Android 使用SurfaceTexture和OpenGL修改相机输出

我试图通过openGL过滤器过滤来自相机硬件的流，然后在GLSurfaceView中显示它。当openGL渲染帧时，LogCat会反复抛出一个错误：

[未命名-3314-0]更新最大值：清除总账错误：0x502

0x502是一个通用的openGL错误，并不能真正帮助我找到问题所在。这是一系列代码的工作方式（或者至少应该是我脑海中看到的工作方式），我已经在下面复制了我的代码。我希望其他人能看到我的问题所在

创建新的MyGLSurfaceView。这将在内部创建新的MyGL20Renderer对象。此MyGLSurfaceView设置为内容视图

一旦MyGLSurfaceView完成膨胀/初始化，此完成事件将触发渲染器创建DirectVideo绘制对象，该对象将编译/链接定义的着色器并将其添加到openGL程序中。然后创建一个新的openGL纹理对象，然后使用纹理对象ID调用MainActivity

从渲染器调用MainActivity方法时，它将使用传递的openGL纹理对象创建新的SurfaceTexture对象。然后，它将自己设置为曲面的onFrameListener。然后创建/打开摄影机对象，将创建的SurfaceTexture设置为视频流的目标，并启动摄影机提要

如果提要中有可用的帧，onFrameAvailable将向渲染器发送渲染请求。这是在openGL线程上获取的，该线程调用SurfacetTexture的UpdateMaximage（），该线程将帧内存加载到openGL纹理中。然后调用DirectVideo的draw对象，并运行openGL程序序列。如果我注释掉这条.draw（）线，上面提到的错误就会消失，因此问题似乎就在这里的某个地方，但我不排除它是由不正确链接/创建的纹理引起的

MainActivity.java

public class MainActivity extends Activity implements SurfaceTexture.OnFrameAvailableListener
{
    private Camera mCamera;
    private MyGLSurfaceView glSurfaceView;
    private SurfaceTexture surface;
    MyGL20Renderer renderer;

    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);

        glSurfaceView = new MyGLSurfaceView(this);
        renderer = glSurfaceView.getRenderer();
        setContentView(glSurfaceView);
    }

    public void startCamera(int texture)
    {
        surface = new SurfaceTexture(texture);
        surface.setOnFrameAvailableListener(this);
        renderer.setSurface(surface);

        mCamera = Camera.open();

        try
        {
            mCamera.setPreviewTexture(surface);
            mCamera.startPreview();
        }
        catch (IOException ioe)
        {
            Log.w("MainActivity","CAM LAUNCH FAILED");
        }
    }

    public void onFrameAvailable(SurfaceTexture surfaceTexture)
    {
        glSurfaceView.requestRender();
    }

    @Override
    public void onPause()
    {
        mCamera.stopPreview();
        mCamera.release();
        System.exit(0);
    }

MyGLSurfaceView.java

class MyGLSurfaceView extends GLSurfaceView
{
    MyGL20Renderer renderer;
    public MyGLSurfaceView(Context context)
    {
        super(context);

        setEGLContextClientVersion(2);

        renderer = new MyGL20Renderer((MainActivity)context);
        setRenderer(renderer);
        setRenderMode(GLSurfaceView.RENDERMODE_WHEN_DIRTY);

    }
    public MyGL20Renderer getRenderer()
    {
        return renderer;
    }
}

MyGL20Renderer.java

public class MyGL20Renderer implements GLSurfaceView.Renderer
{

    DirectVideo mDirectVideo;
    int texture;
    private SurfaceTexture surface;
    MainActivity delegate;

    public MyGL20Renderer(MainActivity _delegate)
    {
        delegate = _delegate;
    }

    public void onSurfaceCreated(GL10 unused, EGLConfig config)
    {
        mDirectVideo = new DirectVideo(texture);
        texture = createTexture();
        GLES20.glClearColor(0.5f, 0.5f, 0.5f, 1.0f);
        delegate.startCamera(texture);
    }

    public void onDrawFrame(GL10 unused)
    {
            float[] mtx = new float[16];
            GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT | GLES20.GL_DEPTH_BUFFER_BIT);
            surface.updateTexImage();
            surface.getTransformMatrix(mtx); 

            mDirectVideo.draw();
    }

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

    static public int loadShader(int type, String shaderCode)
    {
        int shader = GLES20.glCreateShader(type);

        GLES20.glShaderSource(shader, shaderCode);
        GLES20.glCompileShader(shader);

        return shader;
    }

    static private int createTexture()
    {
        int[] texture = new int[1];

        GLES20.glGenTextures(1,texture, 0);
        GLES20.glBindTexture(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, texture[0]);
        GLES20.glTexParameterf(GLES11Ext.GL_TEXTURE_EXTERNAL_OES,
             GL10.GL_TEXTURE_MIN_FILTER,GL10.GL_LINEAR);        
        GLES20.glTexParameterf(GLES11Ext.GL_TEXTURE_EXTERNAL_OES,
             GL10.GL_TEXTURE_MAG_FILTER, GL10.GL_LINEAR);
     GLES20.glTexParameteri(GLES11Ext.GL_TEXTURE_EXTERNAL_OES,
             GL10.GL_TEXTURE_WRAP_S, GL10.GL_CLAMP_TO_EDGE);
     GLES20.glTexParameteri(GLES11Ext.GL_TEXTURE_EXTERNAL_OES,
             GL10.GL_TEXTURE_WRAP_T, GL10.GL_CLAMP_TO_EDGE);

        return texture[0];
    }

    public void setSurface(SurfaceTexture _surface)
    {
        surface = _surface;
    }
}

DirectVideo.java

public class DirectVideo {


    private final String vertexShaderCode =
            "#extension GL_OES_EGL_image_external : require\n"+
            "attribute vec4 position;" +
            "attribute vec4 inputTextureCoordinate;" +
            "varying vec2 textureCoordinate;" +
            "void main()" +
            "{"+
                "gl_Position = position;"+
                "textureCoordinate = inputTextureCoordinate.xy;" +
            "}";

        private final String fragmentShaderCode =
            "#extension GL_OES_EGL_image_external : require\n"+
            "precision mediump float;" +
            "uniform vec4 vColor;" +
            "void main() {" +
            "  gl_FragColor = vColor;" +
            "}";

        private FloatBuffer vertexBuffer, textureVerticesBuffer;
        private ShortBuffer drawListBuffer;
         private final int mProgram;
            private int mPositionHandle;
            private int mColorHandle;
            private int mTextureCoordHandle;


    // number of coordinates per vertex in this array
    static final int COORDS_PER_VERTEX = 2;
    static float squareVertices[] = { // in counterclockwise order:
         -1.0f,  1.0f,
         -1.0f,  -1.0f,
         1.0f,  -1.0f,
         1.0f,  1.0f
    };

    private short drawOrder[] = { 0, 1, 2, 0, 2, 3 }; // order to draw vertices

    static float textureVertices[] = { // in counterclockwise order:
        1.0f,  1.0f,
        1.0f,  0.0f,
        0.0f,  1.0f,
        0.0f,  0.0f
   };

    private final int vertexStride = COORDS_PER_VERTEX * 4; // 4 bytes per vertex

    private int texture;

    public DirectVideo(int _texture)
    {
        texture = _texture;

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

        ByteBuffer dlb = ByteBuffer.allocateDirect(drawOrder.length * 2);
        dlb.order(ByteOrder.nativeOrder());
        drawListBuffer = dlb.asShortBuffer();
        drawListBuffer.put(drawOrder);
        drawListBuffer.position(0);

        ByteBuffer bb2 = ByteBuffer.allocateDirect(textureVertices.length * 4);
        bb2.order(ByteOrder.nativeOrder());
        textureVerticesBuffer = bb2.asFloatBuffer();
        textureVerticesBuffer.put(textureVertices);
        textureVerticesBuffer.position(0);

        int vertexShader = MyGL20Renderer.loadShader(GLES20.GL_VERTEX_SHADER, vertexShaderCode);
        int fragmentShader = MyGL20Renderer.loadShader(GLES20.GL_FRAGMENT_SHADER, fragmentShaderCode);

        mProgram = GLES20.glCreateProgram();             // create empty OpenGL ES Program
        GLES20.glAttachShader(mProgram, vertexShader);   // add the vertex shader to program
        GLES20.glAttachShader(mProgram, fragmentShader); // add the fragment shader to program
        GLES20.glLinkProgram(mProgram);          
    }

    public void draw()
    {
        GLES20.glUseProgram(mProgram);

        GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
        GLES20.glBindTexture(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, texture);

        mPositionHandle = GLES20.glGetAttribLocation(mProgram, "position");
        GLES20.glEnableVertexAttribArray(mPositionHandle);
        GLES20.glVertexAttribPointer(mPositionHandle, COORDS_PER_VERTEX, GLES20.GL_FLOAT, false,vertexStride, vertexBuffer);

        mTextureCoordHandle = GLES20.glGetAttribLocation(mProgram, "inputTextureCoordinate");
        GLES20.glEnableVertexAttribArray(mTextureCoordHandle);
        GLES20.glVertexAttribPointer(mTextureCoordHandle, COORDS_PER_VERTEX, GLES20.GL_FLOAT, false,vertexStride, textureVerticesBuffer);

        mColorHandle = GLES20.glGetUniformLocation(mProgram, "vColor");

        GLES20.glDrawElements(GLES20.GL_TRIANGLES, drawOrder.length,
        GLES20.GL_UNSIGNED_SHORT, drawListBuffer);

        // Disable vertex array
        GLES20.glDisableVertexAttribArray(mPositionHandle);
        GLES20.glDisableVertexAttribArray(mTextureCoordHandle);
    }
}

应该是

texture = createTexture();
mDirectVideo = new DirectVideo(texture);

着色器

private final String vertexShaderCode =
        "attribute vec4 position;" +
        "attribute vec2 inputTextureCoordinate;" +
        "varying vec2 textureCoordinate;" +
        "void main()" +
        "{"+
            "gl_Position = position;"+
            "textureCoordinate = inputTextureCoordinate;" +
        "}";

    private final String fragmentShaderCode =
        "#extension GL_OES_EGL_image_external : require\n"+
        "precision mediump float;" +
        "varying vec2 textureCoordinate;                            \n" +
        "uniform samplerExternalOES s_texture;               \n" +
        "void main() {" +
        "  gl_FragColor = texture2D( s_texture, textureCoordinate );\n" +
        "}";

mColorHandle=GLES20.glGetUniformLocation（mProgram，“vColor”）

应该是

mColorHandle=GLES20.glGetAttribLocation（mProgram，“s_纹理”）

从DirectVideo draw.glVertexAttributePointer等中删除初始化内容。将其放入一些初始化函数中

public void draw()
{
    GLES20.glBindTexture(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, texture);
    GLES20.glDrawElements(GLES20.GL_TRIANGLES, drawOrder.length,
            GLES20.GL_UNSIGNED_SHORT, drawListBuffer);
}

502是
GL\u无效\u操作
。在调用UpdateMaximage之前，是否可以尝试显式检查错误<代码>Assert.assertTrue（GLES20.glGetError（）==0）可能是您所做的某些操作导致了错误，并且直到UpdateMaximage调用它时才会被查询。从错误消息中不清楚该错误是由UpdateMaximage引起的，还是以前的未决错误。事实上，您是正确的。draw函数在初始化过程中运行良好，但在第一个onFrameAvailable发出渲染请求时进行的第一次draw（）调用中，断言失败。您必须在整个draw函数中散布断言，直到找到导致错误的OpenGL调用。实际上，进一步处理这个问题；假设glGetError将“错误”重置为0，则问题可能出在draw函数中。我将调试输出设置为有条件的，当在updateMaximage（）调用之前调用onDrawFrame时，在updateMaximage（）调用之后但在DirectVideo.draw（）调用之前，以及在DirectVideo.draw（）调用之后调用onDrawFrame时，没有错误。前两个过程没有错误，但第三个过程没有错误。所以，我之前发布的行为似乎是触发断言的前一帧渲染的残余错误。好的，我将尝试一下，看看会出现什么。谢谢我相信这确实解决了问题。非常感谢。（并且接受了；迟做总比不做好）嗯@DanCollins我遵循了所有这些步骤，但只得到了一个灰色屏幕。。。有什么建议吗？坐标也错了，奇怪的三角形。对于本机电话使用，请使用以下命令：
static float squarevertexts[]={-1.0f，1.0f，-1.0f，-1.0f，1.0f，-1.0f，1.0f}；静态浮动纹理[]={0.0f，0.0f，1.0f，0.0f，1.0f，1.0f，0.0f，1.0f，}我已经用你的建议尝试了这个项目，并创建了一个GitHub回购协议，结果是：。我移动了GLES20.glvertexattributepointer（mTextureCoordHandle、每个顶点的COORDS\u、GLES20.GL\u FLOAT、false、vertexStride、textureVerticesBuffer）；方法调用DirectVideo以使其工作。显示的图像仍为镜像反转。任何修复此问题的建议都非常受欢迎。若要删除镜像反转，请将{0.0f，0.0f，1.0f，1.0f，0.0f，1.0f，}替换为{0.0f，1.0f，1.0f，1.0f，1.0f，1.0f，0.0f，}
public void draw()
{
    GLES20.glBindTexture(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, texture);
    GLES20.glDrawElements(GLES20.GL_TRIANGLES, drawOrder.length,
            GLES20.GL_UNSIGNED_SHORT, drawListBuffer);
}