到目前为止，我已经使用了不同的着色器，并在播放视频时将它们应用于自定义VideoSurfaceView。一切都很好，直到今天我想添加伽玛效果：
public class GammaEffect implements ShaderInterface {
/**
* Initialize Effect
*/
public GammaEffect() {
}
@Override
public String getShader(GLSurfaceView mGlSurfaceView) {
String shader = "#extension GL_OES_EGL_image_external : require\n"
+"precision mediump float;\n"
+"varying vec2 textureCoordinate;\n"
+"uniform sampler2D inputImageTexture;\n"
+"uniform float gamma;\n"
+"void main() {\n"
+"vec4 textureColor = texture2D(inputImageTexture, textureCoordinate);\n"
+"gl_FragColor = vec4(pow(textureColor.rgb, vec3(gamma)), textureColor.w);\n"
+"}\n";
return shader;
}
}
在自定义VideoSurface类上：
public class VideoSurfaceView extends GLSurfaceView {
private static final String TAG = "VideoSurfaceView";
private VideoRender mRenderer;
private MediaPlayer mMediaPlayer = null;
private static VideoSurfaceView mSurfaceView;
private Context mContext;
private static ShaderInterface effect;
public VideoSurfaceView(Context context) {
super(context);
mContext = context;
setEGLContextClientVersion(2);
mRenderer = new VideoRender(mContext);
setRenderer(mRenderer);
mSurfaceView = this;
}
public VideoSurfaceView(Context context, AttributeSet attrs) {
super(context, attrs);
mContext = context;
setEGLContextClientVersion(2);
mRenderer = new VideoRender(mContext);
setRenderer(mRenderer);
mSurfaceView = this;
}
/**
* initializes media player and the effect that is going to be applied on
* video. The video is played automatically so you dont need to call play.
*
* @param mediaPlayer instance of {@link MediaPlayer}
* @param shaderEffect any effect that implements {@link ShaderInterface}
*/
public void init(MediaPlayer mediaPlayer, ShaderInterface shaderEffect) {
if (mediaPlayer == null)
Toast.makeText(mContext, "Set MediaPlayer before continuing",
Toast.LENGTH_LONG).show();
else
mMediaPlayer = mediaPlayer;
if (shaderEffect == null)
effect = new NoEffect();
else
effect = shaderEffect;
}
@Override
public void onResume() {
if (mMediaPlayer == null) {
Log.e(TAG, "Call init() before Continuing");
return;
}
queueEvent(new Runnable() {
@Override
public void run() {
mRenderer.setMediaPlayer(mMediaPlayer);
}
});
super.onResume();
}
private static class VideoRender implements Renderer,
SurfaceTexture.OnFrameAvailableListener {
private static String TAG = "VideoRender";
private static final int FLOAT_SIZE_BYTES = 4;
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[] mTriangleVerticesData = {
// X, Y, Z, U, V
-1.0f, -1.0f, 0, 0.f, 0.f, 1.0f, -1.0f, 0, 1.f, 0.f, -1.0f,
1.0f, 0, 0.f, 1.f, 1.0f, 1.0f, 0, 1.f, 1.f,};
private FloatBuffer mTriangleVertices;
private final String mVertexShader = "uniform mat4 uMVPMatrix;\n"
+ "uniform mat4 uSTMatrix;\n" + "attribute vec4 aPosition;\n"
+ "attribute vec4 aTextureCoord;\n"
+ "varying vec2 vTextureCoord;\n" + "void main() {\n"
+ " gl_Position = uMVPMatrix * aPosition;\n"
+ " vTextureCoord = (uSTMatrix * aTextureCoord).xy;\n" + "}\n";
private float[] mMVPMatrix = new float[16];
private float[] mSTMatrix = new float[16];
private int mProgram;
private int mTextureID[] = new int[2];
private int muMVPMatrixHandle;
private int muSTMatrixHandle;
private int maPositionHandle;
private int maTextureHandle;
private SurfaceTexture mSurface;
private boolean updateSurface = false;
private static int GL_TEXTURE_EXTERNAL_OES = 0x8D65;
private MediaPlayer mMediaPlayer;
public VideoRender(Context context) {
mTriangleVertices = ByteBuffer
.allocateDirect(
mTriangleVerticesData.length * FLOAT_SIZE_BYTES)
.order(ByteOrder.nativeOrder()).asFloatBuffer();
mTriangleVertices.put(mTriangleVerticesData).position(0);
Matrix.setIdentityM(mSTMatrix, 0);
}
public void setMediaPlayer(MediaPlayer player) {
mMediaPlayer = player;
}
@Override
public void onDrawFrame(GL10 glUnused) {
synchronized (this) {
if (updateSurface) {
mSurface.updateTexImage();
mSurface.getTransformMatrix(mSTMatrix);
updateSurface = false;
}
}
mProgram = createProgram(mVertexShader,
effect.getShader(mSurfaceView));
GLES20.glClearColor(0.0f, 1.0f, 0.0f, 1.0f);
GLES20.glClear(GLES20.GL_DEPTH_BUFFER_BIT
| GLES20.GL_COLOR_BUFFER_BIT);
GLES20.glUseProgram(mProgram);
checkGlError("glUseProgram");
GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
GLES20.glBindTexture(GL_TEXTURE_EXTERNAL_OES, mTextureID[0]);
mTriangleVertices.position(TRIANGLE_VERTICES_DATA_POS_OFFSET);
GLES20.glVertexAttribPointer(maPositionHandle, 3, GLES20.GL_FLOAT,
false, TRIANGLE_VERTICES_DATA_STRIDE_BYTES,
mTriangleVertices);
checkGlError("glVertexAttribPointer maPosition");
GLES20.glEnableVertexAttribArray(maPositionHandle);
checkGlError("glEnableVertexAttribArray maPositionHandle");
mTriangleVertices.position(TRIANGLE_VERTICES_DATA_UV_OFFSET);
GLES20.glVertexAttribPointer(maTextureHandle, 3, GLES20.GL_FLOAT,
false, TRIANGLE_VERTICES_DATA_STRIDE_BYTES,
mTriangleVertices);
checkGlError("glVertexAttribPointer maTextureHandle");
GLES20.glEnableVertexAttribArray(maTextureHandle);
checkGlError("glEnableVertexAttribArray maTextureHandle");
Matrix.setIdentityM(mMVPMatrix, 0);
GLES20.glUniformMatrix4fv(muMVPMatrixHandle, 1, false, mMVPMatrix,
0);
GLES20.glUniformMatrix4fv(muSTMatrixHandle, 1, false, mSTMatrix, 0);
GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4);
checkGlError("glDrawArrays");
GLES20.glFinish();
}
@Override
public void onSurfaceChanged(GL10 glUnused, int width, int height) {
}
@Override
public void onSurfaceCreated(GL10 glUnused, EGLConfig config) {
mProgram = createProgram(mVertexShader,
effect.getShader(mSurfaceView));
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");
}
muMVPMatrixHandle = GLES20.glGetUniformLocation(mProgram,
"uMVPMatrix");
checkGlError("glGetUniformLocation uMVPMatrix");
if (muMVPMatrixHandle == -1) {
throw new RuntimeException(
"Could not get attrib location for uMVPMatrix");
}
muSTMatrixHandle = GLES20.glGetUniformLocation(mProgram,
"uSTMatrix");
checkGlError("glGetUniformLocation uSTMatrix");
if (muSTMatrixHandle == -1) {
throw new RuntimeException(
"Could not get attrib location for uSTMatrix");
}
// int[] textures = new int[1];
GLES20.glGenTextures(2, mTextureID, 0);
// GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mTextureID[0]);
// mTextureID = textures[0];
GLES20.glBindTexture(GL_TEXTURE_EXTERNAL_OES, mTextureID[0]);
checkGlError("glBindTexture mTextureID");
// GLES20.glTexParameterf(GL_TEXTURE_EXTERNAL_OES,
// GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_NEAREST);
// GLES20.glTexParameterf(GL_TEXTURE_EXTERNAL_OES,
// GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR);
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);
/*
* Create the SurfaceTexture that will feed this textureID, and pass
* it to the MediaPlayer
*/
mSurface = new SurfaceTexture(mTextureID[0]);
mSurface.setOnFrameAvailableListener(this);
Surface surface = new Surface(mSurface);
mMediaPlayer.setSurface(surface);
mMediaPlayer.setScreenOnWhilePlaying(true);
surface.release();
try {
mMediaPlayer.prepare();
} catch (IOException t) {
Log.e(TAG, "media player prepare failed");
}
synchronized (this) {
updateSurface = false;
}
mMediaPlayer.start();
}
@Override
synchronized public void onFrameAvailable(SurfaceTexture surface) {
updateSurface = true;
}
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 checkGlError(String op) {
int error;
if ((error = GLES20.glGetError()) != GLES20.GL_NO_ERROR) {
Log.e(TAG, op + ": glError " + error);
throw new RuntimeException(op + ": glError " + error);
}
}
} // End of class VideoRender.
} // End of class VideoSurfaceView.
＆＃34; checkGLError＆＃34;方法返回1282.这是第一次这样做而且我不明白为什么。
我在Stack上搜索了答案，但我找不到适合这种情况的东西。你能否对你应该改变什么发表意见？
答案 0 :(得分：0)
我认为问题出在你设置UV数据的地方：
GLES20.glVertexAttribPointer(maTextureHandle, 3, GLES20.GL_FLOAT,
false, TRIANGLE_VERTICES_DATA_STRIDE_BYTES,
mTriangleVertices);
你没有3个UV值，你有2个，所以你正在运行数组的末尾。在普通的原生C OpenGL ES中，这可能是段错误; Java允许对数组进行边界检查意味着您会收到错误。
答案 1 :(得分：0)
问题在于Gamma着色器的创建方式。在没有编译器的情况下编辑C代码有点棘手，我不得不做一些更改和代码的最终版本：
public class GammaEffect implements ShaderInterface {
/**
* Initialize Effect
*/
public GammaEffect() {
}
@Override
public String getShader(GLSurfaceView mGlSurfaceView) {
String shader = "#extension GL_OES_EGL_image_external : require\n"
+"precision mediump float;\n"
+"uniform samplerExternalOES sTexture;\n"
+"varying vec2 vTextureCoord;\n"
+"float gamma;\n"
+"void main() {\n"
+"gamma = 2.0;\n"
+"vec4 color = texture2D(sTexture, vTextureCoord);\n"
+"gl_FragColor = vec4(pow(color.rgb, vec3(gamma)), color.a);\n"
+"}\n";
return shader;
}
}
像魅力一样工作。希望它能帮助想要学习GLSL的程序员！