如何使用OpenGL ES着色器转换rgbaToYuv，然后渲染到ImageReader的表面

// 创建OpenGL ES上下文并与当前线程关联
EGLContext eglContext = EGL14.eglGetCurrentContext();
EGLDisplay eglDisplay = EGL14.eglGetCurrentDisplay();
EGLSurface eglSurface = EGL14.eglGetCurrentSurface(EGL14.EGL_DRAW);

// 创建顶点着色器和片段着色器的源代码
String vertexShaderSource = "..."
String fragmentShaderSource = "..."

// 编译和链接着色器
int vertexShader = compileShader(GLES20.GL_VERTEX_SHADER, vertexShaderSource);
int fragmentShader = compileShader(GLES20.GL_FRAGMENT_SHADER, fragmentShaderSource);
int program = linkProgram(vertexShader, fragmentShader);

// 创建纹理对象并绑定RGBA图像数据
int[] textures = new int[1];
GLES20.glGenTextures(1, textures, 0);
int textureId = textures[0];
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureId);
// 将RGBA图像数据绑定到纹理上
...

// 创建帧缓冲对象并将纹理附加到颜色附件上
int[] framebuffers = new int[1];
GLES20.glGenFramebuffers(1, framebuffers, 0);
int framebufferId = framebuffers[0];
GLES20.glBindFramebuffer(GLES20.GL_FRAMEBUFFER, framebufferId);
GLES20.glFramebufferTexture2D(GLES20.GL_FRAMEBUFFER, GLES20.GL_COLOR_ATTACHMENT0, GLES20.GL_TEXTURE_2D, textureId, 0);

// 渲染矩形并将结果渲染到帧缓冲的纹理上
GLES20.glUseProgram(program);
// 设置顶点坐标和纹理坐标
...
GLES20.glDrawArrays(GLES20.GL_TRIANGLE_STRIP, 0, 4);

// 读取帧缓冲的像素数据到字节数组
byte[] pixels = new byte[width * height * 3 / 2];
GLES20.glReadPixels(0, 0, width, height, GLES20.GL_RGBA, GLES20.GL_UNSIGNED_BYTE, ByteBuffer.wrap(pixels));

// 将YUV格式的像素数据传递给ImageReader的表面
Image image = imageReader.acquireNextImage();
ByteBuffer yBuffer = image.getPlanes()[0].getBuffer();
ByteBuffer uvBuffer = image.getPlanes()[1].getBuffer();
yBuffer.put(pixels, 0, width * height);
uvBuffer.put(pixels, width * height, width * height / 2);
image.getPlanes()[0].getBuffer().position(0).limit(width * height);
image.getPlanes()[1].getBuffer().position(0).limit(width * height / 2);
image.close();