我正在使用GLSurfaceView来显示Camera Feed，因为当我在设备上使用外置摄像头（通过USB插入）时，预览会被镜像，我只能“取消镜像”它一个GLSurfaceView。它工作得很好，但过了一段时间（可能是2分钟，或10），视图不再显示任何更新，只是冻结。我把日志放在public void onDrawFrame(GL10 gl)方法中，我可以看到它经常被调用，直到它冻结，然后不再调用。这些是我冻结的唯一日志：
11-29 11:01:39.761 2431-2506/com.xxx D/MyGLSurfaceView: #onDrawFrame
11-29 11:01:58.154 2431-2446/com.xxx I/art: Background partial concurrent mark sweep GC freed 9(288B) AllocSpace objects, 3(3MB) LOS objects, 39% free, 6MB/10MB, paused 6.019ms total 25.478ms
11-29 11:02:05.265 2431-2446/com.xxx I/art: Background partial concurrent mark sweep GC freed 6(192B) AllocSpace objects, 5(6MB) LOS objects, 39% free, 7MB/12MB, paused 5.228ms total 49.221ms
11-29 11:02:36.496 2431-2446/com.xxx I/art: Background partial concurrent mark sweep GC freed 11(336B) AllocSpace objects, 3(3MB) LOS objects, 39% free, 6MB/10MB, paused 7.752ms total 28.387ms
11-29 11:03:10.488 2431-2446/com.xxx I/art: Background partial concurrent mark sweep GC freed 242(12KB) AllocSpace objects, 3(3MB) LOS objects, 39% free, 7MB/12MB, paused 12.263ms total 41.651ms
11-29 11:03:24.016 2431-2446/com.xxx I/art: Background partial concurrent mark sweep GC freed 18(720B) AllocSpace objects, 5(6MB) LOS objects, 39% free, 6MB/10MB, paused 7.029ms total 26.553ms
11-29 11:03:58.696 2431-2446/com.xxx I/art: Background partial concurrent mark sweep GC freed 18(640B) AllocSpace objects, 3(3MB) LOS objects, 39% free, 6MB/10MB, paused 6.227ms total 27.462ms
11-29 11:04:44.049 2431-2446/com.xxx I/art: Background sticky concurrent mark sweep GC freed 234(12KB) AllocSpace objects, 3(3MB) LOS objects, 29% free, 8MB/12MB, paused 8.683ms total 17.247ms
我在某处使用了一些示例代码来使用GLSurfaveView，因为我对其工作方式没有任何概念，代码是这样的：
import android.content.Context;
import android.graphics.SurfaceTexture;
import android.hardware.Camera;
import android.opengl.GLES11Ext;
import android.opengl.GLES20;
import android.opengl.GLSurfaceView;
import android.util.AttributeSet;
import android.util.Log;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.opengles.GL10;
class MyGLSurfaceView extends GLSurfaceView implements GLSurfaceView.Renderer, SurfaceTexture.OnFrameAvailableListener, Camera.PreviewCallback {
private static final String TAG = MyGLSurfaceView.class.getSimpleName();
private static final String vss = "attribute vec2 vPosition;\n" +
"attribute vec2 vTexCoord;\n" +
"varying vec2 texCoord;\n" +
"void main() {\n" +
" texCoord = vTexCoord;\n" +
" gl_Position = vec4 ( vPosition.x, vPosition.y, 0.0, 1.0 );\n" +
"}";
private static final String fss = "#extension GL_OES_EGL_image_external : require\n" +
"precision mediump float;\n" +
"uniform samplerExternalOES sTexture;\n" +
"varying vec2 texCoord;\n" +
"void main() {\n" +
" gl_FragColor = texture2D(sTexture,texCoord);\n" +
"}";
private SurfaceTexture mSurfaceTexture;
private boolean mUpdateTexture = false;
private FloatBuffer mVertex;
private FloatBuffer mTextCoordinates;
private int[] mTexture;
private int hProgram;
private Camera mCamera;
private Camera.Size cameraSize;
public MyGLSurfaceView(Context context) {
this(context, null);
}
public MyGLSurfaceView(Context context, AttributeSet attrs) {
super(context, attrs);
this.init();
}
private void init() {
setEGLContextClientVersion(2);
setRenderer(this);
setRenderMode(GLSurfaceView.RENDERMODE_WHEN_DIRTY);
float[] vtmp = {-1.0f, -1.0f, 1.0f, -1.0f, -1.0f, 1.0f, 1.0f, 1.0f};
this.mVertex = ByteBuffer.allocateDirect(8 * 4).order(ByteOrder.nativeOrder()).asFloatBuffer();
this.mVertex.put(vtmp);
this.mVertex.position(0);
float[] ttmp = {1.0f, 1.0f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 0.0f};
this.mTextCoordinates = ByteBuffer.allocateDirect(8 * 4).order(ByteOrder.nativeOrder()).asFloatBuffer();
this.mTextCoordinates.put(ttmp);
this.mTextCoordinates.position(0);
}
@Override
public void onResume() {
Log.d(TAG, "#onResume");
super.onResume();
}
@Override
public void onPause() {
Log.d(TAG, "#onPause");
super.onPause();
this.releaseCamera();
}
@Override
public void onFrameAvailable(SurfaceTexture surfaceTexture) {
this.mUpdateTexture = true;
this.requestRender();
}
@Override
public void onPreviewFrame(byte[] data, Camera camera) {
// process bytes here
}
@Override
public void onSurfaceCreated(GL10 gl, EGLConfig config) {
Log.d(TAG, "#onSurfaceCreated");
this.initTexture();
this.mSurfaceTexture = new SurfaceTexture(mTexture[0]);
this.mSurfaceTexture.setOnFrameAvailableListener(this);
this.mSurfaceTexture.getTransformMatrix(new float[16]);
try {
this.openCamera();
}
catch (IOException e) {
e.printStackTrace();
this.releaseCamera();
}
GLES20.glClearColor(1.0f, 1.0f, 0.0f, 1.0f);
}
@Override
public void onSurfaceChanged(GL10 gl, int width, int height) {
Log.d(TAG, "#onSurfaceChanged");
GLES20.glViewport(0, 0, width, height);
this.mCamera.startPreview();
this.mCamera.setPreviewCallback(this);
this.hProgram = loadShader();
}
@Override
public void onDrawFrame(GL10 gl) {
Log.d(TAG, "#onDrawFrame");
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
synchronized (this) {
if (this.mUpdateTexture) {
this.mSurfaceTexture.updateTexImage();
this.mUpdateTexture = false;
}
}
GLES20.glUseProgram(this.hProgram);
GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
GLES20.glBindTexture(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, this.mTexture[0]);
int th = GLES20.glGetUniformLocation(this.hProgram, "sTexture");
GLES20.glUniform1i(th, 0);
int ph = GLES20.glGetAttribLocation(this.hProgram, "vPosition");
GLES20.glVertexAttribPointer(ph, 2, GLES20.GL_FLOAT, false, 4 * 2, this.mVertex);
GLES20.glEnableVertexAttribArray(ph);
int tch = GLES20.glGetAttribLocation(this.hProgram, "vTexCoord");
GLES20.glVertexAttribPointer(tch, 2, GLES20.GL_FLOAT, false, 4 * 2, this.mTextCoordinates);
GLES20.glEnableVertexAttribArray(tch);
GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4);
GLES20.glFlush();
}
private void initTexture() {
this.mTexture = new int[1];
GLES20.glGenTextures(1, this.mTexture, 0);
GLES20.glBindTexture(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, this.mTexture[0]);
GLES20.glTexParameteri(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_WRAP_S, GLES20.GL_CLAMP_TO_EDGE);
GLES20.glTexParameteri(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_WRAP_T, GLES20.GL_CLAMP_TO_EDGE);
GLES20.glTexParameteri(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_NEAREST);
GLES20.glTexParameteri(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_NEAREST);
}
private static int loadShader() {
int vshader = GLES20.glCreateShader(GLES20.GL_VERTEX_SHADER);
GLES20.glShaderSource(vshader, vss);
GLES20.glCompileShader(vshader);
int[] compiled = new int[1];
GLES20.glGetShaderiv(vshader, GLES20.GL_COMPILE_STATUS, compiled, 0);
if (compiled[0] == 0) {
Log.e("Shader", "Could not compile vshader");
Log.v("Shader", "Could not compile vshader:" + GLES20.glGetShaderInfoLog(vshader));
GLES20.glDeleteShader(vshader);
vshader = 0;
}
int fshader = GLES20.glCreateShader(GLES20.GL_FRAGMENT_SHADER);
GLES20.glShaderSource(fshader, fss);
GLES20.glCompileShader(fshader);
GLES20.glGetShaderiv(fshader, GLES20.GL_COMPILE_STATUS, compiled, 0);
if (compiled[0] == 0) {
Log.e("Shader", "Could not compile fshader");
Log.v("Shader", "Could not compile fshader:" + GLES20.glGetShaderInfoLog(fshader));
GLES20.glDeleteShader(fshader);
fshader = 0;
}
int program = GLES20.glCreateProgram();
GLES20.glAttachShader(program, vshader);
GLES20.glAttachShader(program, fshader);
GLES20.glLinkProgram(program);
return program;
}
private void openCamera() throws IOException {
this.mCamera = Camera.open();
final Camera.Parameters parameters = this.mCamera.getParameters();
parameters.setPreviewSize(1280, 720);
this.mCamera.setParameters(parameters);
this.mCamera.setPreviewTexture(this.mSurfaceTexture);
}
private void releaseCamera() {
synchronized (this) {
try {
if (this.mCamera != null) {
this.mCamera.stopPreview();
this.mCamera.setPreviewCallback(null);
this.mCamera.release();
this.mCamera = null;
}
}
catch (Exception e) {
Log.e(TAG, e.getMessage());
}
}
}
}