GLES20.glCreateProgram();
        if (program != 0) {
            GLES20.glAttachShader(program, vertexShader);
            checkGlError("glAttachShader");
            GLES20.glAttachShader(program, pixelShader);
            checkGlError("glAttachShader");
            GLES20.glLinkProgram(program);
            int[] linkStatus = new int[1];
            GLES20.glGetProgramiv(program, GLES20.GL_LINK_STATUS, linkStatus, 0);
            if (linkStatus[0] != GLES20.GL_TRUE) {
                Log.e(TAG, "Could not link program: ");
                Log.e(TAG, GLES20.glGetProgramInfoLog(program));
                GLES20.glDeleteProgram(program);
                program = 0;
            }
        }
        return program;
    }
    
    private void setViewport(int width, int height){
    	if(mFullScreenRequired){
    		mViewWidth = width;
    		mViewHeight = height;
    		mViewX = mViewY = 0;
    	}
    	else{
    		float fRatio = ((float) mBufferWidthY / (float) mBufferHeightY);
			mViewWidth = (int) ((float) width / fRatio) > height ? (int) ((float) height * fRatio) : width;
			mViewHeight = (int) (mViewWidth / fRatio) > height ? height : (int) (mViewWidth / fRatio);
			mViewX = ((width - mViewWidth) >> 1);
			mViewY = ((height - mViewHeight) >> 1);
    	}
    }

    private void checkGlError(String op) {
        int error;
        while ((error = GLES20.glGetError()) != GLES20.GL_NO_ERROR) {
            Log.e(TAG, op + ": glError " + error);
            throw new RuntimeException(op + ": glError " + error);
        }
    }
    
    private final static int BUFFER_COUNT_MIN   = 2;
    
    private List  mValidDataList = Collections.synchronizedList(new LinkedList());
    private List  mEmptyDataList = Collections.synchronizedList(new LinkedList());
    
    public void newDataArrived(final byte[] data)
    {
        byte[] newData;
        if (mEmptyDataList.size() > 0)
        {
            newData = mEmptyDataList.remove(0);
        }
        else
        {
            newData = new byte[data.length];
        }
        System.arraycopy(data, 0, newData, 0, data.length);
        mValidDataList.add(newData);
        this.requestRender();
    }

}