问题
I have creating a custom camera app, I am using GLsurfaceview, GLSurfaceview.Renderer for creating camera preview. I have successfully completed it, now am trying to apply filters (sepia mode, blank n white etc) on camera preview. How can I apply effects on camera preview.
normal view
filter applied
And this is my GLSurfaceView.Renderer
public class MainRenderer implements GLSurfaceView.Renderer,SurfaceTexture.OnFrameAvailableListener{
private 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 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 int[] hTex;
private FloatBuffer pVertex;
private FloatBuffer pTexCoord;
private int hProgram;
private Camera mCamera;
private SurfaceTexture mSTexture;
private boolean mUpdateST = false;
private CameraPreview mView;
Context mContext;
private String fileName;
private File sdRoot;
private String dir;
private ExifInterface exif;
private int orientation;
private android.hardware.Camera.PictureCallback pictureCallBack = new Camera.PictureCallback() {
public void onPictureTaken(byte[] data, Camera camera) {
fileName = "IMG_" + new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date()).toString() + ".jpg";
File mkDir = new File(sdRoot, dir);
mkDir.mkdirs();
File pictureFile = new File(sdRoot, dir + fileName);
try {
FileOutputStream purge = new FileOutputStream(pictureFile);
purge.write(data);
purge.close();
} catch (FileNotFoundException e) {
Log.d("DG_DEBUG", "File not found: " + e.getMessage());
} catch (IOException e) {
Log.d("DG_DEBUG", "Error accessing file: " + e.getMessage());
}
// Adding Exif data for the orientation. For some strange reason the
// ExifInterface class takes a string instead of a file.
try {
exif = new ExifInterface("/sdcard/" + dir + fileName);
exif.setAttribute(ExifInterface.TAG_ORIENTATION, "" + orientation);
exif.saveAttributes();
} catch (IOException e) {
e.printStackTrace();
}
mContext.sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.fromFile(pictureFile)));
}
};;
public MainRenderer(CameraPreview cameraPreview, Context context) {
mView = cameraPreview;
mContext = context;
mCamera = getCameraInstance();
float[] vtmp = { 1.0f, -1.0f, -1.0f, -1.0f, 1.0f, 1.0f, -1.0f, 1.0f };
float[] ttmp = { 0.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f };
pVertex = ByteBuffer.allocateDirect(8 * 4).order(ByteOrder.nativeOrder()).asFloatBuffer();
pVertex.put ( vtmp );
pVertex.position(0);
pTexCoord = ByteBuffer.allocateDirect(8*4).order(ByteOrder.nativeOrder()).asFloatBuffer();
pTexCoord.put ( ttmp );
pTexCoord.position(0);
}
public void close()
{
mUpdateST = false;
mSTexture.release();
mCamera.stopPreview();
mCamera.release();
mCamera = null;
deleteTex();
}
public void takePicture(File file,String dir,int orientation){
this.orientation = orientation;
sdRoot = file;
this.dir=dir;
mCamera.takePicture(null,null,pictureCallBack);
}
private void initTex() {
hTex = new int[1];
GLES20.glGenTextures(1, hTex, 0);
GLES20.glBindTexture(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, hTex[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 void deleteTex() {
GLES20.glDeleteTextures ( 1, hTex, 0 );
}
@Override
public void onSurfaceCreated(GL10 gl, EGLConfig config) {
initTex();
mSTexture = new SurfaceTexture ( hTex[0] );
mSTexture.setOnFrameAvailableListener(this);
try {
mCamera.setPreviewTexture(mSTexture);
} catch ( IOException ioe ) {
}
catch (Exception e){
}
GLES20.glClearColor ( 1.0f, 1.0f, 0.0f, 1.0f );
hProgram = loadShader ( vss, fss );
}
public Camera getCameraInstance() {
Camera c = null;
Camera.CameraInfo ci = new Camera.CameraInfo();
try {
for(int i=0;i<Camera.getNumberOfCameras();i++){
Camera.getCameraInfo(i,ci);
if(ci.facing== Camera.CameraInfo.CAMERA_FACING_FRONT)
c=Camera.open(i);
}
} catch (Exception e) {
}
return c;
}
private static int loadShader ( String vss, String fss ) {
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;
}
@Override
public void onSurfaceChanged ( GL10 unused, int width, int height ) {
GLES20.glViewport( 0, 0, width, height );
Camera.Parameters param = mCamera.getParameters();
List<Camera.Size> psize = param.getSupportedPreviewSizes();
if ( psize.size() > 0 ) {
int i;
for ( i = 0; i < psize.size(); i++ ) {
if ( psize.get(i).width < width || psize.get(i).height < height )
break;
}
if ( i > 0 )
i--;
param.setPreviewSize(psize.get(i).width, psize.get(i).height);
//Log.i("mr","ssize: "+psize.get(i).width+", "+psize.get(i).height);
}
param.set("orientation", "portrait");
mCamera.setParameters ( param );
mCamera.startPreview();
}
@Override
public void onDrawFrame ( GL10 unused ) {
GLES20.glClear( GLES20.GL_COLOR_BUFFER_BIT );
synchronized(this) {
if ( mUpdateST ) {
mSTexture.updateTexImage();
mUpdateST = false;
}
}
GLES20.glUseProgram(hProgram);
int ph = GLES20.glGetAttribLocation(hProgram, "vPosition");
int tch = GLES20.glGetAttribLocation ( hProgram, "vTexCoord" );
int th = GLES20.glGetUniformLocation ( hProgram, "sTexture" );
GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
GLES20.glBindTexture(GLES11Ext.GL_TEXTURE_EXTERNAL_OES, hTex[0]);
GLES20.glUniform1i(th, 0);
GLES20.glVertexAttribPointer(ph, 2, GLES20.GL_FLOAT, false, 4*2, pVertex);
GLES20.glVertexAttribPointer(tch, 2, GLES20.GL_FLOAT, false, 4*2, pTexCoord );
GLES20.glEnableVertexAttribArray(ph);
GLES20.glEnableVertexAttribArray(tch);
GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4);
GLES20.glFlush();
}
@Override
public synchronized void onFrameAvailable ( SurfaceTexture st ) {
mUpdateST = true;
mView.requestRender();
}
}
回答1:
Apply filter in OpengGL just basically perform some operations on the value of gl_FragColor in your fragment shader. Some complicated filter might need to perform calculations(dimensions, coordinates) in vertex shader.
For example, if you want to apply black/white filter, change your fragment shader like following.
private 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" +
" vec4 tc = texture2D(sTexture, texCoord);\n" +
" float luminance = 0.3 * tc.r + 0.59 * tc.g + 0.11 * tc.b;\n" +
" gl_FragColor = vec4(luminance, luminance, luminance, 1.0);\n" +
"}";
You can find more example and filter effect in Android GPUImage.
来源：https://stackoverflow.com/questions/37827275/modify-camera-preview-with-effects-using-glsurfaceview